Type 26 Frigate (City Class) (RN) [News Only]

[xav]

I say scratch T26 and focus on T2050

Group of British Naval Companies Unveiled their Warship of the Future: Dreadnought T2050

At DSEI 2015, a series of futuristic concept images on what a new surface ship for the Royal Navy could look like in 2050 has been released by a group of leading British naval electronic systems companies, working alongside Defence Equipment & Support (DE&S – part of the MOD) and the Defence Science and Technology Laboratory (DSTL – part of the MOD).

Speed of light weapons; graphene coated, ultra-strong acrylic hull which can be made see through; tethered quad-copter radar; locally 3-D printed drones; supercavitating torpedoes and a floodable rear docks all feature.

http://www.navyrecognition.com/index.ph ... ew&id=3127

[Gabriele]

I'm not sure i'm reading this right:

Richard Partridge, chief of naval systems at Rolls-Royce, added that although GT/hybrid arrangements will normally conduct low-speed/transit and ASW operations on the electric drive and high-speed operation on the ‘boost’ gas turbine, the GT can also support operations at ship speeds below normal electric drive/gas turbine threshold speed, when required by the operational scenario.

What do "operations" mean here, i wonder....? Are they saying that you can (inefficiently) run the gas turbine at lower than optimal GT speed (which is nothing special and not even something i'd boost about) or does it mean that the GT can be used to generate power for the ship's systems other than propulsion...?
Because more than pure speed, what worries me is available power for future ship systems. The MT30 can provide a lot of power for future systems, but does the propulsion architecture allow it to be used?

[seaspear]

Would that be on very quiet asw operations at slow speed

[marktigger]

one of the big issues is when you have to start playing "power games" with the sensors like Radar and ECM It will eat allot of electrical power

[shark bait]

one of the big issues is when you have to start playing "power games" with the sensors like Radar and ECM It will eat allot of electrical power

I agree, it is some what shortsighted. Doing a little reading it appears it is a cost cutting measure.

Our detailed analysis shows that improved survivability can be achieved with a single-GT CODLOG arrangement, more than a classic twin-GT arrangement, where the loss of the aft engine room can mean loss of propulsion. There is also the benefit of lower procurement and through life costs.........Having spent many years evaluating various options, BAE systems and the MoD converged on hybrid electric-mechanical as the best balance between performance, survivability and affordability.

[shark bait]

What do "operations" mean here, i wonder....? Are they saying that you can (inefficiently) run the gas turbine at lower than optimal GT speed (which is nothing special and not even something i'd boost about) or does it mean that the GT can be used to generate power for the ship's systems other than propulsion...?
Because more than pure speed, what worries me is available power for future ship systems. The MT30 can provide a lot of power for future systems, but does the propulsion architecture allow it to be used?

To me that suggests supplying extra power to the ships system by divunb the propeller at slow speeds rather than the electrics.
It could suggest they can drive the motor's in reverse to generate more power but I doubt this.

[desertswo]

What do "operations" mean here, i wonder....? Are they saying that you can (inefficiently) run the gas turbine at lower than optimal GT speed (which is nothing special and not even something i'd boost about) or does it mean that the GT can be used to generate power for the ship's systems other than propulsion...?

Unless there is some twist in the design of which I am unaware, this diagram presents CODLOG as I know it.

Here:



The MT-30 will not act as a generator for the other ship's services. I suspect that in order to move and still conduct ASW ops, they will run the MT-30 at the lowest possible RPM before compressor stall causes the PLC to shut it down. Also, they will de-clutch one red gear and let it trail shaft. That will slow her down. Operationally, this does one other thing you may not consider but is an old trick that still works: "turn count masking." In trail shaft, a single screw really messes with the ability of a submarine to accurately identify the target, forcing them to come shallow and have a look. Bad juju for the submarine.

Because more than pure speed, what worries me is available power for future ship systems. The MT30 can provide a lot of power for future systems, but does the propulsion architecture allow it to be used?

No.

To me that suggests supplying extra power to the ships system by divunb the propeller at slow speeds rather than the electrics.

No.

It could suggest they can drive the motor's in reverse to generate more power but I doubt this.

Really no.

BTW, I know Gabriele was positing the questions, but I was having issues making quotes work correctly.

[ArmChairCivvy]

Someone got jumpy for that same reason, nested quotes having an attribution problem.

Have simply started to take the attribution off as the quotes are editable just like any other text.
- the select & quote facility still saves a lot of hassle, so one minor quirk is neither here or there

[~UNiOnJaCk~]

If you read my post you would see that I was quoting xav, when he said to take it with a pinch of salt, his words not mine. He also states that this was given to him at DSEI so we can take it that it was from someone on the stand.

Yes, i see upon re-reading the conversation.

In the same post he says he is trying to get to talk with the programme manager, to see if he can get any definative answers to a number of questions he has. So please don't make it sound as if I am discrediting his posts.

It was an observation not an accusation. No need to be defensive.

On the contrary, I replied that I am looking forward to any info he can glean from BAE, at the moment he seems to be finding it hard work, so we can but live in hope.

Indeed, though i think that at this stage we are unlikely to find out much in the way of new information - from any source - until the ships themselves start to roll off the production line, as it were.

[Gabriele]

Because more than pure speed, what worries me is available power for future ship systems. The MT30 can provide a lot of power for future systems, but does the propulsion architecture allow it to be used?



No.

Exactly. And that's why i hate the CODLOG choice that has been made. It risks being a tombstone on future growth paths.

It would have been much, much better to got CODLAG like on the italian FREMM, removing some of the limitations while keeping the advantages. CODLOG is a step in the wrong direction.

I hate the idea of finding out in a decade that the Type 26 is "doomed" by her propulsion architecture like Challenger 2 is doomed by the rifled cannon.

The Chief of the defence staff not long ago said that british equipment costs a lot because it is often gold plated. The truth is worse still: the equipment is terribly expensive, but to add insult to injury, the gold plates are nowhere to be seen.

[Ron5]

one of the big issues is when you have to start playing "power games" with the sensors like Radar and ECM It will eat allot of electrical power

I agree, it is some what shortsighted. Doing a little reading it appears it is a cost cutting measure.

Our detailed analysis shows that improved survivability can be achieved with a single-GT CODLOG arrangement, more than a classic twin-GT arrangement, where the loss of the aft engine room can mean loss of propulsion. There is also the benefit of lower procurement and through life costs.........Having spent many years evaluating various options, BAE systems and the MoD converged on hybrid electric-mechanical as the best balance between performance, survivability and affordability.

As far as I know, there are only two destroyer/frigate full electric ship classes in the world, the Type 45's and the Zumwalts. Apart from the electric thing, they also share the dubious honor of being so appalling expensive, only a fraction of their planned numbers have been/will be, built. The Type 45 as also been beset with problems. That's not coincidence.

Google electric ships and you'll find a number of studies that have conclude that FEP for escorts is just not worth it. The benefits are marginal and the expense & complexity of the additional equipment required to mix and match differently "shaped" electricity are off putting.

Nobody is designing or building FEP escorts. Nobody. That should give you a clue. Hybrid systems rule.

[Ron5]

Because more than pure speed, what worries me is available power for future ship systems. The MT30 can provide a lot of power for future systems, but does the propulsion architecture allow it to be used?



No.

Exactly. And that's why i hate the CODLOG choice that has been made. It risks being a tombstone on future growth paths.

I hate the idea of finding out in a decade that the Type 26 is "doomed" by her propulsion architecture like Challenger 2 is doomed by the rifled cannon.

The Chief of the defence staff not long ago said that british equipment costs a lot because it is often gold plated. The truth is worse still: the equipment is terribly expensive, but to add insult to injury, the gold plates are nowhere to be seen.

If the Type 26 is doomed by its propulsion system then so is every other escort in the world either in service or being built or being designed.

Well except for the 6 Type 45's and 3 Zumwalts. And of those two, the Type45 does not have sufficient excess power to operate rail guns and the like. So we're down to the Zumwalts. How much do they cost again????

[Halidon]

Hate to pick nits with you, Skipper, but I believe that diagram is technically CODLAG not CODLOG.

[shark bait]

It could suggest they can drive the motor's in reverse to generate more power but I doubt this.

Really no.

Of course you can, as soon as any induction motor reaches negative slip it acts as a generator (of course you need systems to accept the power). I believe the Italian FREMM does just that.

It would have been much, much better to got CODLAG like on the italian FREMM, removing some of the limitations while keeping the advantages. CODLOG is a step in the wrong direction.

Exactly my point, why deny yourself of that flexibility.

The Type 45 as also been beset with problems. That's not coincidence..............Nobody is designing or building FEP escorts. Nobody. That should give you a clue. Hybrid systems rule.

The T45's problems are a whole different kettle of fish. They went with the intercooler plus recuperator design, which nobody likes and has turned out to be a dead end with only 6 examples in service.

I can accept a Hybrid system rule if the GT utilise excess power for the ships systems.

[desertswo]

Hate to pick nits with you, Skipper, but I believe that diagram is technically CODLAG not CODLOG.

It is and it isn't. CODLOG isn't "diesel and" gas turbine; it's "diesel or" gas turbine. The drawing would look the same. The difference is when you start the gas turbine in the CODLOG ship, you take the electric motors off line. It's all done by the push of a button, certainly in engineering main control, but possibly even on the bridge.

[desertswo]

It could suggest they can drive the motor's in reverse to generate more power but I doubt this.

Really no.

Of course you can, as soon as any induction motor reaches negative slip it acts as a generator (of course you need systems to accept the power). I believe the Italian FREMM does just that.

I know, but one needs to understand that when systems like this are designed to the end user's standards, consideration is given to the lowest common denominator; the Mark One, Mod Zero, Sailor, One Each who must operate, maintain and depending on the navy in question (this certainly would be the case in the USN), repair the equipment. Maybe the T-26 will allow the motors to run in as you describe but I seriously doubt it, because to reverse and become generators, as I understand red gear design, unless there is an ability to de-clutch from one and clutch into another that runs backward, that motor is going to run in the same direction as the gas turbine. That's real messy, and apologies in advance to Halidon, hardly "sailor proof." Far more likely that the bus tie breaker that provides power will open and a brush and ring assembly in the motor will engage to generate electricity, while a different bus tie breaker closes sending power back through the board and through a series of rectifiers and transformers, either step up or step down, so that the motor can be paralleled with the diesels in phase and at the same voltage and frequency, so that one or the other doesn't get "driven" like a motor, and trust me when I tell you as someone who has seen a Fairbanks-Morse 8 and 1/8 10 cylander, 20 piston opposed, dual crank diesel engine become a motor when a shore power breaker failed to open, it won't just be ugly, but fugly! Better all around to simplify things and remove that capability altogether.

[Ron5]

CODLAG is for ships where the gas turbine is not powerful enough on its own to propel the ship at desired speed. The electric motors have to supplement. The cost is added complexity & cost i.e. more expensive things to break.

The MT30 is the most powerful marine GT in service. An outstanding machine that has power enough to not require help. Hence CODLOG for the Type 26's.

Anyone who thinks the FREMM power train is superior either a) will not have to pay the extra or b) will not have to do the maintenance.

Personally I do not understand why the French & Italians did not chose a superior, European product from Rolls Royce which would have given them better ships instead of opting for an American product that not even the USN are selecting for its latest & greatest.

Same for the Germans, their new F125 would be much better with the Rolls GT. Max 29 MW for a 7k ton ship? SMH.

[Tony Williams]

Engines are somewhat outside my main field of interest, but this presentation might be of interest: http://higherlogicdownload.s3.amazonaws ... 02012c.pdf

Unfortunately it's only the slides rather than the text, but there's still a lot in information here on propulsion choices.

[Ron5]

Engines are somewhat outside my main field of interest, but this presentation might be of interest: http://higherlogicdownload.s3.amazonaws ... 02012c.pdf

Unfortunately it's only the slides rather than the text, but there's still a lot in information here on propulsion choices.

Slides would be a whole lot different if done today, MTU is now wholly owned by Rolls Royce

[ArmChairCivvy]

Anyone who thinks the FREMM power train is superior either a) will not have to pay the extra or b) will not have to do the maintenance.

I understand that this was in reference to an earlier mention by SB about the Italian FREMMs. That one left it unclear whether only the propulsion choice was being addressed, or the noise level while doing ASW work at the required speeds. From the latter POV it needs to be considered that the Italians added variable pitch propellers.
- in my books that would add complexity (=cost), but would it be a lesser cost than the economies achieved in the propulsion (and running it/ the ship over decades)?

Like TW, my main interest is not the engines but the implications of the choices made.

[Gabriele]

CODLAG on the italian FREMM is an example of what you can do. It has 1 GT and 4 diesels, exactly like the Type 26 will have.
However;

- You can make 15 knots on the diesels alone for silent ASW, detaching the GT via clutch and keeping it off; (like on Type 26, no more no less)
- You can sprint to over 26 knots using the GT alone
- You can get to higher speed using GT + Diesels (CODLOG can't)
- You can keep the GT going at speeds lower than 15 knots when you are expecting to need repentine accellerations which do not mix well with the on / off GT times
- With the GT going, the electric motors are dragged on the shafts and work as generators (CODLOG can't)

The GT is a LM2500+ G4, a 32 MW turbine.
The diesels are Isotta Franschini VL-1716, 2,1 MW each, but already there are plans to put bigger diesels in as the navy wants an higher diesel-only speed (and max speed as a whole).

[shark bait]

I know, but one needs to understand that when systems like this are designed to the end user's standards, consideration is given to the lowest common denominator; the Mark One, Mod Zero, Sailor, One Each who must operate, maintain and depending on the navy in question (this certainly would be the case in the USN), repair the equipment. Maybe the T-26 will allow the motors to run in as you describe but I seriously doubt it, because to reverse and become generators, as I understand red gear design, unless there is an ability to de-clutch from one and clutch into another that runs backward, that motor is going to run in the same direction as the gas turbine. That's real messy, and apologies in advance to Halidon, hardly "sailor proof." Far more likely that the bus tie breaker that provides power will open and a brush and ring assembly in the motor will engage to generate electricity, while a different bus tie breaker closes sending power back through the board and through a series of rectifiers and transformers, either step up or step down, so that the motor can be paralleled with the diesels in phase and at the same voltage and frequency,

I'm not 100% sure I followed that comment so apologies if I'm not barking up the wrong tree. You don't physically reverse the motor, you reverse the slip, so driving the rotor faster then the stators magnetic field. It's the same principal as regenative breaking, quite a simple system. Matching frequencies is of course needed, this can be controlled by altering the generators input frequency. Nicely this is self regulating and its why it's used for wind turbines, variable rotor speed always matches the supply frequency.

[Ron5]

CODLAG on the italian FREMM is an example of what you can do. It has 1 GT and 4 diesels, exactly like the Type 26 will have.
However;

- You can make 15 knots on the diesels alone for silent ASW, detaching the GT via clutch and keeping it off; (like on Type 26, no more no less)
- You can sprint to over 26 knots using the GT alone
- You can get to higher speed using GT + Diesels (CODLOG can't)
- You can keep the GT going at speeds lower than 15 knots when you are expecting to need repentine accellerations which do not mix well with the on / off GT times
- With the GT going, the electric motors are dragged on the shafts and work as generators (CODLOG can't)

The GT is a LM2500+ G4, a 32 MW turbine.
The diesels are Isotta Franschini VL-1716, 2,1 MW each, but already there are plans to put bigger diesels in as the navy wants an higher diesel-only speed (and max speed as a whole).

In other words, lot of extra cost & complexity that gains nothing which could so easily been avoided by the choice of a more powerful GT.

[shark bait]

In other words, lot of extra cost & complexity that gains nothing which could so easily been avoided by the choice of a more powerful GT.

There is no doubt is is more costly and complex, but it would increase the total electrical capacity of the ship considerably, so thats your trade off.

As it stands the T26 is trying to be as low risk and low cost as it can be, which I totally agree with, which is obviously why it has been given the simpler propulsion method.

[Gabriele]

In other words, lot of extra cost & complexity that gains nothing which could so easily been avoided by the choice of a more powerful GT.

And flying pigs can be obtained with a cheap, large sling.