BC Ferries says electronics glitch likely caused hard landing at dock

A British Columbia ferry terminal was knocked out of service for months after a BC Ferries boat slammed into the berth, injuring three people.

Coastal Inspiration experienced a hard landing at the Duke Point ferry terminal on Vancouver Island on Dec. 20, 2011. The 520-foot ferry was approaching the dock at 1452 when it failed to completely slow down to enter its slip.

All evidence leans toward an unexpected failure in the maneuvering system that controls the variable-pitch propellers to respond to application of the controls by the bridge. Initial findings indicate that an electronics malfunction was the root cause, BC Ferries said in a Dec. 21 press release.

The terminal berth sustained significant damage and the vessel's port-side doors were damaged, BC Ferries reported. The vessel was to to be pulled from service and replaced by another vessel.

The hinge arm on Coastal Inspiration's bow door was damaged beyond repair. The part was ordered and delivered from Europe. The door sustained buckling damage and required realignment, but did not need to be replaced.

There were two minor injuries to passengers and one minor injury to a crewmember on board.

The landing terminal sustained damage to the starboard wingwall and pilings, the lower ramp abutment, lower apron hinges, lower apron and hydraulic cylinders. There was also electrical damage.

Reconstruction of the Duke Point terminal was expected to commence in mid-February, with the expectation that it would reopen in mid-April.

Coastal Inspiration returned to service Jan. 25.

The vessel was built for BC Ferries in 2007 by Flensburger Schiffbau in Flensburg, Germany. It is one of three Super C-class ferries built for BC Ferries.

In the October/November 2008 issue of Professional Mariner, writer Alan Haig-Brown noted that the ferry is powered by four eight-cylinder MAK 8M32C main diesel engines, each producing 5,361 hp at 600 rpm, to turn at a constant speed. Electric power generated is used for the ship's two 11,000-kW electric-drive motors that turn the propeller shafts at either end. These shafts are fitted with 16-foot-5-inch-diameter controllable-pitch propellers that turn at a constant speed of 140 rpm when the respective drive motor is engaged.

Coastal Inspiration has forward and aft screws that give it a speed of 23 knots. The vessel has a capacity of 370 cars and its passenger and crew capacity is 1,604.

BC Ferries declined a request from Professional Mariner for further details of the incident, which was still under investigation in January.

A 2007 report by Seattle naval architects and marine engineers Glosten Associates found that, in the Super C-class ferries, "the head reach in a crash stop from 21 knots appears to exceed the C-class vessels." In other words, the Super C-class vessels take farther and longer to come to a stop compared to the smaller C-class vessels.

Glosten Associates had been commissioned by BC Ferries to do a due diligence review of the ferries while they were under construction. The report made note of the propulsion system which uses fixed-speed propulsion instead of variable-speed drives.

Fixed-speed propulsion works to "simplify the overall system and eliminate high maintenance," but leaves the propulsion machinery constantly running at full rpm, the report states. "The primary drawback is at the dock; when the nearly feathered propeller is rotating at full rpm, any failure in pitch control could have severe consequences."

Coastal Inspiration and its sister ships Coastal Renaissance and Coastal Celebration are all propelled by fixed-speed propulsion and variable-pitch propellers. Six other vessels have fixed-speed, variable-pitch systems, and nine other ships including conventional C-class are equipped with variable-speed, variable-pitch propulsion systems.

BC Ferries says all 18 are considered controllable-pitch propeller systems, or CPPs.

In addition to the internal BC Ferries investigation, the Transportation Safety Board of Canada is investigating the incident.

By Professional Mariner Staff