US Naval Institute News Service reports,
“An electrical fire in a transformer forced USCGC Healy (WAGB-20), one of two American icebreakers, to cancel its Arctic mission, USNI News has learned.”
The fire and Healy’s return to port have been mentioned in comments here at least a couple of time, but this clearly puts an end to any possibility the ship might be quickly repaired and return to the Arctic this year. “This is the second time in four years that a fire cut Healy’s summer mission short.”
The post talks a bit about “…controlled parts exchange with other ships at the pier. That’s a fancy term for cannibalization.” That helps keep Polar Star and the medium endurance cutters operational, but Healy is one of a kind so that is not even a possibility for some systems.
Keeping ships reliable and underway as they approach and pass 30 years of age gets increasingly difficult and possibly uneconomical. In this case, where we have no “bench strength,” it could be disastrous.
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If it’s only a transformer and immediate related equipment (circuit breakers, switches etc>) they have a shot either finding a replacement or getting one wound (subject to factory lead times – recently transformers were in short supply because of energy grid expansion)
But yes – keeping a 30 year old icebreaker operational is difficult in part due to the harsh operating conditions
In case someone is not familiar with USCGC Healy’s electric propulsion system, I managed to find its single line diagram — albeit a low-resolution one — on slide 20 of this presentation:
https://www.slideserve.com/yates/harmonic-and-distributed-generation-interaction-issues-in-the-u-s-navy-all-electric-ship-program
The general layout is pretty standard and inherently pretty redundant: a split power plant and main switchboard, cross-connected propulsion transformers, and double-wound propulsion motors. The design ensures that in the event of any single component failure — diesel generator, switchboard, propulsion transformer, frequency converter, or even some components within the propulsion motor — both shafts would remain turning. This is extremely important on an icebreaker as a non-rotating propellers can be easily damaged by ice. Of course the ship’s operational capability would be limited and a lower-priority mission would likely be cancelled.
If this Reddit post is to be believed, the damaged component is not a propulsion transformer supplying power, but an “exciter transformer” used to magnetize the propulsion motor rotor*:
https://www.reddit.com/r/uscg/comments/1eoixe2/comment/lhgzhyz/
(*if there’s an electrician here, please help me out with proper terminology)
The post also mentions a backup unit that “was not working”. Unfortunately they don’t elaborate further if it was a duplicated component or a spare unit that had to be plugged in.
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