(VANITY) Why are the Queen Elizibeth class carriers not nuclear powered?

June 4 2012 | me

[moonshot925]

The 2 Rolls Royce MT30 gas turbines on the Queen Elizabeth class don't seem very powerful compared to the 2 A4W nuclear reactors on the Gerald R. Ford class

[tanknetter]

Money.

The De Gaulle was hideously expensive, and the Brits took note. As it is, the Cameron Gvt is now trying to reverse course on it’s decision to go with a “conventional” (cats and wires) launch/recovery setup instead of STOVL ... CATOBAR being much more expensive than they planned for.

[freebilly]

Did the British ever build an engine that performed up to standards...?

[moonshot925]

Rolls-Royce Merlin series

[null and void]

Touché!

[mortal19440]

The Rolls jet in their Maritime Nimrod only had 1 or 2 inflight failures in it’s history. The were in service from the early 70’s until March 2010.

[moonshot925]

Yes. The upfront costs of nuclear power are enormous and the returns are very slow. But it leaves room for future upgrades like rail guns and laser CIWS.

[moonshot925]

I made a mistake. The A4W is used on the Nimitz class. The A1B is used on the Ford class.

[James Thomas]

I do not possess the inside military knowledge that you all do, but, since I have read “Charley Wilson’s War”, I understand that there has been a disparity between the capabilities of the U.S.A. and the U.K. for a long time.

[KarlInOhio]

The advantage of nuclear power is primarily the ability to go anywhere in the world without worrying about refueling the ship. If the operational area is primarily the North Atlantic and Mediterranean with an Argentine smack-down every few decades there may not be much of a need for the carrier to be nuclear powered.

[Oztrich Boy]

Every plane fitted with Pratt & Whitney TF30 would have been better with a Roll-Royce Spey

[neodad]

Since they have never built a nuclear aircraft carrier, I imagine the learning curve would be steep...

[hattend]

QE is about half the tonnage isn’t it?

[Gandalf_The_Gray]

Did the British ever build an engine that performed up to standards...?

I believe the P-51 (WWII) started out w/ a Rolls Royce V12 until we got the Allison into production. They were also in on the ground floor with turbo jet engines. They also proved that burying jet engines inside the wings was not such a great idea...

Regards,
GtG

[hattend]

I believe the P-51 (WWII) started out w/ a Rolls Royce V12 until we got the Allison into production.

Other way around.

[hattend]

Looked it up:

QE = 65,000 tons
Ford= 102,000 tons

Not quite half the weight

[jmacusa]

I was about to correct him. You beat me to it.

[jmacusa]

The Brits just don’t have the money. Nice folks in general. They just live on a small island and are limited by that.

[tanknetter]

But it leaves room for future upgrades like rail guns and laser CIWS.

Not necessarily. Nuclear reactors don't produce electricity (exception being spacecraft nuke plants, which produce very limited amounts of energy through atomic decay). They produce steam, which is used to spin turbines, which can be jacked into generators to produce electricity.

The ship, therefore, needs to be designed with a nuke plant big enough to create enough steam to both propel the ship (either through turbines hooked into the shafts/propellors through reduction gear, or into big electric engines in a turbo-electric setup) and to create enough electricity to power all the electronics, electricity-based weaponry, EM catapults, etc.

The more electric goodies you start tacking on to a design, the larger the electrical generation plant must be, which causes a cascading increase in the size of the steam-generating nuke plant. In a 65,000 tonne hull, that's going to create issues. Heck, it's creating issues in the older Nimitz-class ships as they get upgraded during RCOH (mid-life refueling overhaul), and one of the reasons why the EM catapults going into the Ford won't be backfitted onto the earlier ships. The existing nuke plants can't produce enough steam for everything ...

[Caulkhead]

“Since they have never built a nuclear aircraft carrier, I imagine the learning curve would be steep...”

On the other hand we’ve been building nuclear submarines since 1959 and are currently half way through building our latest batch, the Astute class, so I doubt we’d struggle too much.