PHASE 2 DESIGN FOR YEAR 2010

Transcription

1 WTA TEAM INTERNAL WORKING DRAFT PHASE 2 DESIGN FOR YEAR 2010 First Administrative Draft Prepared by: Seaworthy Systems, Inc. and Glosten-Herbert LLC with contributions from Don Burg Air Ride Craft, Inc. July 19, 2002 Internal review by on / / Designated WTA Team Reviewer: Requested Review Deadline: / / The information contained in this working paper represents work in progress. The WTA s final recommendations of ferry service expansion will reflect study in a number of different technical areas. Therefore, information in this report may change depending on the results of the interrelated technical studies. Prepared for:

2 Table of Contents 1. Introduction Phase 2 Large Ferry Requirements Hull Form Improvements Reducing Emissions/Kilowatt-Hour Alternative Prime Movers Diesel vs. Gas Turbine Fuel for Diesel Engines Diesel Emissions Reduction General Arrangement Weights Speed and Power Propulsion System Main Propulsion Engines Emissions Control Equipment Electronic Control Direct Water Injection Diesel Exhaust Oxidation Selective Catalytic Reduction Exhaust Gas Emission Reduction Propulsers Electrical System Costs Construction Cost Annual Operating Costs Life Cycle Cost Emissions/Passenger Mile Potential Improvements in Phase 2 Design...19 References...21 Appendix A - Small Fuel Cell Ferry...22 Appendix B Renderings, Lines, Arrangement, Machinery and Structure Drawings of Phase 2 Ferry...24 Appendix C Major Equipment List for Phase 2 Ferry...36 Appendix D Outline Specification for Phase 2 Ferry...38

3 Phase 2 Low Emission Ferry Page_1 1. INTRODUCTION AND BACKGROUND Glosten-Herbert LLC has been retained by the San Francisco Bay Area Water Transit Authority (WTA) to prepare a concept design for an innovative ferry of the future characterized by low emissions and intended for nominal year 2010 Construction. Designated the Phase 2 ferry by WTA, the design was to make use of advanced technologies believed to be commercially available in 2010 to achieve the lowest possible emissions. With time technology is expected to change; especially with respect to diesel engines, fuels and emission control equipment; and as the year 2010 approaches the ferry of the future is likely to be quite different from the design described in this report. Seaworthy Systems, Inc., a subcontractor to Glosten Herbert, was tasked to prepare the Phase 2 concept design with assistance from Glosten Herbert. Seaworthy prepared a rough concept set of characteristics for a small Sub Chapter T monohull fuel cell powered 12.4 knot ferry and then went on to prepare an in-depth concept design for a large Sub Chapter K diesel propelled 35 knot catamaran ferry with a seated passenger capacity of 350. This report provides a brief description of the small fuel cell ferry (Appendix A) and a more detailed description of the large Phase 2 diesel ferry design including arrangements, outboard renderings, specifications, major machinery list, structure and performance characteristics. An estimate of the emissions output was made and compared to the U.S. Environmental Protection Agency (EPA) Tier 2 Emission Standards [1] * that have been adopted by WTA. The JJMA report [2] was useful in sorting out alternative technologies and fuels however, the Phase 2 ferry design and its innovative features and equipment represent Seaworthy s best judgment at the time this report was prepared of how to achieve WTA s goals of lowest possible emissions. 2. PHASE 2 LARGE FERRY REQUIREMENTS The WTA requirements for the Phase 2 large ferry are as follows: Safe and reliable commuter passenger ferry service Passenger Capacity 350 seated Service Speed 35 knots Service Speed 250 nm Construction Time Frame 2010 Emissions As low as possible with 2010 commercially available technology Wake Wash Low Accessibility ADA compliant U.S. Coast Guard Certification Sub Chapter K - Lakes, Bays and Sounds Service Life 25 years The most demanding of the above requirements and the one of primary interest for the Phase 2 design is lowest possible emissions using projected year 2010 commercial technology. From the * Numbers in brackets [ ] refer to references listed at the end of this report

4 Phase 2 Low Emission Ferry Page_2 beginning of the design cycle it was decided to use utilize improvements in hull design to lower overall power required and therefore emissions as well as technologies to reduce emissions per break horsepower hour from the propulsion device. Well into the Phase 2 vessel design cycle the desire for outside seating for 35 percent of the passengers was expressed. This extra seating would not increase the ferry passenger capacity. The Phase 2 ferry design includes this outside seating but there are consequences that will be discussed later in this report. Near the end of the Phase 2 ferry design cycle it was learned that there was an interest in having the ferry certified by U. S. Coast Guard (USCG) under the IMO High Speed Craft Code (HSC). This desire became known too late to be incorporated into the current Phase 2 ferry design. Based on previous experience with HSC ferry certification Seaworthy believes that HSC certification will add significant cost to vessel construction and to the cost of operation throughout the ferry s life. Side vs. bow (or end) loading and unloading of passengers is an issue not resolves until late in the Phase 2 design when WTA decided that ferries and terminals would both be designed for side and bow loading. Prior to this decision bow loading was selected for the Phase 2 ferry by Seaworthy because it is believed to be more efficient in overall operation with faster turn around times and can lead to a simpler terminal design than for side loading. 3. HULL FORM IMPROVEMENTS The Phase 2 ferry was designed by Seaworthy with the participation of Glosten Herbert using the air assisted catamaran technology to reduce propulsion power and emissions. This patented technology has been developed by Don Burg of Air Ride Craft, Inc. and incorporated into his SEACOASTER type vessels. Its benefits can be applied to the WTA ferry system by incorporating the technology into shipyard technical proposals as a patented feature. The Seaworthy/Glosten Herbert design utilizes the air assisted catamaran hull feature to create a year 2010 ferry design with emissions less than 1/25 of the 2007 EPA requirements. The Phase 2 ferry is an air assisted catamaran where blowers are utilized to force air into cavities under each hull. No flexible seals or skirts are utilized. The effect of the air bubble is to reduce frictional resistance and, we believe, to reduce wave making resistance and therefore wake wash at cruising speeds. This technology is currently in the late stages of development although it is mature enough to have produced a number of vessels that are now in operation. A 149 passenger ferry has been operating commercially on 10 to 25 mile runs in Lake Erie (the Island Rocket II). This boat, although far from optimum (its composite hull is excessively heavy), has been running successfully and profitably and has proven the basic benefit of the technology in reducing total propulsion power requirements and increasing speed. It should also be noted that there have been no adverse comments reported with respect to this ferry s wake wash or noise characteristics. A 100 aluminum demonstration boat funded by the Office of Naval Research is in the planning stage and is expected to be delivered in the fall of Calculations have indicated that the use of this air-assisted catamaran technology can result in a significant reduction in total propulsive power compared to conventional similar sized

5 Phase 2 Low Emission Ferry Page_3 catamarans at speeds above 25 to 30 knots. At a 35 knot service speed the power required for the Phase 2 ferry, including the lift fans, is expected to be 21 percent less than a conventional catamaran ferry, Figure 1. As speed increases above 35 knots the powering advantage of the Phase 2 ferry increases such that at about 47 knots the power required is only about 50 percent of the conventional catamaran ferry. Phase 2 vs. Conventional Total Engine BHP Required Speed - Knots Phase 2 Ferry Conventional Catamaran Figure 1 At 35 knots the 21 percent lower power for the Phase 2 ferry represents a 21 percent reduction in fuel burned and an off the top 21 percent reduction is exhaust emissions as compared to the conventional catamaran ferry. This reduction is independent or any efforts to reduce specific emissions/kwh of the propulsion device. From Figure 1 it is obvious that the optimum service speed for the Phase 2 SEACOASTER type ferry would more likely be in the 40 to 45 knot range however, for this design it has been assumed the ferry will operate at 35 knots maximum and the propulsion power plant has been selected and designed for the 35 knot speed. There are no model tests, computer generated studies or actual measurements of wake wash available for air assisted catamaran hulls like the Phase 2 ferry. In a very general sense the less power it takes to propel a hull at a given speed the less wake it will produce thus, the Phase 2 ferry above 30 knots will produce less wake than a conventional ferry of the same speed, size and displacement but below 30 knots will produce a wake greater than a conventional ferry.

6 Phase 2 Low Emission Ferry Page_4 Another generalization that can be made is that a dynamically supported hull will produce less wake at cruising speed than a displacement supported hull thus, the Phase 2 ferry will produce less wake than a conventional high-speed displacement ferry of the same speed, size and displacement. Until the design of the Phase 2 ferry goes beyond the concept stage it can only be said that the wake wash should be slightly better than a ferry with a conventional hull form above 30 knots and perhaps slightly worse in a narrow range somewhere between 15 and 25 knots. 4. REDUCING EMISSIONS PER KILOWATT-HOUR FROM PROPULSION DEVICE Propulsion is the primary and dominant onboard energy requirement of a high-speed passenger ferry. While improvements in hull design discussed above may greatly lower the amount of energy required per passenger transported, the propulsion system will still consume nearly all of the onboard energy generation capacity. The optimum selection of a propulsion system is therefore an extremely critical step in the design of a successful high-speed ferry. A balance must be reached between initial cost, engine rating at design service speed, operating costs, maintenance costs, and the total emissions per passenger mile or trip. 4.1 Alternative Prime Movers The high horsepower requirements of the Phase 2 ferry in combination with limited allowances for space and weight lead to only two practical propulsion system choices; diesel engines or gas turbines. The rate of improvement in alternative propulsion system efficiencies and outputs are expected to outpace diesel and gas turbine technology within the next 8 years but such alternative systems will most likely not be ready to replace diesels and gas turbines by the year 2010 in large high-speed ferry service. 4.2 Diesel vs. Gas Turbine Gas turbines have certain advantages over diesels with respect to emissions/kwh and equipment weight but they also have some serious drawbacks including higher initial cost, higher annual maintenance costs and higher fuel costs. The relative position of gas turbines and diesels with respect to initial and maintenance costs and fuel rate are not expected to change by the year Diesels, on the other hand, are expected to benefit from improvements in emission reduction technologies more than gas turbines because of new regulations and the total number of diesels in operation compared to gas turbines. For these reasons diesel engines were selected for the Phase 2 ferry propulsion. 4.3 Fuel for Diesel Engines Fuel additives and alternative fuels such as gases, bio-diesel and water emulsions have not been considered for use in the diesel propulsion engines of the Phase 2 ferry. We believe very significant emissions reductions are achievable through other means and the use of ultra-low sulfur diesel. Improving the quality of fuel, which is expected to occur with new ultra-low sulfur blends in year 2006, reduces sulfur oxides (SOx) emissions in direct proportion to the fuel sulfur content. After 2006, No. 2 diesel fuel will contain 15-ppm sulfur, down from today's low sulfur

7 Phase 2 Low Emission Ferry Page_5 fuel with 100 ppm. Use of ultra-low sulfur diesel fuel is expected to reduce SOx in diesel exhaust by 85 percent. 4.4 Diesel Emissions Reduction It is important to note that more than 99 percent of diesel engine exhaust comprises nothing more than gases that exist in the air we naturally breathe nitrogen, oxygen, carbon dioxide and water. The remaining half of one percent (0.5 percent) comprises the harmful emissions that we seek to reduce through new technology. These harmful emissions species are nitrogen oxides (NOx), carbon monoxide (CO), unburned hydrocarbons (HC), particulate matter (PM), and sulfur oxides (SOx). Existing and advanced technology incorporated into the Phase 2 ferry diesel propulsion plant includes; direct water injection, electronic timing and control of engine fuel injection and exhaust valves, oxidation catalysts and selective catalytic reduction, all of which help engines run cleaner and more efficiently. The benefit of these technologies compared to today s untreated diesel engines are given below. Direct water injection (DWI) is expected to reduce nitrogen oxides (NOx) by 50 to 60 percent with no negative impact on fuel rate or engine components. Electronic control (EC) of fuel injection and valve timing is expected to reduce fuel consumption by 5 percent which is equivalent to a 5 percent reduction is all harmful exhaust emissions. An oxidation catalytic converter (EO) placed directly downstream of the manifold is expected to reduce carbon monoxide (CO) and unburned hydrocarbons (HC) by 80 to 90 percent and particulate matter (PM) by 50 percent. A selective catalytic converter (SCR) placed downstream of the oxidizer is expected to reduce NOx by 85 to 90 percent. By the time the Phase 2 ferry is under construction the following EPA emission standards, from [1] as given in [2], will be in effect. Table 1 EPA Emission Standards Displacement NOx + HC CO PM Enforcement Category (liters/cylinder) (g/kwh) (g/kwh) (g/kwh) Year 1 >37 kw, disp,< ;< 3300 kw ;> 3300 kw

8 Phase 2 Low Emission Ferry Page_6 The benefit of the above technologies for the Phase 2 ferry will be assessed later in this report. 5. PHASE 2 FERRY GENERAL ARRANGEMENT The Phase 2 ferry demi-hulls have a greater beam than conventional catamaran demi-hulls and they have less separation. The net result however, is a greater total beam on deck than conventional catamarans. This additional beam provides the extra deck area to accommodate 350 all on one level. The Phase 2 outboard renderings, ferry lines plan and general arrangement plans are provided in Appendix B, a major equipment list in Appendix C and a complete outline specification in Appendix D. The overall dimensions and capacity of the Phase 2 ferry are: Length, Main Deck Beam, Molded Beam (Inc. Rub Rails) Beam Demi-hull Draft (max. Blower OFF) 5.50 Freeboard Fwd (Blower OFF) 8.00 Aft (Blower OFF) 7.00 Passenger Capacity, Seated 350 Wheelchairs Total seated Standing (approx.) 130 Maximum Total 488 Crew 5 In addition to the seated passengers, the Phase 2 ferry has the potential to carry approximately 130 additional standing passengers in the main cabin bringing the total passenger capacity up to 488. The Phase 2 ferry could easily be certified by the USCG for this greater capacity. The overflow capability should be a great advantage when needed during the peak rush hours. The Phase 2 ferry is designed as a bow loader and has passenger accommodations on the main deck only. The purpose is to speed the loading and discharge of passengers, reduce wind resistance, lower structural weight, provide a greater margin of stability, lower construction cost and possibly reduce crew size by one especially when operating at less than full capacity. The hull collision bulkhead and the forward bulkhead of the passenger cabin are both located 20 aft of the bow. Collision accelerations were computed for two conditions at a 35 knot speed. Assuming the ferry runs into a brick wall, the bow crushes back to the collision bulkhead and comes to a stop and the resulting acceleration is 2.75 g. Assuming the ferry runs aground and stops in its own length of 140, the resulting acceleration is 0.7 g. These collision accelerations

9 Phase 2 Low Emission Ferry Page_7 place no restrictions on the arrangement or type of seating according to the HSC and the 20 setback of the passenger accommodations is acceptable. Passenger seating is provided in the main cabin for 350 plus 8 tie down locations for wheelchairs. Main cabin seating is arranged in fore and aft rows with wide aisles between to speed loading and discharge of passengers. This type of arrangement and bow loading also speeds crew security sweeps and trash clean up after each passenger discharge. Generous athwartship passageways are provided forward, amidships and aft. A row of seats runs along the outboard sides of the cabin and facing inboard. Three rows of back to back seats are in the interior of the cabin. All seated passengers face one side of the ferry or the other giving them a direct panoramic view out the side windows. Nineteen-inch wide individual upholstered seats with armrests between each pair are mounted on continuous aluminum box bases. The continuous bases provide easy mounting for the individual seat units, contain compartments below for life jackets and make deck sweeping and cleaning easier than with open base seating. There are two ADA classed heads located near centerline at the aft end of the main cabin. The woman s head contains one regular and one ADA toilet stall plus two sinks and a fold down changing table. The men s head contains one ADA toilet stall, two urinals, two sinks and a fold down changing table. There is a food/drink snack bar located forward of the heads at the aft end of the main cabin. This is a relatively simple affair where prepackaged snacks and drinks would be served. Primary passenger access to the main cabin is through the bow gates and through the four 4 wide bow doors aligned with the inside fore and aft passages. Sheltered storage for approximately 14 bicycles is provided on the fore deck under the fairings. The bow doors are weathertight and would be closed and dogged by the crew. During operation passengers would be prohibited from the open main forward deck but they would have access to the open main deck aft. Access to the aft main deck is through two 3 wide weathertight doors. The two forward and one aft stairways to the upper deck would be blocked with a snap hook and rope with signs stating CREW ONLY and EMERGENCY PASSENGER ACCESS ONLY. Passenger access to the upper deck is restricted to emergency situations when passengers need to be evacuated from the main cabin. In such a case the upper deck and open main deck forward and aft provide the necessary USCG required Qualified Area of Refuge (QAR). There are 8 fifty-person life rafts on the upper deck as well as a rigid inflatable rescue boat aft (not shown on drawings). The upper deck is for crew access to the pilothouse and other equipment and is available for other purposes such as photovoltaic solar collectors. This is one of the uses of the upper deck on the Phase 2 ferry. A flat low profile array of photovoltaic solar collectors is secured to the deck. The array provides about 8 kw of DC electric power to operate much of the ferry equipment. In emergencies passengers can stand on the solar collector. An option is shown on the arrangement drawings for bench seats on the upper exterior deck for 124 passengers. This seating would not change the passenger capacity of the ferry. If this option

10 Phase 2 Low Emission Ferry Page_8 is exercised then the photovoltaic array on the upper deck would be eliminated and the diesel generator capacity would have to be increased with its attendant increase in exhaust emissions. If the upper deck seating option is exercised the aft stair would provide the only underway access to and from the upper deck with the forward stairs available only for passenger discharge. At a ferry speed of 35 knots it is not expected many passengers would take advantage of upper deck open seating due to the very windy conditions. The pilothouse is located on the upper deck forward where it has full 360-degree visibility. Bow loading ferries need to have especially good visibility of the bow for docking purposes. Although the reverse slope pilothouse front windows appear to be in conflict with the high speed nature of the Phase 2 ferry the reverse slope is a critical element to the bow visibility and are necessary for bow loading. The main passenger cabin and pilot house are heated and are supplied with fresh forced air but there is no air conditioning. The main cabin heating uses waste heat from the main propulsion engines. The pilothouse is heated with electric resistance heaters. 6. WEIGHTS The light ship weight of the Phase 2 ferry was estimated parametrically from similar sized vessels with similar speeds and payloads (deadweight or DWT). The weight estimate is shown in Table 2 below: Table 2 Light Ship Weight : Structure Hull 49.0 lt House 10.0 lt Propulsion & Aux 41.3 lt Electrical 7.8 lt Outfit & Control 21.0 lt 5% Margin 6.5 lt Total lt Deadweight loads and total full load displacement are shown in Table 3 below:

11 Phase 2 Low Emission Ferry Page_9 7. SPEED AND POWER Table 3 Deadweight: 350 Pass. + crew 26.2 lt Special cargo 0.0 lt Fuel 12.1 lt LO, Antifreeze 0.1 lt Injection Water 6.1 lt Urea 1.3 lt Potable Water 1.1 lt Stores 1.0 lt Subtotal 47.9 lt Light Ship Weight: lt Full Load Displacement lt Propulsion and lift fan power requirements were determined by Don Burg of Air Ride Craft for the Phase 2 ferry design at a full load of long tons (lt). Figure 2 below shows the relationship between required propulsion power, lift fan power, total delivered power and the total required engine power for a speed range of 25 to 50 knots. The total required engine power reflects powering the lift fans hydraulically off the main propulsion engines and the use of the HAD surface piercing propulsers /35 Phase 2 Ferry Horsepower Speed - Knots Propuls er Pow er Pp Lift Fan Pow er Pl Total Delivered Pow er Total Engine BHP Figure 2

12 Phase 2 Low Emission Ferry Page_10 8. PROPULSION SYSTEM The Phase 2 ferry design consists of a single Wartsila 12V 200 main diesel engine in each hull. Each drive train consists of a main engine clutch, a short cardin shaft, a ZF two speed reversing reduction gear and a tail shaft. The tail shaft connects to a Hydro Air Drive (HAD) ducted surface piercing propeller. Each main engine also drives a hydraulic pump clutched to the forward end of the engine that is used to drive a hydraulic motor attached directly to the American Fan Co. blowers forward. The main propulsion engines are resiliently mounted as is the exhaust system and high quality silencers are included as part of the SCR s to reduce noise and vibration. The hydraulic motors, transmission lines and blower motors will require special attention including resilient mounting and noise insulation. The blower intakes are fitted with high attenuation silencers to reduce outboard and inboard noise. The blowers, blower outlets and some of the surrounding hull structure will be insulated with sound deadening material. As the Phase 2 ferry slows down to maneuvering speed before entering the terminal area the blowers will be shut down to further reduce external noise. Noise levels inside and outside the Phase 2 ferry are not expected to be any different from a conventional ferry of similar side and speed. 8.1 Main Propulsion Engines The Wartsila 12V200 marine diesel engines have the following principal characteristics at maximum continuous rated output (100 percent MCR) RPM 2400 kw 7.54 liter cylinder volume 200 bar peak firing pressure 21.2 bar mean effective pressure 4.56 kg/sec intake air flow 3.75 bar relative charge air pressure 59 C air temperature after charge air cooler 31,304 m 3 /hour exhaust gas flow 385 C exhaust gas temperature after turbocharger 300 mmh20 maximum exhaust gas back pressure 205 g/kwh fuel consumption at MCR 201 g/kwh fuel consumption at 90 percent MCR 198 g/kwh fuel consumption at 75 percent MCR 10.4 g/kwh maximum NOx emissions (untreated) at MCR. Auxiliary systems comprise an engine-driven lube oil pump and lube oil system, high temperature cooling water, low temperature cooling water, sea water, and a starting air system (40 Bar). The engine dry weight is kg. Add lube oil, water, flywheel, mounting feet and a built-on seawater pump and the total weight is 15,585 kg per engine. 8.2 EMISSIONS REDUCTION EQUIPMENT

13 Phase 2 Low Emission Ferry Page_11 As mentioned above the intent is to run the Phase 2 ferry diesels on ultra-low sulfur fuel. In addition the following emission reduction features will be applied to the main diesel engines Electronic Control By year 2010, the reference year for the Ferry of the Future, the Wartsila 200 series engines are expected to employ electronic control of fuel injection and valve timing. This change would reduce fuel consumption per kwh by 5 percent and therefore reduce emissions of fossil fuel byproducts (HC, CO, CO2, PM, SOx) Direct Water Injection (DWI) Nitrogen oxides (NOx) are the main byproduct of combustion and they contribute to acid rain as well as the formation of harmful ground-level ozone and photochemical smog. Water is an effective NOx reducing agent by limiting the temperature peaks during the combustion process, which account for most NOx production. DWI offers advantages over conventional water-fuel emulsions, specifically the factors of poor emulsion stability, poor injection reliability with emulsions, and degraded engine performance in non-water mode. Benefits of DWI include the following. NOx emissions reduced by 50 to 60 percent. No negative impact on engine components. Seamless operation with or without the water injection equipment online. The engine can be transferred to "non-water" operation at any load. Space requirements for equipment are minimal. Capital and operational costs are said to be low. Ratio of injected water to injected fuel ranges from 0.4 to 0.7. The key of DWI is the special injector valve that has passages for both fuel and water. The water must be clean and fresh. A control system energizes a high-pressure pump, which draws water from a storage tank and passes it through a media filter, a flow fuse, and a solenoid valve atop each injector (one per cylinder). The injector has separate passages and needle valves for water and fuel, permitting operation on fuel-only if necessary. Water injection occurs before fuel injection, serving to cool the combustion space and reduce NOx formation. The water injection event is completed before fuel injection to permit the ignition and combustion processes to occur undisturbed. Depending on engine type, the water supply pressure is 210 to 400 bar. The flow fuse functions to interrupt the supply of water should the needle valve stick open or closed. The electronic control unit determines the timing and duration of water injection. NOx reduction is most effective at engine loads greater than 40 percent Diesel Exhaust Oxidation (EO) The diesel oxidation catalytic converter is placed immediately down stream of the engine turbochargers. It is a stainless steel canister with a honeycomb structured catalyst support fixed into the exhaust stream. The platinum or palladium metal catalyst coatings inside convert exhaust gas pollutants to less harmful gases by a process of chemical oxidation. The catalyst is

14 Phase 2 Low Emission Ferry Page_12 most effective at converting carbon monoxide (CO) and unburned hydrocarbons (HC) into CO2 and water vapor. The level of particulate matter (PM) oxidation is influenced by the content of liquid HC particles in the particulate, which varies with engine design and fuel type. The CO and HC are oxidized by about 90 percent by the catalyst and PM levels are lowered by about 50 percent Selective Catalytic Reduction (SCR) For still further NOx abatement, the SCR module is even more effective than DWI, reducing this emission species by 85 to 95 percent. Used together, the SCR and DWI technology would all but eliminate NOx emissions from the propulsion plant. Where DWI affects conditions of the combustion space to reduce NOx formation, SCR uses a safe chemical and catalyst process to eliminate NOx after it has formed. The SCR uses a solution of urea in water, plus the heat of the exhaust gas, to yield nitrogen and water. The aqueous ammonia (40wt %) is a harmless substance borrowed from the agricultural industry. The solution is injected into the exhaust stream at temperatures of C, and decays to ammonia. The ammonia and exhaust gas mixture pass through a catalyst process that converts the NOx and ammonia into nitrogen and water vapor. The typical SCR system comprises a reactor, which contains several catalyst layers, a dosing and storage system for the reagent, and a control system. The SCR reactor is a square steel container. Engine load governs the rate of urea injection. To achieve the most accurate control, the urea injection control unit receives feedback from a NOx measuring sensor after the catalyst. The catalyst elements typically endure for the 3 to 5 years on continuous operation with liquid fuel. It is possible that the catalyst elements could last longer with the introduction of ultra-low sulfur diesel fuel. Sulfur is a known bad actor for the SCR. The main operational costs arise from the consumption of urea (ca g/kwh) or 40wt % urea solution. The engine load profile and the ability to refuel govern the size of the urea tank. Assuming the ferry was operating at full ahead, without interruption for 12 hours, each engine's SCR would consume 600 kilograms of urea solution, or approximately 160 gallons. It is not expected that a ferry would operate at full ahead without interruption for so long. Wartsila Compact SCR units are presently available for all engines in the Wartsila portfolio Exhaust Gas Emission Reduction The Wartsila 12V200 engines of today are mechanically controlled and without any emissions treatment have the following exhaust gas characteristics: Table 4 NOx + HC CO PM < 6.40 g/kwh < 3.50 g/kwh < 0.20 g/kwh

15 Phase 2 Low Emission Ferry Page_13 Comparing these figures with the EPA standards in Table 1 above for a cylinder volume of 7.54 liters, it can be seen that these engines already meet all of the year 2007 EPA emission standards for NOx +HC of 7.8 g/kwh, CO of 5.0 g/kwh and PM of 0.27 g/kwh. This is one reason why the Wartsila engines were selected for the Phase 2 ferry. With equipment available as standard options on the Wartsila 12V200 engines today (DWI and SCR) the Wartsila 12V200 engines would have the following exhaust gas characteristics: Table 5 NOx + HC CO PM < 0.36 g/kwh < 3.50 g/kwh < 0.20 g/kwh With all the emission treatments described above (DWI, SC, EO & SCR) the Wartsila 12V200 engines would have the following approximate exhaust gas characteristics: Table 6 NOx + HC CO PM < 0.4 g/kwh < 0.5 g/kwh < 0.1 g/kwh These emissions are far below the 2007 EPA standards. 8.3 Propulsers The HAD drives [3] are an essential element of the Phase 2 ferry design. The Phase 2 ferry hull rides on an air cushion with almost all of that air escaping past the hull s transom. A conventional water jet with its intake flush with the bottom of the hull would ingest mostly an air-water spray mixture making it completely ineffective. The water jets could be moved to one side of the demi-hull and its intake diverted and formed to take suction through the rigid hull side skirt but this arrangement will have significant efficiency losses compared to a normal water jet intake. The HAD, on the other hand, is designed so the propeller rotor operates half submerged at cruising speeds as a surface piercing propeller. This is exactly the situation existing at the aft end of a SEACOASTER type hull when it is up on cushion and running above about 10 knots. At slow and maneuvering speeds the propeller is fully submerged even with the cushion blowers near full throttle. Herein lies the need for the two speed gearbox. With the full propeller rotor submerged the shaft experiences a large increase in torque that tends to lug the engine down at low rpm. When fully submerged propeller thrust also increases even though the blade design is fairly inefficient for such a condition. By shifting the reduction gear to a higher ratio (2.2:1 from 1.875:1) the main engines are able handle the higher torque and the higher thrust of the fully submerged propeller is available for maneuvering.

16 Phase 2 Low Emission Ferry Page_14 Other claimed benefits for the HAD include higher efficiencies than water jets at high and low speeds, avoidance of propeller rotor cavitation damage and less subject to incapacitation by debris ingestion. Since the HAD is a new technology there are no tests or measurements of maneuverability at this time. It is known that conventional surface piercing drives suffer from poor backing power because of the blade shape and the high torque lug down of the main engine from the propeller rotor being fully submerged. The two speed gear box will eliminate the high torque engine lug down problem. With the engine s ability to spin the fully submerged propeller rotor at higher speeds both reverse and ahead fully submerged thrust should be equal to or better than a water jet leading to equal or better low speed maneuvering of the Phase 2 ferry compared to a conventional catamaran ferry. Assisting with maneuverability are the dagger board type rudders behind each HAD propeller rotor. These can be lowered to so they encompass the entire slip stream of the fully submerged propeller rotor for low speed maneuvering. As speed increases the rudders can be gradually raised so that at high speeds they encompass only the top half of the propeller rotor slip stream. Steering in this condition is essentially being accomplished by deflecting a water air spray mixture minimizing resistance. 9. ELECTRICAL SYSTEM The largest loads on the electrical system of a conventional ferry are electric heating and air conditioning. Another major factor in driving up the size of electric generators on ferries is the very large starting load for electric fire pumps. The Phase 2 ferry has no air conditioning, only a forced fresh air circulation system. The Phase 2 ferry does not have electric main cabin heating but instead uses waste heat from the main engine cooling water. The phase 2 ferry does not have electric fire pumps and instead has hydraulically driven fire pumps powered off the blower hydraulic system. The fire pumps are immediately available anytime by shunting power from the blowers to the fire pumps. With the large hydraulic capability available two 300 HP fire pumps and several upper deck fire monitors could be installed making the ferry a valuable asset for fighting fires along the waterfront and on other vessels. Without the three largest electric loads the two generators on the Phase 2 ferry can be of very modest size. At the present time they are estimated to be no more than 60 kw (80 bhp). Once a more detailed analysis of electric load and the solar electric system is undertaken the size of the generators may very well be reduced to about 30 kw. Only one of the two generators would operate at a time.. Because of the small size of the generators on the Phase 2 ferry they are proposed to be powered by small diesel engines of 1.4 liters/cylinder displacement or less. The generator diesels would meet the respective EPA emission standards in force in the year 2010 from Table 1 above or: NOx + HC CO PM < 7.20 g/kwh < 5.00 g/kwh < 0.20 g/kwh

17 Phase 2 Low Emission Ferry Page_15 Because of their small size no special emission control equipment is recommended for the diesel generators. 10. COSTS The following costs are based on recent commercial high-speed aluminum catamaran ferry building contracts and operating expenses and various assumptions on the number of operating hours/day and days/year and on the costs of crew, fuel and other supplies and services Phase 2 Ferry Construction Cost The construction cost is based on a design and build ferry contract for 1 to 2 vessels for a commercial ferry operator. Similar sized (300 to 400 passenger) high-speed (34 to 38 knot) aluminum catamaran ferries built in the last year have a total construction cost divided by length and beam equal to $1570/square foot. Various factors are applied to account for; the lower Phase 2 ferry cost of having only one level of passenger accommodations instead of two, less total installed horsepower than a conventional catamaran ferry, an increased cost due to a maximum continuous engine rating instead of a medium duty continuous engine rating, a cost increase factor to account for the emission control equipment and a factor to account for the additional cost associated with the more complicated hull shape. The construction cost is derived in the table below: Table 7 Phase 2 Ferry Construction Cost Factor Total $ New Construction 1 of 1 or 1 of 2 (2002 dollars) Similar size 1570 $/sq. ft Total bhp 7500 Hp Medium Continuous (MC) 38 kn. 140 x 40 Base Cost vs. 2 level factor bhp factor of 1/3 total MCR-MC 1.08 of 1/3 total factor Equipment factor 1.05 of 1/3 total Structural complication factor 1.07 of 1/3 total TOTAL (1 of 1 or 2) $

18 Phase 2 Low Emission Ferry Page_ Annual Operating Costs The total Phase 2 ferry annual operating costs are broken down into the cost of crew, fuel, urea of the SCR, fresh water for DWI and onboard service, sewage disposal, consumables (oil, antifreeze, cleaning gear, etc.), insurance and miscellaneous fees and licenses. Coast Guard work rules for crews say a maximum of 12 hours can be worked in any 24 hour period. The range of the Phase 2 ferry is 250 nm at 35 knots which translates into 7.14 hours of operation. In reality, with terminal time, maneuvering time and restricted area slow downs this would probably translate into about an 11hour operating day for the rush hour commuting service. Mid-day about half of the commuter ferries could be shut down between 10:00 am and 3:00 pm with less frequent service. In the late evening after 10:00 pm only one quarter of the ferries would need to operate to serve theater and dinner patrons. On weekends ferry schedules would be less frequent and only one quarter to one half of the ferries would need to be in operation. The 250 nm range of the Phase 2 ferry is not enough to serve these off rush hour services with only one refueling per day. In order to cover the rush hours, mid-day, late evening and weekend services two complete crews are assumed and twice/day refueling are required. Operating days per year at 5 full days and two half days for weekends would be equivalent to 312 days. In future WTA studies the ferry design, schedules, range, crew logistics and refueling capabilities need to be rationalized for specific ferry routes and the number of passengers expected on those routes. Non-rush hour services would probably operate at a net loss and should be considered as a service to the public, not as a revenue generating operation. The annual costs provided below in Table 8 below: Table 8 Vessel Operating Costs Cost/yr 2002 $ Snack bar assumed to be a break even operation 0 Crew (5) Captain n0 per yr Sr. Deck Deck Total per yr Benefits factor shifts Fuel 250 kn x 260 days at average daily vessel loading 5347 bhp (83% mcr), 4950 bhp (77% mcr) Rate 199 g/kw-hr Avg. kw 3841 kw lb/hr gal/hr Hours/day 7.14 hrs Fuel burned 1729 gal/day Cost/gallon 1.2 $/gal Cost/day $ Cost/Yr 312 days 2 refuels

19 Phase 2 Low Emission Ferry Page_17 Urea Solution Cost at Average daily vessel loading Rate (40% solution in 22.5 g/kw-hr H2O) lb/hr gal/hr Hours/day 7.14 hrs Urea used gal/day Cost/gal 1.25 $/gal Cost/day $ Cost/yr 312 days 2 refill Fresh Water Cost (Injection & Potable) at average daily vessel loading Injection Rate (0.5 x fuel lb/hr rate) gal/hr gal/day Potable water 270 gal/day Total/day gal/day Cost/gal $/gal Coat/day $ Cost/yr 312 days 2 refill Sewage disposal 360 gal/day Cost/gal 0.05 $/gal Cost/day 18 $ Cost/yr 312 days 2 empty Consumables (Oil, Coolant, Cleaning 200 $/day gear) Cost/yr 312 days Maintenance Routine/yr $/yr 2.5 yr drydocking $ 2.5 yr maintenance $ 2.5 yr/yr cost Total Insurance 5500 $/month Miscellaneous Fees, Licenses 6000 Cleaning Crew 2 persons 15 $/hr 48 hr/wk TOTAL OPERATING COST/YEAR $ Life Cycle Cost The lift cycle cost of the Phase 2 ferry, assuming a 25 year life, is the average yearly cost of the vessel capital cost at 7.5 percent interest, the annual ferry operating costs minus the assumed

20 Phase 2 Low Emission Ferry Page_18 scrap value of the ferry after 25 years. The total life cycle cost and average yearly costs in 2002 dollars are computed in the table below: Table 9 Life Cycle Cost (assumed year 2002 $ and 25 year life) Vessel Cost $ yr $ Debt Service 100% 7.5% interest for 25 yrs $/mo Operation Cost $/yr Scrap Value after 25 years Total 25 year cost $ Life Cycle Cost $/yr EMISSIONS PER PASSENGER MILE Without a specific route and operating profile it is not possible to compute an emissions per passenger trip. In lieu of the per trip emissions the total exhaust emissions per passenger mile has been computed for a conventional ferry requiring 21 percent more power than the Phase 2 ferry and meeting the EPA year 2004/2007 requirements and the Phase 2 ferry. Both ferries are running at 35 knots with a full load of 350 passengers. The conventional ferry uses low sulfur fuel of 100 ppm while the Phase 2 ferry is uses ultra-low sulfur fuel of 15 ppm. Table 10 Conventional vs. Phase 2 Ferry Emissions/Passenger Mile Phase 1 Pollutant Conventional Phase 2 % Reduction NOx + HC g g 95.9 CO g g 91.9 PM g g 70.6 SOx 85.0 The Phase 2 ferry emissions reduction from a conventional year 2004 to 2007 ferry using the selected features of direct water injection, electronic control, exhaust oxidation and selective catalytic reduction lower the Phase 2 ferry emissions per passenger mile to insignificant levels.

21 Phase 2 Low Emission Ferry Page_19 The reduction in sulfur oxides in the emissions is assumed to be in direct proportion to the sulfur content of the fuels. 12. Potential Improvements of Phase II Design In the next iteration of the WTA Phase II boat design, consideration should be given to alternatives that may improve the efficiency of operating the blowers used for air lift. The present design has the blowers driven by fixed displacement hydraulic motors that are powered by variable displacement hydraulic pumps. Each main engine drives one pump that supplies oil to the hydraulic motor driving the blower on the same side of the vessel. The hydraulic system is necessary in order to be able to run the blowers and the propulsion engines at independent speeds. The blowers need to be run at a nearly constant power level. There is some variation a little less at rest than at full speed and less at light passenger loads but not as much as would experienced when the main engine goes from idle to full speed. The variable displacement pump on the engine allows more oil to be pumped (per revolution) at low speed and less oil per revolution at high speed so that the blowers can be properly controlled. An alternative design would be to drive the blowers with diesels as on existing SEACOASTER vessels. This solution however adds two more small (300 HP) diesels to the vessel with their attendant emissions, weight, complexity, etc. Another alternative is to drive the blowers with electric motors and have larger generators. This is also a problem as the emissions from the generator engines will increase to a more significant fraction of the total. Also, the loading when the vessel is at rest without the blowers operating will be very low and potentially dirty. If the presently developing technology of High Temperature Superconducting (HTS) cryogenic cooled motors and generators becomes available by the time these vessels are to be built, another solution may exist the all electric solution. If all operations were electric, all power could be produced by only two main engines each driving a cryogenic cooled, generator built of HTS wire. Power can then be supplied to the various ship s services and the blowers. Each propulsion shaft would be driven by variable speed HTS motor. HTS motors and generators typically have efficiencies of better than 95% over a range of power from 5% to 100%, and are typically 40 to 60 % lighter than conventional motors and generators. The electric drive of the fans would have a drive efficiency of better than 90% compared to an efficiency of about 60% for the hydraulic system. In terms of power generation, this would save over 300 hp on the blower drives alone. If 300 HP is needed for two blower, total power = 600 HP If the transmission efficiency is 60%, power generated = 600/0.6 = 1000 HP If the transmission efficiency is 90%, power generated = 600/0.9 = 667 HP Savings with electric drive = 333 HP

22 Phase 2 Low Emission Ferry Page_20 In addition to the lower total power generation, operating only generator engines at constant speed and eliminating other engines will help to reduce the emissions. The big question is the weight. Can enough weight be saved with HTS to be a practical drive system? References 1. The Clean Ferry Resolution, Resolution No COE, San Francisco Commission on the Environment 2. New Technologies and Alternative Fuels - Draft Working Paper on Alternative Propulsion and Fuel Technology Review, Water Transit Authority, J.J. McMullen & Booz Allen Hamilton, January 8, Hydro Air Drive Promises Higher Efficiencies, Speed at Sea, December 2001

23 Phase 2 Low Emission Ferry Page_21 APPENDIX A Preliminary Study of Small Sub Chapter T Fuel Cell Ferry This preliminary study was intended to describe the possible characteristics a small Sub Chapter T 149 passenger fuel cell powered ferry using a projected 500 kilowatt (kw) maximum continuous rating (MCR) output fuel cell having a size/output ratio of 2.0 cubic feet/kw and a density of 40 pounds/kw. This fuel cell has a low output and has large space and weight requirements. The fuel cell output is direct current (DC) electric power so the fuel cell output would be further reduced through electrical losses before reaching the propulsion device. For such a low available power and a high volume and weight requirement a monohull ferry running at displacement speeds makes the most sense economically. The propulsion system was assumed to be the fuel cell feeding a switchboard, feeding DC current to a single DC propulsion motor through a speed and direction controller, driving a conventional shaft and propeller. For such a system with the fuel cell operating at 85% MCR and considering electrical losses the net available shaft horsepower (SHP) was 376 kw or 504 horsepower. With this available power a simple single chine hull form was developed that would have sufficient internal volume and buoyancy for the fuel cell power plant and sufficient deck area for 149 passengers and that would run at a speed-length ratio of Note: Speed length ratio is the vessel speed in knots (Vk) divided by the square root of the waterline length ( LWL). When vessel speed is less than Vk/ LWL = 1.34 it is said to be running in the displacement mode. When speed is Vk/ LWL = 1.34 the vessel is said to be running at hull speed. For a typical displacement hull form this is the theoretical maximum speed for a vessel of length LWL. The resulting ferry had the following dimensions: LOA 94 LWL 89 Beam at waterline 20 Depth of hull 11 Draft 5 Displacement 100 long tons With the available fuel cell propulsion system output of 504 SHP the ferry made hull speed of 12.5 knots. The endurance of the fuel cell ferry was 2 days considering 10 to 12 hours of operation per day. A large battery bank was also provided to give the ferry the ability to get home at reduced speed should the fuel cell fail. The fuel cell would burn ultra-low sulfur diesel fuel. Emissions for this ferry would be very close to zero. The hull and single level superstructure of this ferry are constructed of steel. Passenger accommodations are on the main deck only and consist of padded bench type seats of 2, 3 and 4 person capacity arranged in transverse rows, a single ADA compliant head, space for 3 wheelchair tie down locations and a bike rack on the fore deck. The pilothouse was located at

24 Phase 2 Low Emission Ferry Page_22 the forward end of the passenger cabin and was only about half the width of the main deck. Passenger boarding was over the bow or through side gates on the open forward and aft main deck. Main cabin entry was on either side of the pilothouse from the fore deck or on centerline from the aft deck. This small fuel cell powered ferry would be good for short commuter run service or for Bay excursions. Work on this ferry was suspended at the end of April 2002 as interest in the large 350 passenger 35 knot low emissions ferry emerged.

25 Phase 2 Low Emission Ferry Page_23 APPENDIX B Renderings, Lines Drawing, Arrangement Drawings, Machinery Drawing and Midship Section

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