Washington State Ferries has stopped acquiring replacement generators for two vessels because of a risk of explosive arc flashes occurring when the powerful new equipment is hooked up with the aging propulsion systems.
Secretary of Transportation Paula Hammond informed members of the House and Senate transportation committees by e-mail Friday.
She told them the manufacturer has been notified to stop making the direct current, or DC, generators intended for use on the Kaleetan and Yakima. The state ordered nine of them for $5.3 million and as of Friday had received four at a cost of approximately $2 million.
The problem does not endanger the safety of the passengers and does not require the 144-car vessels be removed from service. The Kaleetan serves the Bremerton-Seattle route and the Yakima handles travel between Anacortes and San Juan Islands.
Hammond told lawmakers that in 2009, amid design work on how the electrical system would connect to the replacement generators, questions arose on whether this type of generator could safely function without arc flash being created.
“While this has never happened to date, this put into question whether the generators can be used at increased power without unacceptable consequences and breakdowns. We have studied the risk, and have determined the risks unacceptable to WSDOT,” she wrote.
An arc flash is a short circuit through air that flashes over from one exposed live conductor to another conductor or to ground. There are studies estimating arc explosions cause one to two deaths per day in the U.S.
Hammond said alternative plans to replace the generators are in the works with a more detailed briefing available for them this week. She could deliver the update Thursday at the meeting of the Joint Transportation Committee in Redmond.
Ferry leaders ordered generators designed with enough increased power to run the boats using only two of their four engines. The goal was to cut down on fuel use and thus save money on fuel purchases. Those anticipated fuel and cost savings are assumed in the department’s current budget.
Lawmakers received the news in Hammond’s first “Transportation Alert.” She intends to send these updates to committee members every two weeks. The aim is to improve communication following complaints from lawmakers that they did not get told about an error in design of a highway ramp in Tacome before hearing about it in the media.
From Hammond’s alert:
The recent experience of WSDOT’s lack-of-good communications on the SR 16 ramp design error has led to discussions throughout our agency on my continued expectations of a transparent and fully accountable operation. We are re-doubling our efforts on timely recording and reporting of problems as they arise, even as we continue to identify and implement solutions.
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