4,400 Pax Vehicle Ferry Case Study (Public Entity)
Draft June 30, 2008

Introduction

The ferry was placed into service in 2005 and is designed to carry 4,400 passengers and 30 vehicles.1  Although the vessel is designed to carry vehicles, vehicles are not carried by the vessels of this class at this time, but the vehicle parking areas still exist and have not been used for other purposes.  The vessel’s service speed is 16 knots.

The ferry has four passenger decks.

• Main Deck — The main deck is approximately 310 feet long and 70 feet wide.  The main deck has four pedestrian entry points, two at each end of the deck.  Two gangways provided at each terminal allow pedestrians to board the ferry at the end of the vessel which is facing the terminal (two other gangways service entry points at the end of the second deck).  Along the center line of the vessel, two lanes are provided for vehicle parking.  Along each side of the vessel, two enclosed spaces separated by a double leaf fire door (magnetically held in the open position) contain passenger seating areas.  Four stairs (one in each enclosed space) which are located near the ends of the vessel connect the main deck to decks two and three.  In addition, two elevators2 (one on each side of the vessel located near the middle of the vessel) connect the main deck with decks two through four.

  
  Figure 1.  Main Deck Original Design

• Second Deck (Saloon Deck) — The second deck is approximately 284 feet long and 70 feet wide.  The second deck has four entry points, two at each end of the deck.  Two gangways provided at each terminal connect the entry points at one end of the ferry.  Except at the ends where the entry points are located, the deck is enclosed and is divided in half by a fire barrier equipped with two double leaf fire doors located near the sides of the vessel.  Interior seating is provided in both halves, with a men’s and women’s toilet room provided in one half and a snack bar provided in the other half.  Four stairs and two elevators starting from the main deck connect the second deck to the third deck with the elevators continuing on to the fourth deck.

  
  Figure 2.  Second Deck Original Design

• Third Deck (Bridge Deck) — The third deck is approximately 264 feet long and 70 feet wide.  The deck is enclosed except for two small outside seating areas at the ends of the deck and two narrow outside seating areas along the sides.  Like the second deck, the enclosed part of the deck is divided in half by a fire barrier with two double leaf fire doors.  One half contains the men’s and women’s toilet rooms and seating, and the other half contains only seating.  Four stairs from the second deck provide passenger circulation to the third deck.  Four other stairs provide further passenger circulation to the fourth deck.  The two elevators starting at the main deck also service the third deck and continue on to the fourth deck.

  
  Figure 3.  Third Deck Original Design

• Fourth Deck (Hurricane Deck) — The fourth deck is approximately 251 feet long and 70 feet wide.  Only the center part of the deck is open to passengers.  The enclosed passenger portion of the deck is divided in half by a fire barrier with two single leaf fire doors.  Seating is provided in both halves.  Along the sides of the enclosed passenger part of the deck, two narrow outside seating areas are provided.  Four stairs and two elevators service the enclosed passenger parts of this deck.

  
  Figure 4.  Fourth Deck Original Design

Methodology

A representative of the Access Board reviewed the original designs of the vessel with a representative3 of the ferry to identify passenger features that would not meet the 2006 draft passenger vessel accessibility guidelines.4  The ferry representative proposed new designs for the identified features so as to meet the draft guidelines and estimated how much the redesigned features would add to the vessel’s construction cost, if constructed in 2006.

The ferry representative reported that the cost to construct the vessel was approximately $40 million in 2001 dollars.  The ferry representative estimated it would cost approximately $50 million to $55 million to construct a similar vessel in 2006.  The ferry representative estimated that the proposed designs to meet the draft guidelines would add $722,600 to the vessel’s construction costs, or an increase of approximately 1.4 percent.  The new designs would also lead to the loss of three fixed seats in the snack bar area, and another 47 fixed seats in the other seating areas of the 2,100 seat vessel which represents a fixed seating loss of 2.4 percent.  Automatic doors were provided at 12 exterior locations and at eight interior fire doors.  Although the US flag passenger fleet has had little exposure to the use of automatic doors, each automatic door is estimated to incur an annual maintenance cost of $900 to $1,100 and may need to be replaced every three to five years.

Actions taken on features in the original vessel designs to create designs meeting the draft guidelines for a new vessel are discussed below.  The case study sought to identify actions that: 1) have significant impacts, 2) incurred additional costs but did not have significant impacts, or 3) have other outcomes which should be noted.

An action is identified as having a significant impact where the redesign of the feature would add more than 0.5 percent to vessel’s construction costs; would substantially reduce the vessel’s usable space or necessitate an increase in the vessel’s size; or would present major operational issues.  An action is identified as incurring an additional cost but not having a significant impact where a specific cost can be attributed to the redesign of a feature but it does not meet the criteria for a significant impact.

Actions That Have Significant Impacts

1.  Accessible Means of Escape

Except for the outside seating areas on the third and fourth decks, the ferry representative indicated the US Coast Guard requires that each space must have two means of escape to the areas of refuge located at the ends of the vessel on the main and second decks.  Per the evacuation plan, in an emergency, the vessel would go to the nearest terminal and passengers would disembark via the entry points on the main and second deck.  Where the vessel could not return to a terminal, another ferry would come to offload passengers from the entry points located on the main deck.  Based on this evacuation plan and Coast Guard requirements, the draft guidelines require two accessible means of escape (AMOE) from the upper decks to the main deck, and (on the main deck) one AMOE to each end of the vessel.  V207.

The ferry representative proposed in the new designs, the two elevators (which have a size complying with the draft guidelines) would be used as components in the two AMOE from the second, third and fourth decks down to the main deck instead of changing the layout of two sets of stairs.  In the existing vessel, the elevators are equipped with emergency power.5  The ferry representative evaluated whether to add six areas of temporary refuge (ATR) at the elevators (one at each elevator on decks two through four) to the new designs or to provide an automatic sprinkler system in the ferry to avoid needing ATR.6  Although the sprinkler system was about $39,000 more expensive than the ATR option, the ferry representative decided for reasons related to passenger movement in emergencies and the impact on seating areas to propose that the new designs have an automatic sprinkler system complying with NFPA 13.  This action increased the cost of the new designs by $343,000.

Actions That Incur Additional Costs But Do Not Have Significant Impacts

2.  Exterior Doors with Required Coamings

On the main deck, four entry points are provided (two at each end of the vessel).  Beyond these entry points, to enter the enclosed seating spaces which are located on the sides of the vessel, four double leaf manually operated hinged doors are provided (one at each end of the two enclosed sides of the main deck).  The US Coast Guard requires that these doors be provided with coamings (raised thresholds) three inches high.  On each side of the doors, ramps with slopes that do not exceed 1:12 connect the top of the coamings.  These weathertight doors seal against the ramp surfaces.  The draft guidelines require all four doors to be accessible because the doors are part of required accessible routes and AMOE.  V206.2.2, V206.3, V206.4, and V207.

The draft guidelines allow doors required to have coamings to have ramps on both sides of the coamings provided the doors are automatic.  V404.2.5 Exception 3 and V404.2.5.2.1.  The ferry representative indicated they would make the doors automatic which is estimated to increase the cost of the new designs by $80,000 (at $20,000 per door).

The ferry representative expressed concerns that the US Coast Guard (USCG) may not allow automatic doors at these locations.  Based on an informal review of the case study by the Marine Safety Center of the USCG, the USCG noted no problems with use of automatic doors at these locations.

3.  Other Exterior Doors

Second (Saloon) Deck – In addition to the four entry points on the main deck, on the Saloon deck four additional entry points are provided (two at each end of the vessel).  From these entry points, access into the vessel is through 10 double leaf sliding doors (five at each end of the vessel).  These sliding doors are provided with high thresholds which are ramped on both sides.  As none of the sliding doors are required by the Coast Guard to have coamings, the draft guidelines require in the new designs that at least one door7 at each end of the vessel to have a threshold which does not exceed ½ inch8 and have maneuvering clearances9 on both sides which do not exceed 1:48 in any direction.  V206.2.2, V206.4, V404.2.4.4, and V404.2.5.1.

The ferry representative indicated in a new design, they would propose to reduce the thresholds and remove the ramps at one door at each end of the vessel and would install drain troughs and related drainage piping.  Because of the reduced threshold height, this drainage system is needed to keep rain water from entering the vessel due to the movement of the vessel.  This action is estimated to increase the cost of a new vessel by $29,500 (at $14,750 per door).  In addition, because the sliding doors require a force of more than 5 lbs to open (V404.2.910), the ferry representative proposed to make the two sliding doors automatic at a cost increase of $40,000 (at $20,000 per door).  Therefore, the total cost increase for these two doors is $69,500.

Third (Bridge) Deck – On the third deck, a small outside seating area is provided at both ends of the vessel which is entered by one single leaf hinged door with a high threshold that is ramped on both sides.  Also, along each side of the vessel a narrow outside seating area is provided which is entered by two double leaf hinged doors and two double leaf sliding doors with high thresholds that are ramped on both sides.  As none of the doors are required by the Coast Guard to have coamings, the draft guidelines require in the new designs that at least one11 door to each outside area be accessible and have a threshold which does not exceed ½ inch and have maneuvering clearances on both sides which do not exceed 1:48 in all directions.  V206.2.2, V206.4, V404.2, 404.2.4.4, and V404.2.5.1.  The ferry representative proposed in the new designs to reduce the thresholds and remove the ramps at four hinged doors (one at each of the four outside seating areas) and install drain troughs and related drainage piping.  This drainage system would increase the cost of the new designs by $59,000 (at $14,750 per door).  As the draft guidelines has no force opening requirements which apply to exterior hinged doors, the issue of whether these four doors are recommended to be automatic was not evaluated.

Fourth (Hurricane) Deck – On the fourth deck, on each side of the vessel a narrow outside seating area is provided which is entered by two double leaf sliding doors with high thresholds that are ramped on both sides.  The draft guidelines require one12 door to each narrow outside seating area to be accessible.  V206.2.  The ferry representative proposed in the new designs to reduce the thresholds and remove the ramps, and install drain troughs and drainage piping, at one sliding door on each side.  This action is estimated to increase the cost of the new designs by $29,500 (at $14,750 per door).  In addition, because the sliding doors require a force of more than 5 lbs to open (V404.2.913), the ferry representative proposed to make the two sliding doors automatic at a cost increase of $40,000 (at $20,000 per door).  Therefore, the total cost increase for these two doors is $69,500.

The ferry representative expressed concerns that the US Coast Guard (USCG) may not allow automatic doors at these locations.  Based on an informal review of the case study by the Marine Safety Center of the USCG, the USCG noted no problems with use of automatic doors at these locations.

4.  Interior Doors

On all four passenger decks, the eight fire doors located amidships (magnetically held in the open position) have thresholds higher than ½ inch to limit the passage of smoke and flame when the doors are shut.  Each door is a double leaf hinged door, except for the doors on the fourth deck (Hurricane Deck) which are single leaf hinged doors.  As each functions either as part of an accessible route or an AMOE, the draft guidelines require each to be accessible.  V206 and V207.  The ferry representative proposed in the new designs to reduce the thresholds to comply with the draft guidelines and use different gasket material to limit passage of smoke and flames.14  This action at the eight doors is estimated to increase the cost of a new vessel by $21,600 (at $2,700 per door).  In addition, because the gaskets would probably make it more difficult to open the doors (should passengers need to pass through them when closed in an emergency) and probably would not comply with the door force opening requirements for interior hinged doors, the ferry representative proposed to make all eight fire doors automatic at a cost increase of $80,000 (at $10,000 per door).15  Therefore, the total cost increase for these eight doors is $101,600.

The ferry representative expressed concerns that the US Coast Guard (USCG) may not allow automatic doors at these locations.  Based on an informal review of the case study by the Marine Safety Center of the USCG, the USCG noted no problems with use of automatic doors at these locations.

Other Outcomes

6.  Transportation Seating

General Seating – There are approximately 2100 fixed transportation seats on the ferry as shown below which includes 20 seats in the snack bar area (discussed further below).  Where 2001 to 2150 seats are provided, the draft guidelines require 17 wheelchair spaces dispersed throughout the seating areas, including one at a table in the snack bar area.  V222.3.  The ferry representative proposed to add 17 wheelchair spaces as shown below, resulting in the net loss of 50 fixed seats (including 3 at the snack bar).16

This action to provide wheelchair spaces is estimated by the ferry representative to have a minimal impact on the seating needs of the passengers and has an insignificant cost impact on the new designs.

Snack Bar Area – The snack bar area on the second deck has 20 fixed seats.  Nine of the 20 seats are at tables, with the two corner tables each having two adjacent seats and five other seats along a table which faces the snack bar service counter.  No other tables or counters are provided in the passenger areas of the vessel.  Because the seating in this area is classified as transportation seating and because of the dispersal requirement for wheelchair spaces, the draft guidelines require one wheelchair space with knee and toe clearance to be provided at a table/counter in this seating area.  V222.3.3.  The ferry representative proposed in the new designs to remove three seats at the side of the snack bar area to provide one wheelchair space (of the 17 required) at a table.  This action is estimated by the ferry representative to have a minimal impact on snack bar operations due to the net loss of three seats and has an insignificant impact on the cost of the new designs.

7. Life Jacket Storage Facilities

Each deck has life jacket storage lockers of different sizes holding the two types of life jackets, adult and children. For purposes of this case study, each life jacket storage locker was required to be accessible.  V807.  The ferry representative proposed to provide complying doors at the lockers.  This action is estimated to have an insignificant cost impact on the new designs.

8.  Electrical Power, Fuel Consumption, and Vessel Stability

The ferry has two 370 KW generators that have sufficient excess capacity to supply the automatic doors.  The ferry also has one 300 KW emergency generator that has sufficient excess capacity to power the automatic doors when used as a component in an accessible means of escape.  The cost to connect the automatic doors with the emergency generator is included in the automatic door cost estimates above, and the original designs already had the elevators connected to the emergency generator.  The ferry representative estimates the proposed designs, to meet the draft guidelines, would have a minimal impact (at an insignificant cost) on the vessel’s electrical power and fuel consumption, and no impact on its stability.

9.  Passenger Boarding System

The case study did not evaluate the impact of the draft guidelines on the passenger boarding system used at the two terminals to embark and disembark passengers from the ferry.

Summary

The ferry representative estimated the cost for constructing a similar vessel based on the original designs to be approximately $50 million to $55 million in 2006 dollars.  The ferry representative estimated that the proposed designs to meet the draft guidelines would add $722,600 to the vessel’s construction costs, or an increase of approximately 1.4 percent.  The new designs would also lead to the loss of three fixed seats in the snack bar area, and another 47 fixed seats in the other seating areas of the 2,100 seat vessel which represents a fixed seating loss of 2.4 percent.  Although the US flag passenger fleet has had little exposure to the use of automatic doors, each automatic door is estimated to incur an annual maintenance cost of $900 to $1,100 and may need to be replaced every three to five years.  The construction cost estimates are summarized below.