CASE STUDY Commercial Marine

Alaskan high-speed catamaran improves fuel efficiency and cabin comfort with mtu engines

Posted on November 28, 2016

The Alaska Marine Highway System’s (AMHS) high-speed vehicle ferry <i>FVF Chenega</i> offers locals and tourists front row seats to Alaska’s magnificent scenery. Some hail the world-class views spotted from the highway system’s routes on par with even the most opulent Alaskan cruise ships, with the added benefit of having access to Alaska’s more narrow straits and fjords.


Alaska Marine Highway System


mtu Series 4000 M73L


Reliability, fuel efficiency, cabin comfort and minimized maintenance waste


Prince William Sound, Alaska, USA

We’ve seen a 5-7 percent reduction in fuel consumption.

George Poor - chief engineer, Alaska Marine Highway System
Named after the Chenega Glacier, located in Prince William Sound, Chenega was built by Derecktor Shipyards in Bridgeport, Connecticut and came into service in 2005. In 2014, the Chenega’s original four 16-cylinder Model 595 engines were replaced by four new 20V 4000 M73L diesel engines, which produce 3,600 kW (4830 bhp) each. The engine installation and testing was managed by engineers from mtu America with support from Pacific Power Group, a local mtu distributor, Elliot Bay Design Group, at Foss Maritime Shipyard located in Seattle.
“We’ve seen a 5-7 percent reduction in fuel consumption,” said George Poor, chief engineer, Alaska Marine Highway System.

mtu set the gold standard

The Chenega’s sister ship, the Fairweather, underwent a similar repower the previous year. Each measuring 235 ft. (72 m) long, the Chenega and the Fairweather are the fastest vessels in the fleet and after their repowers they are capable of speeds up to 40 knots while carrying 210 people and 31 vehicles. Engineers from mtu America, along with members of the Chenega’s crew and other AMHS representatives ran the ship’s new engines through a series of extensive performance and endurance tests on Puget Sound, which concluded with positive results.
“The engines performed perfectly, as we expected, due to the extensive system testing conducted by the mtu, Foss, and AMHS teams during the construction phase of the project,” said Andrew Packer, senior manager, marine application engineering, mtu America. “We were able to constantly monitor the performance of each engine as it responded to the Chenega’s control system during sea trials. The success of this project would not have been possible without the team at Foss, Elliott Bay Design Group, Pacific Power Group and all of our partners who helped along the way.”

A trusted ally in Alaskan transportation

The year-round ferry system is a critical component of Alaska’s transportation infrastructure. The system offers Alaskan residents a critical connection to goods and services by connecting 35 coastal communities, several of which are not accessible by road. The 11-vessel AMHS fleet is designed to carry passengers, motorcycles, large freight containers and everything in between, traversing a total of 3,500 miles between coastal communities.
The Chenega normally operates in Prince William Sound. Depending on the season, the Chenega provides a steady flow of imported tourists and groceries, and exported seafood product, high school athletic teams, and residents visiting out-of-town doctors. Many passengers opt to ride the ferry over an airplane, not for cost savings, but so their journeys won’t be at the mercy of weather. Oftentimes, the highway system’s ferries are not as susceptible to cancellations due to inclement weather as airplanes can be.
Fast catamaran ferries like the Chenega are an essential mode of transportation, especially for the independent travelers who pass through the area on their routine commutes. It’s easy to see why: the faster the vessel, the shorter the commute. In addition to convenience, the swiftness high-speed catamarans deliver allows the system to serve certain routes more efficiently than they would with slower, traditional mono-hulled vessels. High-speed catamarans are ideal for the highway system’s longer routes, where vessels can build speed and deliver passengers and goods in the same day, which keeps operational and crew costs down.

Streamlined design, streamlined maintenance

The Chenega’s new engine is integrated directly into the ship’s automation system, which dramatically streamlines the crew’s monitoring practices. The streamlined design of the mtu Series 4000 also translates into streamlined maintenance tasks. This means the Chenega spends more time cruising and less time in the shop for tune-ups and maintenance checks. The new design eliminates the need for disposable lube oil filters, and as a result, the engine produces less waste. Chenega’s maintenance technicians also experience improved parts and service availability due to the engine’s higher market presence.
“Our crew enjoys simplified and reduced frequency of maintenance tasks as compared to what was required for our previous engines,” said Poor.

Smooth seas ahead

The Chenega’s crew, the group that is most familiar with the vessel’s intimate details, has noted dramatic improvements in cabin comfort. Most notably, the crew has reported a significant reduction in noise on the passenger deck since the new engines were installed. This improvement can be attributed to the resilient mounting of the engines, which greatly reduces structurally transmitted vibration. These resilient rubber mounts are specifically designed for mtu, while other engine manufacturers sometimes still use the “mount on a hard surface” practice. Between a smoother ride, the elimination of startup smoke, streamlined maintenance practices and improved fuel efficiency there are smooth seas ahead for the Chenega.