Author Topic: Excuse my ignorance  (Read 1790 times)

Offline ysi_maniac

  • I will die understanding not this world
Excuse my ignorance
« on: May 23, 2015, 01:13:42 AM »
WWII Battleships used to be driven by steam turbines.

I asume it was vapour of water. Was that water recycled? Was vapour of water exhausted by the funnal along with fuel smoke? Was water resupplied with sea water?  ??? ???

Offline Logan Hartke

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Re: Excuse my ignorance
« Reply #1 on: May 23, 2015, 01:25:53 AM »
Short answer, it was recycled using a condenser.

Quote
After the steam passed through the turbines it could have been exhausted to the atmosphere to create the temperature/pressure differential across the turbines without using an elaborate set of condensers and pumps. Many small steam engines and steam powered locomotives operated this way. However, the ship's boilers had to produce large amounts of steam to propel the turbines, and that required large amounts of very pure boiler feed water. Sea water could not be used as boiler feed because it contains salts and minerals that would erode the generating tubes in the boilers causing them to fail. Feed water was produced by distilling sea water to eliminate the impurities. A very large distillation plant and huge amounts of energy would have been required to distil enough pure feed water for the boilers to keep the turbines spinning. It was much more efficient to recover the spent steam and reuse the pure feed water. Only relatively small amounts of feed water had to be distilled to replace steam that leaked out of the system.

Here's a pretty good overview of the operation of that type of boiler in relatively simple terms with good diagrams illustrating the operation.

USS Oklahoma City CL91/CLG5/CG5 Propulsion Plant
Phillip R. Hays PhD LT USNR-R



Cheers,

Logan

Offline ysi_maniac

  • I will die understanding not this world
Re: Excuse my ignorance
« Reply #2 on: May 23, 2015, 01:30:24 AM »
^^^^^
Thanks a lot !

Offline Logan Hartke

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Re: Excuse my ignorance
« Reply #3 on: May 23, 2015, 02:19:18 AM »
No problem. I've been reading about a lot of this stuff, recently. Short version, US ship steam plants in WWII were decades ahead of everyone else. They were more powerful, more efficient, more advanced, more reliable, smaller, more damage resistant, easier to maintain, and safer than a comparable plant in another nation's ship. It's really incredible and not something I believed at first, but it's basically true.

The British had led the world with their Parsons steam turbines for years, but their technology had not really advanced much since WWI. Institutionally, British shipbuilding industry (and, consequently, the Royal Navy) was very resistant to any major propulsion changes. By contrast, the US had seen many advances in the commercial sector with its powerplants throughout the 1920s and 1930s and Admiral Bowen pushed to incorporate these advances in the various classes of US ships that were built in the 1930s. Through these somewhat experimental efforts in the decade before WWII, the US was able to establish the formula that would serve them so well during the war. Other nations, like Germany and Japan, would experiment with some of these high-pressure, high-temperature plants during the war, but they were very unreliable, negating their advantages. They were also less efficient and far more dangerous in operation.

Some of this development is covered here, but it's also addressed in a few good books if you want some recommendations.

Steam Technology & the Dawn of "High Steam"

Cheers,

Logan

Offline Weaver

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Re: Excuse my ignorance
« Reply #4 on: May 23, 2015, 04:14:09 AM »
Part of the reason for the differing philosophies of the USN and the RN was that the latter was thinking primarily in terms of short-range operations in the North Sea and Mediterranean, and also had a large number of world-wide bases to refuel it's ships, so the "risk" of high steam didn't seem to have much payoff. The USN, by contrast, was looking at fighting a war across the Pacific, so range considerations were always of very great importance.
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Offline raafif

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Re: Excuse my ignorance
« Reply #5 on: May 23, 2015, 09:27:03 AM »
the RN still had sail-power in WW2 !  A relative was taught to make sails in the RN in WW2 & used the skill to start a company making tents / big-tops etc.

There is also a true story of a Flower-class corvette sailing to Sth Africa from the UK when they ran out of fuel half-way across the Sth Atlantic - no instruction was given in sailing a large ship by this method tho.  Deck awnings were designed to also be used as sails or to disguise the shape of the ship. 

Offline Volkodav

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Re: Excuse my ignorance
« Reply #6 on: May 23, 2015, 09:28:49 PM »
The US was also miles ahead in electrical plant, the weight difference between a cruiser set USN vs RN was roughly equivalent to a triple 6" mount.  The RN was quite conservative in a lot of ways, while they innovated with Dreadnought, steam propulsion, carrier aviation etc. they could also be quite slow to fully capitalise on those innovations.  An example of this was in their reluctance to adopt small tube boilers.

I remember reading something years ago about the different styles of command, I think written by a retired senior RN officer, outlining the benefits and draw backs of each.  They were the Autocrat, Bureaucrat and Technocrat, the Autocrats being responsible for most innovation and the Bureaucrats for most of the conservatism, while the technocrats often missed out on senior command and would fall in behind the Bureaucrats.  The piece suggested that between the wars the Bureaucrats gained precedence during the severe post war contraction of the RN with many of the Autocrats being overlooked for high command seeing them resign or retire.  I don't know how true this was but the general message was in tight financial times the Bureaucrats tend to gain precedence and it is as good an explanation as any that I have come across.