Rear Admiral Parry does not hold back re the engine problems on the latest destroyers

[NutLoose]

In fact he gives them both barrels over the failings of the Government

Labour saddled Navy ships with dodgy engines (http://www.msn.com/en-gb/news/uknews/labour-saddled-navy-ships-with-dodgy-engines/ar-BBv3yGn?li=AA59G2&ocid=spartanntp)


Rebooted the thread to correct my Spelling issues.

Replies

alfred_the_great (http://www.pprune.org/members/118221-alfred_the_great)
His name is Parry.


Heathrow Harry (http://www.pprune.org/members/326184-heathrow-harry)
Damned if you do, damned if you don't
If they'd bought American the same people would have been moaning about loss of Britsh jobs and British skills
PS the engines don't cost "about £1 Bn apeice " - but the ships do....................

[Jimlad1]

Current status of T45s and why they are all alongside.

HMS Daring – test-fired Aster missile 11/7/16. Due to deploy to Gulf soon?
HMS Diamond – completed Operational Sea Training. Has just returned from visit to Ireland and operating in Scottish waters.
HMS Dragon completed major refit, recommissioned 8/7/16 and has just returned from visit to Amsterdam.
HMS Defender – undergoing routine maintenance after returning home on 7th July from successful 9-month deployment to the Gulf.
HMS Duncan – Completed Gulf deployment last year. Been in UK waters and led Jutland 100 commemorations in May. Now in refit.

[pr00ne]

Jimlad1,

You missed one..,

[Navy_Adversary]

Indeed he did, a quick search reveals HMS Dauntless is not on the list, any updates?:8

[Melchett01]

Hasn't Dauntless been reduced to harbour training ship status or something along those lines? If I recall it was around Easter time and due to manning as well technical issues.

Edited: having just checked, Philip Dunne, former Min DP, seemed to suggest this harbour training status appears to be a permanent fixture for ships about to go into re-fit, which means Dauntless will be non-operational for a while yet before the same happens to another vessel.

//https://ukdefencejournal.org.uk/hms-dauntless-temporarily-reduced-harbour-training-ship/ (https://ukdefencejournal.org.uk/hms-dauntless-temporarily-reduced-harbour-training-ship/)

Only a politician could spin spending in excess of £1Bn on a warship and then parking it alongside as a training aid as a good thing! I know the rules of the game are to fight for your own service, but frankly what's been done to the RN is shocking from an operational perspective.

[t43562]

Aren't the recuperators the things that keep getting bent? They *are* American.

[Evanelpus]

Electoral politics, well well, who'd have thought it?;)

[Torquelink]

From Wikipedia for what it's worth . .

The Northrop Grumman intercooler as fitted in the WR-21, on Type 45 destroyers, were not designed to operate in water temperatures beyond 30c. Rolls-Royce said that the NG intercooler had been built as specified, but that conditions in the Middle East were not "in line with these specs". The House of Commons defence committee had in 2009 warned that "persistent overoptimism and underestimation of the technical challenges combined with inappropriate commercial arrangements" would lead to increased costs. The Northrop Grumman intercooler of the first Type 45 destroyer, HMS Daring, failed in the mid-Atlantic in 2010 and had to be repaired in Canada, with further repairs for intercooler failure in 2012 in Bahrain. The Type 45's pioneering Integrated Electric Propulsion (IEP) system uses two WR-21s and two Wartsila 2MW diesel generators to power everything on board, including weapons systems in addition to propulsion and other functions, leaving the ships vulnerable to "total electric failure". The Ministry of Defence said: "The Type 45 was designed for world-wide operations, from sub-Arctic to extreme tropical environments, and continues to operate effectively in the Gulf and the South Atlantic all year round."[6]

The Rolls Royce turbines themselves are extremely well-designed, but the Northrop Grumman intercooler has a design flaw causing the turbines to fail occasionally. [7]

[PhilipG]

As I read some articles on these intercoolers, including articles such as: -

"The turbines are of a sound design but have an intercooler-recuperator that recovers heat from the exhaust and recycles it into the engine, making it more fuel-efficient and reducing the ship’s thermal signature. Unfortunately the intercooler unit has a major design flaw and causes the GTs to fail occasionally. When this happens, the electrical load on the diesel generators can become too great and they ‘trip out’, leaving the ship with no source of power or propulsion."

I do wonder why the intercoolers are not just removed from the system and replaced with a bit of trunking, at least in the interim, it must better to have electric power reliably, even if you have to refuel more often and your thermal signature is increased, or is that just too simple a solution.

[cornish-stormrider]

Maybe we should ask our boy racers - they are the experts in intercoolers that can get eleventy bazillion horsepower out of a 1.2 corsa

You'd think that they could have thought about some extra cooling by a medium more suited to it, water maybe....

[Stuff]

The Northrop Grumman intercooler as fitted in the WR-21, on Type 45 destroyers, were not designed to operate in water temperatures beyond 30c.

The Northrop Grumman intercooler of the first Type 45 destroyer, HMS Daring, failed in the mid-Atlantic in 2010 and had to be repaired in Canada

The mid-Atlantic had water greater than 30C?

[glad rag]

successful 9-month deployment to the Gulf.

well done, now define successful. returning under it's own steam?

[Lonewolf_50]

GR
returning under it's own steam?
Wait a sec, no flucking steam.
2 × Rolls-Royce WR-21 gas turbines, 21.5 MW (28,800 shp) each
2 × Wärtsilä 12V200 diesel generators, 2 MW (2,700 shp) each
Welcome to the 21st century, and about the last 30-40 years in maritime propulsion for corvette/frigate/destroyer class combatants.

[megan]

no flucking steamThere is, out the exhaust pipe. Product of combustion, water vapour, CO2, plus other bits and pieces.

[pulse1]

successful 9-month deployment to the Gulf.

I know at least one Naval person who was grateful for his deployment being a lot shorter than that because of engine problems.

[esa-aardvark]

I spent 6 weeks on a freigher a couple of ears ago.
130000 tons deadweight, speed on test 25+ knots.
Engine 10 cylinder 100000hp diesel. I am sure that you
could cool down the diesel exhaust somehow, intercoolers ?

Would it be better to go back to such low tech that actually works.

Mind you we did break down in the Indian Ocean, but that was
repairable by the crew in a few hours. actually the vessel had spares
(cylinders, pistons, etc) on board to fix more or less anything. I did ask
and even a cylinder change at sea was possible
John

[glad rag]

I know at least one Naval person who was grateful for his deployment being a lot shorter than that because of engine problems.
Quite agree!!

[Wageslave]

Maybe we should ask our boy racers - they are the experts in intercoolers that can get eleventy bazillion horsepower out of a 1.2 corsa

I doubt any boy racer has ever fitted an intercooler. Aftercoolers maybe, but not intercoolers.

The System we are talking about is not about getting gazillion horsepower, it is about huge fuel economy improvements, something boy racers also know zip about!

[Tourist]

I spent 6 weeks on a freigher a couple of ears ago.
130000 tons deadweight, speed on test 25+ knots.
Engine 10 cylinder 100000hp diesel. I am sure that you
could cool down the diesel exhaust somehow, intercoolers ?

Would it be better to go back to such low tech that actually works.

Mind you we did break down in the Indian Ocean, but that was
repairable by the crew in a few hours. actually the vessel had spares
(cylinders, pistons, etc) on board to fix more or less anything. I did ask
and even a cylinder change at sea was possible
John

I can't decide if you are being serious or not.

On the off-chance you are, do you also suggest that we swap all the Typhoon engines for high bypass fans from Airbus and Boeing as well? After all, they are far more reliable and get much better mpg.

[Stuff]

it is about huge fuel economy improvements

and it has achieved this beyond even the designer's wildest dreams. Being tied up alongside uses very little fuel indeed!

[PDR1]

I doubt any boy racer has ever fitted an intercooler. Aftercoolers maybe, but not intercoolers.

The System we are talking about is not about getting gazillion horsepower, it is about huge fuel economy improvements, something boy racers also know zip about!

Huh? Dilettante boy racers may fit turbochargers or superchargers in pursuit of speed and power. Serious boy racers will also fit an intercooler between the blower and the cylinders to reduce the charge temperature, increase charge density and provide even greater power. Pretty well every turbodiesel car and truck on the road has an intercooler to increase the maximuym power capacity and improve efficiency.

I believe the device you are referring to is actually a heat-exchanger, which is used to transfer waste heat energy from the exhaust back into the intake air to improve overall thermal efficiency. The fact that matlots can't grasp the difference is a shortcoming in the matlot intellect rather than the boy-racer one.

PDR

[Bing]

I believe the device you are referring to is actually a heat-exchanger

Technically I believe it's called a recuperator, but as I'm only a matelot I may have that wrong...

[BEagle]

When the intercooler pump in my Teutonic tourer failed, the supercharger was inhibited whenever an 'inlet temp high' condition was sensed. The performance was worse than with the normally aspirated version as the EMU defaulted to a very conservative condition; fortunately it was an easy and quick extended warranty fix.

Back to aviation and matelots, wasn't it the Sea Vixen which had the ultimate blend of mixing systems - with fuel cooled, hydraulically driven AC generators?

[teeteringhead]

wasn't it the Sea Vixen which had the ultimate blend of mixing systems - with fuel cooled, hydraulically driven AC generators? BEags mon brave:

May I put in a counter bid for the windscreen wipers on the mighty Wessex?

Electrically driven hydraulic pumps which drove Bowden cables to the wipers. :eek: The final touch of genius by Mr Sikorski was to locate the Captain's wiper motor between the co-pilot's feet and vice-versa.

When one of the pumps leaked hydraulic fluid copiously - which was often - one had to choose as handling pilot either one whose feet were swimming in OM-15, but who could see out, or a pilot with dry feet who couldn't. :ugh:

And it always seemed a little "over-engineered" when the requirement was to wipe a flat screen on an aircraft with a Vmax probably lower than BEags' "Teutonic Tourer" :ugh::ugh:

[lsd]

Ah......the Wessex wiper motors! On one of my early solo fights (in the rain) in the queen of the skies it was somewhat distracting to observe the smoke and smell of burning coming from the co-pilots wiper motor. After some anxious moments wondering how this was possible and considering multiple turning off of switches, a dim recollection from ground school about this bizarre arrangement provided a solution - and saved us from the embarrassment of the crewman in the cabin firing off the fire extinguisher whilst struggling to climb up through the co-pilots seat.
And they were considerably less effective on our flat screen at slower speeds than on the curved and faster E-type ..... back in those days Teutonic tourers were for insurance salesmen not lords of the skies.

Hat, coat, door....

[NutLoose]

JENKINS

Join Date: Jan 2002
Location: Chicken Run
Posts: 26
How about the British light turbine twin with an Avgas cabin heater?

Most American light piston twins had the same, indeed similar is fitted in the Chinook, still it's better than light singles that draw air over the exhaust, which is OK until it leaks. :)

[esa-aardvark]

So Tourist, what is the benefit of gas turbines which appear
not to work reliably (*6) ?

[Wageslave]

Huh? Dilettante boy racers may fit turbochargers or superchargers in pursuit of speed and power. Serious boy racers will also fit an intercooler between the blower and the cylinders to reduce the charge temperature, increase charge density and provide even greater power. Pretty well every turbodiesel car and truck on the road has an intercooler to increase the maximuym power capacity and improve efficiency.

I believe the device you are referring to is actually a heat-exchanger, which is used to transfer waste heat energy from the exhaust back into the intake air to improve overall thermal efficiency. The fact that matlots can't grasp the difference is a shortcoming in the matlot intellect rather than the boy-racer one.


Huh? Why not read the post before replying so inaccurately?

As I said, they may well fit superchargers but I guarantee you none have ever fitted an intercooler. Look up what an intercooler is. No car or truck on the road has one.

To quote yourself, but in the pursuit of accuracy this time, and to repeat myself, "I believe the device you're referring to is actually an "aftercooler". If the motor industry chooses to misname a technical aviation derived device there is no need for us to do so too, is there?
Quite unlike your toy Vauxhalls it looks as if the device on the ships is indeed an intercooler as it is placed between the low and high pressure turbines - unless I've misread the script.

You might also notice I made no comment on the heat exchanger so correction on that point is superfluous to say the least.

[msbbarratt]

@esa_aardvark,

Engine 10 cylinder 100000hp diesel. I am sure that you
could cool down the diesel exhaust somehow, intercoolers?

Given the impressive efficiencies (they come within a nat's whisker of the theoretical 50% limit) that are achieved by the modern large ship diesel engines, there's nothing left in the exhaust to recover after the turbo chargers and whatever other tricks they employ. They even go as far as to use the air compressed under a descending piston to push up the adjacent one on its up stroke.

Would it be better to go back to such low tech that actually works.

At the expense of fuel efficiency, yes. The good old Olympus has about the same power output, ish, will work for 1,000,000 years but will drink more fuel. And Olympus is a much better name than WR21, or Trent, or whatever.

Diesels aren't as useful in a warship - slow to respond to the telegraph, and they're the wrong shape (tall) and take up a lot of space. A 100,000 HP diesel in a 130,000 ton freighter is, comparatively speaking, just a small unit at the back of the ship. The same engine in a 8,000 destroyer would pretty much mean that there's nothing else on the ship!

As for not liking running in hot water - the Persian Gulf gets pretty warm, as any submariner who has served out there (plus any submarine equipment designer) will tell you. I'm told that the ambient internal air temperature on T boats whilst submerged in the Persian Gulf during the summer was in the order of 50 deg C. Hot. Submarines there are big black rubber coated things basking in warm shallow waters under a scorching sun, and the T's air con plants were designed for the North Atlantic... Now imagine living and working in that for 2 weeks with no shower... yeurk! Round of applause for our submerged friends I think.:D

No one should be surprised that the Gulf sea water gets hot. RR are the design authority for literally every RN engine working out there, so they surely know (not they they built the recuperator). No doubt that somewhere within the inbox of a variously inhabited designation in Abbey Wood is a concerned email from people who know to people who need to know, but weren't there long enough to be able (or be obliged) to do anything about it.

[barnstormer1968]

Wageslave
Bit of thread drift, but you will find that some cars do indeed have intercoolers. Perhaps you aren't into modifying cars and so are unaware of which group add intercoolers quite often.

[Tourist]

So Tourist, what is the benefit of gas turbines which appear
not to work reliably (*6) ?

Ah, you were serious.

Ok,

1. They are very reliable. The gas turbine is not the problem on the T45. I will stick my neck out and say that gas turbine engines are more reliable than piston engines as a general rule. If you tried to get the similar performance from a diesel engine that you get from a gas turbine, the diesel will have more failures. Look at aero engines. Astonishingly reliable.

2. The diesel engine in that freighter took a very long time to get that freighter up to the 25kt speed you quote. Warships have a requirement to be very much quicker both in top speed and in acceleration and deceleration. The power to weight and size ratio of a gas turbine is vastly superior along with much faster response times.

3. Due to the way drag works in displacement vessels, very simplistically without going into Froude numbers etc it is easier to get a long ship to a high speed than a short ship. A diesel engine that could get a relatively short warship to 30+ kts would take up most of the ship.

https://en.wikipedia.org/wiki/Hull_speed

Incidentally, that freighter may have once done 25Kts in a trial, but what speed did it actually bimble around at? I'm guessing no faster than 18kts, probably around 15kts?
That is the speed range most ships traverse the world at, and that is the speed diesels excel at.

4. You mention maintenance. Gas turbine units can be swapped out through specifically designed routes in the ship. The Spares are carried on RFAs. Good luck with that on a freighters vast Diesel engine.


Plus you need more than 1 engine for redundancy etc.



Ask yourself why warship designers all over the world are not using diesel engines.

Is it because they are all idiots, or is it perhaps slightly less simplistic than you imagine?

Note that steam powered warships were just as quick (many slightly quicker) and nearly everybody (super carriers and big subs aside, they stuck with steam!) moved from steam to gas turbine once they became available.

[West Coast]

hydraulically driven AC generators?

Just how did those work?

[t43562]

This link is helpful - I'm not sure if it has been posted before or not - sorry if it has:

Putting the Type 45 propulsion problems in perspective | Save the Royal Navy (http://www.savetheroyalnavy.org/putting-the-type-45-propulsion-problems-in-perspective/)

[BEagle]

...hydraulically driven AC generators?

Rather than a straightforward engine driven accessory gearbox, doubtless using the ubiquitous variable angle swash plate so beloved of UK designers for constant speed devices, a simple hydraulic motor turned the AC generator shaft. Much like the hydraulic motors which drive high output fuel delivery pumps in some tanker aircraft.

Whereas an engine driven accessory drive (before the days of cross-drives) is clearly dependent on a serviceable engine, an hydraulic motor needs hydraulic pressure from the main hydraulic system, no matter how many pumps are actually working at the time. Probably easier to maintain constant motor speed as well.

But did the 'Vixen really use such a system?

[Wageslave]

Barnstormer, yes, thread drift but I say again, no car or truck has to my knowledge ever been fitted with an intercooler, as clearly explained in my post which you may care to read thoroughly in order to find out why.

[ORAC]

Not according to this Flight article in the 1960s. Yes, a hydraulic pump driving an alternator for the AI radar. But also two 28V generators off the engine auxiliary geRbox.

https://www.flightglobal.com/FlightPDFArchive/1960/1960%20-%200186.PDF#navpanes=0&scrollbar=0&page=1&view=FitH,0

[keith williams]

Most of the Sea Vixen systems used 24 Volts DC. Some of the instruments and navigation systems used 115V AC, which was provided by inverters. AC for the Red Top and Firestreak systems was provided by two hydraulically driven Alternators.

If you go to the "Sea Vixen.org" website and look under "History" you will find various documents including Pilots' Notes.

[BEagle]

Thanks, Keith!

It would seem that the Red and Green hydraulic systems powered the AC alternators for the radar and missile systems - and that there was indeed a heat exchanger in each engine fuel feed line, the purpose of which was to cool the fluid of these general services hydraulic systems as well as to heat the fuel for filter de-icing.

What a very complicated aeroplane the 'Vixen truly was!

[fallmonk]

Huh? Why not read the post before replying so inaccurately?

As I said, they may well fit superchargers but I guarantee you none have ever fitted an intercooler. Look up what an intercooler is. No car or truck on the road has one.

To quote yourself, but in the pursuit of accuracy this time, and to repeat myself, "I believe the device you're referring to is actually an "aftercooler". If the motor industry chooses to misname a technical aviation derived device there is no need for us to do so too, is there?
Quite unlike your toy Vauxhalls it looks as if the device on the ships is indeed an intercooler as it is placed between the low and high pressure turbines - unless I've misread the script.

You might also notice I made no comment on the heat exchanger so correction on that point is superfluous to say the least.


I can assure you sir almost every truck on the roads does have a inter cooler !

[Out Of Trim]

An intercooler is any mechanical device used to cool a fluid, including liquids or gases, between stages of a multi-stage compression process, typically a heat exchanger that removes waste heat in a gas compressor.[1] They are used in many applications, including air compressors, air conditioners, refrigerators, and gas turbines, and are widely known in automotive use as an air-to-air or air-to-liquid cooler for forced induction (turbocharged or supercharged) internal combustion engines to improve their volumetric efficiency by increasing intake air charge density through nearly isobaric (constant pressure) cooling.

[esa-aardvark]

Tourist,

actually I was not seriously suggesting a change to diesel.
When I worked (oh joy) I was more or less brainwashed
into the attitude, "only judge the result".
On that basis your statement "The gas turbine is not the problem on the T45"
falls far short. Regardless of the solution these ships should always have
adequate power available. My opinion is that the character who signed the contract
as well as the contractor who failed to say "this might not work" should be sactioned.

Having performed major acceptance tests in my (aerospace) career I would have needed a
lot of vaseline to deal with that one.

I do think that we should get away from the attitude of
"supporting british indistry". That approach just means it will be worst, not best.
Still, I don't want to give more time to this, and remember "Blue streak was the best ever"
John

[NutLoose]

West Coast this will explain it to you

http://www.k-makris.gr/AircraftComponents/CSD/C.S.D.htm

Patent US2908151 - Constant speed drive - Google Patente (http://www.google.ch/patents/US2908151)

[Wageslave]

I can assure you sir almost every truck on the roads does have a inter cooler !

Jeez! You clearly take me for a complete dummy and that's pretty offensive, especially as it isn't me that's just plain 100% wrong and I've explained it over an over again. Please excuse the thread drift!

On this forum we love to berate the meeja for sloppy technical inaccuracy and yet even amongst ourselves (unless fallmonk is meeja - his reply certainly suggests it) despite repeated reminders to RTFQ there are still some who blindly refuse to read the FQ and persist in refusing to accept the correct answer. How does one explain?


No, fallmonk, not one truck on God's clean earth has an intercooler. Read my post above to see why, it is there in black and white, why/how can you not read and absorb it??? It is perfectly plain.

If my words of two syllables are too much try reading Out Of Trim's post, that says exactly the same thing in different two-syllable words although that too drifts off into the long grass when it describes automotive use. An intercooler is any mechanical device used to cool a fluid, including liquids or gases, between stages of a multi-stage compression process,

Do you know any cars/trucks with two-stage supercharging? No, you don't. Unless you wanted to go drag racing on Everest there would be no point, would there?

If it is a Merlin 61 (Am I right there?) or similar optimised for high altitude work with back to back or two-stage supercharging the cooler in between the stages is - guess what? An "inter"cooler.

If however it is single stage supercharging, as it is in EVERY earth-bound piston engine I've ever heard of (trucks, trains, Astramax vans, Chelsea Tractors etc) the cooler "after" the blower is an "aftercooler", regardless of incorrect labelling by the technically challenged manufacturer/boy racer in question.

The most basic awareness of the different purposes of supercharging would make all this completely obvious, so perhaps if it is not clear a bit of a refresher on supercharging is in order?

This isn't being pedantic, it is a very simple definition between two quite different applications, each of which has its correct name and is just very, very basic supercharging theory that every CAA CPL stude should know if they've sat that particular paper.

[msbbarratt]

I think wageslave is forgetting that the air also gets compressed in the cylinder, which is the last stage of compression in the piston engine, and comes after the radiator commonly referred to as an intercooler.

And plenty of cars have twin turbos, some even have three now.

[NutLoose]

Intercoolers do not have to go between stages of compression, they are also used to cool the charge on engines such as the Continental GTSIO 520 before it enters the cylinder. It is a heat exchanger plain and simple.

[PanzerJohn]

On a forced induction engine as the the intake charge is compressed its gets very hot, the intercooler/heat exchanger removes a lot of this heat which means the cylinders receive a cooler and therefore denser and more effective charge. I have drag raced and built both supercharged and turbo motorbikes.

[msbbarratt]

It turns out that the major contributor to charge heating is the heat transferred from the turbine to the impeller.

The current Mercedes F1 engine separates the turbine from the impeller by a long ceramic shaft. This eliminates heat transfer, and they manage without an intercooler altogether. This in turn eliminates a huge amount of air pipe (helped by the turbo being at the back of the engine and the impeller at the front) simplifying the whole installation and gaining aerodynamic advantage as a result.

[Fonsini]

"The six engines, which are worth £1 billion each....".

I love journalists, even the most illogical statements escape their attention.

[Heathrow Harry]

I know a few and they are quite odd people TBH - but TV people are worse............