Trivia. Go anywhere multiple unit

The issue of route clearance seems to come up regularly on the forum. Is there a multiple unit that could provide a passenger service to every station on the network? My thought is the Class 156 but I’m far from knowledgeable enough to be certain. At 23m x 2 it’s probably too long for some places.

Stratford International will probably cause some issues due to the signalling on HS1, as I guess the only units fitted with TVM-430(Transmission Voie-Machine) and KVB(Contrôle de Vitesse par Balises) are electric ones.

The RETBERMTS-fitted 158s from TfW?

_toommm_ said:

The RETB-fitted 158s from TfW?

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Does TfW have RETB-fitted ones?

Spoorslag '70 said:

Does TfW have RETB-fitted ones?

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Or whatever signalling is used on the Cambrian COast

Network Rail's 950 might be the closest you'll get to a go anywhere unit, so that would lead me to think that for passenger service the best you'd get would be a 150.

Trawling through the clearance tables in the PDF copies of the Sectional Appendix, these seem to be the "most permitted" DMUs in each region:

• Anglia: Classes 150 and 170. There are a few places where one can go and not the other and both are banned from significant sections of the London suburban lines.
• Kent, Sussex, Wessex: Class 121. Can go pretty much everywhere, with only a few restrictions on certain chords and platforms.
• London North Eastern: Class 150, with class 158 in a very close second.
• London North Western (North): Class 121. Seems to be the only permitted DMU on significant parts of MerseyRail, probably for similar reasons to being permitted on nearly all of the Southern third-rail network.
• London North Western (South): Class 150. Just about beats the class 121 by being permitted to operate in passenger service on the routes out of Marylebone and the Bletchley flyover.
• Scotland: Class 156. Class 150 is a very close second, despite having had very limited use in the area...
• Western and Wales: Class 150, but it's not permitted much in the Thames Valley area, where a 165 would be required.

So it seems the closest thing to a "go anywhere" DMU is the class 150, unless you want to travel over large parts of the third-rail land, in which case you'll need to dig up some 121s...

_toommm_ said:

Or whatever signalling is used on the Cambrian COast

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European Train Control System on the Cambrian. RETB is just in the Scottish Highlands

I’ve searched the last ten years of posts and reckon, based on regular proposals by forum members, that it has to be the 442...

Spartacus said:

Network Rail's 950 might be the closest you'll get to a go anywhere unit, so that would lead me to think that for passenger service the best you'd get would be a 150.

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It cant go down the cambrian line but otherwise is a good shout

201001?

Thought 150s were barred (in passenger service at least) from the Durham Coast due to stepping differences on curved platforms? Likewise don't 158s have to have the suspension airbags deflated to go down the HOWL?

for a truly "go anywhere" machine a class 08 or 09 would be the closest. Not great for speed or capacity, mind!

Pretty sure 150s aren’t cleared for the Cumbrian Coast due to restrictions through the Maryport tunnel?

Even so, 150s, 158s and 156s must be in with a shout out of the current regularly used passenger trains.

Parallel said:

Pretty sure 150s aren’t cleared for the Cumbrian Coast due to restrictions through the Maryport tunnel?

Even so, 150s, 158s and 156s must be in with a shout out of the current regularly used passenger trains.

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I would have thought a 150 was a go anywhere trains because its 20 long vehicles. The others are 23m and they are restricted because of overthrow on curves. Wonder what the problem is in Maryport tunnel...

Coaches used to have C1 on them which was loading gauge. When Mk3's came in they were C3 - but this isnt simple.

Surely a 230 would be the answer?

ICE variant for most lines, battery variant for merseyrail?

156s are a bit longer but 150s are a bit wider. So if the problem is limited side clearance on a straight bit of track the 156 might fit where the 150 doesn't.

edwin_m said:

156s are a bit longer but 150s are a bit wider. So if the problem is limited side clearance on a straight bit of track the 156 might fit where the 150 doesn't.

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thanks.

What's cleared into Stourbridge Town?

vlad said:

What's cleared into Stourbridge Town?

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139/153. I suspect the 950 too although I'm not too sure.

156 in Scotland . Example the GSW and EK line , 158s/170s due to doors i think cant run

I'd say the 150 is the closest to a go-anywhere unit. There are places mentioned above where they aren't cleared, but these are probably because there has never been a need to use them there rather than any fundamental incompatibility. The similarity to the dimensions of the Mk1 coach and the existence of many EMUs based on the same bodyshell supports this.

The major exception would be where signalling constraints apply, specifically the Cambrian and the Scottish RETB routes. 150s used the Cambrian under previous signalling so should still be physically compatible, and if any get ERTMS before withdrawal they could probably run there without restriction. They have also run under RETB when it was used on the Cambrian and East Suffolk lines, but may not be compatible with the upgraded RETB now used in Scotland.

The question of route clearance gets overblown on this forum. Far more importance gets attached to it to underline why this or that will or won't happen. Yes there are restrictions, but from a practical perspective many of these are not insurmountable.

The other thing to bear in mind is that there is a big difference between "not cleared for" and "banned from". For example, Pacers are not cleared for large parts of the network but that does not mean that they are banned or otherwise unsuitable. It's simply that there was never any need to consider their suitability for operation in areas they would never be deployed. This means that they, like many other types of train, could theoretically visit any part of the network. It's simply down to the necessary paperwork having been done.

One of the greatest causes of route restrictions is weight, specifically axle loadings, but, as this thread is about MUs, we can forget that. The other is body profile and protrusions, usually footsteps. Length really doesn't play much of a role, especially when you consider how many places 23m DMUs have been already. As has already been pointed out, they tend to be a tad narrower and taper towards the ends to mitigate against the effect of a slightly larger overhang. It's the footsteps and treadboards that tend to be an MU's undoing. These are usually the reason why restrictions are placed on certain stock in various locations, requiring speed restrictions, isolation of the air suspension or even removal of the steps altogether. But, as I said above, these problems are not insurmountable. The Networker family is the most restricted MU design on the network, and yet a small change to the ride height was sufficient to allow them to be cascaded to the Bristol/Gloucester area without restriction. Consideration will also be given to units being "out of gauge" due to door failures, etc (e.g. with the doors open, a Cl158 becomes significantly wider).

As a side point, EMUs can fail to be cleared for a route due to the potential for interference with signalling. Unless the signalling has been "immunised" then certain classes will not be cleared.

I would also suggest that RETB/ERTMS need not be a barrier to operation. These are radio-based signalling systems that could easily be installed, and I would not be surprised if portable RETB or ERTMS sets are available for use.

O L Leigh said:

I would also suggest that RETB/ERTMS need not be a barrier to operation. These are radio-based signalling systems that could easily be installed, and I would not be surprised if portable RETB or ERTMS sets are available for use.

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There were certainly portable versions of the original RETB equipment and I assume there still are for the modified system now used. A portable unit could even be used by engineers to obtain the "token" for a particular section to protect a worksite.

However the only interface on a RETB unit is the radio - the system is enforced by TPWS loops that work via the train's normal TPWS equipment. ERTMS is much more complicated as it has to read the balises mounted on the track, and also needs accurate position information by counting wheel rotations. A portable unit couldn't do either of these unless the train had the necessary equipment to plug into.

Is the ventilation in places like the mersyrail, thameslink and crossrail tunnels good enough to allow DMUs? or are those areas EMU only?

What about a 153 ?

And do we count the IOW railway to be part of the national network ?

plugwash said:

Is the ventilation in places like the mersyrail, thameslink and crossrail tunnels good enough to allow DMUs? or are those areas EMU only?

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On Merseyrail, the ventilation is insufficient for a regular DMU service to ever operate (so no Wrexham flyer!) but AIUI 66s could be sent on engineering works as could, presumably, the 950.

TRAX said:

What about a 153 ?

And do we count the IOW railway to be part of the national network ?

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(i) Think I read on here 153s are barred from Portsmouth Harbour due to steps at the no.2 end. They were regular there as 155s as they didn't have those steps then.

(ii) If we do, perhaps the 483s are the answer, but for the lack of a juice rail in most places... They certainly won't be too tall for any bridges or tunnels!

I would say the ultimate go anywhere train (possibly with the exception of the tunnels under Liverpool) would be the class 201/202/203 units with their restriction 0.

Paul