Mark 4 Coach couplers

[josrey]

Hey Guys,

I've been increasingly interested in all things trains and have been reading this forum alot and trying to gain alot of technical knowledge and one thing I can't seem to find is what couplers Mark 4 Coaches have between them does anyone know.......?

 

[dubscottie]

Tightlock although they are at a different height to EMU stock.

 

[hexagon789]

It's tightlock couplings between all the coaches and buckeye between the TOE (Tourist Open End) and the 91. This BR-Era formation plan demonstrates:

 

[Pumbaa]

Where did the 9th trailer come from, for the current setup?

 

[swt_passenger]

Where did the 9th trailer come from, for the current setup?

My ECML electrification book written in 1991 refers (in the past tense) to an additional order for 31 coaches having already been added to the original order to bring it up the total of 314. So I think there can only have been a very short period of operation in 8 car sets,

AIUI the original 283 included the DVTs and IIRC various intended spares.

 

[Pumbaa]

Thanks.

 

[Wilts Wanderer]

The original formation was standard 2+8 Intercity formation but BR quickly added an additional FO to bring up to 2+9. Later on the Mallard refurbishment turned the previously TRFB buffet cars round to become TRSB with standard seats.

 

[61653 HTAFC]

The original formation was standard 2+8 Intercity formation but BR quickly added an additional FO to bring up to 2+9. Later on the Mallard refurbishment turned the previously TRFB buffet cars round to become TRSB with standard seats.

GNER formed an extra set using spare vehicles and 89001. Since then, a number of vehicles have been destroyed in crashes, reducing the fleet size.

 

[dubscottie]

GNER formed an extra set using spare vehicles and 89001. Since then, a number of vehicles have been destroyed in crashes, reducing the fleet size.

89001 was used by GNER during the period when the 91s availability was poor prior to the rebuilding of the 91s.

There was never enough spare vehicles to make a full extra set.

The whole Mk4 order is a minefield as some coaches ordered as FO became TSO.

Some bodyshells even arrived painted and numbered as FO only to leave Met-Cam as TSO.

This was after the decision to scrap the Pullman formations and to standardise on DVT, 2x FO, RFM, TSO(D), 4x TSO, TSO(E) for all sets.

After the two GNER crashes and the Mallard refurb it gets more complicated!

On couplings, all the Mk4 (except DVT) can be fitted with conventional buffers/drophead buckeye. The holes for fixing the buffers and for the rubbing plate are there still.

That was the original plan until BR decided to use sealed gangways which is why they have tightlocks.

Its also the reason why the ride was so poor in the early days but that is another story!

 

[43096]

The whole Mk4 order is a minefield as some coaches ordered as FO became TSO.

Some bodyshells even arrived painted and numbered as FO only to leave Met-Cam as TSO.

This was after the decision to scrap the Pullman formations and to standardise on DVT, 2x FO, RFM, TSO(D), 4x TSO, TSO(E) for all sets.

That is incorrect. Under BR some sets had 3 FOs (extra FO vice TSO) and some had 2 which is why the extra build had a mix of FOs and TSOs. (Technically Mark 4 TSOs were actually TOs, but easier to stick with the standard codes).

It was the Mallard programme that standardised the fleet with everything formed DVT, 3xFO, RSM, TSO(D), 3xTSO, TSO(E).

 

[jopsuk]

Wikipedia mentions 12 vehicles total being scrapped- presumably as a result of the Hatfield and Great Heck- does this include the Great Heck DVT? It lists 32 Mark 4 DVTs having been built with 31 still in operation, versus the 31 Class 91 built

 

[route:oxford]

It's tightlock couplings between all the coaches and buckeye between the TOE (Tourist Open End) and the 91. This BR-Era formation plan demonstrates:

So technically, not that it's likely to happen, a Mk3 could be inserted into the formation between the TOE and 91?

 

[43096]

Wikipedia mentions 12 vehicles total being scrapped- presumably as a result of the Hatfield and Great Heck- does this include the Great Heck DVT? It lists 32 Mark 4 DVTs having been built with 31 still in operation, versus the 31 Class 91 built

82221 was scrapped after Great Heck, not that there was much left of it to scrap.

 

[D365]

Yep, there were a number of spare vehicles constructed originally, I believe.

 

[Marklund]

That is incorrect. Under BR some sets had 3 FOs (extra FO vice TSO) and some had 2 which is why the extra build had a mix of FOs and TSOs. (Technically Mark 4 TSOs were actually TOs, but easier to stick with the standard codes).

It was the Mallard programme that standardised the fleet with everything formed DVT, 3xFO, RSM, TSO(D), 3xTSO, TSO(E).

PO, not FO.

 

[43096]

PO, not FO.

And it was SV (for Service Vehicle) not RFM. But as I said on the note about TO vehicles, I used the more widely recognised version.

 

[dubscottie]

That is incorrect. Under BR some sets had 3 FOs (extra FO vice TSO) and some had 2 which is why the extra build had a mix of FOs and TSOs. (Technically Mark 4 TSOs were actually TOs, but easier to stick with the standard codes).

It was the Mallard programme that standardised the fleet with everything formed DVT, 3xFO, RSM, TSO(D), 3xTSO, TSO(E).

Sorry but you are incorrect.

As I said BR had Pullman sets which were the ones with extra FO you refer to. All but 2 were gone by the time they started running to Edinburgh in 1991.

From 1991 onwards all the Mk 4 sets were standard rakes except the 2 used on the Yorkshire Pullman. The mallard refurb just changed how they formed.

For example, 2x RFM became FO, 21x TSO became FO, 30x FO became FOD and the remaining RFM became RSB.

Also while in Intercity livery, the end data panels have them as FO, TSO etc as do all the platform 5 books of the time.

 

[Marklund]

And it was SV (for Service Vehicle) not RFM. But as I said on the note about TO vehicles, I used the more widely recognised version.

Yet it's not what they are...

 

[josrey]

Thanks guys I thought it was tightlock but couldn't find any more information it took me ages to figure out which power cars of the class 43 hold the speed record until reading this forum

 

[43096]

Sorry but you are incorrect.

As I said BR had Pullman sets which were the ones with extra FO you refer to. All but 2 were gone by the time they started running to Edinburgh in 1991.

From 1991 onwards all the Mk 4 sets were standard rakes except the 2 used on the Yorkshire Pullman. The mallard refurb just changed how they formed.

For example, 2x RFM became FO, 21x TSO became FO, 30x FO became FOD and the remaining RFM became RSB.

Also while in Intercity livery, the end data panels have them as FO, TSO etc as do all the platform 5 books of the time.

Interesting approach you have.... First you tell me I am totally wrong, then you back-track and edit your post!

I've had a look at the number of vehicles of each type built and you cannot be right.

The original build was for 31x8-coach sets (+DVT). Vehicles ordered were:
32 x DVT
34 x RFM
32 x TSOE
31 x TSOD
64 x FO
90 x TSO

Ignoring the DVTs, RFMs, TSOEs and TSODs as there was one in each set, that means there needs to be 2 x FO and 3 x TSO per set, which requires 62 x FO and 93 x TSO. There were two Pullman sets for the Tees-Tyne and Yorkshire Pullmans which had two RFMs (hence the order for 34 RFMs). BR cannot have standardised the formations as there are not enough TSOs available to do so.

Subsequent to initial introduction BR ordered an extra 31 vehicles to make all sets 9-car (+DVT), which after a change in the order during construction, were delivered as 5 x FO and 26 x TSO.

To standardise the entire fleet as you say they did, they would need 4 TSOs and 2 FOs per set. Vehicles available were:
69 x FO - require 62
116 x TSO - require 124

So there must have been 6 or 7 sets formed 3xFO, RFM, TSOD, 3xTSO, TSOE. Even then there was no contingency as they had "over ordered" RFMs.

The straight mathematics of it say you are incorrect.

 

[Helvellyn]

Original plan (and I will use the more convential terminology) was 28 sets of DVT+8 trailers+Class 91 and 2 sets of DVT+9 trailer+Class 91.

* 28 sets were conventially formed of DVT-FO-FO-RFM-TSOD-TSO-TSO-TSO-TSOE-91
* 2 sets were Super Pullman sets for the Yorkshire and Tyne-Tees Pullmans and were formed DVT-FO-RFM-FO-FO-RFM-TSOD-TSO-TSO-TSOE

Super Pullman sets (ECML had 2 and WCML had 4) had two RFMs, whereas Pullman sets tended to have an extra FO only (at the expense of a TSO).

Very quickly InterCity decided all IC225 sets would be nine trailers, so 8 extra FOs (11264-11271) and 23 extra TSOs (12490-12512) were ordered. The numbers were revised before construction and instead 5 extra FOs (11272-11276) and 26 extra TSOs (12513-12538) were built. I don't know why the actual coach numbers were amended when the order swapped three FOs for TSOs, especially as all were built under the same Lot No.s as the original FOs and TSOs.

You then had 30 nine coach sets plus DVT and 91.

* 24 standard sets - DVT-FO-FO-RFM-TSOE-TSO-TSO-TSO-TSO-TSOE-91
* 6 Pullman sets - DVT-FO-FO-FO-RFM-TSOE-TSO-TSO-TSO-TSOE-91

This left 2 spare DVTs, 2 spare FOs, 4 spare RFMs, 2 spare TSOs, 1 spare TSOD ans 2 spare TSOEs. Locomotive wise it left 1 spare Class 91, which is one of the reasons GNER re-activated the Class 89.

Hatfield and Great Heck mean only 29 sets now, but the higher number of spare RFMs (from the ordering of 34 to cover the initial two Super Pullman sets) meant two could be rebuilt as FOs 11998 and 11999.

There was also the case where TSO 12405 was built using the bodyshell originally intended for TSOE 12221, so the bodyshell origially intended for TSO 12405 was used as a replacement TSOE but became 12232!

 

[alexl92]

So technically, not that it's likely to happen, a Mk3 could be inserted into the formation between the TOE and 91?

Assuming that the through-wiring was compatible (I forget whether they match or not), physically yes. But the TO(E), the first coach behind the loco, has no gangway at the locomotive end so the extra Mk3 would be a standalone coach; you couldn't walk through to the rest of the train.

I feel like MK3s have tightlock couplings too though, don't they?

Also, please can someone remind me what the D in TO(D) stands for?

 

[43096]

Assuming that the through-wiring was compatible (I forget whether they match or not), physically yes. But the TO(E), the first coach behind the loco, has no gangway at the locomotive end so the extra Mk3 would be a standalone coach; you couldn't walk through to the rest of the train.

I feel like MK3s have tightlock couplings too though, don't they?

Also, please can someone remind me what the D in TO(D) stands for?

Mark 3 LHCS have drophead buckeyes. I'm not sure if these are compatible with Tightlocks in mechanical terms or not. They are derived from the same (US) coupler originally, I believe.

The 'D' in TO(D) is for Disabled - they have wheelchair space(s) and a disabled-accessible toilet.

 

[Helvellyn]

I don't believe you could just insert Mark 3 LHCS stock into a Mark 4 set unmodified. It is one of the reasons InterCity had Mark 4 barrier vehicles, just like it had Mark 3 barrier vehicles for moving HST vehicles.

 

[43096]

I don't believe you could just insert Mark 3 LHCS stock into a Mark 4 set unmodified. It is one of the reasons InterCity had Mark 4 barrier vehicles, just like it had Mark 3 barrier vehicles for moving HST vehicles.

You could insert one between the TO(E) and the 91, but not anywhere else in the set without major modification. Obviously you wouldn't have the through connections to control the DVT, so it would be haul mode only.

There was a proposal to modify a Mark 3 RFM to work in a Mark 4 set back in (I think) NXEC days. After Hatfield and Great Heck the Mark 4 RFM fleet lost two vehicles, and with two RFMs also converted to FO as 11998/9, there are now only 30 vehicles for 30 sets. The lack of a maintenance cover vehicle was the driver for the idea, but it was ultimately not proceeded with.

 

[AnonymousUser1]

So technically, not that it's likely to happen, a Mk3 could be inserted into the formation between the TOE and 91?

no as a TOE has no corridor connection on the loco end

 

[dubscottie]

Deleted

 

[dubscottie]

Interesting approach you have.... First you tell me I am totally wrong, then you back-track and edit your post!

I've had a look at the number of vehicles of each type built and you cannot be right.

The original build was for 31x8-coach sets (+DVT). Vehicles ordered were:
32 x DVT
34 x RFM
32 x TSOE
31 x TSOD
64 x FO
90 x TSO

Ignoring the DVTs, RFMs, TSOEs and TSODs as there was one in each set, that means there needs to be 2 x FO and 3 x TSO per set, which requires 62 x FO and 93 x TSO. There were two Pullman sets for the Tees-Tyne and Yorkshire Pullmans which had two RFMs (hence the order for 34 RFMs). BR cannot have standardised the formations as there are not enough TSOs available to do so.

Subsequent to initial introduction BR ordered an extra 31 vehicles to make all sets 9-car (+DVT), which after a change in the order during construction, were delivered as 5 x FO and 26 x TSO.

To standardise the entire fleet as you say they did, they would need 4 TSOs and 2 FOs per set. Vehicles available were:
69 x FO - require 62
116 x TSO - require 124

So there must have been 6 or 7 sets formed 3xFO, RFM, TSOD, 3xTSO, TSOE. Even then there was no contingency as they had "over ordered" RFMs.

The straight mathematics of it say you are incorrect.

I went an checked my facts unlike yourself!

As I said, the whole Mk4 story is a minefield as posted above.

Should I get into the fun and games with the paint finish on the Italian built bodies or do you know all about it already?

I am sure you know why there is a shock absorber on the drawbar (this thread is about couplings after all).