April 1, 2019
The new propulsion technology appearing on the west coast indicates that the US marine industry is now integrating the demands of the EPA Tier 4 rules to reduce diesel emissions into every aspect of their operations. The last stage of these rules came into effect two years ago, although some engine manufacturers were still testing their solutions involving SCR, with a urea-dosing system and tank. There are now a wide range of marine engines over 600 kW/805 hp meeting Tier 4 emission standards, and engines below that power meeting the easier Tier 3 standards.
Naval architects and builders have been preparing for this new generation of Tier 4 vessels for several years, and progressive owners are aware that a "sea change" has indeed taken place; they understand that a new vessel with reduced emissions and a reduced carbon footprint is now an important element in finding and keeping customers. Whether it is in a ferry, tug, or workboat, the new technology also increases comfort for passengers and crew, improves fuel efficiency, and can enhance safety by providing real-time information on the status of all mechanical systems.
Tier 4 Engines for Fast Ferries
The biggest class of new vessels being built in Washington State is the catamaran fast ferry, 140 to 145 feet long and carrying 350 to 400 passengers. Five of these have been ordered by San Francisco's ferry authority (WETA) and two by Kitsap Transit based in Bremerton, Washington. All seven are being built in Washington yards and are powered by Tier 4 MTU 4000 engines supplied by Pacific Power group, based in Kent, Washington.
This powerful high-speed diesel, manufactured in Germany, is supplied with a complete SCR exhaust after-treatment system in the form of a cube about 2 meters square. The Kitsap ferries are 140 feet long and are powered by two MTU 16V4000 M65L engines and two Rolls-Royce S71 water jets, also provided by Pacific Power Group.
Tier 4 for Tugs
In February, Foss Maritime held a keel-laying ceremony at Nichols Brothers Boat Builders for the first hull of its new class of 100-foot by 40-foot ASD tugs, based on Jensen's popular Valor design. Foss has ordered four boats, with an option for a further six, all with ABS loadline certification, and UWILD notation. The tugs will be powered by two MTU series 4000 Tier 4 mains with power ratings up to 2,240 kW at 1800 RPM, and MTU's catalytic after-treatment technology to reduce emissions.
The engines will turn Rolls-Royce US255 azimuth thrusters and the control package will include condition-based monitoring for the Z-drives and main engines. The tugs will have 90 tons of bollard pull via Markey TES-40 winches, and are described as "multi-functional" to handle ship assist, escort capacity and towing. Additionally, the engine room features a 900 GPM fire pump and monitors, driven by a dedicated auxiliary engine. Delivery of the first four vessels will begin in winter 2020.
Sause Brothers of Coos Bay, Oregon has installed MTU 4000 engines in nine long-haul towboats in the last 15 years, as part of a plan to integrate MTU into their entire fleet. This will see more MTU 4000's in a pair of long-haul tugs under way at Diversified Marine in Portland.
Diesel-Electric Hybrid Ferries
Foot ferries that operate on shorter routes are the best candidates for the next step up in the evolution of low-emission technology, the diesel-electric hybrid with battery banks for silent running. The clearest evidence that this method has finally come of age is the number of well-established companies that are investing in marine research centers to compete in what is still a very limited market. They include multi-national engineering giants like Siemens and ABB, and major engine manufacturers Wartsila, Caterpillar, Rolls Royce/MTU and Volvo.
BAE Systems is one of these big names and has come to the fore recently on the west coast. While its core business is in international defense and aerospace, including design, manufacture and support for naval ships, submarines, radar etc., it also has a significant presence in innovative electrification products for the transit, military, rail and marine markets.
This experience has built a large customer base for the BAE HybriDrive control system with bus manufacturers in Europe and the USA. They have produced more than 10,000 hybrid vehicles now in use in the west coast cities of Vancouver BC, Seattle, San Francisco and Honolulu. BAE hopes to repeat this success in the marine workboat sector – despite its small numbers and lack of assembly-line type mass production.
All American Marine of Bellingham, Washington has installed BAE's nautical version of the system, the patented HybriGen into two vessels, the Enyhdra – a 700-passenger monohull tour boat for Red and White Fleet now operating in SF Bay, and the Waterman, a 70-foot by 26-foot, 150-passenger catamaran ferry for Kitsap Transit launched in January 2019. The Enhydra is the first aluminum-hulled, lithium-ion battery-electric hybrid vessel under US Coast Guard Subchapter K.
The HybriGen system uses all-electric battery operation when maneuvering at slower speeds and engages the variable-speed generators to augment the additional power demands of the traction motor when maneuvering at higher speeds. Speed can be precisely controlled from 1rpm on the shaft up to maximum speed, providing unmatched response and control. Each generator mounts to a variable-speed Cummins QSL9 diesel engine, developing 410hp at 2,100 rpm. The generator also functions as the starter.
On the catamaran, BAE supplied two HybriGen propulsion systems that include two 80 kWh lithium-ion Corvus Orca battery packs, generators, power electronics, a control system and AC electric traction motors. Design was by Glosten, Seattle, specifically for the short routes between Bremerton-Port Orchard or Bremerton- Annapolis.
Fully integrated by BAE Systems, the patented HybriGen provides the operator with a smart system that automatically delivers the exact amount of power to either the propellers or the ship's service loads (or both) from the most efficient source. All American Marine CEO Matt Mullett, said, "Even with fuel prices hovering within the affordable range, vessel operators are looking for more efficient propulsion systems."
Damen Shipyards Group, of the Netherlands, is installing its own hybrid system on two new Minor Class 81-meter car ferries for BC that will become the new standard small ferry class in BC. They are under construction in Romania and will have a capacity of 44 vehicles and up to 300 passengers and crew. BC Ferries determined that LNG is not cost-effective on a vessel this small that is operating from smaller ports. Diesel-electric power generation using two generator sets was chosen, with a battery bank to support hotel loads with the option to increase battery capacity in the future.
Damen is also building ferries for Canada's Lake Ontario claimed to be "the first fully-electric vessels to operate in Canada." The new Amherst Island and Wolfe Island ferries will be propelled by four Schottel Twin Propellers STP 260 FP, each with an input power of up to 550 kW. The main propulsion is provided by batteries with a diesel engine as backup to ensure mobility. "There has been close cooperation with Schottel's international network and propulsion knowledge that we have relied on for decades," said Damen Shipyard's Leo Postma, Area Manager Canada.
The Amherst Island ferry has a length of 68 meters and width of 25 meters, will accommodate up to 300 people and 42 cars, and is due to be delivered in 2020. The Wolfe Island ferry, scheduled for delivery in 2021, will have a length of 98 meters and a width of 25 meters for transporting up to 399 passengers and 75 cars. Both will operate at speeds up to 12 knots, the same speed as conventional propulsion.
Dual Fuel: LNG/Diesel
An alternative path toward clean diesel power is the choice of a dual-fuel (LNG/diesel) marine engine. In this case, BC Ferries is well ahead of Washington State in having five of its biggest car carriers now running entirely on LNG. The three new 107-meter Salish-class ferries were built at the Remontowa Ship Repair Yard SA, at Gdansk, Poland for dual fuel. They are powered by three Wartsila 8L20DF diesels turning Wärtsilä/Marelli alternators each with a maximum power of 1,350 kWe at 1,200rpm, enough to drive one Schottel electric ASD at each end at a maximum 207 rpm via a Wärtsilä/Marelli drive motor. Wärtsilä also provided the fuel conditioning systems, engine management and control systems.
In the last two years, the two biggest vessels in the fleet, the 548-foot Spirit-class boats have been refitted and converted to dual fuel at the same Polish yard. They were launched in 1993-94 and are now expected to serve for another 25 years. The cost was C$70 million each including repower with four Wärtsilä 8L34DF 21,394 hp/16,000 kW engines. BC Ferries said their innovation of LNG delivery by hose from a FortisBC tank truck that parks on the vehicle deck saved more than $100 million in infrastructure costs for an on-shore facility. LNG is available at a very competitive price in British Columbia, and will save the fleet 40 to 50 percent in cost compared to the ultra-low sulphur diesel fuel carried on board as a backup.
While BC is a leader in LNG for ferries, and the home of international tug designers Robert Allan (RAL), there are surprisingly no plans for any dual-fuel tugs in the province. The RAL-designed 32m RAstar 3200-W tug that has been built at a Turkish Shipyard specifically to escort and dock LNG ships at a new terminal on the BC coast is powered by conventional diesel engines.
There has been little progress in the use of LNG in US ferries and workboats, except for a few oil-patch boats on the Gulf Coast. In fact, LNG has had far more success in cargo ships, with almost 300 in service or on order internationally. In the US-flag market, the first steps were taken by TOTE Maritime, which serves Jones Act routes linking the Pacific Northwest with Alaska and Florida to Puerto Rico. In 2016, TOTE deployed two General Dynamics NASSCO-built 3,100 TEU containerships with dual-fuel capability on the Jacksonville, Florida to San Juan, Puerto Rico run.
TOTE will also be the first owner to convert its existing fleet to run on natural gas. The two Orca Class ro/ro vessels, operated by TOTE Maritime Alaska, are undergoing conversion at the Seaspan Shipyard in Vancouver, BC. MAN Diesel & Turbo is managing the work that includes installing two LNG tanks immediately behind the ships' bridge. The gas will be loaded at an LNG bunkering facility to be opened in Tacoma.
In January 2019, Crowley Maritime Corp. put its second LNG-powered ship into service between Florida and Puerto Rico, after making a $550 million investment in two Commitment-class vessels with shipbuilder VT Halter Marine and upgrades in docks and associated equipment. The Crowley subsidiary Jensen Maritime of Seattle provided naval architects and engineers for the project. The El Coquí and Taino are reported to be the first LNG propelled combination container-ro/ro ships in the world.
They are 219.5 meters long and 26,500 dwt with a capacity of 2,400 TEU and 400 cars. Cruising speed is 22 knots. Crowley is based Jacksonville, Fla., also a center for cruise ship operators. They have shown the greatest interest in converting to LNG, since the fuel's lack of particulates and other ecological benefits would give an advantage in marketing, and avoid the problem of meeting new international exhaust standards.
Diesel-Electric Pod Drives
The diesel-electric option has been used in passenger ships since the steam-turbine era and was adopted by the oil-rig DPS service fleet. The result was the all-electric ship where the power plant consists of several generators. This approach provides a versatile power supply to meet all the vessel's needs.
Large electric motors are connected to propeller shafts or azimuthing stern drives (ASD) – this provides a more efficient system, especially when the vessel's mission requires a wide range of speeds and electric power use. Depending on the total demand, not all diesel generators have to be operating at all times. In smaller vessels these can be multiple 600 kW/805 hp units that qualify for EPA Tier 3, avoiding the cost of the larger, more complex Tier 4 models.
Cruise ships have long recognized the advantages of this approach because of their widely-varying speed, large periodic hotel loads, and the environmental requirements in sensitive areas and ports. This trend led to the invention of the gearless podded drive unit, like the ABB Azipod, where the electric motor is mounted inside a streamlined pod beneath the stern. This concept was introduced in 1987 and the range of Azipods now extends from 1.5 mW to the 22-mW model.
They have been adopted into cruise ship design and have been fitted to more than 100 cruise ships, including the largest 5,000-passenger vessels. These modern pod drives make ships of all types significantly more maneuverable – and improve fuel efficiency by up to 20 percent. They have revolutionized the design of ice-breakers, which has created the demand for a new generation of luxurious polar cruise ships with ultra-clean engine technology. This has resulted in a rush to be first to offer the ultimate small cruise ship experience – the polar vacation.
Last year, Lindblad Expeditions took delivery of the second small cruise ship from Nichols Brothers yard on Whidbey Island, Washington powered by conventional MTU Tier 3 diesels and Volvo gen-sets. Now Lindblad is building three polar-class cruise ships designed by Ulstein to the highest ice class (PC5 Category A) and built in their Shipyard in Ulsteinvik, Norway. They will be the first passenger vessels to feature Ulstein's signature X-BOW, now seen on more than 100 commercial vessels. Originally developed for rough conditions, this feature also looks very modern and provides more space in the bow, which can house a spacious lounge and clear views.
With a wide range of diesel generators available from European makers, Ulstein recommended the choice of US-built GE products from GE's Danish partner, VMS Group, and ordered a shipset comprised of two 8L250MDC and two 12V250MDC marine engines. "One of the primary reasons we distribute GE's engines is because they provide the best power per footprint and reduce key emissions while maintaining fuel efficiency," said Peter Krogh Nymand, CEO at VMS Group.
"These engines meet IMO's Tier 3 emission standards (and the EPA's Tier 4) without the use of selective catalytic reduction (SCR) equipment and urea-based after treatment," he noted. The vessels also have other energy-saving features like waste-heat recovery systems from the machinery and ventilation exhaust. ABB is supplying two Azipod DO propulsion units and full power and automation solutions.
ABB Marine managing director Juha Koskela said: "The emergence of a distinct market for expedition cruise ships bound for polar waters plays into two areas of ABB expertise. Azipod propulsion achieves greater maneuverability and improves passenger and crew comfort on-board, while its gearless construction reduces environmental risk. Electrical solutions are more reliable, efficient and environmentally responsible than their mechanical counterparts, as well as better aligned with digitalization. The gearless construction reduces environmental risk, and is designed to consume 20 percent less installed power than conventional propulsors." Ulstein has also designed a new ice class cruise ship for Sunstone, who are having four vessels built at CMHI in China.
Hurtigruten Polar Class
Norwegian company Hurtigruten began offering cruises in 1896 and is the world's largest expedition cruise operator. Under the leadership of CEO, Dan Skjeldam, the company has established a policy of reducing its carbon footprint and increasing its environmental awareness with the design of a new class of high-end small hybrid ships to appeal to the American market. The first of three ships, the 140 meter ice-strengthened (PC-6) MS Roald Amundsen is due for delivery from the company's Kleven, Norway Shipyard in May 2019, while Alaska cruises from its US base in Seattle are planned to start in August 2019.
The 530-passenger Rolls Royce-design ships will be powered by four Bergen B33:45 3.6 MW medium-speed gas engines with a Selective Catalytic Reduction (SCR) system for removal of NOx. This will be the first delivery of two Rolls Royce Azipull 3MW ASD's using permanent magnet technology to turn CP propellers. These four engines will power all the electric systems including winches, bow thrusters, hotel loads etc. The Rolls-Royce Unified Bridge control system will control all the ship's systems.
On the first ship, auxiliary battery power will come from two Corvus 627kWh LG1 lithium-ion batteries housed in two separate rooms to satisfy class requirements for 'safe return to port.' It will reduce fuel consumption and allow all-electric transits at moderate speed. In the second ship, larger batteries will be installed, enabling fully-electric sailing over longer distances into fjords etc. A system totaling 5MWh is anticipated.
Hurtigruten have also contracted with Rolls-Royce for a major environmental upgrade to the main engines on six cruise ships that operate on the Norwegian coast to switch from diesel to LNG gas with a hybrid battery system by 2021.
The French company Ponant has a hybrid diesel-electric polar expedition vessel propelled by LNG under way at the Vard Shipyard in Tulcea, Romania. The keel of Le Commandant Charcot was laid in December, 2018 at Vard Shipyard, a subsidiary of Fincantieri who also have a yard on the Great Lakes. This will be the first exploration vessel to surpass the ecological standards set out in international regulations with PC2 Polar Class certification. It will be able to reach exceptional destinations such as the geographic North Pole and remote sites of the Antarctic continent including the Ross Sea, Charcot Island and Peter I Island, according to Ponant.
The dual-fuel engines are four 14-cylinder and two 10-cylinder Wärtsilä 31DF engines. Wärtsilä will also supply the fuel gas supply system. The two LNG tanks were supplied by GTT with Mark III membrane technology, and have a total capacity of 4,500 m3, allowing the ship to complete its entire route using LNG. The latest generation of electric batteries will make it possible to sail without using the engines for two to three hours at a stretch.
The Ponant icebreaker will be approximately 30,000 gross tons, about 150 meters long, 28 meters wide, and will have a cruise speed of 15 knots in open water. The vessel
can accommodate 270 passengers in 135 staterooms, in addition to a crew of 180 persons. Launch is scheduled for 2021.
Diesel-Electric Hybrid Tug
On a Harbor tug, a hybrid system works in a similar fashion to a ferry, but offers greater savings because tugs spend most of their time on stand-by, when they only need a small amount of power. The Rolls-Royce Hybrid Propulsion System that Nichols Brothers has installed on the new 100-foot by 40-foot tug designed by Jensen Maritime for Baydelta Maritime is directly powered by two Caterpillar C3516 C Tier 3 diesel engines each rated at 1995 kW @ 1600 rpm turning two Rolls Royce 255FP ASD's.
The hybrid system allows for the vessel to operate direct-diesel, diesel-electric or fully-electric. For low-speed work, the ASDs can also be powered by one, two or three CAT C9.3 480V 3-phase generators, each providing 300 Kw at 1,800 rpm via two 424 kW electric propulsion motors. This will allow loitering and transit at up to 7-8 knots in electric-only mode, and a bollard pull of >90 short tons in combined diesel-electric mode. A fourth gen-set is a Cat C7.1 150 Kw 480V, 3-phase at 1,800 rpm sized for use when the tug is not working, to further save on fuel and reduce emissions.
The system has been approved by ABS, explained Atle David Monsen, Rolls-Royce VP Sales, Integrated Ship Systems. He stated: "Deep system integration between engines, electrical equipment, thrusters and automation systems is crucial in hybrid vessels. With Rolls-Royce as a system integrator the risk and complexity for both owner and yard is significantly reduced."
Corvus Energy of BC continues to be one of the leading suppliers of lithium-ion marine batteries, supplying complete battery packs to many Scandinavian ferries, including the marine world's largest battery package to be installed on board Havila Kystruten's coastal vessels on the Bergen-Kirkenes route. These four ferries each measure 125 by 20 meters and accommodate 700 passengers. "This Energy Storage System has a capacity per vessel of 6,100 kWh, which is double the capacity of any existing battery-operated ferries," says Roger Rosvold, Vice President Sales at Corvus Energy.
The vessels will have a hybrid LNG-electric propulsion system with battery, where four gas-powered engines in each vessel run the generators. The system is also adapted to the next generation of technology, using hydrogen fuel cells. The equipment from Corvus Energy is scheduled for delivery in 2020 and the coastal route vessels will be in service from 2021.