Most powerful UK passenger / test consist

[hexagon789]

16,400hp / 665t = 24.6hp/t

Still a little low for a 300km/h train, I think most of the TGVs are nearer 30hp per tonne iirc.

 

[Darandio]

A class 90 light engine - 7860hp and weighs 80 tonnes - about 96hp per tonne

How did you work out 7860hp for a Class 90?

 

[hwl]

How did you work out 7860hp for a Class 90?

I though it was 5,000HP /3728kW....
so 59.17hp/tonne

 

[sprinterguy]

How did you work out 7860hp for a Class 90?

It's the maximum rail power for the class, which is only a peak rating that can't be sustained indefinitely and the usual yardstick for power output is the continuous rating, which is of course 5000hp for a class 90 as noted by hwl.

 

[hexagon789]

How did you work out 7860hp for a Class 90?

Short-term rating is 7,860hp, continuous is 5,000; one reason why a 90 is better pulling away than a 91.

 

[Railperf]

Still a little low for a 300km/h train, I think most of the TGVs are nearer 30hp per tonne iirc.

Yes. Indeed they are.

 

[Darandio]

It's the maximum rail power for the class, which is only a peak rating that can't be sustained indefinitely and the usual yardstick for power output is the continuous rating, which is of course 5000hp for a class 90 as noted by hwl.

Short-term rating is 7,860hp, continuous is 5,000; one reason why a 90 is better pulling away than a 91.

Interesting, thanks.

 

[Railperf]

Short-term rating is 7,860hp, continuous is 5,000; one reason why a 90 is better pulling away than a 91.

Plus a Class 90 has much lower gearing.
I always thought the 7860hp was available when power was up in the yellow area of the ammeters
The difference with a Class 87 was that drivers had more manual control of the power level through the tap changer whereas the 90's power is controlled by microprocessors. The driver simply selecting 0 to 100 percent power.
But the 90s never felt as fast as the equivalent foreign locos of similar power.

 

[Railperf]

A class 90 light engine - 7860hp and weighs 80 tonnes - about 96hp per tonne

Does not qualify. Consist has to be a loco and the minimum amount of coaches to run at its top speed or faster under test.

 

[Railperf]

I recall Class 91s being tested with 5 Mk 4's. That would be around 22hp/t

 

[hexagon789]

Yes. Indeed they are.

I suppose though - one did reach 208mph, so they are no slouches, especially considering that was a longer set.

Plus a Class 90 has much lower gearing.
I always thought the 7860hp was available when power was up in the yellow area of the ammeters
The difference with a Class 87 was that drivers had more manual control of the power level through the tap changer whereas the 90's power is controlled by microprocessors. The driver simply selecting 0 to 100 percent power.
But the 90s never felt as fast as the equivalent foreign locos of similar power.

I believe 90s are quicker off the mark because the microprocessor will put down full power as soon as it can, but with 87s you can't really get into Notch 39 until about 50mph or you just get wheelspin from what I understand.

I recall Class 91s being tested with 5 Mk 4's. That would be around 22hp/t

Or 5 Mk3s and a powered Class 43 DVT, Mk3s being lighter and the 43 giving another 1,770hp.

 

[Railperf]

I suppose though - one did reach 208mph, so they are no slouches, especially considering that was a longer set.



I believe 90s are quicker off the mark because the microprocessor will put down full power as soon as it can, but with 87s you can't really get into Notch 39 until about 50mph or you just get wheelspin from what I understand.



Or 5 Mk3s and a powered Class 43 DVT, Mk3s being lighter and the 43 giving another 1,770hp.

Appx 25hp/t

 

[hexagon789]

Appx 25hp/t

I'll think of something to best the 30 mark!

 

[61653 HTAFC]

...
Or 5 Mk3s and a powered Class 43 DVT, Mk3s being lighter and the 43 giving another 1,770hp.

Though I don't think the 43 would be powering at that point early in the testing phase. IIRC the 43s initially just supplied ETS, until it was discovered that constantly idling wasn't doing the engines any good so they switched to also providing traction.

 

[hexagon789]

Though I don't think the 43 would be powering at that point early in the testing phase. IIRC the 43s initially just supplied ETS, until it was discovered that constantly idling wasn't doing the engines any good so they switched to also providing traction.

Train testing says changing to the 43s powering commenced during testing.

 

[61653 HTAFC]

Train testing says changing to the 43s powering commenced during testing.

Ah. Cheers for the correction, every day's a school day!

 

[hexagon789]

Ah. Cheers for the correction, every day's a school day!

I had thought exactly like yourself that it was when they started running 91s on HST sets in passenger service until I came across the page about 91 testing.

 

[hexagon789]

Found something a tad more powerful since - a test rake with TWO 91s, 5 Mk3a SLEPs and a Class 43 DVT. I make that up to 14,375hp or 31.5hp per tonne.

 

[Railperf]

Found something a tad more powerful since - a test rake with TWO 91s, 5 Mk3a SLEPs and a Class 43 DVT. I make that up to 14,375hp or 31.5hp per tonne.

Were both 91's and the DVT providing traction power? Or was one of the 91's hauling a 'dead' test consist? Would the ECML OLE have coped with such a power draw?

 

[xotGD]

The 68's running top and tail with three carriages for some of the passenger services must have a fairly high power to weight ratio for diesel power. I don't know how heavy the flask trucks are but there's been a pair of 88's pulling a single flask truck which means just shy of 11,000bhp although I realise in both cases both locos are not being used for power at the same time. I've seen a pair of 66's hauling a single flask and it looks quite bizarre having the two massive locomotives and one little truck.

On the Cumbrian Coast passenger turns only the front 68 provided power. Was it different when they worked out of Norwich?

 

[Peter C]

On a slightly more old-fashioned note, the Hawker Siddeley Kestrel (the HS4000):

By Phil Sangwell - HS 4000,Barrow Hill Open Day 1971Uploaded by oxyman, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=7064689


from Wikipedia (above and below quote):

Sale to Soviet Union[edit]
The locomotive was sold to the Soviet Union in 1971 for £127,000,[2] being shipped from Cardiff Docks to Leningrad docks by the MV Krasnokamsk[10] in July 1971.[1] On arrival in Russia, Kestrel was exhibited at the Moscow Rolling Stock Exhibition and then was moved to the All-Union Rail Transport Scientific Research Institute at Shcherbinka[11] where it was re-gauged to 1,520 mm (4 ft 11 27⁄32 in), and tested on a circular test railway[note 7] as well as being used on some parts of the Russian rail network.[3]

After testing of the locomotive the engine was removed for static testing, and the locomotive body ballasted for use in high load tests of other vehicles.[12]

The remains of the vehicle are believed to have been scrapped in 1993.[1]

The most powerful locomotive we had. And we sold it to the Russians, where they essentially hing, drew and quartered it for tests.

-Peter

EDIT:
Here is a photo of the Kestrel, apparently from Russia:

EDIT Part 2:

Here is another photo of the Kestrel, again from Russia, the final resting place of this engine.

 

[LLivery]

Great looking loco, shame it was scrapped.

 

[hexagon789]

Were both 91's and the DVT providing traction power? Or was one of the 91's hauling a 'dead' test consist? Would the ECML OLE have coped with such a power draw?

The caption says both 91s were powering and indeed it looks as though both pans were up.

 

[hexagon789]

The most powerful locomotive we had.

Well, most powerful diesel; most electrics can far exceed Kestrel's at-rail output.

Nevertheless, Kestrel was perhaps a taste of what the proposed 'Super' Deltic might've been like.

 

[507 001]

I would love to record that 0 to 60mph time - though a Class 87 could be quicker still depending on how quick the driver could work the tap changer!

Shove it straight into ‘run up’. Be ‘reet.

Indeed and it would also have been very easy getting up to 150 with that rake I imagine!

Getting it to stop again would be an entirely different matter.

 

[hexagon789]

Getting it to stop again would be an entirely different matter.

If the rails were dry, the hydro-kinetic brakes should do the job quite well, 15%g deceleration iirc.

 

[Bornin1980s]

I believe 90s are quicker off the mark because the microprocessor will put down full power as soon as it can, but with 87s you can't really get into Notch 39 until about 50mph or you just get wheelspin from what I understand.

I don't think any microprocessor controlled loco would be programmed to put down 100per cent power at first opportunity. That would be a waste of energy. A skilful driver, on the other hand, can push an analogue control system as hard as he wants, with no programmed limits. In the days of steam, I believe, working locos beyond their design capabilities was quite routine.

BTW, are the Cl 90s still on their original 1980something microprocessors.

 

[hexagon789]

I don't think any microprocessor controlled loco would be programmed to put down 100per cent power at first opportunity. That would be a waste of energy. A skilful driver, on the other hand, can push an analogue control system as hard as he wants, with no programmed limits. In the days of steam, I believe, working locos beyond their design capabilities was quite routine.

BTW, are the Cl 90s still on their original 1980something microprocessors.

I'm just repeating what I was told that on an 87 you couldn't go into Notch 39 (full power + weak field) at less than about 50mph or you'd tend to get wheelspin and the anti-slip brake would try and correct it, whereas with 90s you could pull the power controller all the way back from a standing start and the traction system would give full power at around 30 mph.

Both classes are 7,860hp maximum output, so I would still suggest a 90 is quicker off the mark based on that but as I say I don't have first-hand experience of that.

 

[alangla]

Heading through Calton Tunnel with a 90 on the back of 4 (I think) Mk3s was certainly an experience. It certainly felt like it was fully opened up as soon as it cleared the pointwork at Waverley.

 

[hexagon789]

Heading through Calton Tunnel with a 90 on the back of 4 (I think) Mk3s was certainly an experience. It certainly felt like it was fully opened up as soon as it cleared the pointwork at Waverley.

Yes I think the North Berwick shuttles were 90+4 TSOs+DVT. I imagine they fairly shifted!