Its great we are building them and I welcome them but it could have been done better. Should have been nuclear for a start, we have got all the power stations coming (maybe) why not a couple of nuclear powered ships.

They will do the job and more but as always been hobbled a bit but short sighted money worries, for a start the fuel in the nuclear powered carrier can last years instead of constantly refuelling at a depot which may not be there (Gibraltar anyone?) in a few years.

Nevermind at least we have got something and with the current misfits in the cabinet we should be pleased at that I guess!

Ok,

so a carrier is never alone in the sea, it needs a task force to supply and protect it, they are WAY to expensive bits of kit to loose.

How big is a task force, how many ships / subs do we need to support the carriers ?

Hope we've allocated the money to pay for that as well.

Oh, and one more thing, three carriers ? I bet we end up with two, that I seem to remember is normal practice.

Oh and whilst I'm here, I love the radar angles on the ships superstructure, just how high are these things ?

I have an idea on how to shorten your articles, I mean they pretty much say exactly the same thing anyhow:

British - too expensive, rubbish, not suitable, shouldn't be thought about, buy elsewhere

American - cheap, perfect, suitable for everything, must be considered above everything else, buy

In a nutshell, that is every article you write.

that by the time these monsters are built the cost will have at least doubled?

If anyone's opening a book, put me down for a tenner on that.

I love a dead cert. ;)

Well it'd be boring to write about how a pure-Brit piece of kit actually worked to a spec that made it fit for its tactical or strategic purpose, and how it had been brought into service for exactly the budgeted consideration (or a smidge under) on the timescale promised without becoming a political football or boondoggle.

It'd be nice to read about how Britain's technical leadership has produced useful equipment that secures British jobs for a generation and provides an environment where new skills will be developed under a rational leadership that thinks beyond the next election.

I'm sure Lewis would write about such things if they actually existed. Because it wouldn't be boring, it'd be a mythic revelation of Religious proportions.

Never mind the implications for the cost of the air wing, and the capability of the ship. Given the massive increase in the price of oil recently, and the fundamental reality that it will not becoming down any time soon, if ever, personally I'd have seriously reconsidered nuclear power simply on fuel cost grounds.

When Greedy Brown discovers that he's spent all the dough buying 42 day votes and the rests been sent to Brussels.

And Lewis your as right as a very right thing that these should be nuclear powered and they are really badly designed / overpriced. It's a British tradition to be cr4p at everything isn't it?

Paris - because she prefers nuclear powered equipment as well.....

Lewis again makes many good points!

We could buy 2 US Nimitz class carriers for £4bn, a far more capable piece of kit. Alternatively we could get ourselves a couple of the new Gerald R Ford class, at about the same price (although we would have to wait a little longer).

My personal choice would be to build 2 or 3 more Helicopter Carriers like HMS Ocean (with enough upgrades to allow them to actually operate the Harrier), which could be ready in about 4 years at a unit cost of probably £300mill per ship. At the same time we contract the US for a couple of large, mostly automated supercarriers for £4bill total to be ready in about 2016. We could then flog the interim Helicopter carriers off to anyone who wants them. We also get the rights to build 6 nuclear Aegis cruisers instead of the Type 45, perhaps fitting them with our (well sort of) SAMPSON radar and Aster missiles, to act as escort ships that can actually keep up with the carrier.

This would be cheaper and faster than designing and building the damn things ourselves.

Given that;

The UK no longer exports anything of consequence

The ships at Felixstowe are often Panamanian registered with five Filipinos on board

The decline of the country's fortunes renders foreign wars unaffordable.

The design is clearly compromised solely to produce minimum running costs.

With all due respect to the sailors, what is it all for?

Anything other than domestic political ends? Assisting with US foreign policy ?

I think that the Dyson is a fine piece of kit. We just need to scale it up a bit to obtain a military-grade hoovering of the public purse -- that's really bringing in the PPP thinking!

Let's assume that these carriers come in on budget and that (as the Beeb reports) 10,000 British jobs will be "created" (i.e. 3,000 people will come off the dole and 7,000 people will gain a set of skills that will land them on the dole shortly after the completion of the project... and that's if the contractors don't get smart and hire skilled Eastern European labour instead). That still makes something like 300K per *job*, which seems like a mighty expensive piece of make-work to me. (Yes, yes, think of all the *related* jobs that will miraculously spring up all over Scotland as a result of this.)

I guess it doesn't make for good headlines in the Sun, but I love the way that we never, ever learn about building our own kit when there's already stuff out there that has already been tested and had its kinks worked out for us. Not that any other country learns either, but at least we could profit from others' outlay. Surely with BAE deep in the pockets of US lawmakers we could hit them up for a deal on a nuke carrier that would arrive in half the time and probably roughly on budget since the US Navy has already paid through the nose to the contractors for us?

I'm very much reminded of a similar fiasco in the US with Amtrak -- essentially, Bombardier promised a factory (ooooooh, jobs) in Vermont if they got the deal over Alstom and the existing Euro-companies who would, of course, build it at home and ship it over. Result? The 'Accela' is nothing of the sort and comes in late, over budget, and plagued by manufacturing problems because Bomardier makes mostly planes, not trains. So at best a few thousand jobs were created (temporarily) at the price of literally billions of dollars in lost revenue for Amtrak and for all the people who've ever been stuck on its shoddy service. This when they could have had an ICE or TGV train set for rather less and probably could have extracted some useful concessions on some other front as well.

BTW, the comments on the BBC piece are fantastic. Tw*t-o-Tron ho!

Is that you can only do what the yanks approve of, otherwise you're stuffed.

Renmember that the Falklands war was essentially one because the Americans were prepared to send the Brits frejh supplies of (uprated) Sidewinder missiles, but the French wouldn't send the Argentinians fresh supplies of Exocet missiles. Reverse those two decisions and the result of the war changes...

...Lewis is a navy flyboy who wants more of the same.

Problem is carriers are better known as 'big targets' and haven't a cat in hells chance of surviving in a real war. Obsolescent dinosaurs that we should never be wasting money on - not in the age of unmanned combat UAVs that can do the job much better from smaller platforms that you can afford to lose.

Lewis you have it almost exactly the wrong way round - what we need is MORE guided weapon frigates and destroyers, a UAV-based naval air force, and no stupidly expensive big targets.

Willy waving mentalities went out decades ago.

The falklands war was 'won' not 'one'. Although I suppose there has only been one war down there recently that blighty's been involved in.

However, the benefit to our forces of being given a chance to test the sidewinder missiles is certainly fundamental to the victory from all the post analysis I've seen.

... is that the Yanks will sell you the hardware, but won't sell you the keys to let you run the software.

Anyone want to buy a Mark 3 Chinook? Never been used...

It has always seemed laughable to me that the Invincible class are called "aircraft carriers" when the only aircraft that can use them are Harriers, taking off up a ski slope and landing vertically. I mean, it's wonderfully imaginitive, a good way of deploying reasonable aircraft a long way from home, but aircraft carriers then ain't.

I tend to agree with the comments about catapults: the usefulness of a carrier increases dramatically with the firepower which can be deployed, and the bang for bucks here is poor when compared with previous generation US carriers.And, as has been commented, there are much cheaper places to build big ships than Scotland - if we want to go it alone, it would make far more sense for the heavy building to be done in China or India. We could always give the workers there a vote in our elections, as the Gibraltarians do in European elections.

And I've long speculated that the F35 will bring to an end both the F22 and Eurofighter programmes by delivering most of the capability (and more relevant capability) at a better price point than the first gen of the next gen fighters.

They really ought to have gone nuclear though.....

I think Mr Page might be a bit miffed with that description, since he was a diver and EOD wallah.

Carriers as targets... There was a simulation in which a "maveric" USN Admiral in charge of the OpFor managed, by exploiting the perfect knowledge available to him in his simulation, to overwhelm a CBG's defenses with large numbers of cheap platforms. It's true that a Carrier requires help to survive and possibly true that the few Type45s that we'll have aren't going to be up to snuff for the job, combined with the weak CAG and poor AWACS that the new carriers are going to bring to the party. But most of the time they are perfectly viable secure rear bases for power projection, and worth having for that purpose (including peaceful purposes).

We aren't in the era of unmanned air superiority fighters yet and possibly never will be thanks to light-lag and machine autonomy issues. Drones do a decent job of some kinds of air support, but a combination of manned and unmanned is probably going to have the flexibility that modern combat forces need. Without air superiority fighters, the current crop of Drones are just targets to the other side's fighter planes, even if they're '50s-era MiGs. Fighters need a big base to operate from. Lewis explained the advantages of Carriers for this job.

As to willy-waving, have you *seen* how diplomacy works? It's *all* about willy-waving. Especially in the Middle East. Remember what warfare essentially originates from: the extension of diplomacy into the physical sphere.

One piece which all media is missing that these designs are catapult-less. This makes them considerably less efficient in terms of policying the Gulf, Dar-es-Salam or other current "hot" spots.

It however enables them to operate where no UK or US carrier can operate at present - in the far north or the far south where steam from the catapults freezes straight away and they jam all the time (that is the reason why Russians have decided not to use them on Kuznetcov class).

So, how long till an antarctic or arctic war?

Probably built with a nod to North Atlantic anti submarine operations. The existing carriers have similar characteristics (including no external lifts from hanger to flight deck for rough sea operations).

Making the carriers bigger doesn't make them an easier target. I'd put money on it that if you could hit somehting that big from a distance, you could hit something 4x smaller. Aren't some of the UK missiles accurate to a couple of meters?

Also, I believe Lewis was picking up on where the Yanks have done it better. Not saying they are better, just some bits.

Cheers Lewis, you've just improved my Thursday.

The vast majority of this article is misguided and some of it is simply plain wrong. Firstly some thoughts on the power plant. Nuclear power was considered but detailed studies showed it to be much more expensive than a conventionally powered vesel. Personally I am much more inclined to trust people who actually did their sums and know what they are talking about than some tech hack lusting after a new toy to wank over. Nuclear reactors are also fairly big, heavy units - this isn't some dinky submarine - and this goes some way to accounting for the difference in displacement Page is so concerned about - the carriers are not that much smaller, just lighter.

As for a conventionally powered vessel being unable to support steam catapults, this is pure bull. Steam catapults predate nuclear power quite considerably. If Page had done the slightest study into these vessels he would have seen that they are designed with the capabilty to have catapults fitted at a later date for if the aircraft _after_ JSF need them. The decision had already been made to use the VTOL JSF variant for the sake of flexibility - don't put the cart before the horse - and so I'm sure he would have been the first to complain if they had fitted expensive catapults only for them to go unused.

Finally if the design is so bad why have the French bought it? They are fitting theirs with catapults straight away showing that it is not a problem. It also shows that they too were ignorant of Page's insight which presumably recommends the same money on a 40 year old American design that has not been tailor made to British operational requirements.

Mostly they will be needed for facilitating the invasion of countries with reliable supplies of natural gas as increasingly expensive and politically unstable suppliers make it hard for us to get enough fuel for the aircraft carriers.

They do have the capability to be upgraded to have an electromagnetic catapult fitted later, if they ever build one that works. And if they can generate enough power without a nuclear plant.

I'd be interested to know if a refit of a nuclear plant is possible. All ways of spending bucketloads more money of course.

Mind you if they had the power to operate an electromag catapault the railgun and the laser death ray should be working nicely too.

It would have been better to buy a couple of Fords from the septics and a few naval f35s. Our maybe some of the surplus eurofighters the brylcreem boys will have stashed away could be navalised, that shouldn't take more than a few hundred million.

Routine use of catapults only started after WW2, when the steam catapult was devekoped. And if the RN can't get a twin-engined plane off a flight deck in less than 467 ft they're really not trying. If the US Army could do it in 1942...

Booster rockets, maybe.

But the big problem is that saving money paints the aircraft development into a nasty little futile corner that nobody else wants to use. And that's going to blow the budget.

1) Nuclear Power may be more expensive for the SHIP but the pay-off is you get a significantly faster ship (these top out at 28 kn, the Nimitz have been clocked at at least 40kn) which means you can launch heavier aircraft since the airflow over the wing is greater. So the planes that can be launched are able to carry more fuel and stores, clearly a benefit for a combat aircraft! This is especially important since STOVL aircraft are less effective and more expensive (both to buy and maintain) than more conventional carrier aircraft. So you save on the ship but end up with something less efficient and with higher aircraft operating costs. Plus I significantly doubt that this costing was done with oil costing $145/barrel (the current price) which is nearly double the price 12 months ago.

2) Nuclear powerplants may be heavy, but it is mostly shielding, and one nice thing about nuclear powerplants is that the amount of shielding that you need doesn't increase much as you increase the possible power output. So in terms of weight and space nuclear powerplants are not much worse than gas-turbine systems, especially if you consider you have to factor in the weight of fuel for a conventionally powered carrier.

3) Yes steam catapults pre-date nuclear power, but they were used on conventionally powered STEAM vessels, modern warships use gas turbines to power electrical engines (as in these ships). So to have a steam catapult you need to install steam generators, or use a powerplant that generates steam (so a nuclear powerplant then). Alternatively you could use electrically driven linear catapults (as will be used on the new US Ford class super-carriers), but for these you need enormous amounts of power.

4) These are significantly smaller than the current Nimitz class carriers, these are 283m long, compared to 320m for the Nimitz class and 333m for the Ford class. This is not an insignificant difference. Also the American ships displace nearly 50% more and can carry twice as many aircraft.

The Americans built the carriers the way they did for a good reason, now I'm not saying we need exactly the same thing as them but it seems a little short sighted to pay the same amount of money for our Tonka Toy Carriers as they do for a full size supercarrier for something that is significantly less capable

When the revolution comes as the oil begins to run out our carriers won't be able to head off and intimidate Johnny Foreigner like the yank carriers. The yanks in congress are even contemplating legislation to require the USN to make all new surface combatants nuclear, this would lead to them having the only oil independent navy anywhere.

What do they know that we don't?

The difference is the stall speed and size/weight of said aircraft.

The B-25 Mitchell's used for the Doolittle raid have a maximum take-off weight that is 10 tons less than the F/A-18E/F Super Hornet. They are also 8ft shorter than the Hornet. This given you some idea of why modern aircraft need longer take-off runs!!!

I, for one, object to buying anything named after Gerald Ford, the grey man of US presidents. Nobody tried to assassinate him because he was too boring.

If we did buy one of these it would have to be the HMS John Major I'm afraid, with liberal helpings of peas in the officers' mess.

Don't agree with Lewis about the Eurofighter, but I think he has some valid points here, especially the lack of AWACS, which would be a big weakness in any future 'hot' war. And the history of British AWACS aircraft is pretty embarrassing, so we should buy the E-2 from the Yanks, but we won't until we cock our own design up, because the MoD are running the show...

The dude with the glasses is a radioactive John Major

As Yank I want our military using stuff built by American companies in America. Why doesn't the UK demand the same thing. How come during the cold war when America built up it's defense contractors the UK didn't do the same ?? Were they relying on the US to help them out ???

The most valuable reason to have military items built in your own country is that your government, for better or worse, can control the supply of spare, replacement, and consumable items needed to keep the military item functional. This is not a trivial matter, as we in the US have noted many times. I believe a previous post mentioned some Chinook helicopters as needing "keys" to the software that are hindering the use by the UK of those helicopters. I do not know the story there but it illustrates the need for intelligent contracting BEFORE the contract is let.

If in fact the problem is software, then the answer is simple - Open Source software. Brains are not a monopoly of any nation or racial group and there are scientists, engineers, and software people in the UK who can take open source software and code programs to do whatever you want. The UK problem is not a lack of natural talent but fossilized and paranoid management by people who have been empowered to make decisions about things they know nothing about - like judges and politicians. We have the very same problem in the US.

With open source software, you get the source code as well as the compiled code. The proprietary code groups will tell you open source is vulnerable to crackers but that is much less true than with the proprietary code. And the premier magazine of one type of open source software, Linux, is published in the UK. The UK has the talent, it is just not being used effectively.

The Brits make some nice stuff - ASRAAM, for example.

There is nothing wrong with their engineering competence. It is just that, as in most democracies, their government has a tendency to use defence procurement to solve political (rather than strategic) problems.

Unfortuately, they are not wealthy enough to get away with it.

So we sould buy an American aircraft carrier should we? A couple of points:

1) Would the Americans actually agree to sell them to us? There seems to be an assumption that we can talk the Americans in to selling any bit of equipment to us by simply having a nice chat with them.

2) Where are we going to get the crew from? An American nuclear carrier requires 5000 people to operate. The new UK carriers will require under 2000. The UK has a recruitment problem and one of the biggest constraints on current UK military operations is not financial but manpower. So posters to this web site want to solve this by purchasing an aircraft carrier from the USA that will require a crew more than double to what a UK built carrier will require.

But in general, is there anything Mr page likes about the Uk military? If not, then i suggest he emigrates to the USA. Then he can be a hack journalist that writes positive stories.

The military summary of the article is as follows:

aircraft carriers are capital ships.

capital ships are extra KEWL!

Us needs KEWL capital ships to conquer!

And two major problems with that:

One, the UK once used to have the world's best collection of capital ships. It also had a world-wide empire at the time, and most of those colonies and possessions didn't have their own navies, and barely had armies. I used to read the British comics - as well as the US ones - in PNG in the seventies when I was a kid there. There was one that was way over the top and happy to be nothink more than themselfs - perennial British Cockney humour; but there were some really sad ones in the magazines that were in mourning for the loss of Empire and seemed to exude the feeling that we wuz robbed!!!

The British Empire is no more, and the world doesn't seem to have minded. Britain is now part of Europe. The Rest of the World is much more worried about the Senile Dementia USAmericana; I'd much rather not get involved in that.

Two, making something obsolete is a matter of making something cost too much in relation to its value. HMS Dreadnought - the cost of the big guns outweighed the cost of the many smaller guns pre-dreadnoughts sported. The cost of the HMS Dreadnought's steam turbines outweighed the cost of the multiple-stage reciprocating steam engines. But the HMS Dreadnought could outrun and outgun any other capital ship in any other navy, so their cost was outweighed in relation to their value. And the process of weapons standardization meant that the British Empire could manufacture Dreadnought-class capital ships much, much cheaper than anyone else could manufacture pre-dreadnoughts.

Battleships' value was eroded and then demolished by much cheaper aircraft, which could do what they could - sink capital ships - and do what they couldn't - attack Beyond the Horizon targets.

Now, capital ships' value has been eroded by cheap missiles and cheap boats. The US can afford the massive support structure for supercarriers, though it seems the Pentagon is doing its damnedest to bankrupt the US.

In short, what use are they (these carriers), and why are they needed? NATO? That would be believable, except it's nowhere mentioned. US military adventurism? Why? One Boer War should've been one too many for us - why join the US in making BoerWars to order?

Well if they're building the thing in Dunfermline as the article states they may have a bit of bother dragging it a few miles to Rosyth where the MOD base is...

Kain,

The short answer is that we did. The history of the fiasco that is the British arms industry and its incredibly generous support from a string of governments is a woeful episode of British economic history. Lewis Page, the author of this article, covers it at some length in his book:

http://www.amazon.co.uk/Lions-Donkeys-Dinosaurs-Lewis-Page/dp/0434013897

You'll be glad to hear that the leading UK arms company, BAE, is now the proud owner of several American arms companies, including the one that makes the Bradley APC. Its arguable, but its probable that the UK companies used their massive profits to buy American firms.

In return over the last 20 years the British military have wound up with rifles that don't work, light machineguns that were quickly binned, jet fighters that didn't have radar, helicopters that don't fly and now we can expect carriers that are, shall we say, a bit crap.

To be fair that Americans aren't immune to the same things. On the other hand they spend so much money that it makes almost no odds. The US defence budget is around $700bn a year, the UK's is about $60bn - a little waste in the UK goes a long way, whilst a $100bn wasted a year in the US system is largely noise.

http://www.amazon.com/Grand-Theft-Pentagon-Corruption-Profiteering/dp/1567513360

The French have already said they won't be building/buying these - apparently Presdent Sarkozy has decided that the current oil issues make a re-examination of the nuclear option all the more attractive.

What are the odds of the UK Govt actually sending these things into harms way? We are buying two of them, which means we will typically have one at sea at a time, so we send it off to sit off a foreign shore, with attendant escort, and hope no-one takes a pop with a Silkworm they bought from Lucky Lui's discount warehouse. Given the whole thing is very much a political exercise it beggers belief a modern Government would dare risk the flagship of the fleet and the attendant bodycount without a hell of a lot of backup - say land based air umbrella + tanker support.

Whats the availibility of tanker support for the F35 if there are no nearby land bases?

I was there at the time attached to the helicopter squadron on RFA Fort George along with the aircraft on one of the flattops which was also there and we flew all day every day and got the job done in four days - I can't see your point on this one?

Of course we would love to just buy British, but doing so needs to things - Government spending, and a British industry capable of supplying our needs. Thanks to Labour, we have neither.

The end of WW2 coincided with a big swing to more socialist tendencies in UK politics and the mixed curse and blessing of the Welfare State, and a withdrawl from the Empire which was probably the only real source of money that could have funded the bombastic socialist plans. In essence, the Consrvative PM Chruchill had brough such socialists as Clement Attlee and Aneurin Bevan into a wartime unity cabinet, and they repaid him post-war by stabbing him in the back with alarming speed. The result is we have been saddled ever since with a lumbering behemoth of public service that draws massively on the public purse.

Coincidental with the upsurge in welfare budget was a reduction in our military budget, justified mainly by selective use of science to claim we didn't need a large conventional force. Strangely enough, this did not stop the socialists giving away vital UK tech to the Soviets, like the Rolls Royce Nene which ensured the MiG 15 was so deadly over Korea, and the secrets of the nuke bomb.

The best example of this lunacy is the much derided Defence White Paper from Duncan Sandys, which effectively killed off the UK warplane industry. The Army were smarter than the RAF, and drew up a list of pre-reqs for UK tanks (biggest gun possible, thickest armour possible) which cleverly excluded most foreign designs, using the politically charged reminders of out-gunned and out-armoured tankers from WW2 to silence the politicians. This kept Vickers in the tank bizz, and with the Royal Navy eventually cornering the nuke missile bizz, left the RAF as the biggest loser in the long run.

Having got started, Labour (that's the equivalent of the Democrats for you Yanks) took Keynesian economics to an extreme and set about "nationalising" and forcibly "consolidating" industries, ignoring the historical evidence of pre-WW2 France that showed just how insane this idea was. Finally, for the coup de grace, the socialists then let the unions (Labour's bankrollers) run amok, which ensured the remaining industrial capability was so hamstrung as to be compeletly unable to compete with European companies, let alone American or Asian ones. Anyone with the skills and experience that could jumped ship and started looking for work abroad in a massive brain drain. My own father, an ex-REME engineer, left the shrinking UK industry to work for oil companies in the Middle East as they paid FIVE TIMES what he was earning in the UK, without the tax hit, and with more job security. He did miss the real design work he used to do, but with a family to support it wasn't a hard a choice.

Apart from a brief period of capitalistic freedom under Margaret Thatcher that let BAe recover (and they saw sense and started getting as deep in the American market as they could as soon as they could), it's been downhill ever since. Those of you in the US wondering who to vote for in your coming election may like to review the impact of socialist policies here in the UK.

goggyturk- there was actually 2 attempts to kill Gerald Ford when he was in the Oval office.

On the subject of buying the US carriers instead, would they actually sell them to us anyway?

Did we even ask?

We know they probably wouldn't sell us a complete carrier (and we wouldn't want to buy one, since that wouldn't make any jobs), but I'm pretty sure we could negotiate some sort of a deal.

Carriers have there place in any navy. Suppose Turkey and other nearby countries dont let you operate from their own soil we'd be screwed in Iraq and Afganistan. A couple of carriers stationed off the coast provides a base to move troops and equipment in an out by helicopter. Air strikes in aid of troops on the ground can be provided by carrier-bourne fighter/bombers.

Frigates ARE needed to protect carriers against enemy surface and submarine threats. If we're ONLY going to get TWO carriers, then we need a large frigate force to protect global interests and hunt enemy naval assets around the world.

Destroyers generally secure air-defence for Carriers and other assets as part of there ESCORT role. The T45 can do this, but I think we don't need many, though perhapes more than the SIX that are planned.

Frigates intercepting drugs in the caribean? Is this really a bad thing? It won't affect addiction at home but that's a different issue surely? Should our naval assets sit in dock and do nothing unless at war? People would complain more about cost if that happened.

Why do some people think it's OK to buy off-the-shelf kit all the time from other countries? You may have heard about 'food security'? The need to have a secure food producing industry at home? We don't want to risk starving do we? Defence is another area were we need an independent capability. We need to maintain our industry skills.

Suppose the falklands get invaded again? The Americans nearly didn't support us. We'd need to supply ourselfs to do it? And don't anyone start with the whole...'the NHS could use that money'...thing because all areas of life need funding.

And for those that talk about equipment shortages in the Army and how the £4 billion could be better spent there...the reason those shortages exist goes back 10-15 years when people argued we didn't need this or that based on need at THAT time.

You have to cover every eventuallity in advance. It's good we don't have a cold war right now. It gives us time to get Eurofighter/Typhoon up and running along with all the other 'relics of the cold war' kit, so we're prepared (NOT LACKING EQUIPMENT) when a resurgent Russia/China starts sabre rattling.

One of these carriers is going to be in bits being refitted a good chunk of the time. What happens if the working one breaks down on its way to war? Or the enemy gets lucky and manages to put it out of use (no air/submarine/mine defence is perfect)?

A nuke would be more likely to break, or worse suffer a design fault akin to HMS Trafalgar (?).

If an enemy were to threaten the UK with invasion, then it would be possible to use land based aircraft by definition (at least until all the runways are gone, by which time they'd also have sunk the Navy). So this is only really useful for colonial power projection. If the UK decided to stop trying to make other peoples live as we would wish, then we'd stop needing carriers.

"Gas ships can't have catapult launch - lacking the necessary steam - so our carriers won't be able to launch regular carrier planes. "

I seem to recall that the US did not have any problem with catapults on the old diesel powered carriers: USS Kittyhawk for example. So why not with the gas turbine ships?

The Kitty Hawk class were steam powered - they had 4 boilers on board...