HMS Queen Elizabeth
Discussion
Talksteer said:
doogz said:
Mr Sparkle said:
How much power is needed? Would it need another generator/engine?
Not sure on exact figures, but I'll post this:"EMALS is a design feature of the Ford-class carrier.[13] Such a launch system was also considered as a retrofit for carriers of the Nimitz class aircraft carriers, but was not workable due to the high electrical power requirements of the EMALS catapults, requirements that the two Westinghouse A4W reactors on board the ships of this class could not provide."
The electrical systems are driven by a turbo generator which runs off the secondary steam system. It's this system which would be totally undersized to power the catapults especially as the electrical systems in the rest of the ship will have increased in power beyond what the original designers had planned for.
There would be significant issues in fitting a larger turbo generator into the existing machinery spaces especially as the existing systems work fairly effectively.
I would be very surprised however if the last 4 Nimitz class don't end up with the system in their complex overhaul in the mid 2020s. By that time the steam catapult will be the rare legacy system.
Edited by hidetheelephants on Sunday 13th July 16:44
doogz said:
hidetheelephants said:
I imagine the EMALS will involve scary condensers(or possibly whizzbang batteries) the size of rooms discharging in very short spaces of time; it's unlikely to run straight off the power supply, instead charging up like a flash gun as the impulse power required is massive and needs to be travelling over the shortest cable possible. The sudden requirement for 80MW for ~1 second then off again would be a little trying for the poor buggers in the MCR otherwise.
Kinetic system. 100MJ.Edited by hidetheelephants on Sunday 13th July 16:44
QEC's electrical system wasn't designed to produce the amount of power that EMALS requires on a regular basis.
With 2 GTs and all the DGs, it's a similar issue to that faced by the engineers looking at fitting EMALS to Nimitz class.
Our preferential trip goes when we try to run 2 cranes at the same time on one generator; it doesn't matter how many times you tell the deck apes not to do it. With 112MW mechanical power I guess she has perhaps 75-80MW electric; 10-15 will be needed for hotel systems and most of the rest will be thrusting her through the water. It'll be a little like a flashgun with tired AA batteries in, waiting for the 'ready' light to come on so you can fling biggles off the front.
FourWheelDrift said:
It would chew too many sailors legs off is my first thought about that.FourWheelDrift said:
I'm not sure if a conveyor belt will help - the wheels will stay still!
F-35 still grounded http://www.reuters.com/article/2014/07/12/lockheed...
hidetheelephants said:
hehe: Our preferential trip goes when we try to run 2 cranes at the same time on one generator; it doesn't matter how many times you tell the deck apes not to do it. With 112MW mechanical power I guess she has perhaps 75-80MW electric; 10-15 will be needed for hotel systems and most of the rest will be thrusting her through the water. It'll be a little like a flashgun with tired AA batteries in, waiting for the 'ready' light to come on so you can fling biggles off the front.
With time and experience you will learn you are on a hopeless mission.Deckies cannot be trained.
You will learn this
McWigglebum4th said:
Serious question
Why couldn't you use a stupidly massive rubber band
Not entirely different in principle to either the steam or the electromagentic catapult - just a method of storing large amounts of potential energy that you convert to KE very, very quickly.Why couldn't you use a stupidly massive rubber band
My guess as to why its not practical would be the limitiations in materials science would dictate that the elastic band band would be so big and heavy that a large proportion of the stored energy would be wasted accelerating the 10 ton elastic band to 120kts as well as the 10 ton launched aircraft.
And then of course you've got the problem of stopping the 10 ton elestic band that you've just accelerated to 120kts.
A dirty great big crossbow type launcher cranked by a small electric winding motor could work but doesn't give you the stuff for the arrestor system. So we would be back to rope and sand bags to slow down your billion dollar aircraft.
In still think a RATO sled would be worth looking at as you could adapt the sled for drones etc although it would make discreet night opps somewhat difficult.
In still think a RATO sled would be worth looking at as you could adapt the sled for drones etc although it would make discreet night opps somewhat difficult.
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