LNER 800+801 combination on diesel-only lines

[crunchello]

Evening all,

Something I noticed today on a trip back from Edinburgh to Kings Cross was that we were diverted via the Durham coast line due to the engineering works.

The train was formed of a 800 and an 801 (https://www.realtimetrains.co.uk/service/gb-nr:C71423/2025-03-09/detailed for anybody who cares).

My understanding is that the 801s are electric-only other than emergencies - so how does this work across the diesel-only diversion routes? Does it use power from the front unit?

Many thanks

 

[JonathanH]

My understanding is that the 801s are electric-only other than emergencies - so how does this work across the diesel-only diversion routes?

The 5-car 800 is powerful enough to tow the 5-car 801, with the generating unit on the 801 providing hotel power to keep the air conditioning and lighting going on that unit. There is no cross feed.

None of the unelectrified diversionary routes involved are particularly quick.

 

[crunchello]

The 5-car 800 is powerful enough to tow the 5-car 801

So the 801 is in effect a "dead" unit being dragged by the 800?

Does anybody know the actual difference in speed/power etc between this and just having 2x 800s both capable of powering themselves?

 

[800301]

Evening all,

Something I noticed today on a trip back from Edinburgh to Kings Cross was that we were diverted via the Durham coast line due to the engineering works.

The train was formed of a 800 and an 801 (https://www.realtimetrains.co.uk/service/gb-nr:C71423/2025-03-09/detailed for anybody who cares).

My understanding is that the 801s are electric-only other than emergencies - so how does this work across the diesel-only diversion routes? Does it use power from the front unit?

Many thanks

Yes, it will power on 3 engines of the 800 and the 1 engine of the 801, not the fastest combination but still workable, to note is that if the1 engine in the 801 fails, it will lose it’s complete auxiliary power supply and will most likely have to be locked out of passenger use.

 

[hexagon789]

So the 801 is in effect a "dead" unit being dragged by the 800?

Does anybody know the actual difference in speed/power etc between this and just having 2x 800s both capable of powering themselves?

Yes, the 801's engine provides only hotel power for lighting, heating, air-con and auxiliaries but not any power to its traction motors. (It is able to move itself in emergency/sidings/depots at modest speed on its single engine, but on these diverts, the 800 provides all the traction power.)

An 800+801 combo will 'balance' at about 80mph on level track.

 

[deep south]

The Durham coast line used by LNER isn't particularly quick, the GC 180's seem to trundle down until they join the ECML on their schedules, and often have a few minutes to wait at Northallerton, often for 6 or 7 minutes, in case of any delays before joining the ECML "flights"

 

[IanXC]

Remember that a 9 car only has 5 generator units and I think can eventually get somewhere near 125mph, so 10 cars with 4 on diversionary routes with lower linespeeds seems reasonable.

 

[800001]

Remember that a 9 car only has 5 generator units and I think can eventually get somewhere near 125mph, so 10 cars with 4 on diversionary routes with lower linespeeds seems reasonable.

A 10 car only has 3 generator units providing power, the ones on the 800/2.

The one on the 801 only provides hotel power to the 801 unit, eg, air con, lights, toilets etc.

 

[IanXC]

A 10 car only has 3 generator units providing power, the ones on the 800/2.

The one on the 801 only provides hotel power to the 801 unit, eg, air con, lights, toilets etc.

Indeed as has been mentioned above. But some portion of the 9 car's 5 generator units must be providing hotel power anyway, so what is being used for traction power is not as dissimilar to a 10 car 801-800 combination as it would appear at first sight.

 

[Bald Rick]

Indeed as has been mentioned above. But some portion of the 9 car's 5 generator units must be providing hotel power anyway, so what is being used for traction power is not as dissimilar to a 10 car 801-800 combination as it would appear at first sight.

Essentially, an 800+801 10 car combo is just short of the power output, and all up weight, of a Deltic +10.

 

[hexagon789]

Essentially, an 800+801 10 car combo is just short of the power output, and all up weight, of a Deltic +10.

Power-at-rail from a five-car Azuma in diesel mode is about 1,800hp continuous including hotel power losses, so the power-to-weight ratio is about 3.7hp per tonne against 5.2hp per tonne for a Deltic + 10 Mk2 air-cons.

 

[GW43125]

I've done a couple of these formations on diversion, they usually seem quite happy to be trundling along at 60mph on the not-exactly-hilly Durham coast.

 

[1D53]

800+801 10 cars work generally fine on the lower speed routes - you just get issues in Autumn and on inclines - for example the combo is 'banned' between Leeds and Harrogate in Autumn.

 

[Bald Rick]

Power-at-rail from a five-car Azuma in diesel mode is about 1,800hp continuous including hotel power losses, so the power-to-weight ratio is about 3.7hp per tonne against 5.2hp per tonne for a Deltic + 10 Mk2 air-cons.

Fair enough - my arithmetic and assumptions on hotel load were slightly out. But the AC motors and distributed power on the 800s will help use that power slightly more effectively, which helps narrow the gap a bit.

 

[hexagon789]

Fair enough - my arithmetic and assumptions on hotel load were slightly out. But the AC motors and distributed power on the 800s will help use that power slightly more effectively, which helps narrow the gap a bit.

Initial acceleration will be better true, but as I stated above a 800+801 combo on diesel balances at about 80mph; a Deltic can still achieve 100mph even with 13 coaches.

 

[Bald Rick]

Initial acceleration will be better true, but as I stated above a 800+801 combo on diesel balances at about 80mph; a Deltic can still achieve 100mph even with 13 coaches.

Not on the Durham Coast it can’t!

 

[hexagon789]

Not on the Durham Coast it can’t!

No (I think linespeed is 70? so, indeed not quite high enough), but the original question I responded to asked the speed a 800+801 combo could achieve, which according to logs and data taken by the RPS is about 80mph.

 

[Wyrleybart]

I've done a couple of these formations on diversion, they usually seem quite happy to be trundling along at 60mph on the not-exactly-hilly Durham coast.

Also remembering that back in the day, the Grand Central drivers shut down the leading power car on their 2+5s and pottered around one one supplying traction and hotel power. To be fair though, that was still 2000 hp