BC Ferries has launched its first dual-fuelled LNG ferry. Its chief executive officer Mark Collins told Rebecca Moore about the main considerations and innovations
BC Ferries had much to consider for newbuild Salish Orca – delivered in May this year – and its two sister ships as they are the Canadian operator’s first vessels to be fuelled by LNG. Bunkering, safety, crew training and regulatory compliance were all under the microscope when the British Columbia ferry operator commissioned Polish shipyard Remontowa to build the Salish class trio.
BC Ferries president and chief executive officer Mark Collins told Passenger Ship Technology that the drivers for choosing LNG were twofold: “It is a clean fuel, abundant in British Columbia, and half the price of diesel. It is not often cleaner fuel is less expensive – in effect the technology is paying us to be green.”
Indeed, BC Ferries is particularly fortunate because LNG is available at a very competitive price in many areas of North America, including British Columbia, compared with its cost in other areas in the world.
So BC Ferries was “very enthusiastic” about using LNG, Mr Collins said. “There is no other technology on the planet that can cut a fuel bill in half. This is a huge step change in fuel operating costs.” Using LNG will save BC Ferries 40-50% in fuel costs.
The most innovative aspect of BC Ferries’ new dual-fuelled ferries is their bunkering process. In contrast to the usual way of bunkering LNG via a pier, BC Ferries decided to bring trucks on deck to fuel the ships to save on the infrastructure costs of constructing a bunkering pier.
Mr Collins said the company invented this concept and is the first ropax operator to bunker LNG in this way. So original was the solution that “everyone thought we were mad”. But BC Ferries continued in its quest: “We did risk assessments and we did not see anything that we could not mitigate with good engineering,” Mr Collins explained.
Its originality meant that there were no existing class rules that covered it, so it had to be treated as an alternative design and follow a risk-based assessment by Lloyd’s Register. This meant that the bunkering concept was the first thing to be started when it came to assessing new vessels and the last thing to be finished due to the amount of work involved.
“We don’t have the need for millions of dollars of bunkering” Mark Collins (BC Ferries)
The truck used was purpose designed by the gas supplier Fortis BC so that it could transfer LNG to the 130 m3 storage tanks onboard. A double containment system was created to enable this and a connection point on the truck allows it to connect via hoses to that fully enclosed containment system. BC Ferries’ concept has been picked up by fellow BC ferry operator Seaspan, which has also launched LNG-fuelled roro vessels this year. The standardised interface of the truck means that Seapan uses the same trucks.
Mr Collins is understandably proud of the bunkering concept that the ferry operator created: “We blazed a trail. It means that we don’t have the need for millions of dollars of bunkering [infrastructure]; there is no pipeline to the liquefaction plant as the truck brings the LNG from the plant.
Underwater noise and small ports
Reducing underwater noise was very important because a large whale population lives off the coast of BC. The fact that the electric propulsion system consists of a fixed pitch propeller controlled by variable frequency drive means that “you can continuously control propeller speed from zero to maximum.” Mr Collins said that this meant that the propeller can rotate very slowly when docking and manoeuvring rather than “thrashing at full speed [as it would] with CPP”. It also turns very slowly when low power is needed in shallow areas, leading to much less cavitation and noise.
Another significant consideration was that many of the ports that Salish Orca and its sister vessels will call at are small, so BC Ferries was “very keen” to minimised the overall ship length. The company chose a design that was unique in North America, although fairly common in Europe: an upper and lower car deck but just one single level entry for cars driving onto the ship. In contrast, many of BC Ferries’ fleet use ramps built at two levels from shore.
The benefits were two-fold: “It gave us two decks without having to modify ports and it gave us more capacity at the same length.” Salish class ships can carry 40-50 more cars than the previous ships of similar length overall.
Salish Orca ship has LNG-electric propulsion, with the engines driving three dual-fuel gensets, which supply the electricity to the propulsion motors.
The three main engines are Wärtsilä 8L20DF medium speed engines, with eight-cylinders. They deliver a total 4,400 Kw to alternators provided by Wärtsilä/Marelli, which have an output of 1,425 kW at 600 VAC for the drive motors, also provided by Wärtsilä/Marelli. These are powered via variable frequency drive controls and have an output of 3,600 kW.
A dual-fuel boiler is provided by Pyro and has 406 kW output.
A major impact of BC Ferries’ decision to use LNG is that it decided to have one integrated equipment supplier rather than choose a multitude of different manufacturers. Therefore as well as all of the equipment detailed above, Wärtsilä also provided the fuel conditioning systems, engine management and engine control systems.
“It has a sophisticated electronics system to knit this together,” noted Mr Collins. “LNG has to be managed carefully so there is a highly automated safety system.” The company chose one supplier so that it had “no doubts about the integrity of the system right from the propeller all way up to the captain’s control.”
The fact that Wärtsilä has responsibility for the whole system “gives us great comfort as we can just go to one supplier”. Furthermore, he said, Wärtsilä is an expert on everything to do with how the system interacts both within itself and with the ship.
Two Schottel azimuth fixed pitch propulsion thrusters are placed one at each end of the double-ended ferry, which makes it highly manoeuvrable
Salish Orca main specification
Length: 107 m
Breadth: 24 m
Gross tonnage: 8,728 gt
Class: Lloyd’s Register
Capacity: 600, including crew
Vehicle capacity: 138
Main engine: Wärtsilä 8L20DF
Drive motors: Wärtsilä/Marelli
Propulsion thrusters: Schottel
Dual-fuel boiler: Pyro
Bow/aft visors and vehicle deck hatches: MacGregor
Integrated bridge system: Sperry Marine
Four X-band radars and one S-band radar: Sperry Marine