Great Western Coffee Shop

may be a bit of a strange question but can the class 455 units be coupled to any of the class 15* units?

I don't think so.  Much of the control interface on Class 455 EMUs is via end jumpers and I believe that they are incompatible with any other electric stock, let alone 15xx DMUs. I think No is a pretty safe bet, but we do have experts on these pages who will be able to give a better explanation.

I would tend to say no. It's all part of the stupidity of having so many non standard couplings such that virtually every train has to carry a massive steel bar to couple with any.

The nearest I believe we ever got to a standard coupling allowing you to couple anything to anything and drive from either end was the southern EPB system. With buckeye couplings, air pipes and control jumpers that the Southern perfected in the late sixties whereby you could couple any EPB unit (REPs were restricted), TCs some 33 73/4 (but I don't think the 71s) plus I believe the Thumpers DEMU either end and drive from the front cab. Of course it still required a shunter and there were still incompatible 4 SUBS about although the South Eastern was all EPB (bar 71s). As soon as the SUBS had gone the PEPS (foreunner of 455s) with it's auto coupler arrived.

The Eastern Region was onre of the few regions to fit buckeyes to steam locos for passenger train work coaches especialy for  the corridor tenders.

It's been downhill all the way since even with units with same make of coupling  there are different number of control wires 16X/15X, plus  different size heads which makes coupling difficult. Even buckeyes seem to be different between freight and coaches. Which is why you often see 66s on railtours using the old style screw coupling (loose) although both the loco and coach have buckeyes.

The US standardised the buckeye and air brakes in the early 1900s!

i was just thinking its hard to justifiy building new diesel units however if new emu's were built to replace these he 455's could be used to increase capacity on 150's possibly creating 3 car units a 150 coach eather side of a 455

That's an intereting idea, provided the physical couplers and the control wire configurations are the same it should be relatively easy to slot a 455 trailer into a 150X. the main traction control are straight through so provided the 455 unit could respond to 15X brake and domestic commands all should be well.

The only snag is you'd have to fit an Eberspatcher and associated fuel tank to provide heating. Unless you issued duvets to the passengers.

Whether the 15X would have the power to cope with an extra trailer, particularly West of Newton Abbot our train crew friends might have an opinion. Iit might be possible to add an engine underneath the 455 body. It should still be cheaper than a new build.

Although whether the Health and Safety boys would allow you do that is another matter.

could the diesel engines be modified to generate power for the electric motors on the 455 carrage

Slightly off topic.....

but the reason class 66 locos use an emergency screw coupling with coaching stock, is that the locos aren't fitted with retractable buffers.  the buckeyes couple perfectly well, but the loco buffers foul on the carriage's gangway rubbing plates (below corridor connection), and also make it impossible once coupled to un-couple anywhere except perfectly straight track!  As an aside all class 67's were modified with retractable buffers, but rearely seam to use the buckeye autocoupler either!

  i agree with what your saying but how is this relivant?

In theory yes, but in practice it would be difficult to achieve reasonable performance, modern DMUs are often designed such that there is an engine for each coach this keeps the power to weight ratio down where as EMUs may only have two coaches in a 3 or 4 car formation with powered axles

I had thought that this question referred to a complete set rather than an individual car. I appreciate that it is theoretically possible to include a 455 component vehicle in a 150x set, (leaving aside the power issue). (As there is a bar coupling between the vehicles within a set, TSO cars from the 508 units were incorporated into 455 sets when the 508s migrated north).  However, the 455/56 units per se, won't run with anything else due to their non standard control jumpers.

But...why would anyone want to connect a 455 to a 15x?  Now if a 455 could connect to say a class 67, we could be cooking on gas. ;D

The intermediate couplings & corridor connections on Mk3 EMU trailers are different to those used on the 150/1 and 150/2 cars. They are in fact the same as the Pacer type intermediate connections, ie a bar coupler and a box gangway supported from the bar. The only 150's they would physically couple to are the 150/0's which already of course have a powered centre car.

If you added a trailer coach to a two car 150 you would seriously compromise the ability of the unit to retrieve itself without assistance should one of the engines fail. Class 150's are authorised and capable of of running on one engine should the need arise anywhere they are cleared to operate. Fitting an engine would depend on the availability of the neccessary cross members underneath the vehicle which I doubt exist on the trailer coach. That and the cost of altering the end connections rule out using these cars as intermediate cars in a class 150.

As for the unit end couplings, 455 units use a tightlock and 150's use a BSI. In other words totally incompatible.

I suggest these replies  neatly sum up the mess we are in with couplings.

But this is what keeps 'The Sun' in business. ;)

http://www.rssb.co.uk/rv_coupling_system_data/list_index.asp

thankyou everyone for your replys, i thought it may have been possible to do as the units apart from the jumpers at the front are visually very similar after all they are based on the mk3, this would also have had the added bonus of the finished hybrid looking asif it had always been that way.... i guess this says something t the designers of all new rolling stock KISS.....keep it simple stupid i think more standardisation is needed!

Hello, Henry, and welcome to the Coffee Shop forum!  :)

Thanks Henry for URL, it's even worse than I thought!

I though the Hornby Dubulo/Triange situation was bad enough Perhaps sombody with better mathmatical skills can work out the number of permutations (if I remember my maths it's permutations because order matters rather than combinations). It's going to be 10 to quite a large integer.