DRS Class 88 - electro-diesel

[nightstar.train]

Am I missing something here?

 

The loco is listed as being only 700kW under diesel power, that's under 1000hp...so less than a class 20? Yet it has 4000 bhp under electric guise, about the same as a class 86?

 

The 20's were used in pairs, so what is the point of this loco?

What they're mainly intended for is things like non electrified sidings off an electric mainline, or short hopes down a small branch line off an electric line. They're not intended for say going from Felixstowe to the ECML on diesel power alone.

 

Still a very useful bit of kit though.

[cheesysmith]

I've often wondered why they don't put HST power cars back on the Mk4 sets in lieu of the DVT's as that would give some additional plug door hybrid sets that could go all the way to Aberdeen  - obv once the HST current uses are finished  and the Mk3's have been converted to timer wagons / parcels  / roller disco  ( delete as applicable ) 

Doesn't work. The mk4s, like all other coaching stock uses DC ETH but the HST power cars use 3phase AC for the ETH. Also, you cannot just rectify it as the ETH to the HST coaches is designed it that the AC three phase cycles varies with engine revs, but the voltage stays the same (or is it the phase stays the same and the volts alter, can never remember). This means that the electrics in the ETH on mk3 HST coaches use standard 3phase industrial equipment, doesn't require a motor alternator set (BR had a lot of trouble with these on the AC mk2 coaches), and the AC on the coaches keeps working whatever the engine revs of the power cars, it just works slower at lower revs. It is also why HSTs were classed as DMUs for so long, as the coaches could not be supplied by normal ETH supply.

[Titan]

One question, Does this loco manage the same maximum T.E. on diesel as it does on electric?

[Fat Controller]

Am I missing something here?

 

The loco is listed as being only 700kW under diesel power, that's under 1000hp...so less than a class 20? Yet it has 4000 bhp under electric guise, about the same as a class 86?

 

The 20's were used in pairs, so what is the point of this loco?

The electric rating is 4MW, which converts to 5364 bhp. As others have posted, the diesel engine is strictly for 'last mile' movements; I could envisage such a loco working under the wires to a freight terminal, then using diesel power to run round and shunt. At the low speeds such manouevres are carried out at, the lack of diesel power wouldn't be a problem, as the loco would still be the equivalent of almost three Class 08s.

[Glorious NSE]

The electric rating is 4MW, which converts to 5364 bhp. As others have posted, the diesel engine is strictly for 'last mile' movements; I could envisage such a loco working under the wires to a freight terminal, then using diesel power to run round and shunt. At the low speeds such manouevres are carried out at, the lack of diesel power wouldn't be a problem, as the loco would still be the equivalent of almost three Class 08s.

Probably enough also to get you past any temporary wiring problems/isolations as well.

 

With more electrification underway (complete with a lot of financial pressure,) I think they make a lot more sense - no need to either wire up lots of sidings, or reconfigure how yards work so that you can hand over from a straight electric to a diesel to shunt the train.

They might also change how viable it is to wire some important freight corridors. For instance I suspect running electrics to Felixstowe would be much easier to achieve (not to mention cheaper!) if you only had to wire the single lines towards the terminals (say as far as Felixstowe Beach and the bottom of the bank to North/Central terminals) but none of the terminals themselves.

 

 

[Oakydoke]

I've often wondered why they don't put HST power cars back on the Mk4 sets in lieu of the DVT's as that would give some additional plug door hybrid sets that could go all the way to Aberdeen.....

Would a single HST power car have sufficient grunt to haul a loaded mk4 set and class 91 and maintain timings?

More importantly, what about the lack of redundancy in using a single Diesel engine?

[Allegheny1600]

Am I missing something here?

 

The loco is listed as being only 700kW under diesel power, that's under 1000hp...so less than a class 20? Yet it has 4000 bhp under electric guise, about the same as a class 86?

 

The 20's were used in pairs, so what is the point of this loco?

 

 

One question, Does this loco manage the same maximum T.E. on diesel as it does on electric?

If I understand it correctly,

The loco has plenty of power on tap in electric mode for hauling heavy trains at speed.

In diesel mode, it can still haul the same weight of train, only at a much reduced speed.

 

Horsepower doesn't neccessarily equate to tractive effort, it is what is required to get the load up to speed.

Any more explanation than that and you'd need much more knowledge of physics than I have!

Cheers,

John.

[JeffP]

Thanks for the replies. I'd got it into my head it was 3MW too. D'oh!

[jonny777]

Having seen the photo, all I can say is phew!

 

As an old stager, initially I had thoughts of the old class 88 being re-born, i.e. a 25kv version of the class 58.

[Red Baron]

Doesn't work. The mk4s, like all other coaching stock uses DC ETH but the HST power cars use 3phase AC for the ETH. Also, you cannot just rectify it as the ETH to the HST coaches is designed it that the AC three phase cycles varies with engine revs, but the voltage stays the same (or is it the phase stays the same and the volts alter, can never remember). This means that the electrics in the ETH on mk3 HST coaches use standard 3phase industrial equipment, doesn't require a motor alternator set (BR had a lot of trouble with these on the AC mk2 coaches), and the AC on the coaches keeps working whatever the engine revs of the power cars, it just works slower at lower revs. It is also why HSTs were classed as DMUs for so long, as the coaches could not be supplied by normal ETH supply.

 

My post was with a wry smile and tongue moving towards the cheek   - I know it isn't easy to do.

[Baby Deltic]

Another baboon faced monstrosity.

[ColinK]

I'm at Oxenholme today, where some major engineering work is taking place. A class 70 brought a long train of open bogie waggons into the station and has drawn its train forward one waggon at a time as ballast is being dug up and replaced. This has taken several hours, during which time the class 70 has been using lots of fuel. Perhaps this type of job would suit a 88. Bring the train up the WCML on electric power, use the small diesel engine to shunt the waggons.

[JeffP]

Another baboon faced monstrosity.

That's baboonist!

[Reorte]

Another baboon faced monstrosity.

They're one of the few new things I actually quite like. Admittedly not straight on from the front. Perhaps it's to scare off people who are where they shouldn't be

[Satan's Goldfish]

Would a single HST power car have sufficient grunt to haul a loaded mk4 set and class 91 and maintain timings?

More importantly, what about the lack of redundancy in using a single Diesel engine?

I stumbled over a video shot at Peterborough the other night, one of the things that grabbed my attention was a HST passing through at speed, but there was no power car on the tail end. So yes, it's possible.

[FelixM]

Do you have a link for that, please?

[Satan's Goldfish]

Do you have a link for that, please?

it comes in at 5.30

 

https://m.youtube.com/watch?v=h4CyeGWL6pU

[cheesysmith]

A HST has more than enough grunt on one power car. In fact, it was alway preferable to run a HST with a failed power car on one end rather than put a loco on it. The single power car would have better performance (acceleration/top speed) and would also be able to operate at over 100mph, and also would have faster reacting brakes.this is due to the EP brake in the rear power car proper gating the brake application from both ends of the train. There was/is only a few places on the network where a single power car isn't permitted (the south Devon banks being one that springs to mind), which I think has more to do with the risk of burning out the traction motors rather than the lack of power from the HST power car as such.

[The Stationmaster]

A HST has more than enough grunt on one power car. In fact, it was alway preferable to run a HST with a failed power car on one end rather than put a loco on it. The single power car would have better performance (acceleration/top speed) and would also be able to operate at over 100mph, and also would have faster reacting brakes.this is due to the EP brake in the rear power car proper gating the brake application from both ends of the train. There was/is only a few places on the network where a single power car isn't permitted (the south Devon banks being one that springs to mind), which I think has more to do with the risk of burning out the traction motors rather than the lack of power from the HST power car as such.

 

The South Devon banks restriction is due to the inability of a single power car to restart the train consistently in all weather/rail conditions.  On a good rail on the right kind of day the only awkward spot would be the steepest part of Dainton, bad rail/grotty weather and the 'dodgy' spot becomes much larger.

 

The other problem of working without a rear power car is if the train needs assistance in an emergency as there is no way of coupling a loco to it without a translator vehicle (that doesn't have to be anything special - just something with drop head Buckeyes).

[newbryford]

88001 has been running around the Velim test track in both modes.

 

http://www.mainlinediesels.net/index.php?nav=1000001&lang=en&id=8832&action=shownews#.Vyip4E1wa70

 

http://www.vladanfoto.cz/clanky-british-rail-class-88-in-cz.html

 

Cheers,

Mick

[Classsix T]

Another baboon faced monstrosity.

Could've been worse then...at least it's the face.

C6T.

[Ron Ron Ron]

88001 has been running around the Velim test track in both modes.

 

http://www.mainlinediesels.net/index.php?nav=1000001&lang=en&id=8832&action=shownews#.Vyip4E1wa70

 

http://www.vladanfoto.cz/clanky-british-rail-class-88-in-cz.html

 

Cheers,

Mick

 

 

Hauling loaded coal hoppers.....

 

http://www.mainlinediesels.net/index.php?nav=1000001&file=stadler_2851_62&action=image#title

 

http://www.mainlinediesels.net/index.php?nav=1000001&file=stadler_2851_63&action=image#title

 

 

.

[ColinK]

By the time it gets here there will be no coal trains running.

[newbryford]

(Ta to Si for the heads up)

 

Reported on wnxx that 88002 will be in the UK for the upcoming open day at Gresty Bridge depot on July 23rd.

 

Cheers,

Mick

[Nearholmer]

http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/class-88-ukdual-electro-diesel-locomotive-unveiled.html

 

Kevin