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CaptBones · 10-13-16, 12:53 PM

Steam ships built since at least the 1930’s and even earlier, had an emergency diesel generator. Warships all had at least one, most had two, one forward and one aft. Many steam powered warships had ship service diesel generators in combination with, or even instead of, steam turbogenerators. The diesels could be equipped to do an emergency “black start” in 10 seconds. That’s essential if your steam plant goes “hot and dark”.

In the event of a machinery casualty or damage that causes the steam plant to shut down, you need an alternative source of electrical power to re-start the plant and to provide power to the rest of the ship while the steam plant is being restored. Modern steam plants use electric motors for many auxiliary pumps, including the pumps and blowers for lighting-off the plant from a cold-iron condition. If you were in port and connected to shore power, you used the shore power to run the fuel pumps, feed pumps and forced draft blowers needed for light-off. Once auxiliary steam was available you would shift to the steam driven pumps and blowers. Obviously, if you suffered a casualty or damage that shut the plant down at sea, you couldn’t run a cable back to shore power, so an emergency generator was necessary. Diesel generators were the best choice; they’re rugged and reliable and very importantly, the fuel wasn’t gasoline.

If you research German WWII warship propulsion plants, you’ll find that they had some very advanced high-pressure steam plants, including some equipped with “P-fired” or supercharged boilers that used the boiler exhaust gases to drive gas turbines that powered the forced draft blowers. The USN copied several of those types of high-pressure plants and introduced them in many classes of ships during the 1950’s, ‘60’s and early ‘70’s. Most of those plants operated at 1200 psi 950F, compared to the typical WWII plant at 600psi, 850F. I made my 3rd Class Midshipman Summer Cruise aboard the Navy's first P-fired ship, USS GARCIA (DE-1040) and the KIRK had a 1200psi plant with one ship service/emergency diesel generator (SSEDG). The TARAWA was a "Super 600" plant, 600psi, 850F, but with totally automated boiler controls and combustion controls (also the largest marine boilers ever built). She had two emergency diesel generator (EDG) sets, one forward and one aft; the forward one also drove the bow thruster through a mechanical drive, the generator was declutched when doing that.

10-13-16, 12:53 PM	#8
CaptBones The Old Man Join Date: Nov 2010 Location: Rockton, IL Posts: 274 Downloads: 208 Uploads: 0	Sure... Steam ships built since at least the 1930’s and even earlier, had an emergency diesel generator. Warships all had at least one, most had two, one forward and one aft. Many steam powered warships had ship service diesel generators in combination with, or even instead of, steam turbogenerators. The diesels could be equipped to do an emergency “black start” in 10 seconds. That’s essential if your steam plant goes “hot and dark”. In the event of a machinery casualty or damage that causes the steam plant to shut down, you need an alternative source of electrical power to re-start the plant and to provide power to the rest of the ship while the steam plant is being restored. Modern steam plants use electric motors for many auxiliary pumps, including the pumps and blowers for lighting-off the plant from a cold-iron condition. If you were in port and connected to shore power, you used the shore power to run the fuel pumps, feed pumps and forced draft blowers needed for light-off. Once auxiliary steam was available you would shift to the steam driven pumps and blowers. Obviously, if you suffered a casualty or damage that shut the plant down at sea, you couldn’t run a cable back to shore power, so an emergency generator was necessary. Diesel generators were the best choice; they’re rugged and reliable and very importantly, the fuel wasn’t gasoline. If you research German WWII warship propulsion plants, you’ll find that they had some very advanced high-pressure steam plants, including some equipped with “P-fired” or supercharged boilers that used the boiler exhaust gases to drive gas turbines that powered the forced draft blowers. The USN copied several of those types of high-pressure plants and introduced them in many classes of ships during the 1950’s, ‘60’s and early ‘70’s. Most of those plants operated at 1200 psi 950F, compared to the typical WWII plant at 600psi, 850F. I made my 3rd Class Midshipman Summer Cruise aboard the Navy's first P-fired ship, USS GARCIA (DE-1040) and the KIRK had a 1200psi plant with one ship service/emergency diesel generator (SSEDG). The TARAWA was a "Super 600" plant, 600psi, 850F, but with totally automated boiler controls and combustion controls (also the largest marine boilers ever built). She had two emergency diesel generator (EDG) sets, one forward and one aft; the forward one also drove the bow thruster through a mechanical drive, the generator was declutched when doing that.