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Nautical Question

Posted: 26 Sep 2018, 18:05
by FlyTexas
On the webpage linked below you will see a photograph of the American battleship USS Georgia being launched. There appears to be steam coming from what I assume to be the ship's whistle. Have any of you ever heard of a ship being launched with the boilers up and running? :dunno:

http://www.shorpy.com/node/23838

Brian

Re: Nautical Question

Posted: 26 Sep 2018, 20:53
by Harry Basset
I think a battleship would have its boilers, engines, screws and shafts installed during building before launch. If it was launched "empty" it could capsize due to lack of stability. If the boilers are installed one may have been making steam for testing and generating electric power for domestic services. It would be understandable to blow a siren to add to the excitement of the launching.

Re: Nautical Question

Posted: 26 Sep 2018, 21:47
by blanston12
Yes it's interesting that she has her funnels and much of the superstructure already installed, but no guns. Not certain if stability would be the reason, the lack of weight from the engines would be offset from the lack of weight from the gun turrets but it certainly would be easier to install the engines and boilers before the deck armor was installed

Re: Nautical Question

Posted: 27 Sep 2018, 04:56
by Chris Trott
The turrets, especially on Georgia and her other Virginia-class sisters actually raised the center of mass of the ship and made them less stable as the vast majority of their weight was centered at and above the deck, including the traversing machinery. Having them out would definitely enhance the stability on launch in addition to lowering the draft to ensure proper clearance from the shallow waters around the Bath Iron Works.

As for having the boilers fired, as these ships had 24 boilers, I doubt it was a major task to bring one or two up to provide steam for the ship's whistle and electrical power during the launch. I believe even today it's still fairly common to blow the ship's horn/whistle during launch for ships launched via slipway.

Interestingly, while looking up the powerplants on Georgia, I noticed that the first US capital ship to use steam turbines for primary propulsion weren't laid down until 1911 (the 2 Florida-class Dreadnoughts), 7 years after. Considering that Steam Turbines had been around for several decades by then, it led me to look up when the first British ship with Steam Turbines was laid down and found it to be Dreadnought herself, laid down the year after Georgia. We (the US) lagged well behind on the adoption of the Steam Turbine in ship propulsion, and it led to quite a few problems not only during WWI, but later in WWII as our heavy ships were outclassed by nearly every other nations' both in reliability and speed as we had to whole-sale re-engineer our Dreadnoughts and Battleships with new powerplants to meet the needs of the North Atlantic convoys after multiple failures of the primary propulsion of ships at sea.

Re: Nautical Question

Posted: 27 Sep 2018, 14:39
by FlyTexas
Thank for the help, fellas. :thumbsup: I've never seen a ship launch with a head of steam. :)

Brian

Re: Nautical Question

Posted: 27 Sep 2018, 16:14
by Paul K
FlyTexas wrote:
26 Sep 2018, 18:05
On the webpage linked below you will see a photograph of the American battleship USS Georgia being launched. There appears to be steam coming from what I assume to be the ship's whistle. Have any of you ever heard of a ship being launched with the boilers up and running? :dunno:

http://www.shorpy.com/node/23838

Brian
We never ran a steam plant if the ship was out of the water (i.e. in drydock ) simply because the steam cycle is impossible without the condenser in service. Condensers use sea water as the coolant, and therefore the intakes have to be submerged. That said, it's not impossible if you are happy to lose the steam by venting it, rather than condensing it back into feed water, and no doubt that's what they did in the picture - maybe one boiler, intermittently fired to keep pressure up, constantly venting to maintain a flow through the water tubes, ready to make the whistle blow at the desired moment. Whether any auxiliary machinery could also be run is anyone's guess - again, it depends on the number of boilers running and whether they were happy to loose the steam/feed water to atmosphere.

It's unusual to see that amount of superstructure completed at the time of launching, and the fact that the uptakes were installed allowed them to fire a boiler. Normally, without uptakes and funnels, they wouldn't be able to do so.
Chris Trott wrote:
27 Sep 2018, 04:56
...it led me to look up when the first British ship with Steam Turbines was laid down and found it to be Dreadnought herself, laid down the year after Georgia.
Just to be clear, Dreadnought was the first battleship to be propelled by steam turbines. There were other British ships prior to Dreadnought fitted with turbine propulsion, both civilian and R.N.

Re: Nautical Question

Posted: 27 Sep 2018, 16:21
by FlyTexas
Thanks Paul. :)

Re: Nautical Question

Posted: 27 Sep 2018, 18:00
by Chris Trott
Paul K wrote:
27 Sep 2018, 16:14
Chris Trott wrote:
27 Sep 2018, 04:56
...it led me to look up when the first British ship with Steam Turbines was laid down and found it to be Dreadnought herself, laid down the year after Georgia.
Just to be clear, Dreadnought was the first battleship to be propelled by steam turbines. There were other British ships prior to Dreadnought fitted with turbine propulsion, both civilian and R.N.
Yes, that's what I meant. I know that steam turbines were in use prior to that (in the US as well), but not in "capital" ships. Reading up on the history of Texas several years back highlighted the problems the US experienced with its early turbines in ships of the line. In 1911/1912, the preceeding Florida-class had issues with its steam turbines both in not producing sufficient speed (they were designed to make 20+ knots, but initially were only capable of ~18 knots) and efficiency issues that greatly hobbled their range. As a result, while Florida needed 28,000 shaft horsepower to 4 screws to move a 22,000 ton ship at 21 knots and give a 5800nm cruising range (at 10 knots); Texas and New York received reciprocating engines which produced the same power to 2 screws and moved the 28,000 ton ships at 21 knots with a 7000 nm cruising range. It wasn't until the later New Mexico-class, laid down just as WWI was starting, that the US produced turbines sufficiently powerful and reliable to overtake the reciprocating engines, where 28,000 shaft horsepower pushed the 32,000 ton ships to 21 knots and an 8,000 nm cruising range. As reference, the size of the fuel bunkers did not grow significantly between the 3 classes. It was advances in efficiency that created the gains more than anything. When Texas was refitted after WWI and given new oil-fired boilers (instead of coal), her cruising range was increased to 15,400nm - without a change in bunker volume (~1.2 million gallons of fuel oil). Meanwhile, the New Mexico-class had a range of approx. 16,500nm on about 1.1 million gallons of fuel oil.

Re: Nautical Question

Posted: 27 Sep 2018, 20:11
by blanston12
following up on what Chris said, the early turbines were more compact than the reciprocating/triple expansion for the power they produced but less efficient and since being able to send there battleships across the pacific ocean was very important to the USN, they were late to the turbine party.

The oil vs coal fired boilers was another story, oil fired were much more efficient for there size. A good comparison was the Queen Elizabeth and Revenge class battleships. The QE's had oil fired boilers and could make 24 knots with 75000 hp while the follow on Revenge class, with basically the same size hull and armament, reverted to coal fired boilers could only make 21 knots with 26500 hp.

Oil fired boilers also needed far fewer crew to operate. I read about RMS Olympic (sister to the Titanic), in 1919 she was converted from coal to oil, the size of here engine room crew dropped from 350 to 50.

Re: Nautical Question

Posted: 28 Sep 2018, 00:38
by Chris Trott
Part of that need for crew was because (AFAIK) there were never reliable auto-feeders put into service on ships. This was what kept coal around for quite a long time in the US Rail industry, including some railroads remaining coal powered well after oil burning locomotives were the thing. The ability to auto-feed with an auger from the tender to firebox gave the same reduction in crew workload as oil, but allowed continued use of a somewhat more readily available fuel source in some areas of the country (especially the coal fields of Wyoming and the Appalachians).