Uses for redundant Class 67s.

[al.currie93]

Are you saying that DMU's are not versatile? I would suggest that acceleration is everything especially in terms of journey times and with regard to local stopping services getting out of the way of a train that has little or no intermediate stops.

I don't think that any multiple unit will ever be as versatile as a locomotive hauling coaches in regards to the train composition (how the vehicles can be arranged, what powered vehicle can haul the coaches, segregating the powered vehicles from the non-powered vehicles, replacing them separately and so on) and also regarding what equipment (engines, traction motors and so on) can be installed into the train vehicles. That's what I mean by versatility

Especially given the recent trend, I guess it would appear that acceleration would be high priority for such services that you highlight in your post - however, on other services it would be less of an issue and I don't believe that we know where these new trains would be used. But as I said, acceleration is one aspect of a train - as are cost, simplicity and versatility. Rolling stock procurement is essentially a 'game' of deciding which vehicle option has the aspects that bring the most benefits.

For example, they may look for a train that has a high acceleration, so they'd look at multiple units. These could turn out to be very expensive and complicated systems, as a result of having to have complicated designs due to having to meet emissions regulations and so on. On the other hand, if acceleration is sacrificed a bit, much cheaper and simpler coaches can be sourced instead, which can then be hauled by whatever locomotives are already available (Class 67? Possibly other existing classes?) by nature of their versatility.

Despite what is thought, it may well be that given the circumstances (emissions regulations causing complicated and expansive designs, the desire not to have redundant DMUs in 15 years time for example) the DfT and potential TOCs have calculated that the benefits of the cost, versatility and simplicity aspects outweigh those from high acceleration. Hence, the top priority could well have changed.

I'm not saying that that is the case, but if it is then it makes sense to me that locomotives and hauled-coaches are used

 

[RichmondCommu]

I don't think that any multiple unit will ever be as versatile as a locomotive hauling coaches in regards to the train composition (how the vehicles can be arranged, what powered vehicle can haul the coaches, segregating the powered vehicles from the non-powered vehicles, replacing them separately and so on) and also regarding what equipment (engines, traction motors and so on) can be installed into the train vehicles. That's what I mean by versatility

Just a quick thought here as I'm away from home tonight and cannot sleep! With a modern DMU if one engine was to fail the chances are the engine under the other carriage would get you home. However if a loco fails whilst hauling rolling stock you are stuffed. In which case the DMU will always be more versatile than loco hauled stock.

Not only that but unless you are prepared to run with fixed rake rolling stock all day long DMU's are more versatile to shunt and rearrange due to the fact that they are self powered. The days of the station pilot are long gone.

 

[al.currie93]

Just a quick thought here as I'm away from home tonight and cannot sleep! With a modern DMU if one engine was to fail the chances are the engine under the other carriage would get you home. However if a loco fails whilst hauling rolling stock you are stuffed. In which case the DMU will always be more versatile than loco hauled stock.

Not only that but unless you are prepared to run with fixed rake rolling stock all day long DMU's are more versatile to shunt and rearrange due to the fact that they are self powered. The days of the station pilot are long gone.

Hoping you got to sleep in the end - I was falling asleep when writing my last post :P

Engine failure I'd probably regard as being more an aspect of redundancy than versatility - I believe that it would be easily possible to build such redundancy into a locomotive.

Your second point does make sense, that would be another aspect of versatility. However I still believe that all the other versatility factors that i highlighted earlier make them overall far more versatile.

However, the advantages and disadvantages of locomotives and coaches over multiple units is another discussion entirely - I'm actually pretty sure that I've had a similar discussion with you in the past :P

To get back to the original point that I was making, both locomotive and coach trains and multiple unit trains have their advantages and disadvantages - I for one see both. It may well be that, and I can see possible reasons why (cost, simplicity of design, some aspects of versatility), the advantages of locomotives and coaches are beginning to outweigh those of multiple units, hence why they could now be being considered

 

[alexl92]

There are definitely advantages to both and the point about the DMU being able to continue on one engine is a very good one. However once said multiple unit reaches a suitable point the service will be terminated and the unit taken out of service meaning a shortage of carriages. With LHCS you can just swap the loco over.

It works both ways. Some route need multiple units, some work well with LHCS. Some can be either

 

[Ash Bridge]

There are definitely advantages to both and the point about the DMU being able to continue on one engine is a very good one. However once said multiple unit reaches a suitable point the service will be terminated and the unit taken out of service meaning a shortage of carriages. With LHCS you can just swap the loco over.

It works both ways. Some route need multiple units, some work well with LHCS. Some can be either

It's worth remembering though that back in the days of Deltics, Westerns & Warships, these all being twin engine locomotives, should an engine fail they would have the same limp home capability that a DMU has.

 

[CalderRail]

It's interesting (to me, at least) that the "multiple" aspect of the multiple units is the bit that is becoming an artefact. When do Pendolinos ever work in multiple?

The designation seems to have moved from meaning "can work in multiple couplings" to "is powered by multiple vehicles within the rake".

 

[cf111]

It's interesting (to me, at least) that the "multiple" aspect of the multiple units is the bit that is becoming an artefact. When do Pendolinos ever work in multiple?

The designation seems to have moved from meaning "can work in multiple couplings" to "is powered by multiple vehicles within the rake".

A 22 coach 390 would be some sight!

 

[talltim]

A 22 coach 390 would be some sight!

Bit like this?
http://m5.i.pbase.com/g4/13/575413/2/60094555.PhotosCANON2822copie01.jpg

 

[Chris125]

Are you saying that DMU's are not versatile? I would suggest that acceleration is everything especially in terms of journey times and with regard to local stopping services getting out of the way of a train that has little or no intermediate stops.

I'd argue the current situation with DMUs is distinct from the wider issue of LHCS vs multiple units - the likely expense of buying and leasing new DMUs at this time, along with future uncertainty due to electrification and the availability of underused diesel or even dual-mode locos could overcome the inherent benefits of multiple unit operation and make LHCS a viable alternative for regional services.

 

[RichmondCommu]

I'd argue the current situation with DMUs is distinct from the wider issue of LHCS vs multiple units - the likely expense of buying and leasing new DMUs at this time, along with future uncertainty due to electrification and the availability of underused diesel or even dual-mode locos could overcome the inherent benefits of multiple unit operation and make LHCS a viable alternative for regional services.

Well I'm sure the leasing companies would be delighted if someone could find a use for their locomotives but that shouldn't be the determining factor in whether LHCS or DMU's are procured.

If LHCS were indeed used on regional services you would be forced to have fixed rakes and I can't see the TOC's agreeing to that. I would agree that DMU's are a more expensive option but I think dual mode units would make more sense even if they wouldn't be cheap. The only issue that I can see with dual mode units is that they are heavy but maybe advances in technology will help with that.
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There are definitely advantages to both and the point about the DMU being able to continue on one engine is a very good one. However once said multiple unit reaches a suitable point the service will be terminated and the unit taken out of service meaning a shortage of carriages. With LHCS you can just swap the loco over.

It works both ways. Some route need multiple units, some work well with LHCS. Some can be either

I've traveled on services where the train has been under powered due to the failure of an engine but I've never known it to be taken out of service unless there was a spare set. This includes HST's and Meridians.

I agree that with LHCS if a loco fails you can do a swap but that assumes that the loco fails in a station where there is a stand by loco. If the loco fails in the middle of no where you are screwed. Customers on board are delayed and the line is blocked.
--- old post above --- --- new post below ---

Hoping you got to sleep in the end - I was falling asleep when writing my last post :P

Engine failure I'd probably regard as being more an aspect of redundancy than versatility - I believe that it would be easily possible to build such redundancy into a locomotive.

Your second point does make sense, that would be another aspect of versatility. However I still believe that all the other versatility factors that i highlighted earlier make them overall far more versatile.

However, the advantages and disadvantages of locomotives and coaches over multiple units is another discussion entirely - I'm actually pretty sure that I've had a similar discussion with you in the past :P

To get back to the original point that I was making, both locomotive and coach trains and multiple unit trains have their advantages and disadvantages - I for one see both. It may well be that, and I can see possible reasons why (cost, simplicity of design, some aspects of versatility), the advantages of locomotives and coaches are beginning to outweigh those of multiple units, hence why they could now be being considered

If a loco hauled train suffered a power unit failure I don't think the customers on board would care one bit whether they were a victim of redundancy or a lack of versatility. If indeed a loco suffered a power unit failure I can only assume that it would be disabled so I would be interested to know where you have found the information that you mention. Lower costs and simplicity of design are wonderful until the trains only engine packs up and the nearest loco is over an hour away.

 

[alexl92]

I've traveled on services where the train has been under powered due to the failure of an engine but I've never known it to be taken out of service unless there was a spare set. This includes HST's and Meridians.

Northern Rail. Every single day.

 

[RichmondCommu]

Northern Rail. Every single day.

What, every single day? Other than perhaps Christmas Day? Do you have any facts and figures to back this up?

 

[al.currie93]

If a loco hauled train suffered a power unit failure I don't think the customers on board would care one bit whether they were a victim of redundancy or a lack of versatility. If indeed a loco suffered a power unit failure I can only assume that it would be disabled so I would be interested to know where you have found the information that you mention. Lower costs and simplicity of design are wonderful until the trains only engine packs up and the nearest loco is over an hour away.

I agree in that it wouldn't matter whether it was redundancy or versatility - the point stands that it is perfectly possible to build such redundancy (or versatility) into a locomotive, as per Ash Bridge's quote below.

It's worth remembering though that back in the days of Deltics, Westerns & Warships, these all being twin engine locomotives, should an engine fail they would have the same limp home capability that a DMU has.

The fact that this redundancy was built into Classes 42, 52 and 55 is also the information that I would have sourced regarding such redundancy being implemented. I know that the practise of using one engine to move the train onto a place where the locomotive could be swapped was done with at least on the Class 52 - check the Wikipedia entry for those locomotives if you want one source

Don't get me wrong, I'm not going on an anti-multiple unit rant (I actually quite like the experience of travelling on a 150 at high speeds, mad I know :P ) and I do see where they are obviously advantageous. However I do also see how locomotives have their advantages over multiple units, especially given some aforementioned circumstances now, and can see why they may be chosen in this situation.

EDIT:

Having looked up some information on the Class 55, they too are operated on one engine if need be

 

[sprinterguy]

Northern Rail. Every single day.

That seems exceptional: I travel on Northern Rail services fairly regularly out of Manchester, Leeds and Newcastle, and I haven't come across a Northern Rail DMU with an engine out since I lived in Sunderland long term, some years ago.

 

[The Box Photter]

I seem to recall that some DMUs in the 1980s had one or more of their engines removed to save operating and maintenance costs, whilst others operated as "power-twin" two car units, where both cars in a two car unit had engines.

The de-engined units were renumbered into the 7XXXX series.

The pros and cons of LHCS v Multiple Units have been done to death on here, but I'd leave you with this thought: If we need to station "Thunderbird" rescue locos at strategic points across the network to rescue errant DMUs/EMUs, why not cut out the expense of putting traction packages beneath passenger carriages and go back to using locos? The cost of each carriage would fall considerably and the journey experience for passengers would improve dramatically (except perhaps for those in the front coach, but that would be full of "cranks" anyway). Remember the HST is effectively LHCS sandwiched between two 2,500hp locos.

Then, when the locos were't needed to operate passenger trains, say at night, they could haul freight. Perhaps we could ask Brush if they know of any good loco design that might fit the bill.

 

[alexl92]

What, every single day? Other than perhaps Christmas Day? Do you have any facts and figures to back this up?

Slight exaggeration, I admit. But it feels like barely a day goes by without an announcement on their twitter page that this train or that train is to be short-formed due to a train fault.

 

[sprinterguy]

Slight exaggeration, I admit. But it feels like barely a day goes by without an announcement on their twitter page that this train or that train is to be short-formed due to a train fault.

Though "train fault" often means something other than engine failure.

 

[fgwrich]

Slightly off topic but can anyone explain the reason as to why Scottish 67007 has found it's way down to the south recently - via a low loader to Crewe?

https://www.flickr.com/photos/gcbp/16272567302

 

[Boothby97]

Slightly off topic but can anyone explain the reason as to why Scottish 67007 has found it's way down to the south recently - via a low loader to Crewe?

https://www.flickr.com/photos/gcbp/16272567302

Believe it had some form of fault (cannot remember what), a comment on the photo suggests it was being moved from Tyne Yard to Crewe Electric.

 

[ExRes]

Slightly off topic but can anyone explain the reason as to why Scottish 67007 has found it's way down to the south recently - via a low loader to Crewe?

https://www.flickr.com/photos/gcbp/16272567302

Perhaps they were giving it a high speed run ?

 

[ash39]

It was dumped at Tees Yard for a few weeks due to a wheelset problem which required onward movement by road (presumably, it went to Tees Yard as it's easily accessible by road)

 

[33056]

67007 has been working off Didcot recently; seems to spend much of its time on the Bicester MOD trip;

 

[t_star2001uk]

From what i have heard Chiltern will be keeping 2 67's for a while longer.....