Loco Hauled vs Multiple Units

[L+Y]

Is there anything that could conceivably tilt the economic balance back in favour of locomotive hauled workings to at least say 1960s/70s levels? Or are the advantages of multiple units so overwhelming that barring the odd pocket, there'll never be any meaningful return to locos and stock?

I'd half wondered if battery weights and sizes could force the balance back in favour of containing all the kit in a separate locomotive, but that's purely speculation without any actual knowledge of the topic!

 

[zwk500]

Is there anything that could conceivably tilt the economic balance back in favour of locomotive hauled workings to at least say 1960s/70s levels? Or are the advantages of multiple units so overwhelming that barring the odd pocket, there'll never be any meaningful return to locos and stock?

Not really, no. You might get some push-pull sets find favour again but in general the need for high acceleration and the ability to put carriages quickly on and take them off again is too valuable, and Loco-hauled can't handle that. Loco hauled also requires more infrastructure and staff, something the modern railway is moving away from.

The handful of loco-hauled services that have run since the mid-2000s have generally either been because of a need to put a train out quickly and the Loco was there with drivers able to take it on (or be trained on it relatively quickly), cheaply. Even parcels traffic has moved towards MUs, with the Mail 325s and the 319/769 attempt by Orion.

I'd half wondered if battery weights and sizes could force the balance back in favour of containing all the kit in a separate locomotive, but that's purely speculation without any actual knowledge of the topic!

If anything battery weights boost the argument for distributing the weight along the length of the train.

 

[RobShipway]

Other than Trans Pennine MK5A & class 68, Caledonian Sleeper MK5 and special trains like the Belmond Pullman coaches, then I have to agree with @zwk500 comment.

 

[Western 52]

It would be interesting to see the figures for TfW Mk4 services compared to running more 197s!

 

[JKF]

Automatic coupling would be one thing that would speed up loco changes/addition, my memories of the 80s are of staff spending several minutes crawling about in the four foot to connect up locos and stock to allow reversals. Dwell times were consequently quite long. Having small battery locos that could quickly attach to electric stock to haul over non-electrified sections (saving on the cost/weight of bimode) is about the only thing I can think of that would be useful, or for branch line working where a loco remains at one end charging while a readily charged unit takes the stock back. Some sort of battery swap would likely be more efficient in terms of material and staffing though.

 

[HSTEd]

Ultimately, with multiple units, you can cram batteries into whatever nooks and crannies the train has. With a locomotive they have to be put in the locomotive.

If anything I'd expect batteries to tilt the balance even further towards multiple units, even leaving aside all the operational advantages.

 

[Sorcerer]

Is there anything that could conceivably tilt the economic balance back in favour of locomotive hauled workings to at least say 1960s/70s levels? Or are the advantages of multiple units so overwhelming that barring the odd pocket, there'll never be any meaningful return to locos and stock?

I made a similar thread a while ago, but the short answer is no. For things such as metro, commuter and regional routes, multiple units are more efficient because of quick turnaround times and enabling faster rates of acceleration and deceleration. The only place you might get a return of loco-hauled stock is long distance intercity routes because the cost-benefit of both MUs and loco-hauled stock are similar, but generally the market now trends for multiple units. It's also dependent on the type of loco-hauled stock. A push-pull might be an option. A single loco with shunting movements will definitely not be practical for today's modern railway practices.

 

[Snow1964]

There is general advantages to multiple units.

Locos only really work with specialist rolling stock: sleeping cars, tourist (panoramic view or dining train cars etc. Obviously driving trailers make it easier for reversals.

The main advantage of individual coaches is that it easy to adjust formations where there are seasonal variations. The Southern Railway was very good at a halfway house, kept its coaches in fixed formation sets, but had strengthening sets.

Where we have tended to be poor in UK is to form our express multiple units as clunky multiples. Full length trains or half trains only, never any variation (except the tiny quantity of class 807s).

Even the half trains don't have any facility to insert a 2 coach strengthening set between units (as LSWR did with its electric units over 100 years ago). There is no auto coupler mid set where a strengthening set can be added even mid unit for a busy week.

 

[6Gman]

There is general advantages to multiple units.

Locos only really work with specialist rolling stock: sleeping cars, tourist (panoramic view or dining train cars etc. Obviously driving trailers make it easier for reversals.

The main advantage of individual coaches is that it easy to adjust formations where there are seasonal variations. The Southern Railway was very good at a halfway house, kept its coaches in fixed formation sets, but had strengthening sets.

Where we have tended to be poor in UK is to form our express multiple units as clunky multiples. Full length trains or half trains only, never any variation (except the tiny quantity of class 807s).

Even the half trains don't have any facility to insert a 2 coach strengthening set between units (as LSWR did with its electric units over 100 years ago). There is no auto coupler mid set where a strengthening set can be added even mid unit for a busy week.

In modern finances there are few circumstances which would justify having expensive strengthening sets only to be used "for a busy week".

And the classic "loco on the front end" (as opposed to DVT-style working) would bring Euston to a stand with current frequencies. I used to do loco diagrams in Class 86/87 days and it was difficult enough then!

 

[popeter45]

big advantage to LHCS is when you have more than one use for the locomotives, e.g. using them for passengers by day, cargo or sleepers by night. thats why the class 91's were LHCS not EMU's

while back in the past that made enough sence these days there just isnt enough frieght to justify all the extra locomotives while on the continent in many places they do have enough mixed use to justify LHCS to save costs there

also with a locomotive you lose a entire carriage of capacity vs MU's

In modern finances there are few circumstances which would justify having expensive strengthening sets only to be used "for a busy week".

And the classic "loco on the front end" (as opposed to DVT-style working) would bring Euston to a stand with current frequencies. I used to do loco diagrams in Class 86/87 days and it was difficult enough then!

thats one area i feel the HST's and DVT's worked well, you could extend them with extra carriages as needed but didnt need to swap locomotives at each end. apart from a HST version never being designed, nothing really stopped the idea of a HST adding sleeper carriages late at night to become a sleeper train then detaching to become the first train of the day

Automatic coupling would be one thing that would speed up loco changes/addition, my memories of the 80s are of staff spending several minutes crawling about in the four foot to connect up locos and stock to allow reversals. Dwell times were consequently quite long. Having small battery locos that could quickly attach to electric stock to haul over non-electrified sections (saving on the cost/weight of bimode) is about the only thing I can think of that would be useful, or for branch line working where a loco remains at one end charging while a readily charged unit takes the stock back. Some sort of battery swap would likely be more efficient in terms of material and staffing though.

yea standardised automatic coupling would have gone a long way as would allow stuff like diesel/battery drags of EMU's or even adding a cargo wagon to the back of a MU's for bikes or camping gear during summer months akin to what scotrail did with the 153's on the highland line

 

[AngusH]

Some unlikely but marginally possible ideas:

(a) One possibility I can see would be a hypothetical banning, on safety or pollution grounds, of diesel engines under passenger carriages

If it occurred it would then require diesel engines either to be banned entirely or moved into a non passenger carriage which might end up as a locomotive simply as a convenience.

(b) Equally banning of batteries under passenger carriages, probably for the fire risk, which is more plausible.


(c) Diesel engines might also be banned from being used in the middle of trains, on grounds of pollution, at enclosed stations (like Birmingham New Street) which could perhaps see some move towards a single engine outside the over-roofs.

(d) I could also imagine a hydrogen powered train where the regulations prohibited passengers in the same vehicle as the hydrogen tank. (Not currently required AFAIK in any actual hydrogen train)

(e) One further thought is that at some future point diesel engines may simply not be available in a size that fits under a multiple unit and would have to be put into a locomotive unit. (Although you might as well just stick one in an end carriage on a multiple unit)


Essentially I see this as either regulatory or practical problems.

Whether or not any of these would also remove traction motors from the carriages (which would probably still be a multiple unit) is unknown and most of these are rather improbable.


Alternatively I could see a future setup where every carriage is an individual unit and they get grouped together for different runs rather than being a single multiple unit train.
Think in this case, an intercity train made up of 9 electric single car units combined together (one with a pantograph) and a through power bus, perhaps with a self-powered generator (locomotive) attached on the end to provide power on non-electrified lines. It's not exactly hauled coaching stock, but it's getting quite close.

 

[HSTEd]

Even the half trains don't have any facility to insert a 2 coach strengthening set between units (as LSWR did with its electric units over 100 years ago). There is no auto coupler mid set where a strengthening set can be added even mid unit for a busy week.

The problem with this sort of model is that you end up with lots of expensive rolling stock sitting around doing nothing.

Operating a 7-coach multiple unit isn't that much more expenisve than a 5-coach one. It has the same staff costs, the same pathing costs etc.

You are talking about marginal electricity/diesel and marginal wear and tear.
Against that is all the hassle and staff required to actially put these extra vehicles in and out of the formation.

I'd suggest the latest attempt at calibrating supply to demand with the IEPs has not gone particularly well - with the 5-car units ending up to be an operational headache.

 

[GRALISTAIR]

I miss traveling behind locomotives