Class 801s emergency power pack

[grangergranger]

I have a question. (My bad if its been said somewhere). I know that the Class 801s have an emergency power pack engine which reaches speeds of 30mph.
However, Does anybody know the Range of the power pack as well as the horsepower.

 

[PudseyBearHST]

I have a question. (My bad if its been said somewhere). I know that the Class 801s have an emergency power pack engine which reaches speeds of 30mph.
However, Does anybody know the Range of the power pack as well as the horsepower.

It’a just one generating unit on a Class 801 as oppose to 3/5 on a Class 800 depending on whether it’s 5/9 coaches long. The generating unit is the same as the Class 800 apart from there is physically only one of it located in the second standard class coach. Each generating unit produces a power output of 750hp. Not sure about range but it’s obviously going to be taken out of service as soon as possible and I think maximum speed is 45mph.

 

[class26]

It’a just one generating unit on a Class 801 as oppose to 3/5 on a Class 800 depending on whether it’s 5/9 coaches long. The generating unit is the same as the Class 800 apart from there is physically only one of it located in the second standard class coach. Each generating unit produces a power output of 750hp. Not sure about range but it’s obviously going to be taken out of service as soon as possible and I think maximum speed is 45mph.

I think max speed is 30 mph or at least that was in the tender outline. Please correct if wrong.

 

[hexagon789]

I think max speed is 30 mph or at least that was in the tender outline. Please correct if wrong.

I've seen 25, 30 and 40mph, no idea which is the correct design speed. It may be that they can go faster irl than the designated brief intended on one engine hence the discrepancy?

 

[route:oxford]

I've seen 25, 30 and 40mph, no idea which is the correct design speed. It may be that they can go faster irl than the designated brief intended on one engine hence the discrepancy?

Uphill or downhill?

 

[PudseyBearHST]

I think max speed is 30 mph or at least that was in the tender outline. Please correct if wrong.

Manual says 45mph but whether you would get up to it is a different matter- gradient, 5 vs 9 car, etc...

 

[Wallsendmag]

Ive seen a report of a LNER 801 reaching 45 on diesel

 

[plugwash]

I'd think it would likely make quite a difference whether the train was 5 car or 9 car.

 

[class26]

Ive seen a report of a LNER 801 reaching 45 on diesel

When I quoted 30 mph I was quoting from the original specifications issued by the DFT that it should be able to travel "self propelled" at 30 mph. No doubt with a tail wind etc it would eventually reach a little more

 

[hexagon789]

Uphill or downhill?

I assume level.

 

[hexagon789]

When I quoted 30 mph I was quoting from the original specifications issued by the DFT that it should be able to travel "self propelled" at 30 mph. No doubt with a tail wind etc it would eventually reach a little more

Perhaps 31mph?

 

[Railperf]

I would imagine any speed specified must be the minimum achievable. But i'm sure more than 45mph would be attainable downhill with a favourable tailwind.

 

[Railperf]

What is the capacity of the fuel tank on an 801?

 

[hexagon789]

What is the capacity of the fuel tank on an 801?

1.35m^3 which would be 1350L I assume?

 

[gingertom]

not sure how accurate this is but I'm pretty sure I read somewhere a while back that the 5-car 801 was to have one diesel power pack and 9-car was to have two.

 

[Rob F]

Does the single power pack only drive the axles of the vehicle in which it is fitted or does it drive all powered axles?

 

[PudseyBearHST]

not sure how accurate this is but I'm pretty sure I read somewhere a while back that the 5-car 801 was to have one diesel power pack and 9-car was to have two.

As I’ve said before, one Generating Unit in second standard class vehicle from the front whether it be 5 coach or 9 coach.

Does the single power pack only drive the axles of the vehicle in which it is fitted or does it drive all powered axles?

Just the powered axles of the vehicle to which it is fitted just like any/most other engine or traction motor. I need to check but pretty sure it’s just the inner axles which are powered so axles 2 and 3.

 

[norbitonflyer]

Just the powered axles of the vehicle to which it is fitted just like any/most other engine or traction motor.

Most - The "Blue Pullman" units being the best-known exception. To reduce weight over the leading bogie of the power car (which was under the engine), that bogie was unpowered, but there was a power bogie under the adjacent end of the second car instead. (so the wheel arrangement for a six car unit was 2-Bo + Bo-2 +2-2 + 2-2 +2-Bo + Bo-2 )

 

[PudseyBearHST]

Most - The "Blue Pullman" units being the best-known exception. To reduce weight over the leading bogie of the power car (which was under the engine), that bogie was unpowered, but there was a power bogie under the adjacent end of the second car instead. (so the wheel arrangement for a six car unit was 2-Bo + Bo-2 +2-2 + 2-2 +2-Bo + Bo-2 )

Yes, thats why within seconds of posting, I edited it to add the word most because there’s always an exception on the railway

 

[aleggatta]

it would be interesting to know the rate in which the fuel is turned over on these emergency powerpacks. I know that my grandfathers vintage tractor hates the modern diesel, and has to have an additive put in the tank to stop the diesel sludging up (the tractor is left for months on end in its 'pristine' condition with fuel in tank, much like I expect these powerpacks to!). It would be unfortunate for the fuel to be sludged up just at the time the powerpack is required for use!

 

[PudseyBearHST]

it would be interesting to know the rate in which the fuel is turned over on these emergency powerpacks. I know that my grandfathers vintage tractor hates the modern diesel, and has to have an additive put in the tank to stop the diesel sludging up (the tractor is left for months on end in its 'pristine' condition with fuel in tank, much like I expect these powerpacks to!). It would be unfortunate for the fuel to be sludged up just at the time the powerpack is required for use!

Fuel from the fuel tank gets filtered and goes through low pressure and high pressure pumps before it gets sent to the injector.

 

[aleggatta]

Fuel from the fuel tank gets filtered and goes through low pressure and high pressure pumps before it gets sent to the injector.

whilst I appreciate that, the way the diesel sludges up it just blocks the diesel filter, so no diesel can get to the pumps!

 

[hexagon789]

I need to check but pretty sure it’s just the inner axles which are powered so axles 2 and 3.

I thought all axles on 80x motor cars were driven? The traction motors are not all that powerful so having only two per power car doesn't seem sufficient, unless you meant the emergency power pack only supplies two motors in recovery mode?

 

[PudseyBearHST]

I thought all axles on 80x motor cars were driven? The traction motors are not all that powerful so having only two per power car doesn't seem sufficient, unless you meant the emergency power pack only supplies two motors in recovery mode?

Yes, thanks for correcting me. I’m getting confused with other traction.

 

[hexagon789]

Yes, thanks for correcting me. I’m getting confused with other traction.

It does generally seem to be the more common arrangement with 390s and 22x being set up that way

 

[Rob F]

Just the powered axles of the vehicle to which it is fitted just like any/most other engine or traction motor. I need to check but pretty sure it’s just the inner axles which are powered so axles 2 and 3.

Thanks. The reason I asked is that 80X must have a power bus for when running on AC, so I wondered if the gensets fed into the power bus. The 769 has perhaps demonstrated that this would not be as simple as it seems.

 

[D365]

Thanks. The reason I asked is that 80X must have a power bus for when running on AC, so I wondered if the gensets fed into the power bus. The 769 has perhaps demonstrated that this would not be as simple as it seems.

OT but in the case of the Class 769, they do feed into the 750V DC bus. The power packs "emulate" a third rail supply, albeit with a much reduced power output.

 

[gingertom]

Thanks. The reason I asked is that 80X must have a power bus for when running on AC, so I wondered if the gensets fed into the power bus. The 769 has perhaps demonstrated that this would not be as simple as it seems.

I've just re-read the Hitachi release on the high level design. Ont his point it is clear: the traction converters take from either the AC bus OR the genset, the genset doesn't feed power into the AC bus.
The article also confirms that there's only one power pack in a 5 or 9 car set, so there's 2 if pair of units are connected. So it a 9 car loses AC don't expect performance miracles on a single genset. Page 42. https://www.hitachi.com/rev/pdf/2014/r2014_10_105.pdf

 

[edwin_m]

I've just re-read the Hitachi release on the high level design. Ont his point it is clear: the traction converters take from either the AC bus OR the genset, the genset doesn't feed power into the AC bus.
The article also confirms that there's only one power pack in a 5 or 9 car set, so there's 2 if pair of units are connected. So it a 9 car loses AC don't expect performance miracles on a single genset. Page 42. https://www.hitachi.com/rev/pdf/2014/r2014_10_105.pdf

I think there is some confusion here, as there must be two AC buses. One takes 25kV from the pantographs (on both end cars, only one raised at a time) to the transformers (in one or both end cars). This must pass through all the intermediate cars with no electrical connection to them. The other takes the power at a suitable voltage from the transformers to the supply converters in electric mode, therefore must be AC not DC. In diesel mode it appears each GU drives its own local supply converter only, so must be disconnected from the lower voltage bus, which also avoids the issue of having to get multiple gensets to feed in phase onto the same bus. There must also be yet another bus, probably on the DC side of the traction converters, which allows one GU to power the entire train's auxiliaries and may also allow traction power to be cross-fed to traction converters on other cars.

 

[gingertom]

I think there is some confusion here, as there must be two AC buses. One takes 25kV from the pantographs (on both end cars, only one raised at a time) to the transformers (in one or both end cars). This must pass through all the intermediate cars with no electrical connection to them. The other takes the power at a suitable voltage from the transformers to the supply converters in electric mode, therefore must be AC not DC. In diesel mode it appears each GU drives its own local supply converter only, so must be disconnected from the lower voltage bus, which also avoids the issue of having to get multiple gensets to feed in phase onto the same bus. There must also be yet another bus, probably on the DC side of the traction converters, which allows one GU to power the entire train's auxiliaries and may also allow traction power to be cross-fed to traction converters on other cars.

I think you're right with respect to the 25kV, in that either pantograph can deliver power to both transformers on a 9-car set. I don't think gensets can cross feed adjacent cars for traction purposes* but static converters do have multiple inputs available to them so auxiliaries can be cross fed.

* OT for this thread but I am wondering how the 810s are going to get their traction power from the gensets to the traction converters: 4 gensets, 3? powered vehicles? We could see 4 powered vehicles each with 3 traction motors instead of the 4 as fitted to the 800/801/802 giving a 2-2+B0-A1+B0-A1+B0-A1=B0-A1 wheel arrangement. Keeps the powered vehicles self contained.