A Solution for freight services running diesels 'under the wires'?

[61653 HTAFC]

Something that has come up in this thread: http://railforums.co.uk/showthread.php?t=85155 is the use of diesel locomotives for freight services that are largely run under the wires. There's often been talk of fitting small diesel engines to electric locos allow them to run the 'last mile' to terminals and so on but obviously our restrictive loading gauge is an issue here, as is the extra weight this would entail (including fuel tanks and such).

This got me thinking, and I remembered the existence of the old MLVs on the Southern Region, which had if I remember rightly batteries which were charged from the 3rd rail and allowed them to power services to Dover Marine among other places. Would it be possible to fit battery packs to existing locos that could be charged from the OHLE to provide power for the 'last mile' which would negate the need to put wires up in terminals (which I imagine is also a safety and paracticality issue, particularly with intermodal/mineral traffic)?

If the loading gauge is an issue that prevents a battery pack being installed in the existing bodyshells of say a 90 or 92, would it be possible to convert redundant EMU driving cars or DBSOs into battery vehicles which could be semi-permanently coupled to the locomotives and allow them to be controlled from the DBSO cab?

Of course this would eat into the permissible length of any train operated in such a way, but the 20m of a DBSO wouldn't be a major problem considering the total length of most intermodal services.

I imagine there's some major flaw with my suggestion that someone will waste no time in pointing out. Thoughts?

 

[Muzer]

I don't know much about electrics, but since OHLE (and therefore presumably the electric motors) are AC, and batteries are inherently DC, I expect you'd need some horrific, bulky and inefficient system of inverters and rectifiers, unfortunately. Do correct me if I'm wrong. That's why it was comparatively easy for third rail - the motors and supply current is all DC, so charging a battery and then using it to run the motors is relatively simple - the same will be true for fourth rail in the next lot of deep-level London Underground rolling stock, quite possibly.

 

[rebmcr]

I don't know much about electrics, but since OHLE (and therefore presumably the electric motors) are AC, and batteries are inherently DC, I expect you'd need some horrific, bulky and inefficient system of inverters and rectifiers, unfortunately. Do correct me if I'm wrong. That's why it was comparatively easy for third rail - the motors and supply current is all DC, so charging a battery and then using it to run the motors is relatively simple - the same will be true for fourth rail in the next lot of deep-level London Underground rolling stock, quite possibly.

As far as I can remember, even AC motors on an AC supply get their power through a DC intermediary. I'm sure there's a very clever electronics reason why!

 

[61653 HTAFC]

As far as I can remember, even AC motors on an AC supply get their power through a DC intermediary. I'm sure there's a very clever electronics reason why!

I did consider the issue mentioned by Muzer, but was sure I'd heard something similar to the point quoted above at some point. Either way, if transformers or whatever would be needed then this would be an issue for fitting it inside the bodyshell of an existing loco, but not so much if a 'transformer/battery vehicle' or a new-build was considered. (though my idea was initially for a relatively low-cost solution which would rule out new-buld).

 

[class156]

Surely it would be easier to have shunter locomotives at freight terminals to haul the train the "last mile"?

 

[61653 HTAFC]

Surely it would be easier to have shunter locomotives at freight terminals to haul the train the "last mile"?

You'd think so, and I think this is still done at places where the volume of traffic is deemed to justify it. But equally, such practices have fallen out of favour in many locations and FOCs would rather run a 66 under the wires for a large part of a journey. Perhaps there should be some sort of penalty in terms of access charges if running diesel under the wires for long stretches (or rather, a discount for using wires where provided) but that approach opens a whole other can of worms!

 

[Bevan Price]

You would need a lot of batteries to move a 1500 to 2000 ton freight train. Something like an updated (and more reliable) version of a Class 74 electro-diesel might be a better idea.

 

[Kali]

There is a DC step in AC-AC systems - AC motors work because you can control the frequency of the supply, and that's done from a DC source. Suitable batteries would be be heavier than a small diesel generator set, I'd imagine...

Is anyone building electro-diesels these days?

 

[anthony263]

Is anyone building electro-diesels these days?

Well Bombardier and Seimens have come up with designs and I believe both companies do have some operational loco in europe.

Bombardier have tried to market their uk version of Traxx which does come with an option for a last mile diesel engine to various freight operators although none of them have shown any interest yet in any new electric loco's

That said DRS do have options to order electric versions of the class 68's if there is demand to jusitfy it i.e. if DRS gains more traffic which uses mostly electrified lines such as between Southampton and the midlands using the electric spine.

Another possibile freight service which can go to electric operation is the Wentloog - Southampton freightliner providing if it goes via Reading rather than Salisbury once the SWML and GW is electrified.

I would like to see more freight loco's built including new electric loco's but this will depend on whether it proves to be financially viable for the FOC's

 

[Rhydgaled]

Interesting idea, but:

You would need a lot of batteries to move a 1500 to 2000 ton freight train. Something like an updated (and more reliable) version of a Class 74 electro-diesel might be a better idea.

If a 'last mile' diesel engine really is required, maybe coupling today's electric locos to a PCV (Propelling Control Vehicle, not a DBSO as they carry passengers and could well be useful for passenger services) with a diesel generator on-board would be a better use of resources than scrapping our electric locos to replace them with new-build electro-diesel locos.

 

[GB]

To make "last mile" engines viable, there really needs to be a big push in electrifying as much as the main lines and secondary lines as possible.

Take Hams Hall for example. A very popular place for intermodal traffic and you also have Birch Coppice not far away but the wires end at Nuneaton...no good for a last mile engine.

Also Felixstowe, one of the main origins and destinations for intermodal but the wires stop at Ipswich some 16 miles from the terminal.

I'm sure there are plenty of other examples.

 

[Kali]

A vehicle with a driving cab and a diesel generator, eh? So what is needed is something like a Class 20, only with an engine that doesn't mind being shut down so much.

What would be better is something you can see over from the electric cab & you can multiple work with, that way there's little extra training. However... that's even more weight than a last mile diesel install.

Maybe if the FOCs were charged for a path's worth of electricity regardless then something might be made of all this...

 

[Rhydgaled]

A vehicle with a driving cab and a diesel generator, eh? So what is needed is something like a Class 20, only with an engine that doesn't mind being shut down so much.

What would be better is something you can see over from the electric cab & you can multiple work with, that way there's little extra training. However... that's even more weight than a last mile diesel install.

The trobble is, can you fit a last-mile diesel generator in existing electric locomotives? Wouldn't it be a terrible waste to throw away a whole electric loco to get a new one with a last-mile engine?

Maybe if the FOCs were charged for a path's worth of electricity regardless then something might be made of all this...

That sounds like a good idea. I think I've seen a 90 being swapped for a 66 (or the other way round) from a Pendolino between Crewe and Liverpool, but that was some time ago. So it clearly is possible to change locos for the off-wire bit, maybe charging for the cost of electricity would enourage FOCs to do this so we don't need to worry about fitting diesel generators to electric locos at all.

The only thing is, it wouldn't be fair on FOCs that don't have any electric locos. How many of them are diesel-only FOCs?

 

[HSTEd]

Electrodiesels are alive and well on the continent and in North America (ALP-45DP)
The only real chance for them to fit into our loading gauge restrictions and remain competitive in the power/tractive effort stakes really revolves around the new medium frequency transformer rigs that ABB have developed.

Cuts the weight of the transformer/traction converter by more than half.

 

[W230]

As far as I can remember, even AC motors on an AC supply get their power through a DC intermediary. I'm sure there's a very clever electronics reason why!

I believe it's to do with the fact that 3 phase AC is the most efficient for powering traction motors but cannot be delivered in OLE very easily (ours is all single phase supply).

The single phase AC from OLE is sent through a transformer, then onto a rectifier (becoming DC), before being inverted to 3 phase AC. I think now it's done via a solid state/phase converter.

 

[edwin_m]

The other reason is that three phase motors need their three phases delivering at a frequency that depends on speed, rather than the fixed 50Hz frequency of the traction supply. The easiest way is just to rectify it to DC and have some power electronics to generate the three phases at the correct voltage and frequency that suits the current speed and the demanded power. That's why* you hear the traction packages on things like Networkers making a rising tone as they accelerate and a falling one as they slow down.

*This is intentionally a gross simplification of what actually happens!

 

[#1 driver]

Perhaps there should be some sort of penalty in terms of access charges if running diesel under the wires for long stretches

why ?
what are you going to achieve by that ?

why is this thread trying to fix a problem that doesn't exist ?

Surely it would be easier to have shunter locomotives at freight terminals to haul the train the "last mile"?

have a loco and a driver waiting for trains to arrive at a yard ?
have you seen how many drivers are spare in freight companies now ?

 

[61653 HTAFC]

why ?
what are you going to achieve by that ?

why is this thread trying to fix a problem that doesn't exist ?

We can all be a nay-sayer can't we? :roll: Much like how we can all selectively quote other members' posts to make a point- disregarding the fact in the very same post you selectively quoted from, I also proposed the alternative of incentivising the use of electric traction rather than penalising the use of diesels. Indeed in an earlier post I acknowledged this wouldn't be simple.

You say it's a problem that doesn't exist, and I'd agree that it's not a major priority compared to certain other issues. But at no point did I claim to be an expert- just suggested that something many both inside and outside the industry find frustrating might perhaps have a solution. Of course if it was a simple one, it'd have been done already.

 

[#1 driver]

We can all be a nay-sayer can't we?

no !

Much like how we can all selectively quote other members' posts to make a point.

you want me to quote ALL of your post ?

I also proposed the alternative of incentivising the use of electric traction rather than penalising the use of diesels.

again , why ?
what good is that gonna do ?

You say it's a problem that doesn't exist, and I'd agree that it's not a major priority compared to certain other issues.

you'd agree with something I didn't say ?
:roll:
ok , what other issues ?

But at no point did I claim to be an expert- just suggested that something many both inside and outside the industry find frustrating might perhaps have a solution.

what is frustrating you ?
diesel locos ?

 

[LNW-GW Joint]

why is this thread trying to fix a problem that doesn't exist ?

It is a problem if a class 66-hauled freight is slogging up Shap and Beattock and consuming more capacity than a class 92 would.
NR have proposed in the past that that there would at some point be no 60mph paths on WCML north.
It affects the analysis of whether the WCML is "full" or not.

 

[broadgage]

I doubt that a battery of sufficient capacity could be fitted within the loading gauge and weight constraints of an existing electric locomotive.

A small diesel engine might be a possibility, remembering how much more compact these have become in recent years (driven largely by the need for high speed DMUs)

I recently heard a rumour that the re-building of a long stored class 92 into a diesel/25KV loco is being actively considered, as a trial with a view to doing some more if sucessful.
A suprisingly small diesel engine can move a heavy train at low speed provided that the "gear" ratio is correct, which is easily achieved with modern electric transmission rather than actual gear wheels.

Another option might be a vehicle containing batteries that is attached to the electric loco, as suggested in a previous post.
Lead acid batteries are very heavy, but not that bulky, or put another way the weight limit of the vehicle containing them would be reached long before the cubic capacity.
The raises the possibility of a low enough battery vehicle that it could be coupled in front of the electric loco without impairing the drivers view.
Perhaps similar in external appeareance to the "diesel brake tenders"* of years gone by.

Whatever option is chosen, it seems sensible to extend the wires when possible to end a lot neaer the port or other facility.
A "last mile" diesel could of course move the train a lot more than a single mile, but in view of the limited speed available, it would not normally make sense to run 15 or 20 miles thus.

* for our younger members, these were vehicles fitted with many tons of ballast weights and effective brakes. Intended for use with goods trains that had no continous brake.
In steam days such trains could be stopped with a steam or vaccum brake on the engine and tender, and the hand brake in the gaurds van at the rear of the train.
When diesels replaced steam, it was found that the total brake force available was insuficient due to the diesel locomotive being of lighter weight than steam engine and tender.
Adding a second diesel provided enough brake force but was an extravagant use of such costly machines.
Therefore the diesel brake tenders were used simply to provide extra braked weight. Ther were of very limited height and it was intended that they could be hauled or propeled as needed.
ASLEF took exception to them at times and refused to propel them.

 

[RichmondCommu]

It is a problem if a class 66-hauled freight is slogging up Shap and Beattock and consuming more capacity than a class 92 would.
NR have proposed in the past that that there would at some point be no 60mph paths on WCML north.
It affects the analysis of whether the WCML is "full" or not.

How much diesel hauled freight heads up over Shap and Beattock? Don't forget that freight can be looped at Grayrigg and Beattock in order to reduce disruption to passenger services.

I think its pretty clear that the FOC's have decided that its cheaper to use one loco on freight services rather than change loco's half way. These cost savings can then be passed on to the customer.

 

[#1 driver]

with a diesel loco , a different ( non electrified ) route can be used if required .
or if there is a problem with the power supply for OHLE , diesel can keep going .

 

[DW54]

We can all be a nay-sayer can't we? :roll: Much like how we can all selectively quote other members' posts to make a point- disregarding the fact in the very same post you selectively quoted from, I also proposed the alternative of incentivising the use of electric traction rather than penalising the use of diesels. Indeed in an earlier post I acknowledged this wouldn't be simple.

You say it's a problem that doesn't exist, and I'd agree that it's not a major priority compared to certain other issues. But at no point did I claim to be an expert- just suggested that something many both inside and outside the industry find frustrating might perhaps have a solution. Of course if it was a simple one, it'd have been done already.

And the reason it hasn't is that the FoCs are effectively subsidised through NR to compete with road haulage. The latest draft report from the ORR (http://www.rail-reg.gov.uk/pr13/PDF/pr13-draft-determination.pdf) clearly addresses that. Track access charges for bulk commodities not competing with road haulage are to rise substantially in real terms, but those for intermodal are to be kept well below cost recovery for the reason stated above. The big picture is modal shift to rail, the little picture is modal shift within rail.

 

[edwin_m]

How much diesel hauled freight heads up over Shap and Beattock? Don't forget that freight can be looped at Grayrigg and Beattock in order to reduce disruption to passenger services.

I think its pretty clear that the FOC's have decided that its cheaper to use one loco on freight services rather than change loco's half way. These cost savings can then be passed on to the customer.

It's a big problem and likely to increase as the numbers of both freight and passenger trains both grow.

Loops are used but not as effective as one might expect, because the freight has to start out of the loop straight onto an adverse gradient and with limited power avaiable from the diesel it struggles to pick up much speed. Some of them are also rather short and have slow entry and exit speeds (though this could of course be fixed given the will and the money).

Hopefully at some stage the increased revenue and reduced costs possible by running longer freight trains that spend less time in loops will persuade the operators to adopt more electric haulage particularly on hilly double track routes like the northern WCML.

"Last mile" is probably less relevant for intermodal because the terminals are quite intensively used and therefore providing a shunter is less of an overhead (sorry!). Some terminals have OLE running right up to the start of the loading area and a loop on the approach so an electric loco can run round and propel the train onto the pad while itself staying under the OLE. Bulk terminals may be more relevant, since normally most of the train has to pass through the loading/unloading facility. But even with planned electrifications there will be few bulk freight flows that are mostly under OLE.

Incidentally there is a problem with propelling brake or battery tenders on the modern railway. Many signals will revert to danger when the first wheel passes them, and if the driver is not right at the front of the train he will see this happening. Also by the time the loco gets to the TPWS loops they will have been armed and will apply the brakes.

 

[Loki]

Something that has come up in this thread: http://railforums.co.uk/showthread.php?t=85155 is the use of diesel locomotives for freight services that are largely run under the wires. There's often been talk of fitting small diesel engines to electric locos allow them to run the 'last mile' to terminals and so on but obviously our restrictive loading gauge is an issue here, as is the extra weight this would entail (including fuel tanks and such).

This got me thinking, and I remembered the existence of the old MLVs on the Southern Region, which had if I remember rightly batteries which were charged from the 3rd rail and allowed them to power services to Dover Marine among other places. Would it be possible to fit battery packs to existing locos that could be charged from the OHLE to provide power for the 'last mile' which would negate the need to put wires up in terminals (which I imagine is also a safety and paracticality issue, particularly with intermodal/mineral traffic)?

If the loading gauge is an issue that prevents a battery pack being installed in the existing bodyshells of say a 90 or 92, would it be possible to convert redundant EMU driving cars or DBSOs into battery vehicles which could be semi-permanently coupled to the locomotives and allow them to be controlled from the DBSO cab?

Of course this would eat into the permissible length of any train operated in such a way, but the 20m of a DBSO wouldn't be a major problem considering the total length of most intermodal services.

I imagine there's some major flaw with my suggestion that someone will waste no time in pointing out. Thoughts?

I don't think the loading gauge is any problem. Bombardier's Traxx UK has in fact a last mile engine and its designed for British loading gauge. I think the problem with fitting such an engine in the current locos is that there is no space. Shunters are a pain if they need to operate in some obscure factory where there isn't sufficient track to stable them or no depots nearby for maintenance. Freight companies should be looking for last mile electrics in the future in my opinion.

 

[DW54]

I doubt that a battery of sufficient capacity could be fitted within the loading gauge and weight constraints of an existing electric locomotive.

Light, compact, long service life batteries now in production (see http://www.genewscenter.com/Press-R...Cell-Bus-Using-New-Durathon-Battery-3d0f.aspx). Used in conjunction with some Lithium batteries or KERS inductive flywheel units or Supercaps for short-cycle high-power requirements should supply "last hour" or "last 50 miles" capability. However, I don't know how the inside of a 92 is used, and to what extent kit is either relocatable, replaceable with more up-to-date compact lighter kit, or nowadays completely redundant. So, it would be imprudent of me to suggest that these contemporary developments are or are not applicable to existing 92s.

Whether it would be worth refitting older locos {like 90s or 87s} with AC drive and hybrid off-wire capability is another analysis.

Freightliner are currently working with GE Transportation Systems (the GE Division that makes Durathons) with the "ugly duckling" Class 70s, so they may be the first to be persuaded to trial a retrofit on a withdrawn 87.

 

[D365]

Light, compact, long service life batteries now in production (see http://www.genewscenter.com/Press-R...Cell-Bus-Using-New-Durathon-Battery-3d0f.aspx). Used in conjunction with some Lithium batteries or KERS inductive flywheel units or Supercaps for short-cycle high-power requirements should supply "last hour" or "last 50 miles" capability. However, I don't know how the inside of a 92 is used, and to what extent kit is either relocatable, replaceable with more up-to-date compact lighter kit, or nowadays completely redundant. So, it would be imprudent of me to suggest that these contemporary developments are or are not applicable to existing 92s.

Whether it would be worth refitting older locos {like 90s or 87s} with AC drive and hybrid off-wire capability is another analysis.

Freightliner are currently working with GE Transportation Systems (the GE Division that makes Durathons) with the "ugly duckling" Class 70s, so they may be the first to be persuaded to trial a retrofit on a withdrawn 87.

ACLG could loan 87002!

On another note, 92s are effectively two locomotives in one, this redundancy feature being required at the time in the Channel Tunnel. Almost all of the loco is taken up with complex electronics; there would be little space to play with, if any.

If you were to remove the 'backup' equipment, that example wouldn't be able to run though the tunnel, if the respective regulations still apply. That would reduce flexibility in the fleet.

If last-mile self-power and AC traction is wanted in a locomotive, one may as well bite the bullet on Traxx rather than go through the horrors of retrofitting an older type.

 

[HSTEd]

Light, compact, long service life batteries now in production (see http://www.genewscenter.com/Press-R...Cell-Bus-Using-New-Durathon-Battery-3d0f.aspx). Used in conjunction with some Lithium batteries or KERS inductive flywheel units or Supercaps for short-cycle high-power requirements should supply "last hour" or "last 50 miles" capability. However, I don't know how the inside of a 92 is used, and to what extent kit is either relocatable, replaceable with more up-to-date compact lighter kit, or nowadays completely redundant. So, it would be imprudent of me to suggest that these contemporary developments are or are not applicable to existing 92s

Those batteries are light by comparison with lead acid batteries but nothing compared to lithium ion batteries.
Additionally they are only rated for 0.5C, which means that is a two hour discharge time.... and an 8.4 hour rated recharge time.
It is also rated for only 4500 cycles which mean multiple replacements over the life of the locomotives.

These are far from ideal for a last mile engine.

The cost of deploying these locomotives on a widespread basis is probably more expensive than simply deploying trolley-wire on the "last mile" routes that cause the problem, and possibly using Furrer and Frey movable overhead contact rails for top loading areas that prevent conventional wir being installed.

 

[Rhydgaled]

If last-mile self-power and AC traction is wanted in a locomotive, one may as well bite the bullet on Traxx rather than go through the horrors of retrofitting an older type.

Wouldn't that be a huge waste of the existing 90s and 92s? Difficult or impossible to retrofit a diesel engine in them though, which is why I think encouraging FOCs to use electric where possible and swap locos when the wires run out would be a good idea.