Hood´s boilers and turbines

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Karl Heidenreich
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Hood´s boilers and turbines

Post by Karl Heidenreich »

I´ve been reading Bruce Taylor´s book and found that the boilers in Hood were quite small: some 16 x 15 feet in section. And they could provide the 144,000 bhp needed! Incredible.
But it´s astonishing the fact that the whole system had a problem they called "condenseritis" in which salt water used to create a vaccum to the exhaust steam of the HP turbine gradually destroyed all the system and the Admiralty let that to happen from the 30ies until Hood´s sinking.

Just a thought about it.
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RF
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Post by RF »

Would this have a bearing on another matter - the proposal in the early 1930's to strengthen Hood's deck armour - namely that ''the Government can't afford to spend taxpayers money on things like this'' - so nothing was done.
culverin
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Re: Hood´s boilers and turbines

Post by culverin »

Karl, your observation re condenseritis in Hood was by no means unique to her.
This malaise, which was not fully understood, manifested itself to a huge degree in the Great war.
Form 1914, virtually every Grand Fleet battleship up to the Queen Elizabeths, was afflicted, the work needed to be done in dry or floating docks, taking weeks to rectify. Remedial work could be done at Scapa. Additionally, many cruisers of all types suffered, one of the earliest being the Glasgow.
Also, the type of boilers installed made little difference, despite extensive research into the causes going back to the pre Dreadnought era.
It was time consuming, expensive and inconvenient.
I do not know the degree to which other navies suffered, but condenseritis was not a British warship disease.
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Vic Dale
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Re: Hood´s boilers and turbines

Post by Vic Dale »

The problem of condenseritis may have been due to the inability for sea water to circulate properly around the tubes of the condensers. Warspite passed too close to a sand bank on one occasion and silted up her condensers, but it seems she suffered condenser problems continually.

If there is no vacuum on the exhaust side of a turbine the turbine will only work at half efficiency, so a condenser is provided in the form of small tubes which take the exhaust steam. Cooling water applied to the tubes condenses the steam into water thus creating the vacuum. Poor circulation of sea water around the condenser tubes would reduce vacuum to varying degrees. In very cold water this would not be so much of a problem, but in the Mediterranean and on the Equator it might be difficult to get adequate cooling.

There is also the efficiency of the extraction pumps to consider. The extraction pumps are of two types wet and dry. The dry pump, or air pump, draws air and other gasses from the vacuum and the wet pump takes the condensate. Between them they refine and enhance the vacuum. If neither is working properly the vacuum will not be at it's greatest and the turbine will run less efficiently. In a closed steam system there will always be problems, but it seems that vacuum in the condensers was a continual headache in some of HM Ships.

If the problem was not in the extraction pumps and was limited to the condensers themselves, then it would be the circulation of sea water around the tubes and that could be something to do with hull form, the shape of the inlet and outlet pipes, or possibly build up of salt on the cooling tubes themselves. As to why this should be different in ships of identical design, is anybody's guess. I am not certain if they ever managed to iron out the problem. What I do know is the unfortunate vessel with the problem invariably wound up as canteen boat and last in the column, unless it happened to be Cunningham's Warspite.
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