HMS Queen Elizabeth

[Seight_Returns]

mph1977 said:

or specific steam plant would have had to be provided ...

That's what I meant. Was there ever any provision for this in the design ?

[Esseesse]

I read that this boat will do 25 knots. Is this not quite slow, and if so does it matter?

[Trevatanus]

Esseesse said:

I read that this boat will do 25 knots. Is this not quite slow, and if so does it matter?

It's very big, and will have a number of other boats protecting it, I'm sure it will be fine.

[PugwasHDJ80]

It feels a little slow

you can calculate theoretical speed from effective hull length, displacement and power.

25 knots should need 62mega watts for this size of vessel

theoretically QE has 109MW max available in the ship, and 72MW just for propulsion which would suggest 27.2knots at the top end. All 109MW would suggest a speed of 33knots

[MBBlat]

25 knots it is - and there is probably a small library of reports justifying exactly why that is, and under under which exact conditions it will be achieved. Pure guesswork on my part is that builders trials may well see 27-28 knots in optimum conditions, flat calm, straight out of dock

[Evanivitch]

CDG does 27, and that's a similar size and nuke powered.

The question is, can QE perform a gearbox repair whilst full steam across the Atlantic?

[hidetheelephants]

Evanivitch said:

CDG does 27, and that's a similar size and nuke powered.

The question is, can QE perform a gearbox repair whilst full steam across the Atlantic?

No because there are no gearboxes; she's all electric.

[V8 Fettler]

The top speed of RN carriers has certainly dropped over the years.

[Seight_Returns]

I imagine that historically the speed requirement was as much about needing to generate wind over the deck to assist in launching and recovering aircraft, as much as it was about getting places quickly - and that with a STOVL configuration this is now maybe less important ?

What's the F35B speed for the "rolling vertical landing" now ?

[FourWheelDrift]

Rolls-Royce make the reactors that go into our nuclear subs, what was the hand wringing argument against putting a couple of those into the QE?

[andymadmak]

FourWheelDrift said:

Rolls-Royce make the reactors that go into our nuclear subs, what was the hand wringing argument against putting a couple of those into the QE?

Lots of places in the world won't let your vessel visit if it is nuclear powered. The yanks don't care, but we do apparently.

[ninja-lewis]

FourWheelDrift said:

Rolls-Royce make the reactors that go into our nuclear subs, what was the hand wringing argument against putting a couple of those into the QE?

Would significant increase the size of the crew at a time when the Navy has general manning issues, let alone retaining trained nuclear engineers and technicians.

Cost would significantly increase - in addition to the nuclear reactors themselves, you would have to certify the dockyard to nuclear standards and make arrangements for decommissioning at the end of their service lives.

QE class is expected to have a 50 year life so the current 20-30 year life reactors would have to be refuelled at significant expense and time out of service (3 years for the US Nimitz class).

Surface ships with submarine reactors generally have a poor reputation. RR would need a new, larger design for just 2 ships. The construction of QE class clashes with the construction of the Astute class and early design work for the Vanguard replacements so it is unlikely RR have the capability to take on a third design.

[V8 Fettler]

Seight_Returns said:

I imagine that historically the speed requirement was as much about needing to generate wind over the deck to assist in launching and recovering aircraft, as much as it was about getting places quickly - and that with a STOVL configuration this is now maybe less important ?

What's the F35B speed for the "rolling vertical landing" now ?

The last Ark Royal (Harriers) was reportedly capable of over 30 knots.

It does raise the interesting question of which carrier could reach out quickest to a remote trouble spot, perhaps Belize as an example:

HMS QE with F35s
Last Ark with Harriers
Previous Ark with Buccs.

[AstonZagato]

ninja-lewis said:

FourWheelDrift said:

Rolls-Royce make the reactors that go into our nuclear subs, what was the hand wringing argument against putting a couple of those into the QE?

Would significant increase the size of the crew at a time when the Navy has general manning issues, let alone retaining trained nuclear engineers and technicians.

Cost would significantly increase - in addition to the nuclear reactors themselves, you would have to certify the dockyard to nuclear standards and make arrangements for decommissioning at the end of their service lives.

QE class is expected to have a 50 year life so the current 20-30 year life reactors would have to be refuelled at significant expense and time out of service (3 years for the US Nimitz class).

Surface ships with submarine reactors generally have a poor reputation. RR would need a new, larger design for just 2 ships. The construction of QE class clashes with the construction of the Astute class and early design work for the Vanguard replacements so it is unlikely RR have the capability to take on a third design.

I saw an interesting documentary on USN scientists using excess power from the reactors to synthesise petrol and avgas. The cost was huge but compared to resupply at sea (and the uncertainty of that supply) it almost made sense.

[anonymous-user]

V8 Fettler said:

Seight_Returns said:

I imagine that historically the speed requirement was as much about needing to generate wind over the deck to assist in launching and recovering aircraft, as much as it was about getting places quickly - and that with a STOVL configuration this is now maybe less important ?

What's the F35B speed for the "rolling vertical landing" now ?

The last Ark Royal (Harriers) was reportedly capable of over 30 knots.

It does raise the interesting question of which carrier could reach out quickest to a remote trouble spot, perhaps Belize as an example:

HMS QE with F35s
Last Ark with Harriers
Previous Ark with Buccs.

Ironically, probably older Ark Royal with Buccs, simply due to their longer range and ability to buddy refuel.

But then, if the aggressor you were flying against had a remotely modern air defence system then you'd probably have more chance of coming back in an F-35.

[hidetheelephants]

Inkyfingers said:

V8 Fettler said:

Seight_Returns said:

I imagine that historically the speed requirement was as much about needing to generate wind over the deck to assist in launching and recovering aircraft, as much as it was about getting places quickly - and that with a STOVL configuration this is now maybe less important ?

What's the F35B speed for the "rolling vertical landing" now ?

The last Ark Royal (Harriers) was reportedly capable of over 30 knots.

It does raise the interesting question of which carrier could reach out quickest to a remote trouble spot, perhaps Belize as an example:

HMS QE with F35s
Last Ark with Harriers
Previous Ark with Buccs.

Ironically, probably older Ark Royal with Buccs, simply due to their longer range and ability to buddy refuel.

But then, if the aggressor you were flying against had a remotely modern air defence system then you'd probably have more chance of coming back in an F-35.

An interesting question; having just done a course in basic Naval Architecture and having some formulae which I know practically nothing about other than they are empirically derived, making some broad assumptions about the QE hull form and other things she should be capable of pretty much 28 knots flat out.

[Munter]

It's not beyond imagination that there might be the published top speed, the top speed guaranteed by the supplier, and the actual top speed which nobody want's to tell the wider world. With all 3 being different.

[FourWheelDrift]

QE top speed = not faster than the ships that will be supporting it.

[TTmonkey]

Munter said:

It's not beyond imagination that there might be the published top speed, the top speed guaranteed by the supplier, and the actual top speed which nobody want's to tell the wider world. With all 3 being different.

and another top speed that Scottie could make it go at.

[IanMorewood]

Inkyfingers said:

Ironically, probably older Ark Royal with Buccs, simply due to their longer range and ability to buddy refuel.

But then, if the aggressor you were flying against had a remotely modern air defence system then you'd probably have more chance of coming back in an F-35.

Assuming the old Ark Royal didn't suffer technical problems the moment she left harbour, she was a fairly old ship built to an even older design at the point she was decommissioned and somewhat tired.