Turbo squeel

Good thought Huw - start with the simple.

Or add an oil accumulator to the turbo oil feed to keep oiling it after shutdown.

Rather like the sound a wave makes when going back down a shingle beach - but constant... and loud! It sounds exactly like a supercharger on a large Sulzer diesel engine (e.g. BR Class 47). The Garret turbos on LR's might make a slight "whine" in normal operation, but it shouldn't describable as noisy.

Richard

HST's are supercharged, not turbocharged. Ususually for for railway applications they only have 2 stages of field conversion (the winding on the traction motors are dynamically connected to give "electrical gears" - most BR Diesel Electrics have between 6 and 10) and the motors can handle larger than average currents* so the driver can give it pretty much full throttle from the off without tripping out. A Class

47, for example, has the red line at 8,500 amps and the driver has to be careful with the throttle when moving off or everything comes to a rather embarrassing halt. Pulling a 2,000 ton stone train with an HST power car would require terminal patience with the throttle though - in fact I doubt it could get it moving, whereas a Class 37 with the same 1750 hp could do it easily, if a bit slowly. Class 33's have a neat trick of re-synchornising all 4 traction motors when a button is pressed, giving them amazing ability on slippery rails that would stop other engines - very handy in Whiteball Tunnel coming out of Taunton with 940 tons of Avtur for the RAF at Tiverton (now gone).

• except the second batch that GEC built - they tried to save money.....

Richard

And indeed the "bearings" arn't really, they are oil bearings that rely on the oil to work without damage.

Richard

On or around Thu, 26 Jan 2006 13:17:05 +0000 (UTC), beamendsltd enlightened us thusly:

I was fairly sure they were turbos - they're a different class of diesel engine, effectively, almost a high-speed diesel rather than the medium-speed ones as used in most diesel engines except deltics.

Wikiepedia says "The HST was the first high speed train in Britain: that is, the first train to travel at 125 mph (200 km/h). Its trade name was 'Inter-City 125', later changed to Intercity 125, and it was colloquially known as a 'Screamer', referring to the loud screaming noise made by the Napier turbocharger of the train's 2,250 bhp (1,678 kW) Paxman 'Valenta' engines"

not that they're guranteed to be right. I didn't think they were quite that high output originally.

'ere, this one's interesting:

wot, like traction control for trains? neat.

Actually I've long pondered the possibility of building a miniature version osf an diesel-electric train transmission for a 4x4. Probably using a 415V

3-phase generator and 4x AC motors, one for each wheel. Using AC motors would get access to easy speed control, since speed controllers for AC motors are commonplace nowadays.

Trouble is, it'd probably end up rather heavier than a normal gearbox.

On or around Thu, 26 Jan 2006 13:17:05 +0000 (UTC), beamendsltd enlightened us thusly:

yeah, but then so are the main bearings in the engine...run 'em without oil and they fail PDQ.

Same argument applies to not revving the nuts off a turbo engine from a cold start - let the oil start circulating properly first.

Yebbut you could power the whole shebang with one of the finest powerplants ever produced (IMO), a napier deltic! What a sound, what a rush! The only diesel ever made that is as plesent to listen to as a V8 petrol lump! ;-) Badger.

It could be the second batch were different - certainly the first batch were set up the same for their use in the RN's conventional submarines (the Valenta engine had been round for quite a while).

Indeed, it's a pity Crompton/Parkinson pulled out of the market - the Class 33 had some neat features and are very reliable - even the Southern Reigion couldn't break them!

The bloke who tried to be the programme excentric in the latter days of Tomorrows World has few diesel electric engines on his garden railway (6" guage or something). "Noisey" was the usual comment, but he'd be able to tell you the pit-falls. Mind you, I seem to recall at least one major car maker was looking at this sort of thing a few years back.

Richard

Correct, me quoting someone else's mistake I'm afraid. From the pinzgauer UK website;

"The new 5-cylinder 2.5 litre Volkswagen engine developed for the Pinzgauer"

I'm a little concerned now, I can hear the turbo spooling up in all my cars (apart from the plastic rocket, the turbo in that's not moved in

3 years unless I trip over the box) but don't know what a bad whine sounds like.

Hmm, I think I know what you're talking about now. The Garret on the plastic rocket made a noise that sounds like you've just described, the mechanic who was doing the service didn't spot it for what it was and told me the car was ready, bugger all power and a dreadful din coming quite unmistakably from the turbo and not the recirculating dump valve he'd blamed.. A quick removal of the exhaust from the turbo and a peek with a mirror spotted a big gap in the vanes, £300 sorted it out. I didn't take it back to that mechanic again despite him having worked on the model for about 25 years.

I'm surprised by the number of people who can't hear normal turbo whine, it's quite clear to me on all my cars, even the landy.

Yeah, I was starting with the easily diagnosed alternator belt squeal!

I used to drink that - lethal stuff.

On or around Thu, 26 Jan 2006 15:00:45 +0000, Ian Rawlings enlightened us thusly:

ain't that the same engine as the new VW vans?

though it may of course have been developed for the pinzgauer, for all I know...

On or around Thu, 26 Jan 2006 14:09:48 +0000 (UTC), "Badger" enlightened us thusly:

yeah, amazing engine. The Cunning Germans did much work with high-speed high-output diesel engines for aeroplanes during the war - something to do with not enough high-octane fuel. The Junkers Jumo was an inverted-V

2-stroke diesel, IIRC.

I read somewhere that the Deltic was derived from german research originally. could be wrong though.

On or around Thu, 26 Jan 2006 16:21:17 +0000, Nige enlightened us thusly:

I reckon they should dispense with the dressing-up of the cars as road cars too, either race road cars, or race race cars, but don't dress up race cars as road cars. Touring Cars is the same, F1 teams seem to have a habit of being bought by large car manufacturers and while the people, car and team home base don't change, suddenly it's a "BMW" or a "Renault" or a "Jaguar". At least some of them have some pedigree via engine deals.

I even saw a "Porsche 911" at a show that was entered in the Paris-Dakar, not a Porsche part on it of course, and while it had a

911-alike bodyshell perched on top of it, you'd have to be a total nut to think it was one.

Car racing TV coverage would be improved by much more in-camera shots too, driver-eye level or as close as you can get to it ideally.