Turbine Powerplants on Warships

[M1ster_R0gers]

http://worldofwarships.com/en/news/common/warship-engines/

Hello peoples.  I "exceeded the maximum character limit" in a response to a topic created about power plants on the warships simulated.  I realized that it is worth me writing up here.  As funny as it sounds for me to say - as far as hands on, I am an authority on steam turbine power on US warships.  Your (US)tax dollars paid for my knowledge - and as far as I can recall, everything I am willing to chat about is unclassified.

As far as the first installment of "What Makes a Warship" -

 

Very nice write up, with one correction.  The reverse blades that you talk about here were a part of the Low Pressure turbine. The picture (from the Hornet) is of an LP turbine, the big trunk in the middle is the expanding steam that is leaving the HP turbine. There was a smaller line from the nozzle blocks on the High Pressure Turbine that went directly to the front of the LP turbine, where the reverse blades are housed.  On almost all steam power plants (sans a few experimentals) there are High Pressure and Low Pressure turbines, where the steam sequentially passes through.  The HP turbines had blades that started at about a pinky finger width thick, to the very other end of the LP turbine, which had blades that were a few feet long.  From that point, it went into the main condenser.  The main condenser is a device that works like a car radiator.  Seawater passes through this giant brass contraption that is bolted to the bottom of the turbine at a rate of 10,000 - 50,000 gallons per minute.  This contraption has a thousand(s) small brass pipes to cool the steam in its final phase.  When the steam collapses back into water, it creates a great vacuum (steam is 1,000 time the density of water).  It is designed like your car radiator, where the sea water does not mix with the ship steam, which is kept very clean.  The reason to draw the vacuum is plant efficiency.  Imagine on one side of the turbine, steam is blown in at an incredible pressure, and on the other side, it is getting sucked at incredible vacuum. These plants would produce steam at 600 psi (at 950 degrees F) or 1200 PSI on older DD's - which the 1200 PSI plants were much more efficient that the 600 PSI plants, but killed engineering crews.  Any minor leak could turn into a major catastrophe in seconds.  Steam power still runs the world.  If you get electricity from the grid, it is essentially the same principle in turbines that power most of the ships in WOWS.

Any questions, feel free to ask. - Thanks for your paycheck.
 -Machinists Mate - USN.

[NunsNAmmo]

Not exactly related to your job (I'm a hobby Machinist if that counts), but I had a special question regarding ship duties while underway. I know someone who states he was an EM(N) and served for 7 years aboard the USS Ohio (SSGN-726). He also claims that during that time, he was a "member of the security reaction force team". Would it be typically normal for a Nuke to pull double duty like that while underway? Thanks for your time.

 

[M1ster_R0gers]

Yes.  it is not an oddity - but in the real life the "security reaction force team", I am kind of laughing about here.  Your friend should be proud of the fact that he can handle a PWR power plant, and not stress his abilities to stand guard with a shotgun.  Trust me, a lot of people were "qualified" to do that. 

[NunsNAmmo]

Yes.  it is not an oddity - but in the real life the "security reaction force team", I am kind of laughing about here.  Your friend should be proud of the fact that he can handle a PWR power plant, and not stress his abilities to stand guard with a shotgun.  Trust me, a lot of people were "qualified" to do that. 

 

Understandable. He is very proud of his duties as the guy with the gun. I figured you would assign someone slightly less critical than powerplant staff to something like guard duty on a friggin SSGN.

[M1ster_R0gers]

I find it a bit strange.  I was not on a boomer, actually it was a tender - I was both ship's company and repair for subs and surface ships.  I think that I worked on over 75 submarines in the Med.  I quit counting.  I was also law enforcement on an overseas base.  The boomers ( nuke ballistic missile subs like the Ohio) stayed underwater for their time out.  So any "reaction force" was for their own crew.  Which is crazy - I know how submariners are screened, which is insanely hard.

 

[BBsquid]

I find it a bit strange.  I was not on a boomer, actually it was a tender - I was both ship's company and repair for subs and surface ships.  I think that I worked on over 75 submarines in the Med.  I quit counting.  I was also law enforcement on an overseas base.  The boomers ( nuke ballistic missile subs like the Ohio) stayed underwater for their time out.  So any "reaction force" was for their own crew.  Which is crazy - I know how submariners are screened, which is insanely hard.

 

I wouldnt find it that strange, M1...as OS (you guys would fondly refer to us as twiggits), I know that shipboard security forces were implemented to handle internal and external security threats. While screening for sub duty is extremely rigorous, if I were to make a guess about whether surface or subsurface sailors were more likely to 'crack', I would say the latter. Moreover, even the boomers spent time in port, so a shipboard security force was also for threats that might materialize in home port.

[wtfovr]

Not exactly related to your job (I'm a hobby Machinist if that counts), but I had a special question regarding ship duties while underway. I know someone who states he was an EM(N) and served for 7 years aboard the USS Ohio (SSGN-726). He also claims that during that time, he was a "member of the security reaction force team". Would it be typically normal for a Nuke to pull double duty like that while underway? Thanks for your time.

 

On most warships (specifically US as that is my experience) there isn't enough personnel aboard any ship to do all of the required collateral duties. So most sailors have in addition to their primary job, two or more collateral duty jobs, like Mail petty officer, laundry petty officer, for example.  Another example is an onboard security force.  Larger ships will have a dedicated master-at-arms rating who's sole purpose is to be ship's police force, and some ships have several MAs.  But even on ships with a Master-at-Arms rating, the one or two MAA's is still not enough to do all of the duties, i.e. each division provides sailors on temporary duty to the supply department to help with meals and feeding.   While there they clean the mess decks, take out the trash, provide MAA coverage for the mess decks during meal times.   For the ship's security reaction force, there are gunnersmates assigned to the ship, but usually there aren't enough of them onboard to fully man up a full blown security reaction force.   So volunteers are solicited and those sailors are assigned additional duty for the security reaction force.   The same goes for the damage control teams, there aren't enough sailors to fully man up the fire parties and repair parties, so sailors from supply department, operations department, deck department, supplement the Damage Control rating and engineering department sailors, and go to fire fighting school and damage control school and they make up the bulk of the repair and fire parties that man up the repair lockers.   Just like every Marine is a rifleman, every sailor is a firefighter.  After 9/11, the in-port security requirements skyrocketed, so pretty much every sailor is also a rifleman and qualified in small arms (pistol/rifle/shotgun) and crew served weapons (M60/M240).  The issue is more pronounced now on these reduced manning ships, like the LCS and the DD-1000 Zumwalts, where bean counters are really cutting crews lean and relying on automation, works fine when everything works, but when ships start taking damage, where are the folks going to come from to fight those fires and patch pipes and shore bulkheads?

 

 

Getting back on topic, the HP and LP turbines were the input into the double input- double reduction gears which drive the propeller shaft.   When the switch from steam to gas turbine happened, the HP and LP turbine were replaced by two gas turbine engines (basically a jet engine - in the form of an LM-2500)  One gas turbine engine provided the input where there HP turbine was, and the other gas turbine engine provides the input where the LP turbine was.  Interestingly, the gas turbine engine also has an HP turbine and an LP turbine, however the HP turbine is used to drive the compressor to make the engine self-sustaining, and the LP turbine is a free turbine that drives the input into the reduction gear.     Like the steam turbine, a gas turbine also only turns one way, but there is no astern turbine for a gas turbine ship like there is for a steam ship.  A gas turbine ship also has a separate problem that the steam ship does not in that because the exhaust from the gas turbine is always turning the LP turbine, the propeller is always turning whenever the gas turbine is running.  On a steam ship, they just close the steam valves and the propeller stops turning.   To solve both problems, they implemented variable pitch propeller blades on the propeller.    To come to all stop, the blades of the propeller are set to zero pitch, then to go backwards the pitch of the propeller are set to negative pitch, to go forwards the pitch is set to positive pitch, until it gets to 100%.   Once the pitch is at 100%, to go faster either backwards or forwards, you increase the gas turbine engine power and increase prop RPM like a steam ship.

 

But steam plants were definitely hard on the engineering crew.   To get underway on Monday morning, while everyone else would just go home for the weekend and come back Monday to get underway, the engineering guys would light fires on Friday afternoon, and steam port and starboard through the weekend to get all of the steam piping drained down and warmed up, so that when everyone else showed up on Monday, the engines were "ready to answer all bells."      Once gas turbines engines came along, the engineers could be like normal folks, go home for the weekend, come back on Monday, push a few buttons, and 15 minutes later,  engines are "ready to answer all bells."

[M1ster_R0gers]

I assume that you went through firefighting and DC school in Norfolk also?  It was an interesting time; I am glad that I had that training.  On the tender, I think we had 2 50 cal's and some small arms.  Since we had 1600 crew we did have our own MAA's.  I was stationed in the North Atlantic and the Med, and during my time, personnel retention was in a downward spiral.  In the last advancement period that I was regular enlisted, we had IIRC 13 thousand Machinist's mates vying for 125 advancement slots. 

For that reason, I was offered to cross over to the GST rating, because the new cruisers, destroyers, and frigates were all being produced, and actively replacing everything except the aircraft carriers and the subs.  I was already accepted into college, so my time, as far as active duty, was over.

From my limited time in the engine rooms of Gas Turbine ships, it is a different world.  I was not familiar enough with the gas turbine engine rooms to know how they desalinated water, or provided power (or any of the other typical functions of the engineering space).  But their engineers were definitely much happier than the rest of us.  They said they could fully swap a turbine in an afternoon if necessary. One small control booth - I was used to a wall of gauges and a throttleman and etc.  I walked right by it the first time without even noticing.  Also the fact that the turbines run uncoupled with the rest of the drivetrain is another crazy thing.  For everyone else out there wondering how big these turbines are, they are the same engines that are on a Boeing 747.  So take two of those and put them in a boat.  

Between the two, I think that steam turbines went further and did more for the petrodollar, but by the nature of how steam wears, made every other expense not worth the effort, including the red taped broomsticks.

[DV_Potatobaiter]

I'd imagine the gas turbines the Squids use on their boats are pretty much the same as the Lycoming T-53-L13s and T-53-703s I worked on for 16 years although making far more power than the 850-1400 shaft horsepower I'm used to. What is the fuel used? Is it something similar to JP3 or JP4 or is it more volatile?

[OlPaint]

I'd imagine the gas turbines the Squids use on their boats are pretty much the same as the Lycoming T-53-L13s and T-53-703s I worked on for 16 years although making far more power than the 850-1400 shaft horsepower I'm used to. What is the fuel used? Is it something similar to JP3 or JP4 or is it more volatile?

 

Diesel.  They can also run on JP5, but the normal fuel is diesel.

 

WRT to the article, I thought it was (unintentionally) misleading that they posted a photo of "Turbo-electric drive from a Colorado-class" that was actually one of the SSTG units for hotel & service loads.  The context of the article made it seem like it was one of the primary propulsion turbo-generators. 

 

Douglas

[wtfovr]

Freshwater on Spruance destroyers and the follow-on Ticonderoga/Bunker Hull cruisers was the same as on steam powered ships.  Vapor compression distillation.  The steam came from the waste heat boilers which used the exhaust temp of the gas turbine engines as the heat source to generate steam.   On the Perry frigates, fresh water was reverse osmosis.  Arleigh Burke destroyers is also vapor compression, but instead of a waste heat boiler it's electric heater used to generate steam and I think the newer burkes may have dabbled with RO.

 

For power production the cruisers and destroyers use gas turbine generators. So a total of 7 gas turbine engines (4 main propulsion gas turbine engines and 3 auxiliary power units).  The frigates had 4 Caterpillar diesel generators (along with the 2 gas turbine engines for propulsion)

 

For fuel all ships, steam boiler, diesel, and gas turbine run on DFM / F-76 (diesel) but the snipes would love to run JP-5 if they could.

[DragonOfTheArmory]

http://worldofwarships.com/en/news/common/warship-engines/

 

Hello peoples.  I "exceeded the maximum character limit" in a response to a topic created about power plants on the warships simulated.  I realized that it is worth me writing up here.  As funny as it sounds for me to say - as far as hands on, I am an authority on steam turbine power on US warships.  Your (US)tax dollars paid for my knowledge - and as far as I can recall, everything I am willing to chat about is unclassified.

 

As far as the first installment of "What Makes a Warship" -

 

Very nice write up, with one correction.  The reverse blades that you talk about here were a part of the Low Pressure turbine. The picture (from the Hornet) is of an LP turbine, the big trunk in the middle is the expanding steam that is leaving the HP turbine. There was a smaller line from the nozzle blocks on the High Pressure Turbine that went directly to the front of the LP turbine, where the reverse blades are housed.  On almost all steam power plants (sans a few experimentals) there are High Pressure and Low Pressure turbines, where the steam sequentially passes through.  The HP turbines had blades that started at about a pinky finger width thick, to the very other end of the LP turbine, which had blades that were a few feet long.  From that point, it went into the main condenser.  The main condenser is a device that works like a car radiator.  Seawater passes through this giant brass contraption that is bolted to the bottom of the turbine at a rate of 10,000 - 50,000 gallons per minute.  This contraption has a thousand(s) small brass pipes to cool the steam in its final phase.  When the steam collapses back into water, it creates a great vacuum (steam is 1,000 time the density of water).  It is designed like your car radiator, where the sea water does not mix with the ship steam, which is kept very clean.  The reason to draw the vacuum is plant efficiency.  Imagine on one side of the turbine, steam is blown in at an incredible pressure, and on the other side, it is getting sucked at incredible vacuum. These plants would produce steam at 600 psi (at 950 degrees F) or 1200 PSI on older DD's - which the 1200 PSI plants were much more efficient that the 600 PSI plants, but killed engineering crews.  Any minor leak could turn into a major catastrophe in seconds.  Steam power still runs the world.  If you get electricity from the grid, it is essentially the same principle in turbines that power most of the ships in WOWS.

 

Any questions, feel free to ask. - Thanks for your paycheck.

 -Machinists Mate - USN.

 

 

 

 

 

Retired nuke electrician and I approve of this message.

[DragonOfTheArmory]

I'd imagine the gas turbines the Squids use on their boats are pretty much the same as the Lycoming T-53-L13s and T-53-703s I worked on for 16 years although making far more power than the 850-1400 shaft horsepower I'm used to. What is the fuel used? Is it something similar to JP3 or JP4 or is it more volatile?

 

 

 

 

The base line is the GE LM2500.  There are variants of them but not much changes as far as general construction.

 

 

JP5 is used.  Many for a couple of reasons, not just on the gas turbine ships, but even diesel powered ships or equipped with diesels.  JP5 is not as flammable and is used everywhere just because of the proximity to the aviation side of the house.  Cruisers and destroyers coming along side to get fuel get JP5.  It also made things simpler just from the logistics side.

 

 

With diesels, the storage of the fuel was harder, and it didn't burn as clean and left soot deposits.  I have been told that the biggest advantage is that it helped make maintenance requirements easier due to it not leaving junk inside the cylinders or exhaust, and being able to bring a huge 4 megawatt emergency diesel up to rated speed for loading such as the ones on a Nimitz class carrier was not possible with regular diesel fuel.

[CAPT_Rob]

Freshwater on Spruance destroyers and the follow-on Ticonderoga/Bunker Hull cruisers was the same as on steam powered ships.  Vapor compression distillation.  The steam came from the waste heat boilers which used the exhaust temp of the gas turbine engines as the heat source to generate steam.   On the Perry frigates, fresh water was reverse osmosis.  Arleigh Burke destroyers is also vapor compression, but instead of a waste heat boiler it's electric heater used to generate steam and I think the newer burkes may have dabbled with RO.

 

For power production the cruisers and destroyers use gas turbine generators. So a total of 7 gas turbine engines (4 main propulsion gas turbine engines and 3 auxiliary power units).  The frigates had 4 Caterpillar diesel generators (along with the 2 gas turbine engines for propulsion)

 

For fuel all ships, steam boiler, diesel, and gas turbine run on DFM / F-76 (diesel) but the snipes would love to run JP-5 if they could.

 

One of the first Reverse Osmosis distillation plants was installed in the Spruance class DD USS Paul Foster (DD 964) at some point during her active duty career.  I read on that ship's Facebook page that this plant worked out very well so it wouldn't surprise me if it is used in the Burke DDGs.  Foster is now the Defensive Systems Test Ship out of San Diego and probably still has it installed.

 

In Caron (DD 970) we had the Vapor Compression fresh water system.  During nearly 4 years aboard (most of that underway) the only time we had to go on "water hours" was when we deployed almost straight out of overhaul and found out the shipyard workers couldn't read a diagram to save their butts, routing sea water incorrectly into the system in the forward auxiliary machinery space, forcing a shut down and ruining part of the system.

 

Fortunately our engineers (officer and enlisted) got their heads together and with the Skipper's permission put together (what looked like) a Rube Goldberg like replacement for the ruined gear out of bits and pieces from the pipe and metal shops, lengths of fire hose and only God knows what else.  It worked like a champ and we were off water hours the next day and for the rest of the cruise.  Diagrams, photos and descriptions of the 'thing' were sent to BuShips to explain to them how we managed to end water restrictions even though the waste heat distillation system was consistently reported as trashed.  ChEng (Chief Engineer) kept copies of the photos and information both for him to take to his next ship (Yorktown CG 48) and to pass along to the other ships in our squadron and to his relief aboard Caron.

[Soylent7]

Frigates(FFG) use JP-5 for the gas turbines. Two motors, single shaft(if I recall correctly, they were leased from GE). They also had 2 diesel generators. Fun fact, the diesel void was below the operations berthing and if, during inspection, you forget to replace the seal on the cover, during unrep the berthing will fill up with diesel to about the middle bunk. After cleaning(and replacing all your effects) the diesel smell will last about 4 months.

[Mister_Rawr]

One LCS variant and the new ZUMWALT use Rolls-Royce GTs.  Not much different mechanically, but BIGGER.

 

All LM-2500s and the Allison 501-K34 gas turbine generators run on F-76 - or Diesel Fuel Marine - a lower-grade distillate than JP-5.  They can be configured to use JP-5, and actually function more efficiently that way, but do not under normal circumstances due to the greater cost and small amount of storage for that fuel type.

 

The remaining TICONDEROGAs are presently finishing out having their WHBs and distillation plants removed in favor of reverse osmosis units.  All ARLEIGH BURKEs were constructed from the keel up with ROs, all remaining FFGs have also had their distillation plants replaced with ROs... though I think only the one or maybe two are left in the fleet.  Sadly.

 

As for diesel overfilling into OPS berthing... crap, that would have sucked.  Thank goodness nobody told me about that before my tour on RJA... I would have been down in berthing every UNREP instead of up in the pilothouse.  Fortunately we had a badass for a CHENG and great top snipe.

 

-R

[wtfovr]

From my limited time in the engine rooms of Gas Turbine ships, it is a different world.  I was not familiar enough with the gas turbine engine rooms to know how they desalinated water, or provided power (or any of the other typical functions of the engineering space).  But their engineers were definitely much happier than the rest of us.  They said they could fully swap a turbine in an afternoon if necessary. One small control booth - I was used to a wall of gauges and a throttleman and etc.  I walked right by it the first time without even noticing.

 

Between the two, I think that steam turbines went further and did more for the petrodollar, but by the nature of how steam wears, made every other expense not worth the effort, including the red taped broomsticks.

 

It is a different world on a gas turbine ship.   Even on a nuke plant, there's still a wall of gauges with the throttleman and a reactor operator, but it's in an airconditioned central control station away from the engine rooms - a gentleman's space (snigger).   The engine rooms on gas turbine ships from the Spruances to the Arleigh Burkes were designed to be unmanned during normal operation, but since manpower was available, the Navy decided to keep them manned.  From the central control station on a gas turbine ship (air conditioned of course), you can do everything you need to start and stop the engines, do all of your casualty control, and once everything was up and running, you pass direct control of the engines to the bridge.  No need for a zippo lighter and the dipping the torch in the bucket of fuel and lighting fires in #1 boiler. No need for MM's running everywhere turning valves to drain down steam piping to cross connect plants or opening the main steam stop.

 

Once engine control is passed to the bridge, engineering is now out of the loop in terms of running the engines.  All you do in engineering at that point is do you gauge readings and lube oil samples every hour. Gauge readings? remember the messenger running around with the clipboard writing down all the readings in the engineroom every hour - a 30 minutes process while taking out his rag and wiping up the ubiquitous lube oil that's everywhere on everything?   Today, all the messenger does is push a button, a dot matrix printer prints out all the engine paramenters and gauge readings on continuous feed printer paper.  He tears it off, signs his name, and gives it to the EOOW -  a 1 second operation to push the button, about 5 minutes of waiting for the printer to screech to and fro the gauge readings and engine parameters onto the paper....  then 55 more minutes of lolly-gagging (oh get those lube oil samples) before it's time to push the button again.  Heaven help the messenger if the printer is broken or is out of paper...

 

The Engine Order Telegraph has been relegated from it's primary means of passing engine orders from the bridge to the engine room to a backup - to be used only when central control takes control of the engines.

 

Steam turbines remain the most efficient use of fuel oil.  Diesel engine second, Gas Turbines Engines third, and nuclear power is the worst in terms of efficiency.

 

 

I'd imagine the gas turbines the Squids use on their boats are pretty much the same as the Lycoming T-53-L13s and T-53-703s I worked on for 16 years although making far more power than the 850-1400 shaft horsepower I'm used to. What is the fuel used? Is it something similar to JP3 or JP4 or is it more volatile?

 

The gas turbine engine of a Burke produces 26,500 shaft horsepower.

 

One LCS variant and the new ZUMWALT use Rolls-Royce GTs.  Not much different mechanically, but BIGGER.

 

All LM-2500s and the Allison 501-K34 gas turbine generators run on F-76 - or Diesel Fuel Marine - a lower-grade distillate than JP-5.  They can be configured to use JP-5, and actually function more efficiently that way, but do not under normal circumstances due to the greater cost and small amount of storage for that fuel type.

 

The remaining TICONDEROGAs are presently finishing out having their WHBs and distillation plants removed in favor of reverse osmosis units.  All ARLEIGH BURKEs were constructed from the keel up with ROs, all remaining FFGs have also had their distillation plants replaced with ROs... though I think only the one or maybe two are left in the fleet.  Sadly.

 

As for diesel overfilling into OPS berthing... crap, that would have sucked.  Thank goodness nobody told me about that before my tour on RJA... I would have been down in berthing every UNREP instead of up in the pilothouse.  Fortunately we had a badass for a CHENG and great top snipe.

 

-R

 

Ten years ago, primary fuel was F76 / DFM for ships - steam, diesel, gas turbine.   I did know at the time that there was research at the Naval Post Graduate School into the feasibility of going to a single source fuel (JP-5) to make it easier logistically. JP5 is more expensive than F76 and ships burn much more F76 than airplanes burn JP5.   So when folks above were saying everything was JP-5, I assumed the Navy switched over to just JP5 at significant cost.

 

I can understand the diesel engines on an aircraft carrier running solely on JP-5, as that makes sense as that is the only fuel on a carrier.

 

But other ships, the fuel tanks for the ship's engines carry F76.  The JP-5 tanks are significantly smaller and are dedicated solely to the helicopters embarked.  You can put JP5 in an F76 tank, but once it's in an F76 tank, the JP5 can't be used to fuel aircraft.   The exception is amphibs who do carry a significant quantity of JP5 and can probably run their engines from the JP-5 carried on board, but the JP5 on amphibs belong to the Marine Corps (as part of Class III LFORM) not the Navy and cannot be used for routine normal operations.

 

There is a JP5 head tank for the gas turbine engines, located directly above the gas turbine engines.  It's meant as an emergency supply of fuel to the gas turbine engines when the ship has lost all electrical power.  With the loss of electrical power, you lose your fuel pumps (and firemain and combat systems), and the engines would normally flameout.  But with the head tank, with the loss of electrical power and loss of fuel oil pressure, the fuel source switches automatically to the JP-5 head tank which gravity feeds fuel to the gas turbine engine, so the ship, instead of being dead in the water, can now get away/maneuver from whatever caused the loss of electrical power, until you can reestablish an electrical power to get the fuel pumps running again.  As well as reboot the combat systems so the ship can fight again.

 

The Zumwalts DDGs though, the powertrain is different.  The Rolls-Royce gas turbine engines will run large electrical generators instead of driving a reduction gear.  An electric motor will drive the propellers, much like going back to the turbo-electric drive of the New Mexico, Tennessee and Colorado class battleships from post WW I to WW II.

 

[CAPT_Rob]

Steam power and gas turbine are indeed two different worlds.  I served in a gas turbine powered Spru-can and later in a steam powered LHA.  Both plants have their good and bad points, the steamer was more fuel efficient but the gas turbine more responsive mainly due to the direct engine throttle control from the Helmsman's station on the Bridge.

 

The steam plant in Nassau needed a good deal of time to go from "cold iron" shutdown to full power, hours if I remember correctly.  In Caron we demonstrated real world the ability to go from cold iron to full power in less than 2 minutes while anchored in the Bosphorus.  We had dragged anchor and slid into USS Coral Sea's "swing circle" and as my old shipmate "Murphy" would have it the carrier began swinging in a current eddy.  The watch on deck noticed the danger and called away "Sea and Anchor" and ordered CCS to bring up the main plant.  The LT who was Command Duty Officer (CO and XO were ashore) ran out on deck, took one look and headed for the Bridge.  He made it to the Bridge in less than 2 minutes just as CCS was reporting "Ready to answer bells."  The LT and Quartermaster on watch used the helm and engine power to swing us out of Coral Sea's way even before Deck Force began heaving in the anchor chain.  Once underway it took us nearly 2 hours to find good holding ground well upstream of the carrier.

 

I tell the story because that ability to bring main power up that quickly saved Caron from being damaged seriously or even sunk by collision with an aircraft carrier.  A steam powered destroyer or cruiser in the same position probably wouldn't have made it unless her plant was fully operational.

 

I think it should be mentioned also that one of the things that make gas turbine ships so responsive are the controllable reversable pitch propellors.  Much of your speed control below 1/3 speed is through adjusting the pitch of the prop blades.  And you can go from Ahead Flank to Back Full in seconds without the necessity of engaging reversing gears or turbines by reversing the pitch of the blades.  You can stop an 8,000 ton destroyer moving ahead at 30+ knots in less than 2 ship lengths (1,200 feet) while I have absolutely no idea how long it would take to stop a steam powered ship with fixed props (a mile or more?)

 

Did I mention I LOVE gas turbines?