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1. User's Guide 2. Mode and Service Concepts 3. Operations Concepts 4. Quality of Service Concepts 5. Quality of Service Methods 6. Bus Transit Capacity 7. Demand-Responsive Transit 8. Rail Transit Capacity 9. Ferry Transit Capacity 10. Station Capacity 11. Glossary and Symbols 12. Index Transit Capacity and Quality of Service Manual, 3rd Edition CHAPTER 9 FERRY TRANSIT CAPACITY CONTENTS 1. INTRODUCTION ....................................................................................................................... 9-1 How to Use This Chapter ................................................................................................................... 9-1 Other Resources ................................................................................................................................... 9-2 2. FERRY SERVICE AND FACILITIES ....................................................................................... 9-3 Ferry Service .......................................................................................................................................... 9-3 Ferry Terminals .................................................................................................................................... 9-5 3. FERRY SCHEDULING AND SERVICE PLANNING ........................................................... 9-14 Port Dwell Time .................................................................................................................................. 9-14 Departure Clearance Time ............................................................................................................. 9-16 Transit Time ......................................................................................................................................... 9-16 Arrival Time ......................................................................................................................................... 9-17 Operating Margin ............................................................................................................................... 9-17 Pedestrian Movements .................................................................................................................... 9-18 Service Planning ................................................................................................................................. 9-18 4. VESSEL CAPACITY ................................................................................................................. 9-21 Berth Capacity ..................................................................................................................................... 9-22 Dock Capacity ...................................................................................................................................... 9-27 5. PASSENGER AND AUTO CAPACITY .................................................................................. 9-28 6. CALCULATION EXAMPLES .................................................................................................. 9-30 Calculation Example 1: Vessel Service Time (Passengers) ............................................... 9-30 Calculation Example 2: Vessel Service Time (Automobiles) ............................................ 9-32 Calculation Example 3: Berth Capacity ..................................................................................... 9-33 7. REFERENCES ........................................................................................................................... 9-35 Chapter 9/Ferry Transit Capacity Page 9-i Contents I
Transit Capacity and Quality of Service Manual, 3'd Edition LIST OF EXHIBITS Exhibit 9-1 Examples of Vessels Used for Ferry Transit (2010) ............................................... 9-3 Exhibit 9-2 Examples of Auto and Passenger Ferry Dock Configurations ............................ 9-5 Exhibit 9-3 Illustrative Vehicle Staging Area Diagram .................................................................. 9-7 Exhibit 9-4 Vehicle Staging Area Examples ....................................................................................... 9-7 Exhibit 9-5 Typical Elements of Passenger Ferry Loading ......................................................... 9-9 Exhibit 9-6 Examples of Ferry Passenger Loading and Unloading ....................................... 9-12 Exhibit 9-7 Pedestrian Flow Cross-References ............................................................................. 9-18 Exhibit 9-8 Example of Multiple-Destination Service ................................................................ 9-19 Exhibit 9-9 Vessel Capacity Measurement Locations ................................................................. 9-21 Exhibit 9-10 Berth Vessel Capacity .................................................................................................... 9-22 Exhibit 9-11 Embarking and Disembarking Parameters .......................................................... 9-25 Exhibit 9-12 Passenger or Auto Flow through the Ferry Transit System .......................... 9-28 Exhibit 9-13 List of Calculation Examples ....................................................................................... 9-30 Contents Page 9-ii Chapter 9/Ferry Transit Capacity
Ferry system capacity is a relatively undeveloped topic. Organization of Chapter 9. Transit Capacity and Quality of Service Manual, 3'd Edition 1. INTRODUCTION Ferry service plays a major role in urban transportation systems in many North American cities, such as New York, San Francisco, Seattle, and Vancouver. Ferry transit provides an alternative to cross water bodies that would otherwise necessitate expensive infrastructure that may not be feasible to construct. Ferry transit corridors can also offer direct access to residential and business areas and can potentially reduce the transit travel time that would otherwise be experienced in mixed traffic. There is currently little information regarding waterway system- or vessel-related capacity. Ferry operators are stimulating discussion in this area, but it remains a facet of waterway capacity that is relatively undeveloped (1). The objective of Chapter 9 is to build a framework for determining the capacity of ferry transit services in North America and provide some essential planning and design tools for the development of new facilities and services. Due to the high value of waterfront areas in urban areas, project permitting, space constraints, access restrictions, and a host of other considerations make planning and designing ferry service a challenging activity. Further complicating this challenge is the wide variation in environmental conditions, such as tides and currents, that may be encountered. For example, the extremes of tidal fluctuations that must be accommodated in Seattle are 17 ft, while in San Francisco they are about 9 ft, and in New York they are 6ft. The control of wake wash on shorelines along ferry routes has to be considered and thoroughly studied prior to adopting a route or acquiring vessels. The size and energy in a vessel wake, shoreline geology, location of vulnerable structures, and other marine operations are the main factors that have to be considered. Chapter 9 of the Transit Capacity and Quality of Service Manual addresses the following topics: ⢠Section 2 addresses ferry service and facilities. ⢠Section 3 overviews ferry scheduling and service planning. ⢠Section 4 provides methods for estimating the vessel capacity of ferry berths and docks. ⢠Section 5 provides a method for estimating the passenger and auto capacity of ferry routes. ⢠Section 6 shows examples of the calculations involved in applying this chapter's capacity methods. ⢠Section 7 is a list of references used to develop the material in this chapter. HOW TO USE THIS CHAPTER Sections 2 and 3 provide ferry-specific capacity, speed, and service concepts that supplement the more general material found in Chapter 2, Mode and Service Concepts, and Chapter 3, Operations Concepts. This material provides an introduction to ferry operations for those new to the area and complements the broader material on planning ferry service found in TCRP Report 152: Guidelines for Ferry Transportation Services (2). Chapter 9/Ferry Transit Capacity Page 9-1 Introduction I
Transit Capacity and Quality of Service Manual, 3'd Edition Sections 4-6 are focused toward readers who wish to estimate the capacity of ferry service and are more computation-oriented. OTHER RESOURCES Other TCQSM material related to ferry transit includes: ⢠The "What's New" section of Chapter 1, User's Guide, which describes the changes made in this chapter from the 2nd Edition; ⢠Chapter 2, Mode and Service Concepts, which introduces the ferry mode and the types of vessels used to provide urban ferry transit service in North America; ⢠Chapter 3, Operations Concepts, which provides a general introduction to transit capacity and speed concepts; ⢠Chapter 10, Station Capacity, which provides methods that are applicable to sizing passenger circulation elements of ferry terminals, docks, and berths; and ⢠The manual's CD-ROM, which provides a spreadsheet that implements this chapter's capacity methods, along with a link to an electronic version of TCRP Report 152. Introduction Page 9-2 Chapter 9/Ferry Transit Capacity
Exhibit 9-1 Examples of Vessels Used for Ferry Transit (2010) Multi-destination routes introduce a number of difficult operational problems that may affect capacity. Transit Capacity and Quality of Service Manual, 3'd Edition 2. FERRY SERVICE AND FACILITIES FERRY SERVICE Chapter 2, Mode and Service Concepts, introduced the types of ferry services (i.e., urban, rural, and coastal) and vessels used in North America. This chapter focuses on ferry services and vessels that are part of urban transit systems, although many of the chapter's concepts also apply to other types of ferry services. Ferry Capacity Concepts Exhibit 9-1 provides examples of some of the types of vessels used in ferry transit service in the U.S. The National Census of Ferry Operators (3) provides a comprehensive list of U.S. ferry service providers and vessels. Service Number of Passenger Operator Type Vessels Capacity Speed (knots) New York City DOT Passenger 8 1,200-6,000 16 10 399 12 New York Waterway Passenger 13 149 24 6 97 24 2 370 28 Sea streak Passenger 4 396 36 Golden Gate Transit 3 715 21 Passenger 3 390-450 34 Vallejo Baylink Passenger 4 32 300 Oakland-Alameda Ferry 2 331-388 26 Passenger 2 149-200 NA Blue & Gold Fleet Passenger 7 392-787 10-24 Pierce County Passenger 2 250 11 Washington State Ferries Auto 27 250-2,500 9-30 Source: National Census of Ferry Operators (3) . Unlike other transit modes, where maximum vehicle passenger capacity is ultimately determined by passengers' willingness to crowd aboard transit vehicles, ferry vessels operate under United States Coast Guard (USCG) regulations that limit the number of passengers that can be on board at any one time. This limitation makes it necessary in many instances to have a prepaid holding area where entrance is blocked when the number of passengers in the holding area has reached the vessel's capacity. This restriction can also be accommodated with a first-in first-out (FIFO) queuing corridor. Multiple-destination routes present an even more complex set of requirements. Consider a route that services three ports, A, B, and C. When a vessel departs Port A, the number of passengers on board must be at or below the vessel's USCG capacity. When passengers are discharged at Port B and new passengers embark, the total passengers on board must still be below the USCG limitation. This condition may require the use of pre-ticketing, counting passengers discharged and loaded at each port, or the use of other methods designed to ensure that the vessel's regulatory capacity is not exceeded. Chapter 9/Ferry Transit Capacity Page 9-3 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3'd Edition Ferry Speed Concepts A vessel's mechanical properties, such as propulsion, will affect the vessel's speed and the resulting travel time over a route. Types of propulsion include fixed pitch propeller or controllable pitch propeller, which are common to monohull vessels; water jet, which is common to catamarans; and cable. Some smaller vessels may also be propelled by outboard motors. Some ferries employ a cycloidal propulsion system. Instead of conventional propellers and rudders, power is obtained from two vertical cycloidal propulsors, one at each end of the boat. This technology allows the ferry to make 360-degree turns or to move sideways with no forward or backward movement. A vessel's capital and operating costs will ultimately affect the fare and, hence, the passenger demand. Generally, the power required to propel a vessel increases dramatically as its speed increases. It is common for fuel consumption to double as speeds increase from 25 knots (30 mi/h or 50 km/h) to 30 knots. This fuel consumption impacts operating costs-requiring fare revenues from additional passengers or a higher fare, which may also influence demand. The paradox of this fuel consumption curve is that higher speeds make little difference in overall travel time even on routes exceeding 10 mi (16 km). For example, the difference between a 25-knot vessel and a 30-knot vessel on a 7 -mi (12-km) route would be about 3 min in travel time ( 4). A fast ferry is not necessarily essential for a successful ferry transit service; however, a competitive travel time compared to other travel alternatives is essential. Ferry vessels can have slower maximum speeds than alternative modes, but still have faster travel times due to the ferry service having a shorter route or an alternative facility (e.g., a bridge) experiencing congestion that prevents the vehicles using them from achieving their maximum speed (2). The ability for a ferry vessel to travel at its maximum speed may also be constrained by external factors that lead to a speed limit being imposed on marine traffic. These factors include concerns about shore erosion, wave effects on marinas, and possible collisions with endangered species. Integration with Other Transit Services Because ferries can only take passengers to the water's edge, intermodal transfers are usually required at one and often both ends of the ferry trip. However, when destinations are located close to the ferry terminal, passengers are able to walk to their destinations without having to transfer to another transit mode. Ferries are also capable of transporting bicycles, allowing passengers to bike to their destination. Options for providing intermodal transfers include park-and-ride lots, feeder bus service, roll-on, roll-off bus service (for auto ferries), and terminals located close to rail service (as in New York and San Francisco). The general design considerations for the landside elements of ferry terminals are similar to those for making transfers between other types of transit service and are covered in Chapter 10, Station Capacity. Purpose-built ferry terminals, such as those used for Vancouver's SeaBus, can provide quick and convenient connections to other transit modes, as well as facilitate the rapid movement of a large number of passengers on and off vessels. In other cases, ferry systems-for reasons of cost, environment, or desire to quickly implement service-may use existing dock facilities, which may not be located in optimal locations lntermoda/ transfers are usually required at one or both ends of ferry trips. Ferry Service and Facilities Page 9-4 Chapter 9/Ferry Transit Capacity
Freeboard is the vertical distance between the waterline and the vessel deck or the top of a dock. Exhibit 9-2 Examples of Auto and Passenger Ferry Dock Configurations Transit Capacity and Quality of Service Manual, 3rd Edition for making intermodal transfers. Therefore, the tradeoffs involved with siting ferry terminals need to be carefully considered when planning potential ferry service. FERRY TERMINALS Overview Docks and loading facilities form a system that processes vehicle and passenger movement between shore and ferry. The following sections describe the various elements of this system and considerations that influence passenger flow and the vessel turnaround time, which, in turn, influences a particular dock's or berth's vessel capacity. Ferry Terminal Elements Docks Docking configurations depend upon the vessel; offshore water depths; tidal variations; shoreline development restrictions or desires; and required interfaces to other transit systems, roadways, and pedestrian routes. Auto ferries are typically bow-loaded and hence have dock facilities that accommodate this process, as illustrated in Exhibit 9-2(a). Departing vehicles are stored at landside or overwater vehicle staging areas. Due to tidal variations and differences in vessel freeboard, it is generally necessary to have a transfer span that connects from the fixed pier to the vessel auto deck. Depending on local conditions, these spans may vary in length from a few feet to well over 100ft (30m) and, owing to dead and live loads, require a robust mechanism for adjusting the transfer span's end elevation and slope. (a) Bow loading (Seattle) (b) Bow loading (Copenhagen) (c) Side loading (San Francisco) (d) Side loading (Sydney, Australia) Chapter 9/Ferry Transit Capacity Page 9-5 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3rd Edition Passenger loading for auto ferries can occur via the vehicle transfer span (typically on smaller ferries) or by means of a separate walkway directly to the passenger deck, which is generally about 18ft (5.5 m) above the vehicle deck. Where a separate facility is provided, passenger loading can occur at the same time as vehicle loading, decreasing the overall time required to exchange passengers and vehicles. Passenger ferries are often side-loaded, which can be accommodated by parallel or linear berthing facilities. The most typical dock design has parallel berths, such as those found at Sydney's Circular Quay (Exhibit 9-2[d]). Some dock facilities may have a variety of berthing arrangements to facilitate a range of vessel types. Another option is bow- loading, which is the most common arrangement for ferries operating in New York Harbor. Bow-loading (Exhibit 9-2 [b ])offers significant time benefits, as the vessel does not need to be tied up to the dock and several passenger streams can board simultaneously, but requires that the vessel and dock have the same freeboard as well as special engineering of the docks (2). Again, because of tidal variations, docks are often floating facilities. Floating facilities have the advantage of keeping the relative elevation between the boat and the dock constant in all tidal conditions. However, providing a float large enough to accommodate a passenger holding area may not be feasible, and the inherent dangers of having passengers on a floating structure during vessel docking has resulted in passenger holding areas often being located on fixed piers or on shore. A transfer span is normally still required somewhere between the vessel and the fixed portion of the facility, and a movable gangway is required between the vessel and the landing facility (either fixed or floating). Vehicle Staging Area A critical aspect of an auto-ferry facility is its ability to accommodate vehicle loading and unloading. A number of North American auto-ferry operators request that auto- passengers on longer-distance routes make reservations and/or arrive 30 min to 3 h prior to departure. The suggested arrival time is a function of the anticipated demand and may include time for security and hazardous material checks. For services between Canada and the United States, the advance time may also include customs and immigration checks. The process of vehicle loading and unloading is time consuming and hence requires adequate access facilities and circulation provisions at the terminal. One of the key facilities in this process is the vehicle staging lot. This area allows for the storage of queuing vehicles and a smooth transition between embarking and disembarking vehicle movements. The staging areas can be located over water on a pier or landside. A plan sketch showing potential elements associated with a landside staging area is shown in Exhibit 9-3 and examples are shown in Exhibit 9-4. The various components of staging areas are described below. Ferry Service and Facilities Page 9-6 Chapter 9/Ferry Transit Capacity
Exhibit 9-3 Illustrative Vehicle Staging Area Diagram Exhibit 9-4 Vehicle Staging Area Examples A vessel's capacity to transport vehicles is measured in auto equivalent units {AEUs) that reflect the amount of space used by each vehicle type. Staging areas can be used to organize vehicles by size, weight, and destination prior to loading. Vessel's Auto Deck (a) Seattle Transit Capacity and Quality of Service Manual, 3rd Edition Transfer Span Vehicle Staging Area Fare .-----------.. Collection â¢-@-- --------- ¢:::1 ~~=====c::::::>= (b) Bar Harbor, Maine The staging lot design for embarking vehicles will depend upon a number of factors. These include the following: ⢠Vessel auto-deck capacity: Because the auto-deck size varies considerably from one vessel to another, the concept of auto equivalent units (AEUs) is commonly used to measure auto-deck capacity. Different vehicle types are weighted based on the space they occupy compared to a standard automobile. For example, the typical factor for a recreational vehicle, single-unit truck, or bus is three, and the factor for a semi-trailer truck is five. It is important to consider the average fully loaded volume, as some vessels may have adjustable platform decks that can be fully or partially utilized on a given sailing. If the average fully loaded sailing holds 10 autos, 5 RVs, 5 buses, and 10 semis, then the capacity is (10 x 1) + (5 x 3) + (5 x 3) + (5 x 5) = 65 AEUs. ⢠Loading process: In order to keep the vessel balanced while vehicles are loaded, and to make sure that other vehicles do not block vehicles disembarking at intermediate stops, ferry operators carefully manage the order of vehicle loading from the staging area. Vehicle loading will usually take place under the supervision of experienced crewmembers that are directed by an officer or first mate of the vessel. For these same reasons, vehicles that are first to board the ferry are not necessarily the first to disembark. The staging area should be designed to allow the flexibility of vehicle choice or, alternatively, staff should be available to assign vehicle types to a particular queuing bay. In some cases, such as the Lake Michigan Carferry, vehicles are loaded and unloaded by Chapter 9/Ferry Transit Capacity Page 9-7 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3rd Edition crewmembers or staff only. Auto ferries between St. Thomas and St. John in the U.S. Virgin Islands require drivers to back their vehicles on board; a flow- through arrangement through the car deck is more efficient and is typical of auto ferries. The size of the staging area should, at a minimum, be sufficient to accommodate the vessel auto-deck capacity. However, an overload factor should be considered to accom- modate excess vehicle demand. Washington State Ferries uses an overload factor between 1.3 and 2.2 depending on scheduled ferry headways, plus an additional two lanes for emergency and high-occupancy vehicles (HOVs). Holding-area size may also be influenced by the local tolerance for vehicle queuing on adjacent streets. Well-designed vehicular circulation paths, with suitable signing and striping (e.g., lane numbers), are important to ensure the safe and efficient flow of traffic through the staging area. Barriers or traffic cones are often used to close off any temporary excess queue storage, so as to better define the vehicle path. Vehicle Fare Payment Fare payment and ticket collection practices vary depending upon the type of service. At larger ferry terminals, the fare may be collected (or checked, in the case of pre-ticketing) at booths or ticket machines prior to entering the staging area. Smaller terminals may adopt a less formal process where the fare is purchased from staff roaming through the vehicle staging area or from a crewmember aboard the vessel. Persons traveling with their automobiles tend to adjust their behavior depending upon the demand for the service. That is, if a vessel typically has excess capacity, vehicles will arrive just before a vessel's departure. Hence, there will be a short period of high vehicle arrival volumes that may require a number of staff or ticket booths. Alternatively, if a given sailing is frequently over capacity, motorists will arrive early and there is less need to have high-capacity fare collection facilities. Some systems also exclusively use pre-ticketing, eliminating the need for fare payment at the staging area entrance, although validation of the fare is typically still required and other types of checks (e.g., vehicle height and length, number of passengers, identification checks) may also be performed. Vehicle Disembarking The disembarking process is commonly a direct path from the vessel auto-deck to serve vehicles in a timely manner, although dock and shoreline constraints may require more indirect routings. Some urban ferry terminal designs include special features, such as HOV lanes that feed into the urban street system. Passenger Lobby Area Most passenger ferry terminals have a lobby area that receives passengers walking in from the street and transferring from other transportation modes, and which provides services and other necessary functions. The general configuration of a passenger ferry terminal is depicted in Exhibit 9-5. While the arrangement may vary among various systems, the layout shown can be used as a guide for the different functions. Ticketing is often done in the lobby area and, as with other transit modes, automated vending and online sales are becoming more common. In addition to general shelter, ticketing, and circulation needs, there often are vendor areas where Vehicle arrival patterns tend ta be related to whether a particular sailing usually has excess capacity or not. Ferry Service and Facilities Page 9-8 Chapter 9/Ferry Transit Capacity
Exhibit 9-5 Typical Elements of Passenger Ferry Loading Passenger holding (waiting) area sizing and LOS is discussed in detail in Chapter 10. Transit Capacity and Quality of Service Manual_ 3'd Edition newspapers, coffee, or other small items can be purchased. Space may also be necessary for disembarking passengers to wait for connections to other transportation modes, or for meet-and-greet areas. Load-unload conflict point «---------------------------------, BY Terminal entrance/exit Lobby and Activit ies Prepaid Holding Area Ticket collection and vessel load control Security screening and loading hold point Passenger Ticket Collection and Vessel Load Control "' (1) :::J "" ~ ~ :::T "' :::J "" (1) i3 c (i) "' :::J D.. D.. ~ "' :::J "'hl At the ticket collection and vessel load control point, the ticketed status of all passengers is verified, and an accurate count of the passengers entering the pre-paid holding area is performed. As discussed earlier, vessels are licensed by the USCG for particular capacities that cannot be exceeded. Manual ticket collection and counting and lock-out turnstiles are common methods employed to accomplish this function. It is desirable to perform this function upstream of the prepaid holding area so passengers can flow freely to the vessel when it is time to board. Prepaid Passenger Holding Area or FIFO Corridor A prepaid passenger holding area may be provided where ticketed passengers are staged prior to boarding the vessel. The passenger holding area should be sized at least as large as the vessel, but the level of service (LOS) provided should be appropriate for passenger arrival patterns. Often the bulk of passengers arrive shortly prior to sailing and a lower LOS may be tolerable for short periods of time. An alternative to a prepaid passenger holding area is a FIFO queuing corridor. Passengers may wait in line in the order of arrival for the next sailing. Ticket verification and control of passenger loads can be done manually or by turnstile count at the end of the corridor to prevent vessel overloading, but this point may become the critical bottleneck along the loading pathway and as a result slow the boarding and departure process. LOS standards can be used to size this type of facility, but achieving a particular level in practice can be difficult due to the tendency for passengers to crowd as close to the control point as possible. Passenger Security Screening and Loading Hold Point A security screening point may be necessary within or at the exit of the holding area. The type and extent of screening will vary by system and by threat level, but Homeland Security regulations in place at the time of writing require that it be done. Planners and ferry terminal designers are advised to work with the service provider and the Chapter 9/Ferry Transit Capacity Page 9-9 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3'd Edition Department of Homeland Security to ensure that capacity calculations properly reflect the local procedures. The loading hold point is also the location where passengers are released from the holding area and allowed to proceed to the vessel. Common practices consist of just a simple gate if passenger loads are controlled at the entry to the prepaid passenger holding area. Passenger Load-Unload Conflict Point At some point past the prepaid passenger holding area and prior to boarding the vessel there will be a "load-unload conflict point." This is the point that all disembarking passengers must pass before embarking passengers can proceed to the vessel. To minimize walking and boarding times, it is important to keep this point as close to the vessel as possible, but distances as long as several hundred feet (100m or more) are still common. Passenger Transfer Span As with vehicle loading, there is usually a need to have a transfer span between the fixed or landside portion of the passenger facility and the berth or boarding float. Tidal variations and differences in vessel freeboard have to be considered in the design since vertical differences of up to 20ft (6 m) or more are possible. The total length of transfer spans may be well over 100ft (30m) and require grades that are not ADA compliant. For these reasons, careful planning of facilities and operations is especially critical. Berth or Boarding Float The berth is the location where the vessel ties to the terminal facility. While these are sometimes fixed facilities where tidal or lake level fluctuations allow, they are more commonly floating structures. They provide room for crew operations during docking, storage and usage of boarding ramps or gangways, and service areas for the handling of supplies, water service, and sewage discharge. Actual passenger space may be limited only to that necessary for pathways to access the vessel. The design of the float and the passenger areas should focus on the smooth flow of passengers and on providing safe barriers between passenger areas and other uses. Gangway or Boarding Ramp Gangways come in a variety of types, from large, wide, hydraulically operated systems for large vessels to small and portable hand-carried ramps for smaller vessels. Regardless of the type, it is always difficult to design to prevent trip points, pinch points, and transitions between surfaces. Both the vessel and the board float may be moving relative to each other and may pitch and yaw. As a result this point is often the bottleneck in the entire loading and unloading process. Vessel Entry and Interior Circulation As passengers enter or exit the vessel, the interior layout and relationship of stairways (or ladders) and seating areas to the entrance can influence the time it takes to board passengers. Passageways within the vessel should provide for wayfinding, seating decisions, and queuing at the top and bottom of stairways. Ferry Service and Facilities Page 9-10 Chapter 9/Ferry Transit Capacity
With bow loading, ferries bump against the dock and a gangway is dropped down onto the deck. This saves time in comparison to a ferry maneuvering in, tying up, and a gangway deploying. Transit Capacity and Quality of Service Manual, 3'd Edition Ferry Terminals as a System Well-designed ferry terminals provide fast ferry turnarounds. Saving time on a ferry route through good terminal design is considerably cheaper than increasing speed on the route, because of the power consumption and cost issues associated with higher- speed vessels that were noted earlier. Faster turnarounds allow a vessel to make more trips over the course of the day, which results in a better quality of service and greater capacity. Therefore, ferry terminals should be designed to minimize, to the extent possible, the distances between passenger and vehicle service elements. In addition, the capacity and service time of each individual ferry terminal element should be evaluated to ensure that no one element becomes a bottleneck (i.e., provides substantially less capacity or longer service time than other elements in the system). Terminal siting is also important for minimizing ferry operations costs and maximizing the daily capacity and service frequency provided by an individual vessel. Terminals are often located to minimize the crossing distance (for example, at the ends of points of land), although shoreline land use, harbor depths, environmental constraints, and activity center locations also play roles in determining terminal locations. Ferry Terminal Examples Ferry terminal loading area designs vary considerably. Some examples are provided below and are illustrated in Exhibit 9-6: ⢠Brisbane (Australia) CityCat: Loading occurs from a floating platform (some covered, some not) approximately 110 ft2 (10m2) in area. Passengers first disembark from a single 3-ft (1-m) wide manual gangway. When all passengers have disembarked, passengers may then embark Fares are collected by a combination of an onboard cashier (for those paying cash), and an onboard ticket-validating machine (for those holding multiple-ride tickets and passes). ⢠Sydney (Australia} Ferries: Passenger loading at Circular Quay occurs from a large covered floating platform, which blends seamlessly from the terminal. Passengers pay their fares prior to entering the platform area. The facility design allows passengers to disembark using the upper-deck gangway, while other passengers simultaneously embark on the lower-deck gangway. The disembarking movement is connected to a fenced walkway that leads directly into the terminal. ⢠NY Waterway (New York): Bow loading is used at terminals, which provides several benefits: vessels dock more quickly, passenger movement occurs more quickly as the gangway allows several passenger streams to move simultaneously, and a separate ramp is not required (thus reducing capital costs) as the dock and vessel have the same freeboard (2). ⢠SeaBus (Vancouver): Gangways are located on both the port and starboard sides of the vessel. Passengers are unloaded from one side and loaded on the opposite side. This configuration allows the 400-passenger vessels to be loaded and unloaded within 90 s. Chapter 9/Ferry Transit Capacity Page 9-11 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3'd Edition (a) San Francisco (Ferry Building) (b) San Francisco (China Basin) (c) Vancouver (d) Vancouver (e) Brisbane, Australia (f) New Orleans Other Terminal Design Considerations Elevation differences may exist at several points in the system: ⢠Height difference between the ftxed-landside approach and the water: The fixed- landside approach to a passenger boarding facility is typically high enough above average water level to prevent submergence in all but the most extreme conditions. The height of the stable approach can range from several feet to over 20ft (1m to over 6 m), and is based on historical data. ⢠Water level changes: All waterfront facilities experience changes in the height of the water relative to the fixed approach. Coastal facilities undergo tidal cycles, with normal ranges from little more than 1ft (0.3 m) to over 20ft (6 m). Non- tidal (inland) facilities experience water level changes less frequently, as the result of rain, snowmelt, dam releases, and so forth, which tend to occur in predictable patterns. However, the changes can sometimes be more severe, with Exhibit 9-6 Examples of Ferry Passenger Loading and Unloading Passengers visible against the far wall in picture (c) have just disembarked the vessel from its opposite side. Ferry Service and Facilities Page 9-12 Chapter 9/Ferry Transit Capacity
Transit Capacity and Quality of Service Manual, 3'd Edition ranges in excess of 20ft (6 m). Extreme weather conditions can add considerably to the range at all facilities. ⢠Height difference between passenger loading platform and the vessel: When the loading platform is a fixed-elevation facility such as a bulkhead or pier, the freeboard difference between the platform and the vessel is an access barrier. Because the heights of platforms and vessel decks vary greatly, there will be widely varied and unique height differences for dock-vessel combinations. This height difference may also vary for a particular dock-vessel pair, depending on loading and weather conditions (5). Safety features to accommodate these conditions should include: ⢠Guardrails: Guardrails are critical to ensuring passenger safety because of the inherent dangers of accidentally leaving the path of travel at a marine facility. ⢠Edge treatments and detectable warnings: Tactile edge treatments and detectable warnings for the sight-impaired are important in ensuring passenger safety. ⢠Changes in slopes, heights, materials, and so forth: The path of travel from land to vessel is likely to have frequent changes, particularly slopes. Changes in the height of the loading platform relative to the shore or the vessel, due to tides or fluctuations in river level, will need to be accounted for. Attention to the slope of the ramp should be made for passengers with disabilities but boarding assistance may still be required. In some jurisdictions, ADA requirements applicable to other modes are enforced, with 1:12 ramp slopes and other features. ⢠Non-slip surfaces: Most areas at a marine facility will periodically get wet or damp from water spray. The wide use and application of non-slip surfaces are important for passenger safety. ⢠Assistance: Crew assistance for all passengers in the marine environment is standard practice due to the constantly changing conditions. This positive tradition in the industry will help meet the growing need for access for persons with disabilities. Chapter 9/Ferry Transit Capacity Page 9-13 Ferry Service and Facilities I
Transit Capacity and Quality of Service Manual, 3rd Edition 3. FERRY SCHEDULING AND SERVICE PLANNING The discussion of ferry scheduling and service planning is most easily illustrated by considering all of the steps involved in a one-way ferry trip. The following sections provide details for each schedule element, starting with the arrival of the ferry at the first port. Steps are given with primary attention to passenger ferry service; combined passenger and vehicle ferries may require additional consideration. Some of these elements are further discussed in the berth capacity section, as they influence both the vessel schedule and the time a vessel occupies a berth. Note that while the steps are provided in a logical order, many of the steps may occur simultaneously depending upon the service type, ferry design, and other local conditions. PORT DWELL TIME The overall dwell time of a ferry at a port consists of passenger exchange and vessel clean-up, resupply, and security considerations. The embarking and disembarking volume at the busiest entrance to each vessel is used to measure the passenger or vehicle demand, as this volume will control the total time needed to serve all passengers. Unless a vessel and its berth are designed to accommodate multiple gangways, this demand will be the same as the total passenger or vehicle demand. For larger passenger vessels, passenger embarking and disembarking may occur simultaneously if permitted by safety and security regulations. In this case, the greater of the embarking or disembarking volume at the busiest entrance should be used to determine the loading time. The following sections expand upon the factors that may influence scheduling time. Passenger Disembarking Internal vessel circulation: as mentioned in previous sections, the floor plan or internal design of a ferry may influence disembarkation time, or even prove to be the rate-limiting step for disembarkation time. Vessel exit and gangway time: the time required to exit the ferry and pass over the gangway. Walk time to load-unload conflict point: the time required for all disembarking passengers to walk to the point where passengers are waiting to board. Once all disembarking passengers have cleared the conflict point, they no longer influence ferry scheduling, and passengers can begin to board the ferry (assuming the necessary cleaning and security checks have taken place). Vessel Clean-up and Security Clearance These schedule elements are typically performed in parallel with passenger exchange, so their effect on vessel scheduling may be minimal. Nevertheless, the elements must be considered, especially if the passenger exchange time is less than that required for vessel servicing. Vessel clean-up: crew members may have to clean passenger areas and remove waste from the vessel. The passenger or auto volume at a vessel's busiest entrance will control the service time. Ferry Scheduling and Service Planning Page 9-14 Chapter 9/Ferry Transit Capacity
Fare payment does not affect passenger service time when fares are collected at the entrance to a fare-paid passenger waiting area. Transit Capacity and Quality of Service Manual, 3'd Edition Resupply: time is required to re-stock the vessel with supplies, which may include food or on board vending, fuel, and other items necessary for each journey. Sewage and water: sewage and other waste products may need to be removed from the ferry and water supplies refilled. Empty vessel sweep: it is typical to perform a sweep of the vessel to ensure that all passengers have disembarked. This is important for fare collection as well as from a security standpoint. The vessel sweep may begin as soon as passengers have cleared an area, but must be completed before any embarking passengers board. Passenger Embarking Ticket sales: ticket sales may influence the schedule time on routes where tickets are sold as passengers board. This is not the typical case for higher-capacity systems due to the significant reduction in boarding efficiency. Fare or ticket collection: fare payment and ticket collection procedures vary considerably in the ferry transit industry. At lower-volume terminals, passenger and auto fares are often collected at the gangway or on board. Services that make multiple stops may also wish to collect fares on board to minimize or eliminate the need for staff at each dock. Depending on cash handling and the potential need to issue receipts, the time to serve each embarking passenger may be considerable. During peak tourist times on an Australian ferry, for example, fare payment has been observed to delay a vessel's departure at busy stops, as the line of passengers waiting to pay a cash fare to the on board cashier can extend back onto the loading platform. A longer-distance ferry operator in the San Francisco Bay Area previously employed a modified proof-of- payment system where passenger fares were inspected 15 min after departure, giving passengers time to purchase their fare on board, while eliminating fare collection queues while boarding. At larger terminals, fare payment and collection occurs in the terminal building, prior to the entrance to a fare-paid waiting area. Payment can be made to cashiers or through the use of ticket/token machines and fare gates. Automobile fare payment or validation will typically occur at booths prior to entering the staging area. In either of these cases, fare payment does not affect the embarking or disembarking time. Security screening: security screening is required by Department of Homeland Security regulations, and the level of screening may vary as threat levels change. Screening is unique to each operation and ranges from simple observations of passengers to x-ray of individual parcels or canine screening for explosives. FIFO exit from pre-paid holding area or load-unload conflict point: as discussed previously, the type of holding area influences the boarding process. When the holding area is controlled to prevent overcrowding, a FIFO system is not necessary. However, in cases where there is no holding area, or the holding area is of insufficient size, a process for maintaining the relationship between passenger arrival time at the terminal and ability to board the ferry must be maintained. This process may impact the schedule if it places restrictions on the speed of the boarding process. Walk time to vessel: the time required for all passengers to travel to the vessel entrance or gangway. Vessel entrance or gangway: the stability and pedestrian friendliness of the loading facilities affect the passenger disembarking and embarking time. This also includes the Chapter 9/Ferry Transit Capacity Page 9-15 Ferry Scheduling and Service Planning I
Transit Capacity and Quality of Service Manual, 3'd Edition time to traverse the loading area facilities, which is a function of the length and width of the access walkway /roadway, and the boarding ramp or gangway. Internal vessel circulation: similar to disembarking, the internal vessel design or floor plan may restrict the flow of passengers onto the ferry, which may affect the schedule in extreme cases. DEPARTURE CLEARANCE TIME The following steps determine how quickly a ferry can depart and commence travel to the next port: Gangway removal: the gangway technology will affect the time it takes to place and remove the gangway. There are a number of technologies in use: ⢠Hand winch or manually placed, ⢠Electric, ⢠Hydraulic, and ⢠Bow loading. Mooring disengagement: mooring procedures vary considerably. Examples include: ⢠Blue & Gold Fleet (San Francisco): A three-step process involving fixing the spun line, bell line, and stern line. The mooring time is approximately 1 min in calm conditions; longer at other times. ⢠Golden Gate Ferries (San Francisco): The stern line is fixed and the vessel is left running to maintain tension. The 2-ton gangways rest upon the vessel to keep the vessel in place. This process takes approximately 30 s to complete. ⢠Staten Island Ferry (New York): The vessel is docked with a rack system that guides the vessel. The lower-level gangway is attached with mooring hooks and the upper- and lower-level gangways are then placed on the vessel. Maneuvering time: depending on the ferry type and operation, it may be necessary to maneuver the ferry to prepare for transit to the next port. Vehicle ferries with a single entrance are a common example of when maneuvering time may be required Harbor traffic: depending upon the service location, it may be necessary to take the level of harbor traffic into account when performing ferry scheduling. Harbor traffic may result from major port facilities, small pleasure craft, or even windsurfers, which can cause delays to ferries, particularly on weekends. These conditions may result in congestion or a high-risk environment, forcing vessels to reduce travel speeds. Some locations may enforce restrictions on a direction of travel, meaning that vessels traveling in that direction must yield to vessels traveling in the other direction. TRANSIT TIME The transit time is the time required for the vessel to travel from one port to the next. The transit time is based on the distance between the two ports and the average speed of travel of the vessel. It may not be appropriate to assume a constant vessel speed, since time is required to accelerate up to and decelerate from the cruising speed. Furthermore, other speed restrictions and no-wake zones along the route may impact travel speeds. The travel time should be calculated using typical conditions for the Ferry Scheduling and Service Planning Page 9-16 Chapter 9/Ferry Transit Capacity
Transit Capacity and Quality of Service Manual, 3'd Edition route, including typical sea, wind, and weather conditions as well as currents and the effects of other waterborne vessel traffic. ARRIVAL TIME Similar to departure time, these steps occur in the reverse order when approaching the port: Harbor traffic: high levels of harbor traffic may impact the time it takes for the ferry to arrive at the dock; such impacts require additional schedule time to ensure on-time arrivals. Maneuvering time: the time required to maneuver the ferry in the appropriate position for docking. Mooring time: the time required to moor the vessel; see discussion under departure clearance time. Gangway positioning: the time required to position the gangway between the vessel and the dock. OPERATING MARGIN While the above elements account for the required schedule time for service from one port to another, it is typical to incorporate additional time (an operating margin) to accommodate uncertain or extreme conditions. Schedule reliability: one of the primary reasons to include operating margin in a schedule is to provide schedule reliability. The level of reliability required may vary depending on the ferry service. For example, it is common for commuter-type ferry service to have a higher expectation of schedule reliability than recreational ferry services. Wind, weather, and seas: as mentioned above, the transit time takes into account normal or typical wind, weather, and sea conditions. However, it is advisable to consider the variability of these environmental factors and incorporate additional time to account for the likelihood ofless-than-favorable conditions. Fog: depending on the location of the ferry service, it may be necessary to consider the possible presence of fog, which can dramatically slow vessel speeds, depending on the severity of the fog. Tides and currents: additional time may need to be incorporated into the schedule when there are significant sea level changes due to tides, or when currents and other disturbances may influence travel times. Unusual marine traffic: additional accommodation may be required for unusually high marine traffic levels. Mechanical: mechanical issues may impact ferry service in a variety of ways. For example, a problem with a mechanically moved gangway may result in a schedule delay. The ferry service operator must take these potential issues into account and determine the appropriate additional schedule time needed to accommodate some unforeseen mechanical issues. However, it is not expected that extreme mechanical issues or failures should be accommodated within the schedule due to the relatively low expected occurrence of such issues. Chapter 9/Ferry Transit Capacity Page 9-17 Ferry Scheduling and Service Planning I
Transit Capacity and Quality of Service Manual, 3rd Edition PEDESTRIAN MOVEMENTS The previous section provided a brief overview of the elements that may affect scheduling of ferry service. A number of these elements involve pedestrian flow concepts which are further developed in Chapter 10, Station Capacity. Exhibit 9-7 provides a list of cross references pertaining to pedestrian flow. Item Description Illustration of walkway LOS Illustration of queuing (waiting) area LOS Reference Exhibit 10-4 Exhibit 10-5 Relationship between walking speed and pedestrian space Exhibit 10-10 Relationship between pedestrian flow rate and pedestrian space Exhibit 10-11 Doorway capacity Exhibit 10-26 Fare control passenger headways and capacity Exhibit 10-27 Relationship between walkway width and pedestrian flow rate Equations 10-2, 10-3 Pedestrian LOS on walkways Exhibit 10-28 Queuing (waiting) area LOS Exhibit 10-32 Platform (waiting area) sizing procedure Not applicable SERVICE PLANNING Page No. 10-14 10-14 10-21 10-22 10-40 10-42 10-43, 10-44 10-44 10-55 10-56, 10-57 The above elements aid in determining the one-way travel time from one port to another. Once the overall schedule time from one port to another has been determined for all segments of a planned ferry service, a ferry service plan may be developed. Since the character of ferry routes may vary considerably between operating agencies and locations, it is impractical to define an all-encompassing methodology for ferry service planning. Nevertheless, ferry services may be classified as point-to-point or multiple- destination types of services: Point-to-point ferry services operate only between two ports. In this type of service, all passengers disembark at the end of the journey. Multiple-destination ferry services operate between more than two ports and do not require all passengers to disembark at each stop. As previously mentioned, this type of service requires careful planning to allocate passenger space to various destinations to ensure that all segments can be served while not exceeding the USCG vessel passenger limit. There are many trade-offs when determining ferry fleet sizes and schedules. The operation of a number of small ferries with frequent headways may accommodate the same passenger demand as larger ferries with less frequent headways. The trade-off between ferry size and schedule headway is also influenced by dock capacity, operating costs, and passenger expectations. These trade-offs are complicated in multiple-destination routes. In some instances it may be desirable to have asymmetric service in multiple-destination routes, meaning that not all ferries follow the same pattern throughout the day or by direction. These services can be built by determining the number of trips needed between each pair of destinations and assigning such blocks of service to different ferry vessels in the most economic manner possible. Such services allow for maximum flexibility in serving passenger demand while attempting to minimize the operating cost. Exhibit 9-8 shows an example of a complex multiple-destination service across Puget Sound between Southworth, Vashon Island, and Fauntleroy. One disadvantage of asymmetric service for Exhibit 9-7 Pedestrian Flow Cross-References Ferry Scheduling and Service Planning Page 9-18 Chapter 9/Ferry Transit Capacity
Exhibit 9-8 Example of Multiple- Destination Service Transit Capacity and Quality of Service Manual, 3'd Edition ferry transit service is that it does not allow for "memory" or "clockface" schedules, in which a ferry departs for a destination at regular, repetitive times (e.g., at 20 and 50 min after the hour). ~ ..c +-' ~ 0 ~ ..c +-' ::::J 0 C/) I c 0 ..c en ~ I ~ 0 ~ CD +-' c ::::J ro u. ... 0905~900 1-B.Js 0925 ---- 0930 920 ...... 940 950 950-- F\Jmp 1020 --1-B.Js ~1010 --1010 .,....1030-------- 1040~ 1045---- 1100.::".::_~.!.2~~~"':::d ----1110 1140~----- - 1130 1135 1155 --1155 C.ewchg - -- ~----, 205 122o:::_ __ ~225 ---1230 1255~1245~ ---------1250 ......... C.ewchg 1320 1 3 1 0) __ ::.':::.1310 VvtaF 1340~-;;;;---- 20 1405 ------14 ----------- -1420 C.ewchg --=;:1430 VvtaF 1-8.Js 1445- --=- .----NoSvehldeso 1505~1525 1-8.Js -1455 rootfi\Xo.k. --- 1535 --1530-- 1600 -=====1550 162o~163ii 1605 1640 ..........- _ - ------ 1700 :::;::::::=- -c=-=:::: 1710 ;,;-;1705 2·8.Jsos 17 4 0 ::::::=== 17 2 5 :::-><..::_- --..,__ ___ 1730- ---- 1800:::::.:.::----1805:---. 1750 1830~-==1830 1-B.Js -=:::::::::::::1830 FIJmp 1905 :_- 1855- ._..., .... 1900-FIJmp 1935~ ...... -(1925) ___ -----1920 2-&.sos1940-- 2005--- ---2000------------~ ----2030---- 030 2055-======-------~----·2050 C.owchg 2120 ·-····· 2120------2135)~····(2135) DHMont.hrulhu .â¢â¢â¢ · ⢠d1rect to htHtp fif1p 2145) ... ···· ----2155 ... ··········· ~ ...... Friday 2205 ··· 2220 ...... 2245 Fvla S 2340 005 F.na S 0055=====~~;;~======oo25 vvJaF 0210 0120 Fvla 5- =={)140 VvlaF 240 _____ ---'0250) 2305 VvtaF Vessel #1 . -- Vessel#2: --- Vessel #3: -- Option: v..-~on 10.2.8 Source: Washington State Ferries. Chapter 9/Ferry Transit Capacity Page 9-19 Ferry Scheduling and Service Planning I
Transit Capacity and Quality of Service Manual, 3'd Edition When multiple ferry routes serve a common destination, interlining routes is another option for minimizing the number of vessels required. For example, if one route has a 35-min sailing time (70-min round trip including required layover time and operating margin) and it is desired to operate the route hourly, while another route serving the same destination has a 20-min sailing time ( 40-min round trip), vessels could be scheduled to alternate between the two routes. The combined cycle time for the two routes would be 110 min, which could be operated by two vessels alternating between routes instead of three dedicated to specific routes (two to the longer route and one to the shorter route). Ferry Scheduling and Service Planning Page 9-20 Chapter 9/Ferry Transit Capacity
Exhibit 9-9 Vessel Capacity Measurement Locations Transit Capacity and Quality of Service Manual, 3'd Edition 4. VESSEL CAPACITY Vessel capacity can be calculated for two key locations: berth and dock facility. A route's vessel capacity will be constrained by the lowest-capacity dock facility along the route. These locations are depicted in Exhibit 9-9. Terminal Landside Facilities r--- Main 1 Ramp I L Berth ~~------~ ~------~~ v Dock Dockside Facilities Vessel Route ~--------------------~ En -Route The berth encompasses the passenger loading platform, the gangway connecting the I platform to the vessel, and any walkway facilities connecting the platform to a waiting area or the shore. The dock facility is composed of one or more berths. Within a given hour, a ferry berth may accommodate multiple vessels. Given that each vessel uses a portion of the hour to serve passengers and/ or autos and clear the berth, only a limited number of vessels can access the berth in the hour. The vessel capacity of a ferry berth is defined as the maximum number of vessels per hour that can use the berth at a given level of passenger demand. Ferry operators can determine how the current or planned vessel demand compares to the vessel capacity of the loading facilities, as illustrated in Exhibit 9-10. When a facility operates close to its capacity, any operating irregularities will cause delays to vessels, as they will arrive at the berth only to find it occupied by another vessel. In addition, when a facility operates close to its capacity, any growth in demand will increase each vessel's service time, and thus reduce the time within the hour available to other vessels. In this case, measures may be implemented to decrease the vessel loading and clearance time or, ultimately, to construct an additional berth. Chapter 9/Ferry Transit Capacity Page 9-21 Vessel Capacity
Transit Capacity and Quality of Service Manual, 3'd Edition T = 60 min In situations where vessel capacity is not anticipated to be an issue, quantifying the loading time enables planners and ferry operators to estimate a new route's travel time and to isolate any design issues related to the loading facilities. The vessel capacity of the dock facility is a function of the capacity of the individual berths. The following sections present an overview of the primary factors that determine vessel capacity at each of these locations. BERTH CAPACITY The vessel capacity of the berth is dependent upon three key components: passenger disembarking time, passenger embarking time, and clearance time. The clearance time is the average time from when one vessel is ready to leave the berth to when another vessel is able to use the berth. A portion of the clearance time is made up of the minimum time for one vessel to maneuver out of and clear the berth area and the next vessel to maneuver into the berth. Clearance time also includes the time required to deploy and remove the gangway(s) and any arrival or departure delays caused by harbor traffic. In total, clearance time represents the average time when the berth is unavailable for passenger movement. Disembarking and embarking time is a function of a number of factors, including the passenger or auto demand, the fare collection method, and the design of the gangways and walkways between the vessel and the passenger load-unload conflict point. The vessel and loading design may enable a portion of the embarking and disembarking times to be overlapped. Ferry terminals can also operate like transit centers, where passengers arrive and transfer to another vessel to complete their journey. In these cases, the time a given vessel occupies a berth depends more on the time required for passengers to transfer between vessels and the time required to stagger scheduled vessel arrivals and departures to avoid harbor congestion, than on the disembarking, embarking, and clearance times. This form of operation requires many more berths than a situation in which timed transfers are not provided or where little or no transfer demand exists (i.e., passengers exit the terminal building after arriving and continue to their destination via another travel mode). Exhibit 9-10 Berth Vessel Capacity Quantifying loading time is important even when vessel capacity is not an issue. Vessel Capacity Page 9-22 Chapter 9/Ferry Transit Capacity
Equation 9-1 Equation 9-2 No default values are currently available for ferry capacity parameters; field data collection is suggested. Transit Capacity and Quality of Service Manual, 3'd Edition Disembarking/Embarking Time Factors Berth Vessel Capacity The maximum number of vessels per hour that a berth can accommodate based on a given passenger demand is given by the following expression: where 3,600 Vb=-- tv Vb = vessel capacity of the berth (vessels/h), 3,600 = the number of seconds in one hour, and tv = design vessel service time (sjvessel), discussed below. The design vessel service time is approximated by the passenger or automobile disembarking and embarking times (whichever is higher), the vessel clearance time, and an operating margin, as shown in Equation 9-2. The operating margin addresses the reliability needs discussed previously, ensuring that the estimated vessel capacity can be reliably achieved, rather than being a maximum capacity achievable only under ideal conditions. Little guidance is available for determining this margin other than that it should be based upon observed variations in berth times for existing similar services (similar to the process used in other TCQSM chapters for determining an operating margin for bus and rail transit), or determined by other operating experience. If capacity is not expected to be an issue, and it is only desired to know the average time a vessel will occupy the berth (e.g., for use in estimating average travel time), an operating margin does not need to be calculated. tv = ted + tc + tom where tv = design vessel service time (sjvessel), ted = total embarking and disembarking time (sjvessel), tc = clearance time (sjvessel), and tom = operating margin (sjvessel). Discussions with various ferry operators suggest that commuter embarking and disembarking has very little variation, while tourist services experience significant variation around the mean. There are currently no ferry-related data that would allow a default standard deviation or coefficient of variation to be given; however, one could determine this parameter from a series of field observations. Similarly, no data are currently available to provide a default clearance time; however, one could be determined from observations of current operations or from discussions with vessel captains. Determining the disembarking and embarking times requires field measurements, or estimates of the number of embarking and disembarking passengers or automobiles. The previous discussion on ferry scheduling can provide guidance on how to estimate these times when field data are unavailable, based on passenger demand, terminal and vessel design elements, and fare collection procedures. In general, each step for the scheduling process should be estimated, with many of the steps drawing from the Chapter 9/Ferry Transit Capacity Page 9-23 Vessel Capacity I
Transit Capacity and Quality of Service Manual, 3'd Edition pedestrian flow procedures for stations presented in Chapter 10, Station Capacity. For activities that overlap, care must be taken to use the time from the slowest combination of activities, since this will control the maximum embarking or disembarking rate. Information from terminal design may also be relevant when considering passenger flow within the vessel itself. Finally, queues will likely form where there are delays. The queue-discharge time must also be incorporated into the boarding or disembarking time. The following section provides an example layout for a sequential disembarking and embarking process. Sequential Passenger Disembarking and Embarking This section applies to situations in which passengers disembark from the vessel and have cleared all walkways before passengers are allowed to embark. The service time elements in this process are as follows: 1. Passenger time to disembark the vessel over one or more gangways. This time is related to the number of gangways, the gangway width, and the passenger demand. 2. Disembarking passenger time to traverse the walkway to the dock exit. This time is related to the walkway width and the rate at which passengers exit the gangway( s). 3. If disembarking passengers arrive at the dock exit at a faster rate than the exit can process them, there will be additional delay at the exit. This could be an issue if the exit is narrower than the walkway leading to it, or if a doorway or exit gate is involved. 4. Once disembarking passengers have cleared the area, embarking passengers are allowed from the waiting area onto the walkway leading to the vessel. Entrance to the walkway could be controlled by a door, sliding gate, or other mechanism, any of which will have an associated time to serve all of the passengers in the waiting area. If fares are collected at the waiting area exit, this time should be included in the service time. 5. Embarking passenger time to traverse the walkway to the vessel. This time is related to the walkway width and the rate at which passengers exit the waiting area. 6. Time to board the vessel over its gangway( s). If passengers arrive at the gangway(s) at a faster rate than they can be processed, there will be additional delay at the gangway. If fares are collected at the gangway, this time should be included in the service time. The passenger embarking and disembarking time can be illustrated by the following expression: where t ed = embarking and disembarking time (sjvessel); Many aspects of embarking and disembarking depend on concepts from Chapter 10, Station Capacity. Equation 9-3 Vessel Capacity Page 9-24 Chapter 9/Ferry Transit Capacity
For relatively uncongested situations (i.e., walkway LOS Cor better) with no steep grades, 250ft/min (75 m/min) is a reasonable default passenger speed. Exhibit 9-11 Embarking and Disembarking Parameters Wider ramps, gangways, and doors speed boarding and alighting (more passengers can move side by side) and thereby reduce vessels' terminal time. Transit Capacity and Quality of Service Manual, 3'd Edition 60 = number of seconds in 1 min; Cd = disembarking capacity at the constraining point, typically the minimum of the gangway capacity C9 or the walkway exit capacity Cx (p/min); Ce = embarking capacity at the constraining point, typically the minimum of the waiting area exit capacity Cw, the gangway capacity C9, or the fare collection capacity Ct(p/min); Pd = disembarking passenger volume (p ); Pe = embarking passenger volume (p ); Lw = walkway length (ft, m); Vd = disembarking passenger speed on walkway, from Exhibit 10-10 (U.S. customary units), Exhibit 10-10m (metric units), or defaulted (ft/min, mjmin); and Ve = embarking passenger speed on walkway from Exhibit 10-10, Exhibit 10-10m, or defaulted (ft/min, mjmin). The parameters used to determine embarking and disembarking time are illustrated in Exhibit 9-11. Ce = min(Cw, C9 , Cf) Lw Waiting Area \..../"""\._../ cL (((Pe, Ve Ct Cg ! Pd,vd))) Cx Vessel Gangway Walkway Walkway Exit \...../"'\../ Cd = min(C9 , Cx) Disembarking Note: The gangway is considered as a point and hence the time to traverse its length is not included . Passenger speeds on the walkway can be determined using Exhibit 10-10 and Exhibit 10-11 in Chapter 10, Station Capacity, starting with a known capacity of the gangway or waiting area exit that constrains how quickly passengers can enter the walkway. For example, if the walkway is 6ft (1.8 m) wide and the gangway can process 60 pjmin, the pedestrian flow per unit width entering the walkway from the gangway is 10 pjmin/ft width (33 pjmin/m width). Using the right (uncongested) side of the unidirectional commuter curve in Exhibit 10-11 gives a pedestrian space of approximately 26 ft2 (2.5 m2) per passenger at this pedestrian flow per unit width. Applying this result to Exhibit 10-10 gives an average pedestrian walking speed of 250 Chapter 9/Ferry Transit Capacity Page 9-25 Vessel Capacity I
Transit Capacity and Quality of Service Manual, 3'd Edition ft/min (75 mjmin). These calculations assume walkways that are level or have grades of 5% or less; passengers will travel more slowly on steeper walkways. The disembarking capacity Cd is the point along the disembarking process with the lowest capacity. This will typically be the gangway capacity or the walkway exit capacity, but passenger movement could also be constrained internal to the vessel or, due to fare collection activities, upon exiting. Similarly, the embarking capacity Ce is typically constrained by the exit from the passenger waiting area, the gangway capacity, or the fare collection time boarding the vessel or at the waiting room exit (if applicable). Gangways can be treated as a free-entry fare gate, and their capacities can be determined from Exhibit 10-27 in Chapter 10, Station Capacity. The capacities of other potential constraining points, such as doors or gates, can also be determined from this exhibit. When local data on fare collection times are not available, fare collection service times can be approximated using the values for buses given in Exhibit 6-4 in Chapter 6, Bus Transit Capacity. Simultaneous Passenger Embarking and Disembarking In the event that passenger embarking and disembarking occurs at the same time, inputs to Equation 9-3 should only include the greater of the embarking or disembarking service time. This value is not necessarily dependent upon the magnitude of the embarking or disembarking volume. Although the disembarking volume may be greater than the embarking volume, the service time for embarking passengers may be larger if passengers pay fares when boarding. Sequential Automobile Disembarking and Embarking When automobiles and other vehicles are carried, the time required to load and unload these vehicles will usually control the embarking and disembarking time. This service time is constrained by the time to serve individual vehicles at the gangway, the number of gangway channels available, and the distance between the gangway and the front of the vehicle staging area, as shown in Equation 9-4: where t ed = embarking and disembarking time (sjvessel), hv = average vehicle headway (sjauto), Ad = number of disembarking autos (auto equivalent units), Ae = number of embarking autos (auto equivalent units), Nca Lr Vv = = = number of channels for automobiles, distance between gangway and front of vehicle staging area (ft, m), and vehicle entering/exiting speed (ftjs, mjs). There are currently no default values for headway or vehicle speed; however, these can be determined from field observations. Equation 9-4 Vessel Capacity Page 9-26 Chapter 9/Ferry Transit Capacity
Equation 9-5 Transit Capacity and Quality of Service Manual, 3'd Edition DOCK CAPACITY The vessel capacity of the dock represents the total number of vessels that can be served at the dock facility per hour. The dock facility capacity is the sum of the vessel capacities of the individual berths making up the dock, as shown in Equation 9-5: where V = dock vessel capacity (vessels/h), Vbi = vessel capacity of berth i (vessels/h), and Nb = number of berths atthe dock. Chapter 9/Ferry Transit Capacity Page 9-27 Vessel Capacity I
Transit Capacity and Quality of Service Manual, 3'd Edition 5. PASSENGER AND AUTO CAPACITY The passenger capacity can be calculated at a number oflocations along the passenger's path of travel. These locations are illustrated in Exhibit 9-12 and are broken into three key components: landside, dockside, and en-route. r------~r--------r I I Loading Gangway I I I I Berth ~ I I ~ I I I ~ Terminal Ma inl I Ramp > I Vesse l Route I I ~~-- -- - - -------- - -----~ I I I ~ I I Berth I I I I ~ I I Dock I ----- _IL -L --- --- Lands ide Faci lities Dockside Faci lities En-Route Landside: Methods for determining the capacity of various passenger circulation elements of a ferry terminal are provided in Chapter 10, Station Capacity. In some cases, landside access issues may present a serious constraint on ferry capacity. When this occurs, the Chapter 10 methods should be used to determine whether the terminal constrains passenger flow and, consequently, ferry capacity. Dockside: The passenger or auto capacity of a single berth or the dock as a whole (multiple berths) can be determined using this chapter's methods. The results can be compared against current or planned demand for the service and to the vessel capacities of the dock and its component berths. The maximum number of embarking and disembarking passengers (autos) that can be served at the berth will depend upon the number of vessels serving that berth during the hour. The greater the number of vessels, the greater the total clearance time and, hence, the less time available in the hour to load and unload passengers or vehicles. If the embarking and disembarking time for all vessels at the berth exceeds the available time within the hour, then it can be concluded that the passenger (auto) demand exceeds the berth's passenger (auto) capacity. The maximum number of embarking and disembarking passengers (autos) that can be served at the berth will also depend upon the distribution of embarking and disembarking passengers (autos) at a berth for each vessel. When all passengers (autos) disembark all vessels that arrive at the berth, the embarking demand per vessel cannot Exhibit 9-12 Passenger or Auto Flow through the Ferry Transit System Passenger and Auto Capacity Page 9-28 Chapter 9/Ferry Transit Capacity
Equation 9-6 Transit Capacity and Quality of Service Manual, 3rd Edition exceed the vessel's passenger (auto) capacity. When vessels make multiple stops, a portion of the passengers aboard will not disembark. The difference between the vessel's passenger capacity and the number of passengers remaining aboard at a stop represents the embarking passenger capacity for each vessel. En-route: The en-route capacity of a ferry system is much less complicated. As mentioned previously, the vessel's passenger capacity is set by the vessel's USCG license. Some vessels may have three or four different licenses, whereby the passenger limit will depend upon the size and composition of the crew. Ferry operators may need to match the crew size and passenger license to projected passenger demand. For autos, the concept of AEUs described earlier in this chapter is used to measure the vessel's vehicle capacity on the vessel. This is a method that weights different vehicle categories (e.g., autos, autos with trailers, single-unit trucks) based on the space they occupy relative to an automobile. P = Vcf(PHF) where P = person (auto) capacity on the route's maximum load segment (p/h, autos/h), Vc = vessel's passenger (auto) capacity (pjvessel, autos/vessel), f = vessel frequency (vessels/h), and PHF = peak-hour factor, the ratio of the hourly demand to four times the highest 15- min demand. The PHF is used to reduce a maximum (theoretical) capacity to a design capacity that can accommodate variations in demand from one sailing to the next without requiring passengers to wait for the next vessel. With a few exceptions (such as Vancouver's SeaBus and many ferry services to New York City), most North American passenger ferry operations are operated at headways of 30 min or longer. In the absence of local information, a PHF of 0.90 to 0.95 is recommended for these longer- headway services as an allowance for variations in demand. Smaller PHFs (e.g., 0. 75- I 0.85, similar to bus and rail PHFs) may be appropriate for shorter-headway ferry services. Ferries that require advance reservations can be planned using a PHF of 1.00, as all available space will be utilized whenever possible, and there is no passenger expectation of space being guaranteed on the next departing ferry. Chapter 9/Ferry Transit Capacity Page 9-29 Passenger and Auto Capacity
Transit Capacity and Quality of Service Manual, 3rd Edition 6. CALCULATION EXAMPLES Example Description 1 Vessel service time (passengers) 2 Vessel service time (automobiles) 3 Berth capacity CALCULATION EXAMPLE 1: VESSEL SERVICE TIME (PASSENGERS} The Situation A short passenger ferry route is planned that connects three locations along and across a river in an urban area. For scheduling purposes, it is desired to know how long vessels will stop at each location. The Question What are appropriate vessel service times to plan for at the three stops, during the afternoon peak period? The Facts ⢠The route will use a ferry with a 50-person capacity. ⢠Ticket machines located on the shore will be used to issue tickets; a crewmember will collect the tickets at the gangway. ⢠The ferry has one doorway and hence there is sequential passenger disembarking and embarking. ⢠The average number of embarking and disembarking passengers per stop during the afternoon peak period is forecast as follows: Stop# 1 2 3 Disembarking passengers 10 20 20 Embarking passengers 30 10 10 ⢠The docks have a gangway width of 40 in. (1m). Sloped walkways lead from each dock onto the shore. The walkways have dimensions of 6.5 x 50ft (2 x 15 m) and each walkway ends in a pair of free-swinging gates opening outward into an uncovered waiting area. Embarking passengers are not allowed onto the walkway until the disembarking passengers have exited. Comments and Assumptions ⢠Based on observations of a ferry service with similar mooring operations and gangway equipment to that proposed, the clearance time is estimated to be 90 s ( 45 s upon arrival and 45 s upon departure). ⢠Because berth capacity is not being calculated, an operating margin to account for non-typical conditions does not need to be estimated. Exhibit 9-13 List of Calculation Examples Calculation Examples Page 9-30 Chapter 9/Ferry Transit Capacity
Transit Capacity and Quality of Service Manual, 3'd Edition ⢠From Exhibit 10-27, average capacities for manual ticket collection are 30 pjmin (i.e., 2 sjp ). Both the gangway and the walkway exit gates can be treated as free- admission gates, which have a capacity range of 40-60 pjminjchannel. The lower value ( 40 pjminjgate) will be assumed for the walkway exit gates, as these require physically pushing or pulling the gates to open them, or to keep them open, while the higher value (60 pjminjchannel) will be assumed for the gangway, as passengers can pass through it freely. A 40-in (1-m) wide gangway is the equivalent of one channel. ⢠All input parameters are known. The vessel service time is the sum of embarking, disembarking, and clearance times. As passenger movement along the walkway occurs in one direction at a time, embarking and disembarking times will need to be calculated separately for each stop to determine their contribution to vessel service times. Solution Step 1: Calculate the Disembarking Capacity The disembarking capacity Cd is calculated using the methods given in Chapter 10, based on the minimum of the gangway or exit capacity. Gangway capacity is based on the capacity of a single gangway channel C9 (60 pjmin) and the number of gangway channels available Neg (1), resulting in a gangway capacity of 60 pjmin. Fare collection capacity is based on the number of fare-collection channels N1 and the fare collection service time per passenger tf- Exit capacity is based on the number of exit channels provided Nee (2) and the capacity of a single exit channel Cx ( 40 pjmin), resulting in a capacity of 80 pjmin. The gangway capacity is the most restrictive, so the disembarking capacity is 60 pjmin. _ . fC9 Nc9 J _ . f(60)(1)J _ . Cd- mmtCxNce - mmt(40)(2) - 60 pjmm Step 2: Calculate the Embarking Capacity Embarking capacity Ce is calculated similarly to disembarking capacity. However, as fares are collected when boarding, this process must also be considered in this step. Fare collection is performed by a single crewmember who can check one passenger in 2 s, or 30 pjmin. This is less than the gangway and entrance capacities, so it is used as the embarking capacity. { C9 Nc9 } { (60)(1) } Ce = min 60Nrftr = min (60)(1/2.0) = 30 p/min CxNce ( 40)(2) Step 3: Calculate the Total Embarking and Disembarking Time Equation 9-3 is used to calculate the total embarking and disembarking time t ed· The calculation is illustrated for the first stop: Chapter 9/Ferry Transit Capacity ( pd Lw Pe Lw) ted= 60 -+-+-+-Cd vd Ce Ve ( 10 15 30 15) ted = 60 60 + 75 + 30 + 75 Page 9-31 Calculation Examples I
Transit Capacity and Quality of Service Manual, 3'd Edition ted= 94 S Step 4: Calculate the Vessel Service Time Finally, using Equation 9-2, the average vessel service time tv is the sum of the calculated embarking and disembarking time ted and the clearance time tc given in the problem statement. (The operating margin shown in Equation 9-2 does not need to be included, as only the vessel service time is of interest in this example.) For the first stop, the calculation is as follows: The Results tv= ted+ tc tv= 94 + 90 tv= 184 s Steps 3 and 4 are repeated for stops 2 and 3, resulting in the following estimated vessel service times. These times are for planning purposes and are shown below for each stop: Stop# 1 2 3 Vessel service time (s) 184 154 154 Changing the proposed fare collection system to avoid fare collection at the gangway would improve the vessel service time by an average of 30 sf stop. Improvements in the gangway or mooring technology could also be considered to improve service times, as the planned 90 s forms a significant portion of the total time. CALCULATION EXAMPLE 2: VESSEL SERVICE TIME (AUTOMOBILES) The Situation A new auto ferry route is planned to connect two locations on opposite sides of a bay. It is desired to know how long a typical ferry on this route will occupy the berth when auto demand equals or exceeds the ferry's capacity. The Question What is the average vessel service time when the ferry is fully loaded entering and leaving the dock? The Facts ⢠The route will use a ferry with a capacity of 100 autos. ⢠The fare will be collected in the auto staging area prior to embarking. ⢠The ferry will have sequential auto disembarking and embarking. ⢠The gangway can accommodate two lanes of vehicles and is located 150ft from the front of the vehicle staging area. Calculation Examples Page 9-32 Chapter 9/Ferry Transit Capacity
Transit Capacity and Quality of Service Manual, 3rd Edition Comments and Assumptions ⢠The clearance time, based an investigation of similar mooring and gangway technology, is estimated to be 3 min (1.5 min upon arrival and 1.5 min upon departure). ⢠Because berth capacity is not being calculated, an operating margin does not need to be estimated. ⢠Assume that the vehicle headway is 3.0 sf auto. ⢠Assume thatthe approximate auto entry speed is 10 mijh (14.7 ftjs). ⢠The vessel service time is the sum of embarking, disembarking, and clearance times. Solution Step 1: Calculate the Total Embarking and Disembarking Time As this is an auto ferry, Equation 9-4 is used to calculate the total embarking and disembarking time ted: 3(100 + 100) (2)(150) ted= 2 + 14.7 ted= 320 s Step 2: Calculate the Vessel Service Time The vessel service time tv is the sum of the embarking and disembarking time ted and the clearance time tc given in the problem statement: tv= ted+ tc tv= 320 + 180 tv = 500 s (8 min, 20 s) The Results When a ferry is fully loaded entering and leaving the dock, its average service time will be 500 s. CALCULATION EXAMPLE 3: BERTH CAPACITY The Situation A passenger ferry berth currently serves six ferries during the evening peak hour. The transit agency wishes to add another ferry during the peak hour. The Question Are additional berths required? Chapter 9/Ferry Transit Capacity Page 9-33 Calculation Examples I
Transit Capacity and Quality of Service Manual, 3'd Edition The Facts ⢠The observed average passenger embarking and disembarking time t ed at the berth is 3 min; however, this time can vary somewhat from one ferry to the next. ⢠The observed average clearance time is a total of 4 min (2 min upon arrival and 2 min upon departure). Comments and Assumptions ⢠Because berth capacity is being calculated, the design vessel service time should include an operating margin to account for longer-than-normal embarking, disembarking, and clearance times (for example, due to high passenger demands or harbor traffic). ⢠In the absence of other guidance, the operating margin will be based on the additional time required to limit the failure rate (the percentage of ferry arrivals in which an arriving ferry has to stop and wait for another ferry to depart the berth). In this case, the operating margin is assumed to be an additional1.5 min, meaning that the next arriving ferry will not be delayed as long as the actual vessel service time does not exceed the average time by more than 1.5 min. Steps Step 1: Calculate the Vessel Service Time The average passenger embarking and disembarking time t ed and the average clearance time tc were given. The vessel service time is then given by Equation 9-2: tv = ted + tc + tom tv = 180 + 240 + 90 tv = 510 s (8 min, 30 s) Step 2: Calculate the Berth Capacity Equation 9-1 is used to calculate the berth capacity. Fractional values of vessels per hour are rounded down to the next lower integer value in determining the number of vessels that can be completely served during the course of an hour. 3,600 Vb=-- tv 3,600 vb = 510 Vb = 7 vesselsfh The Results The existing berth is capable of serving the proposed new service in addition to the six existing ferry services. Calculation Examples Page 9-34 Chapter 9/Ferry Transit Capacity
Transit Capacity and Quality of Service Manual, 3'd Edition 7. REFERENCES 1. Neill, S.M., "A Survey of Waterway Capacity and Policy Issues," (working paper, Marine Board Seminar on Waterways and Harbor Capacity, April2001). 2. Bruzzone, A TCRP Report 152: Guidelines for Ferry Transportation Services. Transportation Research Board of the National Academies, Washington, D.C., 2012. http:/ jonlinepubs.trb.orgjonlinepubsjtcrpjtcrp_rpt_152.pdf 3. Bureau of Transportation Statistics. National Census of Ferry Operators. http:/ jwww.bts.gov jprogramsjncfoj. Accessed April 23, 2012. 4. Bay Area Council, Bay Area Water Transit Initiative, 1999. 5. Volpe National Transportation Systems Center, Access for Persons with Disabilities to Passenger Vessels and Shore Facilities, Final Report, U.S. Department of Transportation, Washington, D.C., July 1996. http:/ jntl.bts.gov /DOCS/rptfinaljrptfinall.html. Chapter 9/Ferry Transit Capacity Page 9-35 References I
