Why are there no single or two-car EMUs?

[Mikey C]

Unless you decide as a country to electrify every line, it does seem logical that any route genuinely only needing a relatively infrequent 2 car units would be a low priority for electrification other than small sections of line in an otherwise electrified area

While the odd 2 car service has been operated in the London/South East such as the 456s on the South London Line, the 2 car units were more used to give flexibility in the lengths of services.

 

[Bringback309s]

Like 142's ?

No - having compliant 365's sat in sidings, awarding a franchise to a company replacing two year old trains (SWR) that then says its made a massive loss. I wasn't particularly commenting about DMU's or short EMU's, just what a cock up of an industry as a whole the UK rail industry is. I could go on!

 

[D365]

No - having compliant 365's sat in sidings...

Are there any operators who have been looking for a fleet of 19 pre-used EMUs in the last two years?

 

[30907]

Plenty of single car electric units in other countries

SNCF have quite a few 2-car units, but the only single cars I can think of in Europe are power cars that work with "loose" trailers, still surviving on Swiss narrow gauge lines (and minor Austrian lines?)

 

[4REP]

class 414 2Hap also existed but mainly worked with 4car emu like cigs/veps/ceps/beps and occasionally reps.

 

[AM9]

A single-car EMU would be fun, imagine how good the acceleration would be

That depends on how much power it's traction motors have.

 

[edwin_m]

There are. Possibly the biggest example is Thameslink. Off peak there is massive over capacity on the south of London routes (I have no experience of north of St Pancras, so that may not be the case there!)

That's a rather different issue. If Thameslink had gone for 4-car sets running singly in the off-peak (as they often did before the 700s) then they would be reasonably well filled. There is no need on this route (nor, I would argue, on most others) for a 2-car EMU.

 

[AM9]

I think the units ran as buffet unit to Clacton, non-buffet unit to Walton and the two-car were meant to add capacity and boost performance in the peaks, hence being only two-car.

When introduced, the standard consist of London to Clacton/Walton services was (from the country end), 309/3 - 4-car; 309-2 - 4-car griddle & 309/1. At Thorpe Le Soken, the front 4-car unit detached and served Frinton and Walton, then the rear 6 cars left for Clacton. On the up services, the Clacton section arrived at Thorpe first, and the Walton section joined to maintain the same configuration throughout the diagram.
In the late '60s/early '70s the busiest train of the day, the down 17:40 ran with two 2-car 309/1 units then a 309/2 and 309/3, - a 12-car 100mph train with 3364kW pulling 543 tons (nearly 9hp/tonne - high for the '60s). This service ran fast to Colchester and didn't split -only going to Clacton. Once clear of the signal checks up to Shenfield, this train really did show its heels!

 

[AM9]

There are. Possibly the biggest example is Thameslink. Off peak there is massive over capacity on the south of London routes (I have no experience of north of St Pancras, so that may not be the case there!) ...

The operations disruption of shuffling 4-car units around would seriously affect Thameslink units well outside the peaks. Overall, once inside the zones, there is fairly good patronage of the outer services, -the Sutton loop services as 8-car units slightly less. Energy wise, the additional rolling resistance of a 8 or 12-car unit vs a conventional 4-car unit is a comparatively small part of total requirements, and much of the energy used in acceleration is recovered in regeneration braking.

... The argument for fixed formation, long trains was capacity and the operational inconvenience and inefficiency of splitting, so yes that was the view taken. Conversely though, short DMU fleets are ordered with the reasoning that they can be coupled for peak times, or to serve multiple destinations after splitting. Experience shows this rarely comes to fruition. One man's efficiency is another man's waste of resources, it seems.

In areas with much smaller flows, peak train capacity can be met with part-time extensions of diesel stock, but the energy waste in DMUs is proportional to the weight of the vehicles and none is recovered during braking. As passenger levels increase in recently electrified areas away from the south-east, fixed 8-car sets might become more advantageous.

 

[Islineclear3_1]

class 414 2Hap also existed but mainly worked with 4car emu like cigs/veps/ceps/beps and occasionally reps.

They did work singly on the Lymington and Sheerness branches, Maidstone West, Dorking to Horsham backwaters and I'm sure, other branches on the former South Western Division; however, they were tagged onto peak hour main-line units to add additional capacity

 

[Islineclear3_1]

class 414 2Hap also existed but mainly worked with 4car emu like cigs/veps/ceps/beps and occasionally reps.

Due to the high hp rating of the 4Reps, I don't recall 2 Haps ever working with them unless there were ecs workings and a set of motors were cut out

 

[hwl]

That's a rather different issue. If Thameslink had gone for 4-car sets running singly in the off-peak (as they often did before the 700s) then they would be reasonably well filled. There is no need on this route (nor, I would argue, on most others) for a 2-car EMU.

It would have cost circa 20% more per vehicle to go for 4car on Thameslink vs actual 8/12 car mix along with additional driver requirement for splitting joining and ECS.

In the future multiple of 5 vehicle are the optimum for ETCS computer system cost minimisation hence the 5x 24m unit / half unit solution from Bombarider solutions for GA and LNR.

Short EMUs have:

• a significantly higher cost per vehicle
• are less energy efficient per vehicle
• have extra staff splitting and joining costs per vehicle

Newer EMUS now have regenerative braking so the running cost of longer EMUs has fallen.
Maintenance requirements for modern EMUs are also lower hence less need to be able to rotate the fleet through maintenance.

Reducing capacity off peak is now not seen as cost effective in many cases.

 

[30907]

They did work singly on the Lymington and Sheerness branches, Maidstone West, Dorking to Horsham backwaters and I'm sure, other branches on the former South Western Division; however, they were tagged onto peak hour main-line units to add additional capacity

Back in the early 70s there were single 2-HAP off peak workings out of Victoria - the xx50 Gillingham stoppers (and on the SED 8 and 10-HAP were normal in the peaks until more VEPs became available...)

 

[reddragon]

Because you wouldn't electrify a line that only had demand sufficient for a single carriage train?

Romford - Upminster branch barely needs 2 cars and was only electrified to get rid of a diesel island in the 1980's

The Marlow branch can only takes 2 cars and may get electrified for the same reason.

Perhaps converting an old unit to 2 cars could make sense in such cases.

 

[delt1c]

Romford - Upminster branch barely needs 2 cars and was only electrified to get rid of a diesel island in the 1980's

The Marlow branch can only takes 2 cars and may get electrified for the same reason.

Perhaps converting an old unit to 2 cars could make sense in such cases.

What would be the savings of converting a 4 car to 2car? 1st you have the cost of the conversion then savings would be neglible.

 

[edwin_m]

In areas with much smaller flows, peak train capacity can be met with part-time extensions of diesel stock, but the energy waste in DMUs is proportional to the weight of the vehicles and none is recovered during braking. As passenger levels increase in recently electrified areas away from the south-east, fixed 8-car sets might become more advantageous.

Also the maintenance cost of DMUs is higher overall and probably more dependent on mileage/time in service, so there is more incentive to minimize the number of cars with DMU operation than with EMU.

 

[Lockwood]

What would be the savings of converting a 4 car to 2car? 1st you have the cost of the conversion then savings would be neglible.

Well, for the case of Bourne End, so it would physically fit.

 

[AlexNL]

When you look abroad, you'll see that there are plenty of short EMUs.

For example, in the Netherlands. NS used to operate two car EMUs of the Mat '64 type (length: 52,1m), they still operate two-car SGMm units (length: 52,2m) and even their newest EMUs aren't that much longer. The three car versions of the SNG measures 59,6m in length and the three car FLIRT is 63,2m long.

Other operators have even shorter trains. R-Net's two car FLIRT trains are 45,7m long and the shortest ones of them all can be found in the east. The two car variants of the 'Spurt' (GTW) trains used on the Vechtdallijnen route are only 40,9m long.

 

[61653 HTAFC]

Perhaps converting an old unit to 2 cars could make sense in such cases.

Nothing available with a pantograph on a driving car, so a conversion wouldn't be easy!

 

[delt1c]

Well, for the case of Bourne End, so it would physically fit.

Wouldnt extending the platform be a better long term solution

 

[4REP]

Due to the high hp rating of the 4Reps, I don't recall 2 Haps ever working with them unless there were ecs workings and a set of motors were cut out

Reps had a index ratio of 14 so could do so. Reps could not work in multiple with 4 car emus even with their own class unless motors were isolated.

 

[Peter Sarf]

Back in the early 70s there were single 2-HAP off peak workings out of Victoria - the xx50 Gillingham stoppers (and on the SED 8 and 10-HAP were normal in the peaks until more VEPs became available...)

I seem to recall that , in their latter years, the 2-HAPs got fixed together in pairs becoming 4-CAPs. Not all of the 2-HAPs survived to this stage and I think they were converted for the Coastaway line. The number of 4-CAPs dwindled and, by 1988, these were used on Victoria to Medway (or beyond) services I think in pairs (8 coaches). I used them quite a lot in the evening and they were similar to EPBs but with a loo and some compartments. As for livery i think some HAPs were all over blue as opposed to blue & grey. But that might only have been once they became 4-CAPs.

 

[PeterC]

When introduced, the standard consist of London to Clacton/Walton services was (from the country end), 309/3 - 4-car; 309-2 - 4-car griddle & 309/1. At Thorpe Le Soken, the front 4-car unit detached and served Frinton and Walton, then the rear 6 cars left for Clacton. On the up services, the Clacton section arrived at Thorpe first, and the Walton section joined to maintain the same configuration throughout the diagram.
In the late '60s/early '70s the busiest train of the day, the down 17:40 ran with two 2-car 309/1 units then a 309/2 and 309/3, - a 12-car 100mph train with 3364kW pulling 543 tons (nearly 9hp/tonne - high for the '60s). This service ran fast to Colchester and didn't split -only going to Clacton. Once clear of the signal checks up to Shenfield, this train really did show its heels!

I would have been home from school by that time of the evening, I am sorry that I never saw that formation.

 

[Bob M]

If a 2-car third rail unit were available, the Lymington branch would be a good place for it.

 

[hexagon789]

When introduced, the standard consist of London to Clacton/Walton services was (from the country end), 309/3 - 4-car; 309-2 - 4-car griddle & 309/1. At Thorpe Le Soken, the front 4-car unit detached and served Frinton and Walton, then the rear 6 cars left for Clacton. On the up services, the Clacton section arrived at Thorpe first, and the Walton section joined to maintain the same configuration throughout the diagram.
In the late '60s/early '70s the busiest train of the day, the down 17:40 ran with two 2-car 309/1 units then a 309/2 and 309/3, - a 12-car 100mph train with 3364kW pulling 543 tons (nearly 9hp/tonne - high for the '60s). This service ran fast to Colchester and didn't split -only going to Clacton. Once clear of the signal checks up to Shenfield, this train really did show its heels!

Thank you for clarifying, seems I remembered some bits. Something I often wondered was how able the 309s were at actually reaching 100mph. Certainly a standard 10-car formation doesn't seem all that powerful by modern standards?

The other thing is how much 100mph running there was. From Modern Railways the GEML seems to have still been 90 max in 1962/3.

Just some observations and ponderings

 

[Lockwood]

Wouldnt extending the platform be a better long term solution

Only been there once (twice for the pedant, there and back), but I think there's a station car park or a road in the way.

 

[swt_passenger]

Only been there once (twice for the pedant, there and back), but I think there's a station car park or a road in the way.

It’s the main road, passing at track level, there used to be a level crossing when the line extended to High Wycombe. Anyway, a 4 x 20m EMU could fit the long platform at Bourne End, it’s only the reversal towards Marlow via the shorter platform that needs a short train, and I believe a 3 x 20m EMU would work anyway. It’s the lack of a suitable 3 car EMU in the recent batches that is the only issue. You’d need a special unit and a spare just for that branch...

 

[swt_passenger]

If a 2-car third rail unit were available, the Lymington branch would be a good place for it.

No point when they have enough 450s now, since the 707s came in. You’d need two units to have a maintenance spare, then by the time you add crew training, maintenance, spares holdings it just doesn’t make sense.

 

[nlogax]

If a 2-car third rail unit were available, the Lymington branch would be a good place for it.

Always struck me as the ideal place for a 456..

 

[D365]

Always struck me as the ideal place for a 456..

Again, not much point sending a unit all that way, and having to train local crews on it.