Dinner Board Case Study

Draft - May 4, 2006

Introduction

The dinner boat was constructed in 2002 and carries a maximum of 600 passengers.

Figure 1. Dinner Boat Profile – Original Design

The dinner boat has three passenger decks.

• Main Deck – The main deck is approximately 4752 square feet and contains an enclosed dining area with dance floor. There is a serving pantry, bridal suite, and single-user toilet room at the rear of the dining area. There are open deck areas at each end of the vessel. There are two boarding gates at the front and rear on each side of the vessel. There is an exterior door at the front on one side of the vessel that leads from the open deck area to the dining area, and two exterior doors at the rear of the vessel that lead from the open deck area to the dining area. The doors have 6 inch coamings that are required by the US Coast Guard. There is a main interior stairway in the rear centerline of the dining area, and exterior stairways at the open deck areas on each end of the vessel that connect to the second deck. There is a recessed swim platform at the rear of the vessel that is connected to the main deck by two stairways.

Figure 2. Main Deck – Original Design

• Second Deck – The second deck is approximately 3465 square feet and contains an enclosed dining area. There are toilet rooms for men and women at the front of the dining area, and a bar/serving pantry wrapped around the main interior stairway at the rear of the dining area. There is a pilot house and open deck area at the front of the vessel that is for employees only. There is an open deck area at the rear of the vessel with two exterior stairways that connect to the third deck. There are two boarding gates at the rear on each side of the vessel. There are two doors at the front of the vessel: one leads from the top of the exterior stairway to the dining area; and the other leads from the dining area to the open deck area at the front of the vessel. There are two doors at the rear of the vessel that lead from the open deck area to the dining area. There are fire doors at the top of the main interior stairway. There are two exterior stairways at the rear open deck area that connect to the third deck.

Figure 3. Second Deck – Original Design

• Third Deck – The third deck is approximately 1950 square feet and is entirely open.

Figure 4. Third Deck – Original Design

The dinner boat has a lower deck that is for employees only and contains the engine room, galley, storeroom, and other equipment. There are stairways leading from the galley to the main deck serving pantry and from the storeroom to the main deck dining area.

Figure 5. Lower Deck – Original Design

Methodology

The Access Board contracted with a marine architect to review the original designs of the dinner boat and to identify passenger features that would not meet the draft accessibility guidelines.1 The contractor proposed new designs for the passenger features that would meet the draft guidelines. The contractor chose designs that would have the lowest capital cost and still meet the functional demands of the vessel owner/operator. The contractor also examined the impact of the new designs on the vessel’s space, electrical power, fuel consumption, and stability. The contractor did not evaluate boarding systems for embarking and disembarking passengers from the vessel. The contractor prepared a report describing the new designs and their impacts on the vessel. The company that designed the dinner boat and the vessel owner/operator were given an opportunity to review and comment on the contractor’s report. Where relevant, their comments and the contractor’s responses to the comments are noted below.

The vessel cost approximately $4.5 million to construct in 2002. The contractor estimated the cost in 2005 dollars for constructing a new dinner boat based on the original designs, and a new dinner boat based on the new designs that would meet the draft guidelines. The contractor used a parametric approach based on the contractor’s company data on passenger vessels to estimate the cost for constructing the new dinner boats. The cost estimates include labor hours, materials, a 15 percent surcharge for materials, and a 10 percent contingency. The contractor estimated the cost for constructing a new dinner boat based on the original designs to be approximately $5.1 million. The contractor estimated the cost for constructing a new dinner boat based on new designs that would meet the draft guidelines to be approximately $5.6 million. The contractor concluded that the draft guidelines would add between $0.5 million and $0.6 million to the construction costs for vessel, or a 10 percent to 12 percent increase.

The new designs proposed to meet the draft guidelines are discussed below. The designs are identified as having significant impacts; incurring additional costs but not having significant impacts; or having minimal impacts. A design is identified as having a significant impact where the design 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. A design is identified as incurring an additional cost but not having a significant impact where a specific cost can be attributed to the design but it does not meet the criteria for a significant impact. A design is identified as having a minimal impact where a specific cost cannot be attributed to the design and it will have little impact on new construction of the vessel.

Designs That Have Significant Impacts

1. Accessible Route Between Passenger Decks

The dinner boat has three passenger decks. The draft guidelines require an accessible route to connect each passenger deck. V206.2.1. The draft guidelines permit vessels that are less than 10,000 ITC tons to use limited-use/limited-application (LULA) elevators to connect passenger decks. V206.6 Exception 2. LULA elevators are smaller and less expensive than standard size elevators. The dinner boat is less than 10,000 ITC tons, and the contractor proposed to use a LULA elevator to connect the three passenger decks. The contractor estimated the LULA elevator to cost $233,618.

The contractor proposed to locate the elevator adjacent to the interior stairway in the rear centerline of the dining areas. This location is in proximity to the general circulation path, and allows one side of the elevator shaft to share a steel bulkhead of the existing stair tower.

Figure 6. Dinner Boat Profile – New Design

The elevator pit would be located in the overhead of the engine room, in front of a major transverse watertight bulkhead. The elevator machinery would be located in a cage under the pit and not impact the space in the galley. The contractor assumed that there is sufficient space within the engine room to fit the elevator machinery and that the elevator pit would not cause interference with running exhaust piping, ducting, or electrical cabling.2 The contractor proposed to change the location of the door between the engine room and the galley to the other side of the stairway leading from the lower deck to the main deck. The contractor assumed that the new door location would not adversely impact the equipment arrangement in the galley.

Figure 7. Lower Deck – New Design

On the main deck, the serving pantry counter on the side of the stairway where the elevator is located would be lost. The contractor proposed to increase the serving pantry counter on the other side of the stairway by moving the counter forward approximately 4 feet in order to compensate for the loss of counter space due to the elevator. The contractor estimated the additional counter space to cost $3,133.

Figure 8. Main Deck – New Design

The elevator shaft would have minimal impact on sight lines for passengers in the dining areas on the main and second decks. The elevator shaft would create a substantial box on the third deck that would adversely impact the appearance of the vessel and interfere with panoramic views.3 The top of the elevator shaft is below the fixed portion of the vessel’s mast so the elevator shaft would not impact the air draft of the vessel.

Figure 9. Third Deck – New Design

The elevator and new design of the toilet rooms on the second deck would reduce the usable space in the dining areas. The contractor proposed to lengthen the dinner boat by four feet to retain the same square footage of usable space in the dining areas. The contractor estimated lengthening the vessel to cost $160,631, plus $6,995 for additional generator capacity. The costs for lengthening the vessel and the additional generator capacity are discussed at page 10.

2. Accessible Route to Swim Platform

The recessed swim platform at the rear of the main deck is used occasionally for boarding passengers. The draft guidelines require an accessible route to connect passenger entry points and accessible passenger features within a deck. V206.2.2 and V206.4. The swim platform is approximately 30 inches below the level of the main deck. The contractor noted that designing a ramp to connect the main deck and the swim platform would increase the length of the dinner boat by approximately 7 feet, and would be excessive given the limited use of the swim platform.4 The contractor proposed to use a platform lift. The contractor proposed to eliminate one of the stairways connecting the swim platform and the main deck, and to move the swim platform approximately 18 inches to one side of the vessel and approximately 6 inches forward in order to fit the platform lift where the stairway was located. This design would result in a wider stairway at the other side of the swim platform and a wider door at the top of the stairway. See Figure 8 for the Main Deck – New Design. The contractor assumed that this design would not adversely impact the steering gear equipment. The contractor estimated the platform lift and wider stairway and door to cost $24,695.

3. Doors with Coamings5

The dinner boat has three weather tight exterior doors on the main deck with 6 inch coamings that are required by the US Coast Guard.6 One door is at the front of the main deck, and two doors are at the rear of the main deck. The draft guidelines require at least one accessible route to connect passenger entry points at both the front and rear of the main deck, and the dining area. V206.2.2 and V206.4. Where doors on accessible routes are required to have coamings, the draft guidelines permit ramps to be used.7 V404.2.5 Exception 3. The contractor proposed the following designs to meet the draft guidelines. See Figure 8 for the Main Deck – New Design.

• Door at Front of Main Deck. The contractor proposed to use a 1:12 ramp on each side of the coaming (i.e., double ramp access) and an automatic door opener for the door at the front of the main deck.8 V404.2.5.2.1. The contractor estimated the double ramp access to cost $3,671 and the automatic door opener to cost $10,846.


• Door at Rear of Main Deck Near Toilet Room. The contractor proposed to use a 1:10 ramp on the side of the coaming that faces the open deck area (i.e., single ramp access) and to raise the decking 6 inches on the other side of the coaming for the door at the rear of the main deck near the toilet room. V404.2.5.2.2. and V405.2 Exception 2. The raised decking would extend approximately 14 feet into the corridor adjacent to the toilet room and through the toilet room. The contractor proposed to use a 1:12 ramp at the end of the corridor where the raised decking transitions down to the dining area deck. The contractor estimated the single ramp access and raised decking for the door near the toilet room to cost $24,987.


• Door at Rear of Main Deck Near Bridal Suite. Although the draft guidelines do not require both exterior doors at the rear of the main deck to be accessible, the contractor proposed to use single ramp access and raised decking for the door near the bridal suite to make the vessel more functional. The raised decking would extend approximately 17 feet into corridor adjacent to bridal suite and through the bridal suite and serving pantry. The contractor proposed to use a 1:12 ramp at the end of the corridor where the raised decking transitions down to the dining area deck. The contractor estimated the single ramp access and raised decking for the door near the bridal suite to cost $30,819.
  

Designs That Incur Additional Costs But Do Not Have Significant Impacts

1. Toilet Rooms on Second Deck

The toilet rooms on the second deck have four toilet compartments in the women’s room, and three toilet compartments and three urinals in the men’s room. The draft guidelines require an accessible toilet compartment in each toilet room, and an accessible urinal in the men’s room. V213.2, V213.3, V213.3.1, and V213.3.3. The contractor proposed to increase the floor area of each toilet room by 27 square feet, increase the door width by 2 inches, and reconfigure the fixtures to meet the draft guidelines. The new design resulted in an increase in the number of toilet compartments in the women’s room from four to five, and a decrease in the number of urinals in the men’s room from three to two.9 The contractor estimated the new design to add $8,982 to the cost of the second deck toilet rooms.

Figure 10. Second Deck – New Design

2. Assistive Listening Systems

The dinner boat has a combined public address, entertainment, and emergency alarm system.10 The draft guidelines require an assistive listening system because the public address system is used for entertainment. V219.2. The contractor estimated assistive listening systems for the dining areas on the main and second decks to cost $4,349.

3. Signs

The draft guidelines require certain signs to have raised characters and braille, and/or visual characters that meet minimum requirements.11 V216 and V 703. The contractor estimated signs meeting the draft guidelines to cost $817.

Designs That Have Minimal Impacts

1. Accessible Means of Escape

The draft guidelines require the dinner boat to have at least two accessible means of escape from each passenger deck to an evacuation station based on US Coast Guard requirements for means of escape. V207.2 There are at least two exterior exit stairways connecting the passenger decks on the dinner boat. The draft guidelines permit exit stairways to be part of an accessible means of escape, and do not establish any requirements for exterior exit stairways.12 V410.1.2(e) and V410.2 Exception 3. The contractor proposed to design the interior exit stairway connecting the main and second decks so the riser heights and thread depths would meet the requirements in the draft guidelines. V502.2. The contractor assumed that the design would have minimal impact on new construction.

2. Toilet Room on Main Deck

The draft guidelines require the single-user toilet room on the main deck to be accessible. V213.2. The toilet room meets the draft guidelines except that the sink overlaps the clearance around the water closet. V604.3.1.2. The contractor proposed to locate the sink next to the door between the toilet room and the bridal suite to meet the draft guidelines.13 The contractor assumed that the design would have minimal impact on new construction.

3. Maneuvering Clearances at Doors

The draft guidelines require maneuvering clearances at doors on onboard accessible routes and on accessible means of escape. V404.2.4 and V410.1.2(b). The contractor proposed to change the location of several doors by 18 inches to 22 inches to meet the draft guidelines.14 The contractor assumed that the designs would have minimal impact on new construction.

4. Bar Counter

Vessel Space Impacts

The elevator and new design of the second deck toilet rooms would reduce the usable space in the dining areas. The contractor proposed to lengthen the hull of the dinner boat by two frames or four feet to retain the same square footage of usable space in the dining areas. The two frames would be added around the storeroom at approximately frames 24 to 26. The company that designed the dinner boat used a combination of tonnage frames below the main deck and tonnage openings on the main deck to keep the vessel under 100 gross tons and subject to US Coast Guard regulation under 46 CFR Chapter 1, Subchapter K. The contractor proposed to introduce partial tonnage frames in the engine room and decrease the useable portion of the storeroom in order to keep the lengthened vessel under 100 gross tons.15 The contactor also proposed to add a tonnage opening into the elevator trunk on the main deck. The elevator mechanism would have to be located so as to not interfere with the tonnage opening. The tonnage opening may severely limit the selection of elevators.

The contractor estimated the vessel lengthening costs as follows.16

Electrical Power, Fuel Consumption, and Vessel Stability Impacts

The dinner boat has two diesel generators rated at 170kW each that are sized to handle the electrical load for the vessel.17 The contractor calculated that the elevator, platform lift, and additional lighting and HVAC loads due to the lengthening of the vessel would require an increase in the generator capacity to 190 kW.18 The contractor estimated the increased generator capacity to cost $6,995. Assuming the vessel operates 2,000 hours per year, the contractor calculated the annual fuel consumption for the 190 kW generators would be approximately 30,600 gallons, an increase of approximately 3,200 gallons from the 170 kW units in the original design.

The dinner boat is propelled by two diesel engines rated at 440 hp. Each engine drives a fixed-pitch propeller via a reduction gear. The contractor calculated that the elevator, platform lift, and lengthening of the vessel would add approximately 9 long tons to the weight of the vessel for a full load displacement of 394 long tons. The contractor calculated that the power demand based on vessel resistance would decease by 0.7 percent from 273 hp to 271 hp per propeller; and the power demand based on maneuvering would increase by 2.3 percent from 774 hp to 792 hp per propeller. The contractor determined that the existing engines have ample power to handle this slight change in demand. Assuming the vessel operates 2,000 hours per year at an average engine load factor of 60 percent, the contractor calculated that the annual fuel consumption for the engines would be approximately 55,300 gallons. Depending on the ratio of time maneuvering to time underway at speed, the contractor calculated that the elevator, platform lift, and lengthening of the vessel would affect the annual fuel consumption by -387 gallons to +1,272 gallons.

The dinner boat in original design is reported to have good margins for both intact and damaged stability, but is marginal for subdivision. The contractor noted that lengthening the hull at the aft part of the storeroom may cause the vessel to fail subdivision due to the increased volume of the storeroom if the watertight bulkhead at Frame 13 is damaged. The contractor noted that the problem could be corrected by relocating the watertight bulkhead at Frame 13, adding an additional watertight bulkhead, or increasing the hull depth by an additional 6 inches. The preferred solution would depend upon the actual shape of the floodable length curve. The contractor assumed that adjusting the bulkhead location would have minimal impact on new construction.

Summary

The contractor estimated the cost for constructing a new dinner boat based on the original design to be approximately $5.1 million. The contractor estimated the cost for constructing a new dinner boat based on a new design that would meet the draft guidelines to be approximately $5.6 million. The contractor concluded that the draft guidelines would add from $0.5 million to $0.6 million to the vessel’s construction costs, or a 10 percent to 12 percent increase.19 About 80 percent to 90 percent of the additional costs are attributed to the elevator and the lengthening of the vessel. The cost estimates are summarized below in order of magnitude.

 

Notes

1. The contractor used the draft guidelines that the Access Board made available for public review in 2004. 69 FR 69244 (November 26, 2004). The Access Board has made a more recent version of the draft guidelines available for public review in 2006. 71 FR 38563 (July 7, 2006). Where the 2006 draft guidelines differ from the 2004 draft guidelines, the differences are noted.
2. The company that designed the dinner boat commented that the size of the engine room should be increased due to the elevator pit and machinery. The vessel space impacts are further discussed at page 10.
3. The company that designed the dinner boat commented that the elevator shaft on the third deck would have an extremely negative impact on the appearance of the vessel. The contractor responded that the visual impacts of the elevator shaft could be mitigated by paint, fairings or other designs. The third deck is 1950 square feet. The draft guidelines permit a platform lift to be used to provide access to decks that are less than 3000 square feet. V206.7.5. A platform lift would not have the same adverse visual impact on the third deck as an elevator shaft. The contractor considered using an elevator to connect the main deck and second deck, and using a platform lift to connect the second deck and third deck. The contractor chose to connect all the passenger decks with an elevator because the marginal cost of extending the elevator from two to three decks was less than the cost of an elevator and a platform lift.
4. The contractor noted that the platform lift would be regularly exposed to salt water and would be difficult to maintain. The company that designed the dinner boat commented that the platform lift on the swim platform would be impractical because of the regular exposure to salt water.
5. The draft guidelines require thresholds at doors without coamings to be ½ inch high maximum. V404.2.5.1. The case study assumes that this requirement would have minimal impact in new construction.
6. The doors have a 32 inch minimum clear opening in the original design and meet the clear width requirement of the draft guidelines. V404.2.3.
7. The draft guidelines do not require landings at the tops of ramps at doors with coamings. V405.7 Exception.
8. The company that designed the dinner boat commented that ramps would add to the vessel’s tonnage. The contractor responded that the ramps can be designed so they are removable and not counted in tonnage.
9. The draft guidelines require an ambulatory accessible toilet compartment in toilet rooms with six or more fixtures. V213.3.1 and V604.8.2. In the new design, neither the men’s room nor women’s room would be required to have an ambulatory accessible toilet compartment because each toilet room has less than six fixtures.
10. The 2004 draft guidelines required emergency alarm systems to have visible alarms. The 2006 draft guidelines require emergency alarm systems to comply with the principles of best practice. For purposes of the case study, it is assumed that the emergency alarm system would meet the 2006 draft guidelines.
11. Signs required to comply with the draft guidelines include signs identifying permanent rooms and spaces, directional and information signs, and signs for means of escape. Where all the exterior doors are not accessible, the accessible doors are required to be identified by the International Symbol of Accessibility, and the inaccessible doors are required to have directional signs indicating the location of the nearest accessible door.
12. The draft guidelines permit vessels that carry 600 or fewer passengers to have a 36 inch minimum clear width between handrails. V410.2.1 Exception 2. This requirement does not apply to exterior exit stairways. V410.2 Exception 3. The company that designed the dinner boat commented that it would be relatively simple to design the exterior exit stairways on new vessels with a 36 inch minimum clear width between handrails.
13. The door between the toilet room and the bridal suite would not required to meet the draft guidelines because the rooms are connected by an accessible route. V206.2.2 and V206.5.2.
14. The contractor proposed to change the location of the two exterior doors at the rear of the main deck; the doors to the bridal suite and the toilet room on the main deck; the door connecting the corridor outside the bridal suite and the dining area on the main deck; one exterior door at the rear of the second deck; and the door at the exterior exit stairway at the front of the second deck.
15. Without adjusting the tonnage frames, the lengthened vessel would be over 100 gross tons and would be subject to US Coast Guard regulation under 46 CFR Chapter 1, Subchapter H. The change in regulatory category would significantly increase the vessel’s capital and operating costs.
16. The company that designed the dinner boat commented that the engine room length should be increased by two feet. The contractor responded that the engine room size can be increased in the new design and estimated that adding two feet to the length of the engine room would cost $2,916 for additional structural fire insulation in the overhead of the engine room.
17. The vessel is not required to have an emergency generator or final emergency power source under US Coast Guard regulations. 46 CFR 120.312.
18. The contractor assumed that the assistive listening systems would demand no more electricity than the existing public address system. The contractor also assumed that the main switchboard has sufficient capacity to handle the larger generators. The company that designed the dinner boat questioned the switchboard assumption. The contractor estimated that a switchboard with a higher capacity to cost an additional $2,000.
19. The company that designed the dinner boat agreed that the draft guidelines would increase the vessel’s construction costs by 10 percent to 12 percent.