How efficent are diesel trains?

[andy13]

I was wondering how much fuel a class 57 for example, uses every mile on a flat run, and how much more pulling a pendolino?

Surely a class 153 can't use much more than a double decker bus...

 

[rail-britain]

A diesel loco will typically use one gallon per mile
The Class 47 could do 550 miles on standard fuel tanks

A two car diesel multiple unit will use about the same

 

[andy13]

soi take it the fuel tanks are massive

does a loco use much more pulling a rake of coaches though?

 

[generalvegitable]

it would probably use up a bit more fuel, but think about it, if a train was doing 1mpg and had 200 people on it it would still be outperforming in fuel efficiency the equivalant amount of cars/busses required to carry that amount of people

 

[rail-britain]

A diesel loco can idle for about one hour on one gallon
In effect a class 47 could idle for 3 weeks and then it would be empty!
However this is reduced by about 20% when the loco is supplying ETH

The 550 mile range is based on "normal" operational use
Usually the idle spells are ignored due to the small fuel usage

 

[Metroland]

http://www.dft.gov.uk/pgr/rail/researchtech/research/railemissionmodel.pdf

 

[rail-britain]

http://www.dft.gov.uk/pgr/rail/researchtech/research/railemissionmodel.pdf

What page / section are we looking for?
Table 5 for diesel - shame they use kg/km rather than litres (or 1.176 litres = 1 kg)
Table 8 for electric
Although there are some BIG discrepancies between those and what Network Rail have for electric!

 

[j0hn0]

A diesel loco will typically use one gallon per mile
The Class 47 could do 550 miles on standard fuel tanks

A two car diesel multiple unit will use about the same

If this is true then why were voyagers and meridians built?

Are units so much more convenient that it is the equivalent of the extra fuel used?

 

[generalvegitable]

If this is true then why were voyagers and meridians built?

because a loco hauled train of the same length (including loco) would have far less passenger capacity

 

[poshbakerloo]

If this is true then why were voyagers and meridians built?

Are units so much more convenient that it is the equivalent of the extra fuel used?

they hav faster acceleration etc...
and new diesel trains needed to be built anyway for 125mph running

 

[rail-britain]

There are several advantages to a DMU/EMU/DEMU over a loco hauled service, but equally there are disadvantages

Advantages :
operating costs are lower
track maintenance costs are lower
smaller interchangeable units for services
fixed formation layouts
train operating performance (acceleration / deceleration / top speed)
fuel range is almost 50% more than a loco

Disadvantages :
restricted route use throughout the day / week
may not be able to divert if a route is closed
typically shorter trains / less capacity
integral design means common features in most coaches (engine / toilet, etc)

 

[andy13]

it would probably use up a bit more fuel, but think about it, if a train was doing 1mpg and had 200 people on it it would still be outperforming in fuel efficiency the equivalant amount of cars/busses required to carry that amount of people

But trains are more efficent as they always run on flat surface and no rubber tyres which absorbe a lot of speed

10 carriages = 1 engine on train
10 buses = 10 engines

therefore more weight, surely a loco hauled train is cheaper to run than a dmu?

 

[mumrar]

it would probably use up a bit more fuel, but think about it, if a train was doing 1mpg and had 200 people on it it would still be outperforming in fuel efficiency the equivalant amount of cars/busses required to carry that amount of people

Not sure how you square that calculation, if you have a standard diesel saloon car that gives about 55mpg, containing 5 people, then it's doing 275mpg per passenger, not 200 like your train example

 

[rail-britain]

therefore more weight, surely a loco hauled train is cheaper to run than a dmu?

Sadly not, when you take into account ALL the costs
DMU have much longer service intervals, they are also cheaper to run on the network (access charges)
Yes, a DMU may have more engines, but overall that is still less fuel consumption compared to a loco hauled service of the same capacity, and especially on small capacity
This is one of the reasons why many trains of up to 5 coaches were converted to DMU

 

[j0hn0]

in terms of efficiency, could new powered bogies be fitted to HST coaches and take their power from the diesel engines in the power cars? Similar to IEP.

I just wonder why for all this while, engines have been slung under the coaches causing uncomfortable journeys?

Do the engines have to be near the traction motors?

 

[rail-britain]

That would require a massive re-engineering of the HST and Mk3 coaches, new trains would be cheaper

The main reason for having traction motors under the coaches, is to reduce the hammer effect of the large engine
Take a Class 91 as an example, all the weight bearing load is concentrated on eight wheels

 

[poshbakerloo]

Isnt the Intercity Express gonna be loco hauled?

 

[Metroland]

There are several advantages to a DMU/EMU/DEMU over a loco hauled service, but equally there are disadvantages

Advantages :
operating costs are lower
track maintenance costs are lower
smaller interchangeable units for services
fixed formation layouts
train operating performance (acceleration / deceleration / top speed)
fuel range is almost 50% more than a loco

Disadvantages :
restricted route use throughout the day / week
may not be able to divert if a route is closed
typically shorter trains / less capacity
integral design means common features in most coaches (engine / toilet, etc)

Have you got any demonstrable figures for that, because I am not sure on a number of those points?

 

[ukrob]

There are several advantages to a DMU/EMU/DEMU over a loco hauled service, but equally there are disadvantages

Advantages :
operating costs are lower
track maintenance costs are lower
smaller interchangeable units for services
fixed formation layouts
train operating performance (acceleration / deceleration / top speed)
fuel range is almost 50% more than a loco

Disadvantages :
restricted route use throughout the day / week
may not be able to divert if a route is closed
typically shorter trains / less capacity
integral design means common features in most coaches (engine / toilet, etc)

None of those disadvantages make much sense. Since when was a toilet in each carriage a disadvantage of a unit over locohauled? Which locohauled rakes of coaches did NOT have a toilet in each carriage? What about all the new units which do NOT have a toilet in each carriage?

Your other points are all nonsense too.

 

[Metroland]

In the early 50s the public were told steam was generally inefficient, indeed the railway was as a whole. But at that time it needed no public subsidy. Thanks to all these 'money saving ideas' like CWR, multiple units, power signalling, 40% less network, demanning stations, getting rid of booking offices, goods offices and guards, computerisation it now needs more public money than ever, despite more passengers than in 1947 and the highest fares in Europe. Okay goods traffic has declined, but then there is 40% less network - the part which supposedly carried next to nothing. While the money may be going to fat cats and excessive bureaucracy, I am rather suspicious of some of these claims generally, I mean to make it a lifetime's study just to why the modern railway is just so inefficient financially.

 

[rail-britain]

Your other points are all nonsense too

Details for the costs are on the Network Rail and DfT websites
ATOC released some details that having sets with the same features was inefficient, and I have to agree with them
However there is the cost saving that goes with that
Yes, it does mean the same two coaches have a toilet, but the train already has three and the space by not having the toilet would mean additional seats

Most trains now operate in fixed formation
This means you can no longer modify a set, like was possible with the WCML sets over the weeks of use
An example here would be the Glasgow - Carlisle / Stranraer sets, which would vary between 4 and 7 coaches, depending on expected passenger flow, eventually they became fixed at 5 coaches, and converted to pairs of Class 156 maximum

Maintenance costs are clearly lower
Common parts apply to most of the coaches on a DMU, easily changed to get the DMU back into service
If you have a loco hauled train (such as the ScotRail sleeper) you can have three or four different types of rolling stock on which to carry spares for, equally the associated training costs, and so on

And the list goes on...
I am therefore a full supporter of plastic railway, from a financial point of view
As a passenger I prefer a loco and coaches, but those days are gone now

 

[ukrob]

Details for the costs are on the Network Rail and DfT websites
ATOC released some details that having sets with the same features was inefficient, and I have to agree with them
However there is the cost saving that goes with that
Yes, it does mean the same two coaches have a toilet, but the train already has three and the space by not having the toilet would mean additional seats

And like I said (but you decided not to quote), many (indeed most) modern units do NOT have the same features in each coach, or have a toilet in each coach.

Most trains now operate in fixed formation
This means you can no longer modify a set, like was possible with the WCML sets over the weeks of use
An example here would be the Glasgow - Carlisle / Stranraer sets, which would vary between 4 and 7 coaches, depending on expected passenger flow, eventually they became fixed at 5 coaches, and converted to pairs of Class 156 maximum

I'm not really sure what your point is here? I think we all know what fixed formation means.

Maintenance costs are clearly lower
Common parts apply to most of the coaches on a DMU, easily changed to get the DMU back into service
If you have a loco hauled train (such as the ScotRail sleeper) you can have three or four different types of rolling stock on which to carry spares for, equally the associated training costs, and so on

Totally agree.

 

[rail-britain]

I'm not really sure what your point is here? I think we all know what fixed formation means

There are cost saving elements here
Quite often a loco hauled train would be setup for the maximum expected capacity that day or week
All too often this meant it would run around most of the day virtually empty

This was where EMU and DMU that can split join are useful, and does away with fixed formation
Can you imagine the costs if all the peak hour EMUs had to run around all day!

It's not so bad with intercity type loco hauled services, but again in the past these used to split so that the "unused" portion did not need to continue to the destination
An example here would be the Glasgow - Cardiff from many years ago
It started off from Glasgow as 11 coaches, with the front 6 for Cardiff and the rear 5 for Birmingham (which could be quite confusing southbound), and the opposite northbound
Here is obviously a good example of where locos do make sense, but this can also be effected today with Voyagers and even more so as both sets may be identical (ie the duplication I was on about earlier)

 

[Metroland]

Details for the costs are on the Network Rail and DfT websites
ATOC released some details that having sets with the same features was inefficient, and I have to agree with them

Where? By all accounts the Virgin Voyagers cost 4 times more to run than the loco hauled trains before. Okay, some of this was offset by increased passenger numbers, but surely you must agree a shorter train with the same number of train crew and an engine to maintain under each coach is actually more expensive? I understand the bit about load factor but actually that's not improved since the mid 1970s and in loco hauled days formations actually varied on the time of week and year.

 

[rail-britain]

The Voyager units allow greater flexibility
They may be more expensive to operate overall, but from the TOC point of view they are still cheaper

The advantage of having one engine per coach is for reliability
To start with this was an issue with the Voyager units, as some staff did not know how to disable or isolate the failed engine, resulting in complete train failure (and resulting penalty charges)

As an example I was on a Voyager on Friday 26 June, 13:53 Preston - Haymarket, 221113
This unit only had three of the five engines working
However no penalty charges would have applied, and even though arrival was 25 miniutes late into Edinburgh no passengers missed their connections
Sadly in a loco hauled service once your engine has failed you are pretty much stuffed (unless by luck it is top and tail or HST)

I'm not saying that a DMU in its itself is efficient, it just depends on what type it is being compared to
The Voyager replaced three different types of trains, in some cases the Voyager is cheaper in others the previous rolling stock was
However, by using a standard format of train the overall savings are greater

Compare :
Class 47 with 5 Mark 1 coaches, 150 miles and stopping every 20 miles
v
Class 156 / 158

Class 47 with 10 Mark 3 coaches, 150 miles and one stop
v
Class 390

Class 86 with 6 Mark 2 coaches, 150 miles and three stops
v
Class 220

 

[MCR247]

Why is a 220 v an 86? And 47 v a 390!

 

[yorkie]

But trains are more efficent as they always run on flat surface

No. Gradients are gentler but they do still exist!

and no rubber tyres which absorbe a lot of speed

Steel on steel is more efficient than rubber on tarmac as the latter has more friction. Rubber doesn't "absorb" speed.

10 carriages = 1 engine on train
10 buses = 10 engines

therefore more weight, surely a loco hauled train is cheaper to run than a dmu?

Over about 5 coaches (depending on the loco used and the DMU being compared to), yes loco haulage is indeed more efficient.
--- old post above --- --- new post below ---

Most trains now operate in fixed formation
This means you can no longer modify a set, like was possible with the WCML sets over the weeks of use
An example here would be the Glasgow - Carlisle / Stranraer sets, which would vary between 4 and 7 coaches, depending on expected passenger flow, eventually they became fixed at 5 coaches, and converted to pairs of Class 156 maximum

You can modify DMU sets to change the formation. It's just a lot harder! Therefore, this really should appear under 'Disadvantages' not 'Advantages'

Maintenance costs are clearly lower
Common parts apply to most of the coaches on a DMU, easily changed to get the DMU back into service
If you have a loco hauled train (such as the ScotRail sleeper) you can have three or four different types of rolling stock on which to carry spares for, equally the associated training costs, and so on

Are you sure that the maintenance costs of a Class 180 or Class 222 DMU are less than 2 power cars (effectively locos) and Mk3s?

As for the sleeper, as there are plenty of Mk2s and Mk3s in the country I doubt spares are a major problem? I suspect it would be a bigger problem finding spares for 180s as they are a small fleet. So, again, this so-called advantage for DMUs is more of a disadvantage I think.

And the list goes on...
I am therefore a full supporter of plastic railway, from a financial point of view

So our plastic railway costs less per passenger travelled than the expensive loco hauled railways of e.g. India? No? Thought not

As a passenger I prefer a loco and coaches, but those days are gone now

No they're not. It's just in this country we've made the mistake of going away from it for the most part.
--- old post above --- --- new post below ---

The Voyager replaced three different types of trains,

Oh the irony!!! The main type of train they replaced has been brought back!

in some cases the Voyager is cheaper in others the previous rolling stock was

No it isn't! XC didn't make huge losses in the past. InterCity (including XC) used to operate without subsidy. Imagine that now!

Class 86 with 6 Mark 2 coaches, 150 miles and three stops
v
Class 220

I think you'll find this comparison to be quite interesting if you actually do compare them.

A class 86 is powerful and probably can accelerate to 100mph in a similar time to a Voyager. Yet, being an electric loco, it is far, far more efficient! So your costs are greatly reduced. I suspect you can run 6 coaches for less money than a 4 coach 220 yet the 220 will have a far lower seating capacity.

220s cost more in maintenance than electric locos.

Running 22x DMUs under the wires on Birmingham-Glasgow/Edinburgh services makes no sense at all and would not be done in a sane country e.g. Switzerland, France, etc.

 

[Aictos]

because a loco hauled train of the same length (including loco) would have far less passenger capacity

How do you work that one out?

It had been proven by rail experts that the replacement 220s for the Cross Country route actually had less seats in it then the LHCS it had replaced.

Okay, they might have been more reliable with a engine in each coach vs a single engine or two if it was a HST but still they were far too small for the routes served.

It would have been better to run them as a 10 car DEMU with the shop/buffet/restaurant in the middle of the train and the front coach at the standard end as the guard's area for cycles and baggage etc...

This might have given the same kind of capacity as a HST plus be even more reliable.

 

[MCR247]

How do you work that one out?

It had been proven by rail experts that the replacement 220s for the Cross Country route actually had less seats in it then the LHCS it had replaced.

Okay, they might have been more reliable with a engine in each coach vs a single engine or two if it was a HST but still they were far too small for the routes served.

It would have been better to run them as a 10 car DEMU with the shop/buffet/restaurant in the middle of the train and the front coach at the standard end as the guard's area for cycles and baggage etc...

This might have given the same kind of capacity as a HST plus be even more reliable.

No but with VXC, they were planning to shorten trais and make them more frequent, which didnt work because of reliability. But if you look anywhere else, I reckon a 390 could hold more than an 86 set. hats the problem with Loco Hauled, It limits your abilities to choose how many MK3s you want, as you have to add on a loco & DVT & then get it to fit on a platform!

 

[jopsuk]

How do you work that one out?

It had been proven by rail experts that the replacement 220s for the Cross Country route actually had less seats in it then the LHCS it had replaced.

You missed the "of the same length" part- weren't the loco hauled services that they replaced usually of rather more than three or four carriages + a loco?