Not one for the sonar girls :p
 

A question for the nukes out there. It's the job of the shaft seals to stop water entering the people tank where the shaft penetrates the hull. It does this by using pressurised water from the auxilliary seawater system to leak "outwards". My question is, what happens if the pump fails? Is there a chicken switch to seal the shaft more completely possibly at the loss of propulsion? Thanks for any help.

Great site, btw. :)

Nick

If I remember correctly there's an emergency/maintenance inflatable seal that can be used (I haven't seen it but imagine it's like a toroidal airbag) but the shaft can't/shouldn't turn while it's in use.

they have that problem with the russian oscar class submarines if the shaft isnt turning then water comes in (what helped kill the Kursk crew).

so clamps and special air bags have been fitted to some submarines just not all of them.

Thanks for the replies!

Nick

Is this true of all modern submarines? :o

not all i dont think as i believe only the oscar class have this issue its such a big issue with them that they have to clamp the submarines shaft before it reaches the pier hence why its toed in and out by two or three tugs.

No, it's not. Sounds like a design or maintenance fault.

its a problem with oscar and also the typhoons and delta's seems only to be with twin screwed subs western subs no clue

Righto! USS Tullibee had to use the emergency seal when their screw fell off in the Med. :o

June 16, 1978: "The propeller shaft of the TULLIBEE snaps just outside the hull causing limited engine room flooding and loss of propulsion while TULLIBEE is submerged in the Mediterranean. The flooding is stopped by tightening the emergency packing on the propeller shaft. The submarine quickly surfaces and is assisted by other US naval ships. The TULLIBEE is subsequently towed to Rota, Spain, for repairs."

http://navysite.de/ssn/ssn597.htm

How does the propellor shaft snap? Is it metal fatigue or something else?

never heard anything like that not a total loss of a propellor, heard about throwing a propellor blade HMS Onyx threw a blade during one op.

but a whole propellor what the heck?

throwing a blade can snap the shaft - althow i doubt this is possible in a sub

Arrgggh I clicked on your sig link ... braaainzzz. :hulk:

In Tullibee's case, it was a combination of corrosion and metal fatigue. :oops:

Not one for the sonar girls :p
 

Graaaagh!

Me too...
:oops:

Brainz, Brainz, Brainz
Where can I get a new set?
:-?

Ok. Thanks for the info. Should I take it that this should not have happened? Can you confirm if there was a review or alteration of maintenance/service procedures after this incident?

The rest of the story:

"Near Catastrophic" incident on sub probed
Mon, August 14, 1978
The Lowell Sun
Boston (AP) The Navy is investigating events that led to the breaking of a propeller shaft of a nuclear sub while she was submerged, including allegations by the crew that they would be hesitant to ever serve under the skipper again, according to a report in a Boston newspaper.
The submarine Tullibee broke its single propeller shaft June 16 while submerged in the Mediterranean Sea. The engine room flooded and some crew members said they were lucky they made it out alive. The sub is now in drydock in Rota, Spain, for repairs.
The Navy, which termed the incident "near catastrophic," is investigating reports that crewmen told the captain, Cmdr. Charles Arnest, that the shaft was cracking in seven days before it broke, according to the report. Cmdr. Arnest did nothing about the crew's warnings and omitted any reference to the warnings in his report about the incident, according to allegations by some crewmen reported by the newspaper.
Crewmembers contacted by the newspaper said the breaking shaft was the latest in a series of alleged incidents they say make them hesitant to ever serve under Arnest again.
THE NAVY, in a two-page statement, disputes the various incidents but says the shaft breaking and the unheeded warnings are being investigated by the Navy Judge Advocate General.
According to the crew members interviewed by the newspaper, the engine room crew noticed sand leaking from the shaft's bearing on June 8, shortly after the Tullibee left Naples, Italy. The shaft is a hollow tube filled with sand, which gives it stability. The engine room crew assumed the shaft had cracked inside a bearing because sand was leaking through the bearing and piling up in the bilge.
The crewmen showed the sand to the captain, who said it wasn't coming from the shaft. "His exact words were, 'No, no, that's just sand from the Naples harbor,' " one crewman said.
The crew said the captain came under immense pressure once the shaft broke on June 16 and the engine room flooded. The sub couldn't surface immediately because destroyers were manuvering overhead. Arnest ordered the ships away but had to wait a few minutes. The engine room flooded and the stern dropped about 15 degrees. However, the crew said Arnest kept "a very cool head."

Read another article here:

"Danger and Dissent on U.S. Sub"
http://www.geocities.com/weatherman5...es/danger.html

:arrgh!:

Wow, that's not pleasant at all. I would hazzard a guess that if that shaft broke at or beyond the shaft seal they probably wouldn't have survived. As it was it sounds (from the attached article) that it broke just an inch away. Some would call that a lucky break.

Nick

Ouch! :dead:

so what ended up happening to the captain?