HMS Astute SSTG Repairs Complete
Remember the story of the British submarine HMS Astute (S 119) having her Turbine Generator bearings and shaft damaged during a shipyard test in new construction? At the time, the assumption was that they'd have to do a hull cut to get the shafts repaired. It turns out they didn't have to, according to this story:
BAE has successfully completed repairs on the second of two turbo generator shafts on the £1.2bn first-of-class Astute submarine, damaged in harbour trials last August.Of course, they won't know how successful the repairs actually were until they get to spin them up again, and even then I could imagine their noise performance might suffer. Still, I'm impressed that they could at least get the roundness fixed doing the job in-place.
The company hired a firm which specialises in marine in-situ repairs to reprofile the shafts after they were scored by turning unlubricated in bearings after an oil pump broke down.
Now the shafts are reprofiled an exhaustive series of operations is taking place to flush the turbo generators with oil to remove any unwanted particles that could damage the machinery.
When flushing tests are complete work will begin to re-instate equipment in the confined aft space of the submarine which had to be moved to get at the generators.
Even so, I expect that whatever gremlins moved into the SSTGs prior to the test might make themselves known in the future. Equipment that just never works quite right is, I'm sure, a tradition "enjoyed" by all submariners worldwide.
1 Comments:
“Equipment that never works right…”
1A SSTG on an LPD. Massive lube oil contamination with fresh water—10-15 gallons in an hour.
Repeated tech rep visits. Always the same script:
“It must be salt water.”
“No chloride—must be the gland seals.”
“Seals OK—must be improper operation. Guess you [whinging know-nothings] will have to live with it.”)
Four years later, in-plant test at the manufacturer’s resulted in massive LO contamination with fresh water. Result: a real engineering investigation after six years of on-and-off CASREPs.
The turbine shaft had been scored during precom. The manufacturer sleeved the shaft but didn’t seal-weld the sleeve. Steam from the turbine was leaking between shaft and sleeve and condensing at the bearing. Sure hope the ASTUTE’s SSTG work is better!
1/21/2008 7:52 AM
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