The Royal Navy Discussions and Updates

[StingrayOZ]

I do wonder about a longer and reconfigured type 26.

Having the ships based off the same improved basic hull would make a lot of sense. The Type 45 aren't that new, steel first cut in 2003 but also had a bit of a problematic development when they were tied to the NFR-90. If the UK can fix them, they might still be able to find a buyer for them.

They could also take the opportunity to make a lot high levels of commonality between the ships.
A more common propulsion system, a more common weapons system, machinery etc. A more multi-role approach, with tailoring to specific needs.

 

[John Fedup]

IEP in the Type 45 been problematic so it will be interesting to see how the QE's IEP works out using MT30s. Still think IEP is the way to go but understand why it was rejected for the Type 26 given the history with the Type 45. If the QE version works then one half of it stuck in an enlarged Type 26 would be a candidate for a Type 45 successor.

 

[KiwiRob]

It may end up costing more than if the ships were built to last 30 years in the first place.

Type 31e is being built with a 25 year service life, if it goes to plan they will be on sold after 10-15 years service.

These vessels are being built to a price, they won’t build them if the RN adds equipment which will blow out the cost.

Also on the yard tour we got to see the bow of Astute 7 which Cammel Lairds are building. Interesting because as far as I know number 7 hasn’t been confirmed by the govt.

 

[StobieWan]

I don't think IEP was a bad design choice for Type 45 - it's more of a specification issue - choosing WR-21's as the prime movers, with the expectation that they run one GT plus diesel up and the other GT+ diesel down for a lot of the time - meaning that the accompanying diesel for each GT wasn't of a high output in the anticipation that the GT would always be on tap.

What then seems to have happened is that a number of issues with the GT and the recuperator have emerged and made this mode of operation very unreliable - meaning that both GT's really need to be online for the ship to carry out a lot of it's duties.

There's an article here which outlines some of it and I suspect there are a few here who can comment more accurately than I can.



Type 45 to get third diesel generator to overcome problems

 

[KiwiRob]

Well, thinking about it, if Type 31 needs steel cut asap, and the build process will proceed with about a two year build time per ship, they really will need to start building the replacements directly after that as Type 26 construction will be winding down and there'll be nothing left for either yard to build. This could get interesting.

New vessels for the RFA come next, Cammel Laird are planning to bid on the Solid Support Ship Project.

 

[StobieWan]

New vessels for the RFA come next, Cammel Laird are planning to bid on the Solid Support Ship Project.

Fingers crossed they get them - I did wonder if they'd be opened up for international bid - the tankers don't appear to have been a glowing success in terms of build quality so far, with a lot of rework required.

 

[matt00773]

All this talk of replacing the T45s needs some sense checking. The T45s introduced a number of new advanced technologies all at once from the propulsion system through to the CMS, radar, and missiles. Whilst the operational issues in bringing all this together were frustrating, the overall AAW capability of the T45 is incredible and is seen as the ship of choice in joint expeditions. The T45s will be in operation until the mid 2030s so any discussion on replacement is very premature.

As far as the T45 IEP system goes, this is the state of the art and should continue as the power system of choice for UK destroyer classes in the future. I've never known any ground breaking technology which was perfect straight out of the box and to give up on the development of this now would be completely crazy in my view - especially in light of the progress being made. If you read the parliamentary reports on the IEP system, there's not one person who was involved with the original decision that would make a different choice now - despite the issues. If you recall in the late sixties, when the UK developed the submarine pumpjet, there were issues then but these were sorted out over time and with great overall benefit. The US didn't get pumpjet until Seawolf in the 1980s. To be be at the forefront of military technology, you have to take some risks and be prepared to overcome challenges to reap the rewards.

 

[StobieWan]

No issues with the IEP decision - I just wish they'd gone with LM2500's instead is all - or, if they'd been available at the time, MT-30's. I just don't want to be trying to keep WR-21's working in 25 years time when they're the only ships on the planet to use that GT and all of the spares chain etc will rest solely on those ships.

 

[matt00773]

No issues with the IEP decision - I just wish they'd gone with LM2500's instead is all - or, if they'd been available at the time, MT-30's. I just don't want to be trying to keep WR-21's working in 25 years time when they're the only ships on the planet to use that GT and all of the spares chain etc will rest solely on those ships.

LM2500's would be a climb down in capability and not an appropriate choice for a best in field destroyer. It would be like those countries that select F16s to upgrade their air force - using backdated technology. I don't think the advancement made with WR-21's is understood and the benefit they offer in terms of efficiency and stealth. It is a technology worth pursuing.

 

[John Fedup]

LM2500's would be a climb down in capability and not an appropriate choice for a best in field destroyer. It would be like those countries that select F16s to upgrade their air force - using backdated technology. I don't think the advancement made with WR-21's is understood and the benefit they offer in terms of efficiency and stealth. It is a technology worth pursuing.

IEP is state of the art and hopefully the QE system using MT30s will confirm this. The Type 45 IEP problems are directly related the WR21 GTs. They are a failed design so I don’t understand what benefits they will ever offer. The USN ran away from the RR/NG turbine recuperator design, the RN should have too.

 

[StobieWan]

LM2500's would be a climb down in capability and not an appropriate choice for a best in field destroyer. It would be like those countries that select F16s to upgrade their air force - using backdated technology. I don't think the advancement made with WR-21's is understood and the benefit they offer in terms of efficiency and stealth. It is a technology worth pursuing.

If they were fitted with LM2500's then we'd not be reworking Type 45, at some considerable expense - they work fine in warm weather. They're also a known quantity with a massive customer base. From a pragmatic point of view, going with a proven GT (which the contractor recommended) would have reduced risk and delivered broadly equivalent results. WR-21 is an evolutionary dead end - no-one's buying them, not even the RN.

 

[Systems Adict]

The Type 45 IEP problems are directly related the WR21 GTs. They are a failed design so I don’t understand what benefits they will ever offer

Reading between the lines, the 'failed design' has been examined, the 'flaw' discovered & a way ahead found. Cost wise it makes more sense to spend a small amount of funds on this fix than it does ripping them out & replacing them with something else ??

The USN ran away from the RR/NG turbine recuperator design, the RN should have too.

As a contractor on T45, I know that during every sea trial, the RN had a 'US Serviceman' (Naval / ME) on board, to observe (this included the period after handover of the ship from the shipbuilder to the RN, up until the vessel entered service).

I don't believe the USN 'ran away' from the idea, they just did what they always do, sat & waited till the tech was sufficiently developed enough to do what they wanted. The GE LM2500 is in both the Arleigh Burkes & LCS and can't give the power output that the WR-21's matched with DG's could.
The USN has seen 1st hand the benefits of what a RR aero engine, converted for use at sea can do & in the 10 years between the decisions over the WR-21 & the 'birth' of the MT-30's, the technology has 'improved', due to the amount of work done on commercial cruise liners.

Is it any wonder that the Zumwalt class & the QE class are both using MT-30's ?

Finally, while T45 is a large hull, the MT-30's are larger than the WR-21's, fitting them would require a full redesign below the waterline, right thru the centre of the ship.Adding sections to lengthen a ship is one thing, cutting it into pieces & adding something at the expense of everything else doesn't make much financial sense. Back in the day, it 'sorta' made sense that they went with them, but hindsight is always a wonderful thing...

 

[oldsig127]

Reading between the lines, the 'failed design' has been examined, the 'flaw' discovered & a way ahead found. Cost wise it makes more sense to spend a small amount of funds on this fix than it does ripping them out & replacing them with something else ??

It doesn't seem to me that anyone much is suggesting ripping the engines out of Type 45 and replacing them, rather suggesting ripping out the Type 45 fleet entirely after they reach a relatively shorter life time than normal for RN destroyers. No mid life extension - just move to the replacement class started sooner and away from the issues entirely

oldsig

 

[John Fedup]

Finally, while T45 is a large hull, the MT-30's are larger than the WR-21's, fitting them would require a full redesign below the waterline, right thru the centre of the ship.Adding sections to lengthen a ship is one thing, cutting it into pieces & adding something at the expense of everything else doesn't make much financial sense. Back in the day, it 'sorta' made sense that they went with them, but hindsight is always a wonderful thing...

Would the Type 45 have required two MT-30s had they been available at the time? Would a single MT-30 along with a similar diesel setup as the Type 26 been sufficient? I have to agree it is too late now.

 

[matt00773]

If they were fitted with LM2500's then we'd not be reworking Type 45, at some considerable expense - they work fine in warm weather. They're also a known quantity with a massive customer base. From a pragmatic point of view, going with a proven GT (which the contractor recommended) would have reduced risk and delivered broadly equivalent results. WR-21 is an evolutionary dead end - no-one's buying them, not even the RN.

The T45s work fine in warm water and have done so for years - T45s regularly spend months at a time in the middle east. The total number of failures that drive the discussion and the current redesign of the WR-21 are less than the fingers on one hand. As I stated previously, the benefits of the WR-21 are its ability to operate on 30% less fuel and provide a low heat signature comparative to similar TGs. Mastering this technology is the way forward and will provide a stepping stone for future generations of this type of IEP. It is the LM2500s that are at an evolutionary "dead end". No one went with pumpjets on submarines for nearly two decades after the UK as the technology was being matured. That doesn't mean it wasn't the right way forward.

 

[matt00773]

Would the Type 45 have required two MT-30s had they been available at the time? Would a single MT-30 along with a similar diesel setup as the Type 26 been sufficient? I have to agree it is too late now.

The T45s require two GTs for redundancy so the T26 setup (1 GT) would not be sufficient.

 

[matt00773]

It doesn't seem to me that anyone much is suggesting ripping the engines out of Type 45 and replacing them, rather suggesting ripping out the Type 45 fleet entirely after they reach a relatively shorter life time than normal for RN destroyers. No mid life extension - just move to the replacement class started sooner and away from the issues entirely

oldsig

What issues are you referring to exactly? Once the diesel engine replacement has been complete and the redesigned WR-21 components installed, what possible reason could there be for early replacement?

 

[oldsig127]

What issues are you referring to exactly? Once the diesel engine replacement has been complete and the redesigned WR-21 components installed, what possible reason could there be for early replacement?

You might want to go back though the thread, the same way as I did. Mainly issues relating to the orphan status of the GT, which as I understand it is used nowhere else, and will leave the RN exposed as the only customer of a potentially very expensive supply chain

oldsig

 

[KiwiRob]

IEP is state of the art and hopefully the QE system using MT30s will confirm this. The Type 45 IEP problems are directly related the WR21 GTs. They are a failed design so I don’t understand what benefits they will ever offer. The USN ran away from the RR/NG turbine recuperator design, the RN should have too.

It's not the GT that's the problem, it is the intercooler/heat exchanger that's the problem.

 

[John Fedup]

It's not the GT that's the problem, it is the intercooler/heat exchanger that's the problem.

Yes, the turbine component that got redesigned at the 5000 hour test point. The redesigned GT/recuperator was then tested a further 3000 hours. Subsequent WR-21s typically encountered problems at the 4000-5000 hour point so if the redesigned system had been tested out to 10,000 hours instead of 8,000 hours the flaw would have been discovered. Then there is the hot conditions testing or lack of.

As StobieWan's link in post 12084 mentions, 50 design changes between Darling and Duncan have reduced failures down to 1/3 of the initial rate, which is still too high. The latest plan to address this will be underway shortly. We will have to wait and see how this works out.