British military procurement programmes are pretty standard issued as cost prohibitive owing to a horrendous combination of having a bunch of privileged upper class Neo-empire romanticists running the MoD and being obsessed with having the latest and greatest gear, which means either imported American (without any ‘Special Relationship’ discounts) or homebrew, which tend to be even more expensive.
For the QE retrofit, the cost overruns are a result of America’s problems with EMCATs.
The QE is conventional powered, so doesn’t have the steam generating capabilities baked in to handle traditional steam cats. They originally signed onto the US EMALS programme and planned to retrofit with EMCATs. As it became apparent that EMALS was running monumentally behind schedule and over budget, they re-costed based on steam cats, and came back with over £2bn cost as that involved also installing steam generation capabilities and significant structural reworks to accommodate that.
So those cost projections and overruns are pretty much a very case specific incident, so would not be very useful as a general benchmark for how retrofits might go or cost
Well that depends on how forward thinking the designers were. But even if provisions were not made (Which is more likely), retrofitting cats, especially EMCATs, would be far easier on an LHD than a carrier owing to the fact that LHDs inherently have huge amounts of open spaces built into the design to facilitate the carriage of equipment and vehicles for the amphibious assault forces. As such, they should have a lot more inherent flexibility and leeway to start with, when it comes to retrofit designs.
The main issue I can see if EMCAT retrofits would be the power generating capabilities of the ship. But LHDs would not be carrying huge fixed wing fighter contingents in any case, so having capacitors installed should be able to result that issue.
I agree it would be best to have a fresh design if they want cats and traps on LHDs, but the PLAN has showed itself to be remarkably frugal still when older ships, and have been retrofitting a lot of older classes a lot of us, myself included, originally thought it would have made more sense to scrap or sell off on the cheap.
If they are willing to refit 054s and Sovs when they have so many more brand new FFGs and DDGs coming online, it would make sense that they could also look to retrofit the 075 LHD to the latest standards eventually given no one expects the PLAN to build remotely as many LHDs as FFGs or DDGs, so each LHD becomes an asset more worthwhile to upgrade.
Well, in any case, this discussion about CATOBAR LHD would only be speculation if there's no doctrinal requirement for it. I'd rather bet the PLAN would request a compound helicopter in line with SB-1 or a tiltrotor for their LHDs before a V/STOL fighter/ refitting their LHDs for CATOBAR operation. After the LHDs got filled with normal helos, that is.