The Royal Navy Discussions and Updates

[Systems Adict]

I don't think you realise, but the analogy you provided (Nimrod MR4) is exactly what I was referring to in 'easy' decisions. If the UK had designed something new and advanced rather than using some legacy product (40 years old in this case) lying around, we would be in a very different place with respect to maritime patrol. capability. I agree though that there are a lot of appropriate COTS products that are beneficial in many cases, but you should always be pushing the boundaries of development to improve the gap between yourself and your adversaries.

Sorry Matt, I know that this a Navy thread & that you're drawing comparisons, but your comparisons are between 'apples & pineapples' when you talk about the MR4's & the Nimrod they replaced.

The MR4 was something like 90 - 95% NEW airframe, & only some design characteristics were kept (such as placement of the engines / the bomb bay / overal shape), but it was an entirely different beast.

I can't defend the political decision to scrap them as after spending all that cash to get them where they were, revamping them & having x4 of x12 aircraft ready for flight / flying. It definately felt like a knife to the heart watching that bull-dozer chopping them up to be hauled off for scrap.

Anyway, gonna leave this topic her, draw a line under it & move on, as it's one for the UK RAF page (if one exists).

 

[swerve]

Yes, MRA4 was effectively a new aircraft, but large parts of the old airframe were kept: the fuselage pressure cell & most of the tail. I think that's much less than half, but a lot more than 5-10%. As far as I can see, this was done to get it approved as an "upgrade" of the existing Nimrods, despite being mostly new, especially when the entirely new engines, avionics, etc. were taken into account.

Those old parts were a major cause of problems due to their variability, but trying to sell MRA4 to the MoD & Parliament as a new aircraft was probably a political impossibility.

Too few aircraft wanted for it to be sensible to design & build a new aircraft, & sneaking an effectively new type through as an upgrade was the worst of both worlds. Risk & work needed understated ("it's just an upgrade"), & not enough attention paid to the old airframes. The engineer in charge of evaluating risk ended up being forced out for refusing to sign off the assessment the management wanted, & muzzled with an NDA on pain of losing his pension. He went public after it was scrapped, correctly assessing that he was probably safe.

 

[StevoJH]

Of course its a bit ironic when one of the problems you have is that your replacement wings are *too* good as opposed to not good enough.

Ah, the joys of trying to fit parts built with 21st Century precision to machines built with mid 20th Century craftmanship.

 

[John Fedup]

Here is a link describing the PIP (power improvement program) for the Type 45. The two existing diesels will be replaced by three larger diesels. Unfortunately the power output is not specified but it must be enough to provide a decent speed in the event of total turbine loss. The link also mentions the hot conditions problem. Under hot conditions the GT does not provide enough power to the electric motors causing the electrical system to trip out and I assume it is difficult or impossible to get the turbine back on line. Therefore my question would be, in hot conditions, will the diesels be online with the GT(s) to prevent a trip out?

UK MoD awards £160m Type 45 destroyer propulsion repair contract

 

[matt00773]

Here is a link describing the PIP (power improvement program) for the Type 45. The two existing diesels will be replaced by three larger diesels. Unfortunately the power output is not specified but it must be enough to provide a decent speed in the event of total turbine loss. The link also mentions the hot conditions problem. Under hot conditions the GT does not provide enough power to the electric motors causing the electrical system to trip out and I assume it is difficult or impossible to get the turbine back on line. Therefore my question would be, in hot conditions, will the diesels be online with the GT(s) to prevent a trip out?

UK MoD awards £160m Type 45 destroyer propulsion repair contract

That's exactly the right question. How well will the upgrade perform and what are the operational modes for these kind of scenarios. I expect we'll find out over the course of time but I'm hoping for the best.

 

[StobieWan]

Here is a link describing the PIP (power improvement program) for the Type 45. The two existing diesels will be replaced by three larger diesels. Unfortunately the power output is not specified but it must be enough to provide a decent speed in the event of total turbine loss. The link also mentions the hot conditions problem. Under hot conditions the GT does not provide enough power to the electric motors causing the electrical system to trip out and I assume it is difficult or impossible to get the turbine back on line. Therefore my question would be, in hot conditions, will the diesels be online with the GT(s) to prevent a trip out?

UK MoD awards £160m Type 45 destroyer propulsion repair contract

I don't know but I will guess that the intention would be to provide enough generating power for the grid to weather a GT dropping out, which at the moment the two diesels fitted *can't*. I'm wondering if they'd be running one diesel and one GT down and one GT plus two diesels up to provide a buffer. Original intentiosn seem to have to been to run one island (a GT and a diesel) up vs one down most of the time and that's not been useful due to the way the GT's behave when under stress - they don't degrade gracefully as intended.

I doubt the diesels are there to provide much in the way of speed however - more to just stop the entire power grid tripping out when one of the GT's falls over.

Right now I believe the current diesels deliver about 2Mw each - vs 20 for the GT's - I suspect the diesels were a bit underspec in any event for an IFEP design- probably on the assumption that the variable cycle WR-21's would provide economical cruise power.

 

[John Fedup]

IIRC the initial design only used the GTs for propulsion, one GT running for economic cruise and two for high speed. The two 2MW diesels were for shore hotel load.

 

[StobieWan]

IIRC the initial design only used the GTs for propulsion, one GT running for economic cruise and two for high speed. The two 2MW diesels were for shore hotel load.

That would be about right in one sense - that the design revolved around high availability of the Gt's- tripped over this link below with a bit more information:

Type 45 to get third diesel generator to overcome problems


Specifically:

"At the outset, the design intent was that the IEP system would typically run on a single WR-21 gas turbine alternator (GTA) in a single-island mode, with the second GTA brought on line only in ‘high risk’ operating regimes; the two 2MW diesel alternators were to provide power for harbour services and ‘blackout’ recovery, and not foreseen to perform as true backup generators in the event of GTA failure. In actual fact, as reported in the May 2016 issue, current operating practice tends towards one WR-21 and one auxiliary diesel in single-island mode"

I'd say broadly that WR-21 as a prime mover doesn't do the job...

 

[KiwiRob]

Interesting it looks like the Babcocks Type 31e bid will now be based on the Iver Huitfeldt-class frigate. It's a lot more ship than the enlarged OPV BAE and Cammell Laird are proposing.

Danish ship design consultancy Odense Maritime Technology (OMT) has joined the Babcock-led industry group bidding for the United Kingdom’s Type 31e frigate programme, heightening expectations that the team will bid a design based on the pedigree of the Royal Danish Navy’s Absalon-class support ships and Iver Huitfeldt-class frigates.

 

[hauritz]

Interesting it looks like the Babcocks Type 31e bid will now be based on the Iver Huitfeldt-class frigate. It's a lot more ship than the enlarged OPV BAE and Cammell Laird are proposing.

The Danes seem to know how to get most bang for their buck so they could prove to be decisive in this competition.

Are they basing the design on the Iver Huitfeldt-class or is it more to do with just adopting the Stanflex mission payload system?

 

[Todjaeger]

The Danes seem to know how to get most bang for their buck so they could prove to be decisive in this competition.

Are they basing the design on the Iver Huitfeldt-class or is it more to do with just adopting the Stanflex mission payload system?

The process the Danes used to build the Iver Huitfeldt-class I do not believe the RN would be able to get away with. Much of the hull block work was done in overseas yards in the Baltics, with the fitout done in a now closed Danish yard.

The RN might be looking at adopting the StanFlex modular systems, but I would think that if the RN was heading in this direction, then they would also have wanted to design space for the modules aboard the Type 26 design...

 

[ASSAIL]

Interesting it looks like the Babcocks Type 31e bid will now be based on the Iver Huitfeldt-class frigate. It's a lot more ship than the enlarged OPV BAE and Cammell Laird are proposing.

There seems to have been a cult following of the Absalon and IH design and it's been promoted as the solution to just about anything without regard to Danish circumstance.
Having said that, it is a good compromise between capability and survivability and should British industry/RN produce it for T31e it would help their export ambitions.

 

[wowu5]

Interesting it looks like the Babcocks Type 31e bid will now be based on the Iver Huitfeldt-class frigate. It's a lot more ship than the enlarged OPV BAE and Cammell Laird are proposing.

I can not see any correlation between OMT being part of the Team 31 and the random guess that the base design will be a variant of either ships.
They are simply in a whole different level than what the Type 31 is supposed to be.
If original Danish ships exceed the lowly quota of 250 million pounds per vessel 10 years ago with all their "cost-saving" measures, as demanded by the MOD for the program, then there's no way that it'd be possible for Team 31 to deliver a similar frigate constructed locally in 2020 without breaking the cost requirement by far.

 

[KiwiRob]

The process the Danes used to build the Iver Huitfeldt-class I do not believe the RN would be able to get away with. Much of the hull block work was done in overseas yards in the Baltics, with the fitout done in a now closed Danish yard.

They can do the same thing using UK yards, which appears to be the plan, modules built in yards all over the UK and assembled in Rosyth, just like CVF.

 

[Todjaeger]

They can do the same thing using UK yards, which appears to be the plan, modules built in yards all over the UK and assembled in Rosyth, just like CVF.

You missed the point I was making. Specifically the overseas part. The process the Danes used worked for them because they used Baltic yards to build most of the hull and superstructure at a lower price than if everything was done at a Danish yard.

If the UK tried to have a series of warships build overseas then fitted out at a British for service in the RN that would cause problems...

 

[KiwiRob]

You missed the point I was making. Specifically the overseas part. The process the Danes used worked for them because they used Baltic yards to build most of the hull and superstructure at a lower price than if everything was done at a Danish yard.

If the UK tried to have a series of warships build overseas then fitted out at a British for service in the RN that would cause problems...

When I went to the Cammell Laird Type 31e workshop they were trumpeting how cost effective the UK had now become for shipbuilding, with the pound in the poop, building ships in the UK is becoming more attractive, yards are now bidding on commercial projects which they wouldn't have considered doing several years ago. I'm not saying shipbuilding will ever be what it once was but it is becoming a viable industry again.

 

[StobieWan]

Given the schedule, any Type 31e design will have to be at least as mature as a fully worked set of drawings and better yet, look pretty much like something that already exists. I'm very much with the comment that an OMT involvement doesn't in any way indicate that we're looking at an Iver or similar - we'll see (and soon if there's any hope of meeting the rather demanding timescale.

I'm increasingly of the opinion that 31 is a dangerous diversion and taking a larger order of 26 would be more cost effective. We'll see - wouldn't mind seeing a Sea Ceptor armed Khareef in RN colours but they really need to start cutting steel very soon..

 

[ASSAIL]

Given the schedule, any Type 31e design will have to be at least as mature as a fully worked set of drawings and better yet, look pretty much like something that already exists. I'm very much with the comment that an OMT involvement doesn't in any way indicate that we're looking at an Iver or similar - we'll see (and soon if there's any hope of meeting the rather demanding timescale.

I'm increasingly of the opinion that 31 is a dangerous diversion and taking a larger order of 26 would be more cost effective. We'll see - wouldn't mind seeing a Sea Ceptor armed Khareef in RN colours but they really need to start cutting steel very soon..

I agree with you on further T26.
I would love to see a disciplined costing comparison between T26 hull #5 and T31 development and build costing.
Savings could have easily been made by by incorporating FFBNW on a T26 hull (which is 30% of the total build cost according to most)
The flexibility achieved over the life of the class and the efficiencies gained by a common hull should all cancel out any short term, if any, financial advantage of T31

 

[Systems Adict]

I agree with you on further T26.
I would love to see a disciplined costing comparison between T26 hull #5 and T31 development and build costing.
Savings could have easily been made by by incorporating FFBNW on a T26 hull (which is 30% of the total build cost according to most)
The flexibility achieved over the life of the class and the efficiencies gained by a common hull should all cancel out any short term, if any, financial advantage of T31

The issue is a T26 is almost as big as T45 & the T31e ISN'T supposed to be that big !
(Circa. 90 - 105 metres long / 2.5k - 3.5k tonnes GRT)

In an ideal world the govt would see the cost effectiveness of maintaining a hull size / style / type, as it provides a good baseline to work from. However, in the UK the lunatics appear to have taken over Whitehall / Defence Procurement...

SA

 

[hauritz]

Whatever happened to the T27 concept?

The plan I believe was to base it on the T26 but it would only carry a single helicopter and have a less sophisticated ASW suite ... basically just a stripped back, general purpose version of the T26.

To me it sounds like a far less risky concept then the type 31.