The Royal Navy Discussions and Updates

[KiwiRob]

I know quite a few Brazilians and sadly like the British they show very little interest in their navy. A CVF would effectively be secondhand anyway, not sure its covered by local content legislation you mention. I hardly think a CVF could be regarded as a cast-offs.

I can't quite understand your position, I am saying we should actively seek buyers for a ship that will not see RN services, by so doing helping to preserve the chance of operating a single CVF with a decent air group.

I notice this before when we where discussing the assault fleet, you just go into denial and can't accept the situation or respond creatively to the challenge.

I can't find anything on ARA getting a carrier do you have a link?

I'm pretty certain that naval construction would have even higher levels of local content than civilian construction.

I also think you are the only person who thinks only one CVF will ever see RN service, personally I think that's a load of crap, both will be used, there is no point in only having a single CVF, if you only operate one you might as well not have any.

 

[1805]

I'm pretty certain that naval construction would have even higher levels of local content than civilian construction.

I also think you are the only person who thinks only one CVF will ever see RN service, personally I think that's a load of crap, both will be used, there is no point in only having a single CVF, if you only operate one you might as well not have any.

Who mentioned civilian construction, we are talking about selling an effectivily second hand ship?

I might well be the only person on this forum that thinks only one CVF will see much serivce, but that is a sad reflection of the realism in this debate. However I am quite happy to agree to differ for a quiet life.

I would hope at least few people would agree with your statement: "if you only operate one you might as well not have any" what is the logic behind this??

You have no basis for 2 CVF being kept other than hope, all the evidence point otherwise:

- No effective carrier aviation since the retirement of the FA2 in 2006
- Government publicly stating they would have cancelled both hard they been able to
- RN will run with a single LPH for the next 10 years
- Vague statements from the coalition about the 2nd CVF's future
- Not to mention RAF hostility

My point has always been anticipate problems and prepare for them, not put you head in the sand which seems to be the standard approach here.

 

[swerve]

I know quite a few Brazilians and sadly like the British they show very little interest in their navy.

Since you seem to prefer the company of those who want to reduce the navy to a fleet of patrol boats, I'm not surprised.

A CVF would effectively be secondhand anyway, not sure its covered by local content legislation you mention. I hardly think a CVF could be regarded as a cast-offs.

Yet again, you resolutely turn your back on the point & aim in the opposite direction. Second-hand probably isn't covered by local content rules, but so what? The point is the mindset revealed by the existence of strong local content rules.

And if a carrier ordered & built for the RN but declared to be unwanted & sold on unused isn't a cast-off, then what is?

I can't quite understand your position, I am saying we should actively seek buyers for a ship that will not see RN services, by so doing helping to preserve the chance of operating a single CVF with a decent air group.

I notice this before when we where discussing the assault fleet, you just go into denial and can't accept the situation or respond creatively to the challenge.

I can't find anything on ARA getting a carrier do you have a link?

My point is that there is a decent chance of keeping two carriers, because as is universally acknowledged, a single carrier provides only a part-time capability - something even the current government says is undesirable (hence their assiduous courting of the French) - & because we can't recover enough money from selling one on to make much difference.

I can't recall you saying anything about the assault fleet which has come to pass. We're selling a single Bay. A pity, but not the end of the world. We're keeping Ocean until an unspecified date, but certainly until we have at least one CVF operating, & both LPDs. That's most of the fleet. As I recall, you were saying that we should & would sell off half of the fleet, something which has not even been suggested by anyone else.

The ARA is completely open in saying that it wants a carrier, & proves it's serious by maintaining a carrier air wing & refreshing its carrier qualifications on the Brazilian carrier whenever possible. Tthis is no secret. According to Brazilian & Argentinean journalists posting in English on other sites, & plentiful Spanish & Portuguese language sites (seek & ye shall find), it has proposed to the Marinha do Brasil that it could tack a carrier onto any Brazilian domestic building programme, if it ever gets the money. That 'if' is, of course, the problem. The money may never be forthcoming.

As for my position, it is quite simple. If you propose selling RN ships abroad, then you should, as I keep saying, propose selling them to people who want them, & are willing to pay for them. Selling a ship which will otherwise be scrapped for little more than scrap value (Foch) is not in the same category as selling a new but secondhand ship which is significantly different from what the potential customer would specify if buying new. You have to accept that if they do decide to buy it, you'll only get a fraction of the building cost.

Selling to an up-&-coming nation which is starting to feel confident & able to count itself among the big boys requires sensitivity to what it wants. The BAe press release previously linked to shows that BAe is aware of that, so maybe there is a chance of some British frigates being sold to Brazil, but I'm afraid that you've displayed none at all. You won't give up the idea of selling what you want to get rid of, & expecting the sort of price you could only realistically think of getting for what the customer actually wants.

What we can sell to Brazil (with a bit of luck & a lot of hard work):-
Largs Bay - if we don't get a better offer, e.g. from the Ozzies.
New replenishment ships.
OPVs, perhaps including those ordered by Trinidad & Tobago then cancelled. BAe mentions this class in the previously linked to press release.
Type 26 frigates, customised to Brazilian specifications.
Perhaps four Type 22 frigates at knock-down prices as gap fillers pending the T26s.
Each of these types is on the list because it fits a Brazilian requirement. Nothing is there purely because it's spare. The cancellation of the T&T OPV order enables them to be offered to Brazil almost immediately, but they're a very good fit for one Marinha requirement anyway, & we'd have to build more to supply what they want. The early retirement of the T22s enables them to be offered as a cheap temporary solution pending the availability of T26, because it fits into their training & logistics seamlessly, since they already operate some. The Bay is a good fit for another Marinha requirement, to replace some ancient ex-USN ships. It would only partly fill it, but the good price we're likely to offer makes up for that.

You see? Everything is what they want. CVF & Type 45 aren't.

 

[StobieWan]

And how do you know this, are you a naval construction specialist? Or is it just a guess?

Given that building three smaller carriers would be close on a third times more expensive than the option we went with, I confess I'd appreciate some insight to this thinking. By 1/3 more expensive, I'm referring to the fact that all three ships would require identical fitting out plus more steel and more manufacturing processes than two 65,000 ton carriers. Might as well go for three 65Kt ships if you're going down that route.

The RN looked at this option in detail and decided that two carriers at 65Kt would be the best option.They then went out and ordered all the major bits in one go, which offered an attractive saving in terms of order processing. They're building the two carriers back to back in as rapid a sequence as is possible, offering still further savings in time and labour costs, using a labour force that's fully cognisant of all the issues in assembling the previous unit. I can't work out how it gets much more efficient than that given the yards involved.

It's an efficient use of the yards, and manufacturers available and it's the "drumbeat" process that 1805 seems fond of referring to.

However, I guess I can quote a bunch of professional bean counters

Reducing the Cost of Aircraft Carrier Acquisition | RAND

RAND analysis on cost reduction, published way back in 2005, at the design stage, referring to a number of ways to reduce the costs of acquisition and ownership - there's not a single word on "gee, guys, buy a smaller ship" there..

Given how far in advance of a main gate decision this was, I'm sure if it'd been relevant, they'd have mentioned it.

Ian

 

[1805]

Given that building three smaller carriers would be close on a third times more expensive than the option we went with, I confess I'd appreciate some insight to this thinking. By 1/3 more expensive, I'm referring to the fact that all three ships would require identical fitting out plus more steel and more manufacturing processes than two 65,000 ton carriers. Might as well go for three 65Kt ships if you're going down that route.

The RN looked at this option in detail and decided that two carriers at 65Kt would be the best option.They then went out and ordered all the major bits in one go, which offered an attractive saving in terms of order processing. They're building the two carriers back to back in as rapid a sequence as is possible, offering still further savings in time and labour costs, using a labour force that's fully cognisant of all the issues in assembling the previous unit. I can't work out how it gets much more efficient than that given the yards involved.

It's an efficient use of the yards, and manufacturers available and it's the "drumbeat" process that 1805 seems fond of referring to.

However, I guess I can quote a bunch of professional bean counters

Reducing the Cost of Aircraft Carrier Acquisition | RAND

RAND analysis on cost reduction, published way back in 2005, at the design stage, referring to a number of ways to reduce the costs of acquisition and ownership - there's not a single word on "gee, guys, buy a smaller ship" there..

Given how far in advance of a main gate decision this was, I'm sure if it'd been relevant, they'd have mentioned it.

Ian

The problems the RN currently face are the result of trying to do to much at the same time, if you look at the rate at which the T45 and Astutes have been laid down at a similar time doubling the size of the assault fleet and building to aircraft carriers.

The benefits of ordering both carriers were all lost once the first delay caused a jump in the cost, heaven only knows where we will end up on the total cost.

Building one after each other although in theory is more expensive but in practice is easier to manage into budgets across the medium term and also provides for a more sustainable order book for the ship building industry.

A rough estimate if we say a 45-50,000t ships was only 10% cheaper than a 65,000t one based on the orignal price of £2.9bn, say even at £1.5bn allowing for less economies from packaging together 3 x £1.5bn will still be less than we end up paying in total, but in impact budget terms would be spread out over 2-3 times the time (c25-30 years).

 

[Systems Adict]

The problems the RN currently face are the result of trying to do to much at the same time, if you look at the rate at which the T45 and Astutes have been laid down at a similar time doubling the size of the assault fleet and building to aircraft carriers.

I'm sorry ???

The problems are caused by laying down too many hulls 'at a similar time' ??

I'm sorry 1805, but here's the best bit of advice I can give you.

You've been on here for 12 months now, & it shows that you ONLY pay attention to what's been said in the media, or what your imagination can conjure up.


Can you please take the month of January to go back to the very start of this thread & read thru EVERY POST !!!

If you've got the ability to review the data, you'll ACTUALLY UNDERSTAND the who, the what, the when & the why, of how things have transpired over the last 10 years.

For instance, the Decision to build the carriers was taken on the back of the 1997 / 99 defence review, the Type-45 build stance was taken following the 1997 election & the Govt's withdrawal from Project Horizon. The UK RN Amphibious ships & the LPD's were ACTUALLY down to the previous Conservative Govt, but that's something you'll LEARN, if you undertake the task...


That aside, I'll state the obvious (as I usually do).


The RN is in its present state, not because of decisions it's made, but because of.....

" A LACK OF CHRONIC UNDERFUNDING BY UK GOVT PLC, OVER THE LAST 30 YEARS !!!!"

Now can you please go & 'do your homework', so we can have a sensible discussion, rather than 'arguing' whether you're wrong again...


SA :


PS Don't take the above comments too personally !

I get frustrated by your insistence that YOUR view is correct, but welcome your presence & input to this thread.

 

[1805]

I'm sorry ???

The problems are caused by laying down too many hulls 'at a similar time' ??

I'm sorry 1805, but here's the best bit of advice I can give you.

You've been on here for 12 months now, & it shows that you ONLY pay attention to what's been said in the media, or what your imagination can conjure up.


Can you please take the month of January to go back to the very start of this thread & read thru EVERY POST !!!

If you've got the ability to review the data, you'll ACTUALLY UNDERSTAND the who, the what, the when & the why, of how things have transpired over the last 10 years.

For instance, the Decision to build the carriers was taken on the back of the 1997 / 99 defence review, the Type-45 build stance was taken following the 1997 election & the Govt's withdrawal from Project Horizon. The UK RN Amphibious ships & the LPD's were ACTUALLY down to the previous Conservative Govt, but that's something you'll LEARN, if you undertake the task...


That aside, I'll state the obvious (as I usually do).


The RN is in its present state, not because of decisions it's made, but because of.....

" A LACK OF CHRONIC UNDERFUNDING BY UK GOVT PLC, OVER THE LAST 30 YEARS !!!!"

Now can you please go & 'do your homework', so we can have a sensible discussion, rather than 'arguing' whether you're wrong again...


SA :


PS Don't take the above comments too personally !

I get frustrated by your insistence that YOUR view is correct, but welcome your presence & input to this thread.

I am not taking anything from someone who can't get the displacement of the CDG within 20,000t. If you look at the rate at which the T45 have been launched (only 4 1/2 years between 6). Astutes is in fairness longer but so much else when wrong with the project it wrecked the original schedule.

Funding is not overly generous but if managed wisely it would be sufficient.

And for the record I accept my views are not always right, but there should not be anything wrong with being open to alternative views.....yes ideas should stand up on their own but I do get the feeling sometime people oppose views just because the are not official.

 

[Systems Adict]

I am not taking anything from someone who can't get the displacement of the CDG within 20,000t.

fftopic

I've never asked you to take anything from me, other than a bit of advice.

...& for the record, I was 'shooting from the hip', to make a point about the RN wanting a BIGGER ship than the French, when I quoted the numbers. (Which I also clarified in the statement of post#5509, where I made known that ALL my numbers may be slightly dubious, & should be checked. Something that anybody SHOULD do when reading the ramblings of an unknown author).


As one of the 'Defence Professionals' Group on this forum, I am also aware that people tend to have some belief in my comments.


WHY ??

...It's simple. It's because I'm actually one of the people who works with these ships on a regular basis & has, over the last 15 - 20 years, has left behind some of ' my own sweat ' on MOST of the larger surface ships constructed for the UK RN (with the exception of the Mine hunters, the Archers & the River Classes).

So when I 'quote facts' about T22 / T23 / OCEAN / Aux Oilers / T45 / LPD / LSD(A) , etc, they tend to be based on actual 1st hand knowledge, not info gleaned from 'the Net', or hear say.

However, while my knowledge may abound about the UK RN surface fleet it's, to say the least, 'average' WRT the facts & figures of other navies across the globe. Something that I tend to apologise for when I 'miss-quote' things like the GRT of a carrier. After all, better to be a specialist, focused on a particular area than 'Jack of all trades', Master of none.

But, If you'd taken the time to read either all my postings, or the rest of this thread (like I suggested), you would know this already.


(All comments/responses are welcomed, as long as they are constructive & educational...)



SA :dance

 

[StobieWan]

The benefits of ordering both carriers were all lost once the first delay caused a jump in the cost, heaven only knows where we will end up on the total cost.

Building one after each other although in theory is more expensive but in practice is easier to manage into budgets across the medium term and also provides for a more sustainable order book for the ship building industry.

A rough estimate if we say a 45-50,000t ships was only 10% cheaper than a 65,000t one based on the orignal price of £2.9bn, say even at £1.5bn allowing for less economies from packaging together 3 x £1.5bn will still be less than we end up paying in total, but in impact budget terms would be spread out over 2-3 times the time (c25-30 years).

I'm baffled.


Cost wise, I can't follow your arithmetic. 2x1 = 2, 3 x 0.9 = 2.7 is how I see your 10% cheaper 50Kt 3 carrier build costing out.

Where do you get the idea that you can build three smaller carriers cheaper than the two we got? They'd have to be much smaller and far cheaper to work out that way.

Am I reading your cost assumption of 10% cheaper wrongly?

Ian

 

[swerve]

The problems the RN currently face are the result of trying to do to much at the same time, if you look at the rate at which the T45 and Astutes have been laid down at a similar time doubling the size of the assault fleet and building to aircraft carriers.

The assault fleet was doubled in size between 1993 (Ocean was ordered) & 2007 (last Bay commissioned). The carriers weren't ordered until that process was complete.

What you've described is a series of successive programmes, some of them overlapping, i.e. the normal process of naval shipbuilding, but at a slower rate than in the past. Compare the building rate in the 1970s & 1980s, for example.

 

[kev 99]

I'm baffled.


Cost wise, I can't follow your arithmetic. 2x1 = 2, 3 x 0.9 = 2.7 is how I see your 10% cheaper 50Kt 3 carrier build costing out.

A carrier 10% cheaper than £2.9b comes out at a cost of £2.61b x 3 for a total cost of £7.83b.

But £2.9b wasn't the original price anyway, it was £4b for both carriers, which went up by another £1b after the initial delay. So the 10% cheaper carrier based on the orignal cost of £2b would be £1.8b x 3 for a total cost of 5.4, before the cost of delay which would still have to be applied because the MOD still didn't have the budget to build the first one, also plus additional costs for buying all items in units of one (no economies of scale to be applied). Also we would be stuck with the STOVL version of the JSF for that money.

Where do you get the idea that you can build three smaller carriers cheaper than the two we got? They'd have to be much smaller and far cheaper to work out that way.

Am I reading your cost assumption of 10% cheaper wrongly?

Ian

Absolutely right, they would have to be a great deal cheaper, with almost certainly cheaper engines and electronics, as originally planed the CVF was a bit bargain basement anyway, the only thing that was remotely gold plated on it was the automated weapons handling system, and that was included to save on running costs (less crew).

The idea that we would buy 3 smaller carriers also rather ignores the fact that the MOD's own figures suggest it's cheaper to run 2 bigger ones than 3 smallers ones, which of course was a major factor in the decision to go big.

 

[kev 99]

The assault fleet was doubled in size between 1993 (Ocean was ordered) & 2007 (last Bay commissioned). The carriers weren't ordered until that process was complete.

What you've described is a series of successive programmes, some of them overlapping, i.e. the normal process of naval shipbuilding, but at a slower rate than in the past. Compare the building rate in the 1970s & 1980s, for example.

Worth pointing out that the assualt fleet was only doubled in terms of overall tonnage, it's still resulted in fewer ships and we all know that it's generally cheaper to build fewer larger ships than a greater number of smaller ones.

 

[swerve]

True. From 8 ships & ca 60000 tons to 7 & ca 120000 tons.

 

[kev 99]

True. From 8 ships & ca 60000 tons to 7 & ca 120000 tons.

Of course you could also throw Invincible into the mix pre 2004 retirement for a possible 9 ships, it's very likely that helicopters from at least one carrier would of been used in any amphibious landing.

 

[1805]

I'm baffled.


Cost wise, I can't follow your arithmetic. 2x1 = 2, 3 x 0.9 = 2.7 is how I see your 10% cheaper 50Kt 3 carrier build costing out.

Where do you get the idea that you can build three smaller carriers cheaper than the two we got? They'd have to be much smaller and far cheaper to work out that way.

Am I reading your cost assumption of 10% cheaper wrongly?

Ian

You are seeing money in absolute terms it is in reality a unit of time x value. Building 3 over 25-30 years would also better support the industrial cycle. It does not follow that a single carrier would have been delayed (in fact you are de-risking) and the options around it would have been easier to manage. I understood the original cost was c£2.9bn so c£1.45bn each, if we assume the 45-50 was only c10% cheaper (even if it was the same price) it would still be cheaper than where we have ended up over £5bn but the cost would be spread over at least twice the time.

Yes the carriers would still have been F35b, as this was the original plan, which I still think was viable and had some advantage in rate of operations, although I would be happy to get one with anything fixed wing at the moment.

The 3 carrier would be a bit more attack carrier like than the LHA-6 but basically very similar and one would have replaced the Ocean.

I would have gone for 3 multi role docks that had hanger helicopters (no more than 10-12) c20,000 (one built time the Ocean was, one late 90s and one early 2000) . The first carrier would have started right after the LHD and then so one, till 2025 when the first LHD need replacing.

The tonnage would actually have been less or similar as it was assumed that there would be a replacement for Ocean? 3 x 50k (150k) v 2 x 65 + say 30k (160k)

 

[StobieWan]

You are seeing money in absolute terms it is in reality a unit of time x value. Building 3 over 25-30 years would support the industrial cycle. It does not follow that a single carrier would have be delayed (in fact you are derisking) and the option around it would have been easier. I understood the original cost was c£2.9bn so c£1.5bn each, if we assume the 45-50 was only c10% cheaper (even if it was the same price, it would still be cheaper than where we have ended up over £5bn but the cost would be spread over at least twice the time.

You're making no sense at all. If you're saying that the smaller carriers are 10% cheaper, then buying three of them will be three units at 90% of the cost of the larger units.

That's three units at 0.9 of the unit cost, times three - 2.7 units.


If a can of beans costs £1 (for instance) and I want two cans, it'll cost £2. In your example, we're buying three slightly smaller cans of beans at 90pence each. That's £2.70. That's seventy pence more.

Buying three smaller things at the price of 90% of the bigger thing will cost just a shade under 2 and 3/4 of the price of the two big things.

I'm looking at cost in terms of how much a thing costs here. I have a nagging feeling I'll be doing Peter and Jane explanations on how to add up and take away shortly.

Why are you saying that building three carriers would magically dodge the delays that were imposed? Each is 90% of the cost of the ones we built, with similar construction costs etc. Why wouldn't it be delayed just as the real ones were?

Ian

 

[Hambo]

You are seeing money in absolute terms it is in reality a unit of time x value. Building 3 over 25-30 years would support the industrial cycle. It does not follow that a single carrier would have be delayed (in fact you are derisking) and the option around it would have been easier. I understood the original cost was c£2.9bn so c£1.5bn each, if we assume the 45-50 was only c10% cheaper (even if it was the same price, it would still be cheaper than where we have ended up over £5bn but the cost would be spread over at least twice the time.

Yes the carriers would still have been F35b, as this was the original plan, which I still think was viable and had some advantage in rate of operations, although I would be jsut happy to get one with anything fixed wing at the moment.

The 3 carrier would be a bit more attack carrier like than the LHA-6 but basically very similar and one would have replaced the Ocean.

I would have gone for 3 multi role docks that had hanger helicopters (no more than 10-12 c20,000 (one built time the Ocean was, one late 90s and one early 20) . The first carrier would have started right after the LHD and then so one, till 2025 when the first LHD need replacing.

The tonnage would actually have been less or similar as it was assumed that there would be a replacement for Ocean? 3 x 50k (150k) v 2 x 65 + say 30k (160k)

And round and round again, nearly 800 posts now.

I'm a bit poor at maths and I have no idea how many workers are engaged on the Carrier program.

Lets say for ease of maths, figure plucked out of the air.

1000 shipworkers take 8 years to build one carrier, thats 8000 sets of wages. Lets guestimate that 1500 shipworkers could build 2 carriers in 8 years with a staggered start but following up on mega bloc construction, thats 12000 sets of wages for two, after 8 years the jobs done, building halls clear.

If you have your 1000 shipworkers taking 8 years, then starting all over again for another 8 years then starting again upto your 25-30 year figure, havent you just spent 24,000 sets of wages to build your carriers? Is that efficient?

Wouldnt it be more sensible and economically cheaper to have your 1500 workers building carriers for 8 years, them maybe employ those 1500 workers building 10 frigates for the next 8 years, then maybe employing them to spend 4 years building an amphib and some RFA's, then maybe a batch of destroyers after that??

So therefore in the 25-30 years that you have tied up an expensive workforce building just 3 ships when the same number of staff in that small number of efficient yards could have met all the navys needs? Actually isnt that what has actually happened???? I thought we were already in the middle of a joined up plan to allow military shipbuilding to survive in the UK??

Besides the point that your contractors, as well as building bits of carriers will be building and fabricating parts for other peoples ships, oil rigs, wind turbines etc and might not have production slots when you need them. Added to the fact that in between those long years some of those manufacturers will have gone bankrupt, merged, sold, relocated so you will have to tender again and again for many of the elements of each carrier, so there is a danger that your carriers each become significantly different to the last, number 2 only 80% common with 1, number 3 only 60% common.

 

[1805]

You're making no sense at all. If you're saying that the smaller carriers are 10% cheaper, then buying three of them will be three units at 90% of the cost of the larger units.

That's three units at 0.9 of the unit cost, times three - 2.7 units.


If a can of beans costs £1 (for instance) and I want two cans, it'll cost £2. In your example, we're buying three slightly smaller cans of beans at 90pence each. That's £2.70. That's seventy pence more.

Buying three smaller things at the price of 90% of the bigger thing will cost just a shade under 2 and 3/4 of the price of the two big things.

I'm looking at cost in terms of how much a thing costs here. I have a nagging feeling I'll be doing Peter and Jane explanations on how to add up and take away shortly.

Why are you saying that building three carriers would magically dodge the delays that were imposed? Each is 90% of the cost of the ones we built, with similar construction costs etc. Why wouldn't it be delayed just as the real ones were?

Ian

Well I am assuming it would have been possible to dodge the cost increase of the delay, which is how the sums work. If the delay costs are a % of the contract value even if this had happened it would have de risked. For example, carrier one contract £1.5bn delays cost 1/3 say £500m but you would be stupid to get caught twice (ok I know they are idots so!). In reality your negotiation position would be so much stronger so the 25-30% they got stuck with would have been less.

 

[StobieWan]

Well I am assuming it would have been possible to dodge the cost increase of the delay

On what grounds? That was a government move to defer spending and it hit both carriers as costs sprang from keeping various shipyards on tap and putting up with a large pile of carrier bits lying around. Why wouldn't the delays hit just the same with a three ship build?

Your entire argument for building three carriers currently rests on "then a miracle happens" as far as I can see.

Ian

 

[swerve]

I would have gone for 3 multi role docks that had hanger helicopters (no more than 10-12) c20,000 (one built time the Ocean was, one late 90s and one early 2000) .

So . . . 3 x 20000 ton LHD, instead of 2 x LPD (18500) & 1 x LPH (22000). That's the same number of ships of about the same total tonnage over the same timescale, each more complicated than any of those actually built.

To save money.

I must admit that if you'd offered me three 20000 ton LHDs instead of Ocean, Albion & Bulwark, I wouldn't have complained, but I wouldn't have expected it to save a penny.