Dual-braked B.R. Standard coaching stock

[Merle Haggard]

wsing through an L.M. Marshalling Circular - the 1968-9 edition retained from when I referred to it at work - I noticed an oddity regarding the 19.15 Kensington O. - Perth Motor-rail service in the Summer of 1968.
Two Cartic-4 wagons and two Carflats are conveyed at the rear of the train. Presumably because the Cartics are air brake only, all the passenger stock in front is shown as 'air & vac braked'.
The BSO and TSO could be Mark 2s (but even then, I thought they were either air or vac braked, not both) but the other coaches can only be Mk1s. The well-known books devoted to Mk1/2 coaches are silent on brake types; can anyone shed light on this? This train seems to be the only one requiring dual braking - the other LMR Motor-rail trains only conveyed Carflats.

 

[JonathanH]

I think only Mark 1s were ever dual braked - early Mark 2s were vacuum braked but from Mark 2a, they were air braked as noted here.

https://www.railforums.co.uk/thread...tric-train-heating.207363/page-2#post-4709074

 

[43096]

wsing through an L.M. Marshalling Circular - the 1968-9 edition retained from when I referred to it at work - I noticed an oddity regarding the 19.15 Kensington O. - Perth Motor-rail service in the Summer of 1968View attachment 87393.
Two Cartic-4 wagons and two Carflats are conveyed at the rear of the train. Presumably because the Cartics are air brake only, all the passenger stock in front is shown as 'air & vac braked'.
The BSO and TSO could be Mark 2s (but even then, I thought they were either air or vac braked, not both) but the other coaches can only be Mk1s. The well-known books devoted to Mk1/2 coaches are silent on brake types; can anyone shed light on this? This train seems to be the only one requiring dual braking - the other LMR Motor-rail trains only conveyed Carflats.

Isn't the requirement really that they need to be air braked as the Cartics are air only in the formation?

As far as I know there were/are no dual braked Mark 2s, they were all either vacuum (original Mark 2 build) or air (Mark 2A and later) only. There was some conversion of vehicles at various times, most notably the vehicles used on the Edinburgh-Glasgow services with top'n'tail Class 27s.

 

[Wyrleybart]

Going back several years ago (Wootton Bassett) I was led to believe that it was impossible to dual brake a Mk2 vehicle due to the lack of "boltability" on the underframe. You either had to use the existing mounting points for vac or air equipment and not both. I think this came about with a debate about the Mk2 support coach used with Tangmere which had to be a piped vehicle in either vac or airbrake formations - can't remember which.

 

[edwin_m]

Is it possible the vehicles shown as dual braked were only piped for air? I think this was the case with the mixed trains that ran in Scotland in the 1980s (though may have been the other way round?) which suggests that a dual braked loco was able to operate both air and vacuum systems simultaneously.

 

[Merle Haggard]

Thanks for the comments.
If the stock was indeed air braked only, not dual braked, then the SLSTPs and RBs in these two sets would surely have been unique. All other L.M. trains at the time were vac. (checking up, the first air braked stock allocated to the L.M. were Mk2cs the next year) so they could not be used in any other passenger carrying train.
However, the circular does state 'air and vac' in the footnote and I don't think it should be dismissed as just an error
I wonder what air-braked diesel passenger locos worked the trains Kenny <> Willesden. The D400s had just been delivered and could work the train North of Crewe.

 

[Ash Bridge]

Thanks for the comments.
If the stock was indeed air braked only, not dual braked, then the SLSTPs and RBs in these two sets would surely have been unique. All other L.M. trains at the time were vac. (checking up, the first air braked stock allocated to the L.M. were Mk2cs the next year) so they could not be used in any other passenger carrying train.
However, the circular does state 'air and vac' in the footnote and I don't think it should be dismissed as just an error
I wonder what air-braked diesel passenger locos worked the trains Kenny <> Willesden. The D400s had just been delivered and could work the train North of Crewe.

Wondering if it could have been 25s? When I saw it admittedly a few years later I'm pretty certain that was the usual traction unless my memory is playing tricks?

 

[Tynwald]

This would have been an air braked train. The dual braked vehicles would have been working in air brake mode. No vac only vehicles could have been in the consist.

 

[Cheshire Scot]

Is it possible the vehicles shown as dual braked were only piped for air? I think this was the case with the mixed trains that ran in Scotland in the 1980s (though may have been the other way round?) which suggests that a dual braked loco was able to operate both air and vacuum systems simultaneously.

I don't think 'piped only' would have been 'legal' for passenger vehicles, and certainly not for so many vehicles marshalled together. I think there were very few Mk1s which were air only (and if there were then only on the Southern Region but dual braked Mk1s even if not widespread certainly existed.

I do remember the vacuum braked/ air piped oil tank wagons which ran in an air braked freight train (subject to the regulations on brake force and marshalling) then couple to the rear of the vacuum braked mixed from Fort William to Mallaig - and possibly something similar for fish vans on the Far North line (at least some of the fish vans used in Scotland were (at least latterly) VB and air piped (and steam piped which meant they could be marshalled next to the loco)).

The loco would have worked on AB or VB as appropriate to the formation but not on both, so in the case of the Motorail train on air.

 

[Merle Haggard]

The further complication I had in mind for the Kenny - Willesden loco would have been e.t.h. requirement. I think sleepers were heated even in the summer - the Mk1 sleepers always seemed too hot in my experience!

Possibly there was a shore supply, then (as suggested by Ash Bridge) one of Willesden's then new and smart blue D7660s or 7670s could have been used, hoping nobody noticed the falling temperature.

 

[Cheshire Scot]

The further complication I had in mind for the Kenny - Willesden loco would have been e.t.h. requirement. I think sleepers were heated even in the summer - the Mk1 sleepers always seemed too hot in my experience!

Possibly there was a shore supply, then (as suggested by Ash Bridge) one of Willesden's then new and smart blue D7660s or 7670s could have been used, hoping nobody noticed the falling temperature.

I'd guess 47s have been dual braked in that era (?) - even if not yet eth - for working freightliners which I think were AB from the outset.

 

[CW2]

The Kenny - Willesden leg was nearly always a pair of 25s. The last 20:50 Olympia - Stirling motorail ran on 23/10/81, with 25117 and 25209 providing the power. I cadged a (thoroughly illegal) lift from Olympia to Willesden on my way to work night shift at Willesden PSB. I travelled in the back cab of 25117, the leading loco, and was a bit alarmed to see the face of the Area Manager peering at me from the front cab of 25209. We went our separate ways at Willesden and the topic never got mentioned again ...

 

[Taunton]

Dual brake was a difficult but not impossible combination, and was confined to a very few Mk 1 vehicles, which were converted, having of course been built as vacuum only.

My 1972 first edition "Coaching Stock" book - it even predates when the RCTS got involved - lists the following dual braked vehicles, which is probably most or all of them that there ever were :

4 RB; 28 SLSTP; 4 FO; 6 SO; 7 BSO; 10 FK. That was it. They were all dual heat as well. The whole lot are allocated to the LMR. It does seem to gel with them being used for some Motorail purpose, possibly they were deliberately converted just for this.

 

[Clarence Yard]

The heat used to come on when the electric loco replaced the pair of 25’s at the Mitre. I took it, perhaps wrongly, that the coaches had been pre heated at Willesden Carriage before they reached Kenny O. I travelled on that train in summer between 1971 and 1976 but I never went to sleep before I had witnessed the nocturnal goings on at Crewe station, which I found fascinating.

In those years Mk2 stock was reserved for more important trains on LMR than the Motorails.

 

[edwin_m]

I don't think 'piped only' would have been 'legal' for passenger vehicles, and certainly not for so many vehicles marshalled together. I think there were very few Mk1s which were air only (and if there were then only on the Southern Region but dual braked Mk1s even if not widespread certainly existed.

I do remember the vacuum braked/ air piped oil tank wagons which ran in an air braked freight train (subject to the regulations on brake force and marshalling) then couple to the rear of the vacuum braked mixed from Fort William to Mallaig - and possibly something similar for fish vans on the Far North line (at least some of the fish vans used in Scotland were (at least latterly) VB and air piped (and steam piped which meant they could be marshalled next to the loco)).

The loco would have worked on AB or VB as appropriate to the formation but not on both, so in the case of the Motorail train on air.

Whether allowed or not, pipe only would certainly have left inadequate brake force. I was thinking of both sets of pipes being connected from the loco to the passenger portion and working vacuum with the coaches and air with the wagons. However...

Dual brake was a difficult but not impossible combination, and was confined to a very few Mk 1 vehicles, which were converted, having of course been built as vacuum only.

My 1972 first edition "Coaching Stock" book - it even predates when the RCTS got involved - lists the following dual braked vehicles, which is probably most or all of them that there ever were :

4 RB; 28 SLSTP; 4 FO; 6 SO; 7 BSO; 10 FK. That was it. They were all dual heat as well. The whole lot are allocated to the LMR. It does seem to gel with them being used for some Motorail purpose, possibly they were deliberately converted just for this.

...this quote provides a much more likely answer.

 

[D7666]

[1] maybe people looking too deeply - it just means dual braked stock and the rest of the formation implies air, so the train must have been air. Also, if this is the only wording "dual brake" train the OP can find (and stated that) it could just be a typo or other error; one would reasonably expect what goes out from Olympia does come back, either on the exact opposite working or another one; assymetry suggests error

[2] w.r.t. dual braking active on trains, the LMR carriage marshalling circulars for the early 1980s showed 1S09 204x Euston Glasgow Down postal*** and 1M44 Up balance as all dual brake TPO stock and "both air and vacuum brake to be operative"; to my knowledge the only such trains

[3] w.r.t. to the digression into motive power for Olympia motorail trains off WCML, they could not be 47s, those workings were Stonebridge Park drivers and that depot did not know 47s (or at least not at this period if they learnt them later, not sure they did in BR days). 47s into Olympia motorail of course were possible from WR and elsewhere, but all those that were WCML ACL to/from the Willesden area for diesel forwards were Stonebridge crews only, hence 25s.

[4] w.r.t. Mk2 dual brakes, DB999550 - purpose built departmental Mk2 - was dual ; ok ok the exception to prove the rule, but nonetheless disproves the "can't be done" theory

*** which was The TPO Special, not the West Coast Postal, and frequently mis-reported as such, the WC postal was a seperate, Euston Carlisle, TPO conveying train in the era; The Special was all TPO and bag tenders; digression!

 

[Taunton]

I think the definitive list of dual braked stock from the era matching up for types with the formation quoted rather moves us away from a typo. Motorail was a somewhat marginal costing operation which only justified handed-down Mk 1 stock, if you were going to use that (vac only) with Cartics (air only) something had to be done, and if you wanted the stock to be compatible with the rest of the vacuum Motorail operation on other occasions, this seems the way to go. Actually, I wonder why they bothered with the Cartics in the first place on it. The carflats on the rear were presumably for larger cars.

Mk 1 stock as built, I think, was wholly vacuum, but in addition to this handful of dual braked conversions on the LMR, possibly only ever done to be compatible with the Cartics, there were quite a number on the Southern converted to air brake, just used within the region - they were ETH only as well, as the Southern did away totally with steam heat on their own stock. I remember when Class 33s ran Portsmouth to Bristol sometimes it was Mk 1, sometimes a spare 4-TC, it would be consistent if the roster was always for air braked stock. I see the two carflats in the Motorail formation are also down as dual braked, that must have been another conversion. Am I correct that the carflats were Mk 1 non-corridor stock, obsolete when built, with the bodies stripped off?

Dual braking is difficult to rig but (clearly) not impossible, two lots of brake cylinders etc are needed in the underframe cleverly connected to one set of blocks. It would be interesting if there were any special procedures if moved from one type of train to the other, especially if done quickly before the brakes had leaked off.

Locos which were dual braked as I understand it were one or the other at any one moment by a switch, apart from the Class 73 which had some clever Southern home-designed system which allowed them to have vacuum vehicles on one side of them and air on the other in a single train.

 

[Richard Scott]

Locos which were dual braked as I understand it were one or the other at any one moment by a switch, apart from the Class 73 which had some clever Southern home-designed system which allowed them to have vacuum vehicles on one side of them and air on the other in a single train.

73s have a brake selector switch on the cubicle, assume has to be in vacuum for this arrangement to allow exhausters to run. However would have thought any dual braked loco could run like this as the vacuum is air controlled so brake pipe drops first anyway. Only issue would be the fact one compressor drops out in vacuum mode so maintaining air would be hard?

 

[D7666]

I think the definitive list of dual braked stock from the era matching up for types with the formation quoted rather moves us away from a typo. Motorail was a somewhat marginal costing operation which only justified handed-down Mk 1 stock, if you were going to use that (vac only) with Cartics (air only) something had to be done, and if you wanted the stock to be compatible with the rest of the vacuum Motorail operation on other occasions, this seems the way to go. Actually, I wonder why they bothered with the Cartics in the first place on it. The carflats on the rear were presumably for larger cars.

Mk 1 stock as built, I think, was wholly vacuum, but in addition to this handful of dual braked conversions on the LMR, possibly only ever done to be compatible with the Cartics, there were quite a number on the Southern converted to air brake, just used within the region - they were ETH only as well, as the Southern did away totally with steam heat on their own stock. I remember when Class 33s ran Portsmouth to Bristol sometimes it was Mk 1, sometimes a spare 4-TC, it would be consistent if the roster was always for air braked stock. I see the two carflats in the Motorail formation are also down as dual braked, that must have been another conversion. Am I correct that the carflats were Mk 1 non-corridor stock, obsolete when built, with the bodies stripped off?

Dual braking is difficult to rig but (clearly) not impossible, two lots of brake cylinders etc are needed in the underframe cleverly connected to one set of blocks. It would be interesting if there were any special procedures if moved from one type of train to the other, especially if done quickly before the brakes had leaked off.

Locos which were dual braked as I understand it were one or the other at any one moment by a switch, apart from the Class 73 which had some clever Southern home-designed system which allowed them to have vacuum vehicles on one side of them and air on the other in a single train.

Only 73/0 had that AB+loco+VB (or v.v.) translator feature.

And the first two MLV 68001 and 68002.

It wasn't actually devised to operate trains with LH passenger stock, rather to eliminate LH coaches - the idea BR SR was working on was for trains like the overnight newspaper trains that conveyed LH passenger coaches to be formed EMU+73+NPCCS, or EMU+MLV+NPCCS driven from the EMU cab, using EP braking, and the 73 or MLV doing an EP to vacuum translation rather then AB to VB. OK, one can argue that EP is electric controlled air, but anyway, EP was the plan from the lead cab. ISTR it was even taken as far as planning the EMU to be a 2Hap, there being far more seats [disregarding comfort] on a 2HAP than the usual LH 3set used. So instead of half a dozen short LH sets just used (mostly) one way in the small hours, an EMU otherwise idle at night could be used, and scrap the LH.


PS I have always understood the idea of using Cartic4 on Motorail was to keep total train length down, with each cartic sections able to carry 6-8 cars per equivalent length where an ex-carriage underframe could carry only 3-4. Anyone who remembers Motorail in it's heyday will recall the ridiculous lengths that some of them ran to and that could create all sorts of complexications in any out of course working. Even those ER ECML covered purpose built car carriers pre-dating Cartic could carry 6 cars for the same reason; what were they ? TCV ?

 

[big all]

I think it is being overthought.

It may suggest the brake to be use cover all diagrams off all portions involved but it will only ever under normal circumstances be vacuum or air not both in use as they react differently, require different techniques and indeed often differentials use, for example, vacuum 60mph air 70mph London areas southern

I suspect there would be portions attached and detached from the motorail requiring differences in brakes and heating requirement but just a guess ??

And yes an ED had a proportion valve - I think it allowed a vacuum braked train to propel a dead air braked train ??

 

[Taunton]

It wasn't actually devised to operate trains with LH passenger stock, rather to eliminate LH coaches - the idea BR SR was working on was for trains like the overnight newspaper trains that conveyed LH passenger coaches to be formed EMU+73+NPCCS, or EMU+MLV+NPCCS driven from the EMU cab, using EP braking, and the 73 or MLV doing an EP to vacuum translation rather then AB to VB.

Wonder why the Southern didn't just convert the NPCCS to air brake like they did with the Mk 1 passenger stock. They were clearly trying to get rid of vacuum, like steam heating, on anything internal to them.

In passing, were those steam locos which kept Westinghouse air brakes into the 1960s (Liverpool Street and some of Scotland, or even Isle of Wight) actually dual braked, or air only?

 

[Townsend Hook]

Wonder why the Southern didn't just convert the NPCCS to air brake like they did with the Mk 1 passenger stock. They were clearly trying to get rid of vacuum, like steam heating, on anything internal to them.

In passing, were those steam locos which kept Westinghouse air brakes into the 1960s (Liverpool Street and some of Scotland, or even Isle of Wight) actually dual braked, or air only?

The Isle of Wight O2s and coaching stock were air only. Until it’s most recent overhaul, I understand that the Isle of Wight Steam Railway’s ‘Calbourne’ still had the marks on the boiler backhead where the vacuum ejector was mounted until it was removed before delivery to the island.

 

[D7666]

Wonder why the Southern didn't just convert the NPCCS to air brake like they did with the Mk 1 passenger stock. They were clearly trying to get rid of vacuum, like steam heating, on anything internal to them.

In passing, were those steam locos which kept Westinghouse air brakes into the 1960s (Liverpool Street and some of Scotland, or even Isle of Wight) actually dual braked, or air only?

No not in 1958/1960 - from when the first MLV and 73/0 concepts dates from they were not trying to get rid of vacuum there was far too much of it about. At that period there was still much steam on SW side none of which had a plan to go; transfer of WOE to WR and EXE-WAT D800s [vac anyway] and the Bomo line electrification was not happneing at this time.

The /original/ Bournemouth line plan, BEFORE the one that actually went ahead, assumed that vacuum braked stock would be retained on some peak hours workings, and for the boat trains, of which there were a considerable number then, and they were looking into push-pull operating both peaks and boats with sets of nominally loose LH vac 27-way cabled stock with a loco at one end and a driving trailer at the other. Before anybody introduces muddles this has absolutely nothing whatsoever to do with the TC units 601 and 700 formed from exEMU cars. The Bomo line rolling stock plans went through quite a number of iterations before what we know happened was authorised.

There were numerous push-pull tests with JA and MLV and EMU some of which utulised Bullied vacuum brake LH stock - the latter being what the boat sets were largely composed of at that time.


If one sits back with 20:20 vision and ask why didn't SR do it then one may as well ask why didn't BR do it in 1955; the reasons are the same, the SR was just a microcosm of the whole.

 

[Merle Haggard]

In passing, were those steam locos which kept Westinghouse air brakes into the 1960s (Liverpool Street and some of Scotland, or even Isle of Wight) actually dual braked, or air only?

This could be a real diversion!
It's one of the complexities I'm still trying to understand - pity my interest then was mostly in the number on the cab...
The brakes on the loco could be vac, steam or air(Westnghouse). Reading the RCTS LNER loco 'Green Guide' the LNER / ER converted loco brake power right up to nearly the end of steam.
I can remember that when the Woodford - Banbury 'shuttle' was worked by L1s, the distinctive sound (1,2,......) of the pump could be heard, but I'm pretty sure the Thomson BCK it hauled was vac. and the pump was for the loco. Why didn't I look when they coupled after running round???
And, veering far away I know, when the E.R. introduced AWS widely, the freight locos involved had to have their brakes changed to vac. to respond. That's why an O4 could be used on a (? Mr Pegler's?) railtour right at the end of steam (train brakes were also added on conversion). One Q7 was vacuumed for AWS about 2 weeks before it was condemned...

Thanks for all the responses to my original question. Sometimes, I've had comments (e.g., the clerical effort in proof reading would not have let a typo through - I was there! and that the use of Cartics was for length), but these have been covered by others, thanks again.

Further search shows that the Cartics were introduced on Motor-rail services in 1964 (M95001 up, in the NPCCS series). This was about the time of introduction of AB MGR wagons, but AB diesels must have been rare then.

 

[Taunton]

Further search shows that the Cartics were introduced on Motor-rail services in 1964 (M95001 up, in the NPCCS series). This was about the time of introduction of AB MGR wagons, but AB diesels must have been rare then.

Weren't the Cartics on the same articulated chassis/running gear as the first Freightliner sets, which were also air brake? These began in 1965 and developed quite rapidly. Air braked Mk 2a passenger stock (with converted Mk 1 refreshment vehicles) came in 1967; I presume the dual braked Mk 1 conversions discussed above were done before that.

I believe both the MGR and the Freightliner were Gerry Fiennes idea, both picked up and developed with money obtained by Beeching from the Ministry after the two of them talked it through.

The 1972 listing I referred to above also lists 9 Cartic quads in the passenger series, built 1964-7, air braked, I presume just for Motorail. They are numbered next to the 14 2-tier car vans built for the ER in 1961-2, which had internal hydraulic lifts between the two levels into the well between the bogies. I believe there was a fatal loading accident with them with a car driven over the edge when the lift was at the bottom, after which the lower level was not used again.

 

[eastwestdivide]

Wonder why the Southern didn't just convert the NPCCS to air brake like they did with the Mk 1 passenger stock

I'd guess to allow interworking of the parcels stock with other regions - the parcels trains went far and wide and weren't confined to the SR.

 

[edwin_m]

Weren't the Cartics on the same articulated chassis/running gear as the first Freightliner sets, which were also air brake? These began in 1965 and developed quite rapidly. Air braked Mk 2a passenger stock (with converted Mk 1 refreshment vehicles) came in 1967; I presume the dual braked Mk 1 conversions discussed above were done before that.

I believe both the MGR and the Freightliner were Gerry Fiennes idea, both picked up and developed with money obtained by Beeching from the Ministry after the two of them talked it through.

The 1972 listing I referred to above also lists 9 Cartic quads in the passenger series, built 1964-7, air braked, I presume just for Motorail. They are numbered next to the 14 2-tier car vans built for the ER in 1961-2, which had internal hydraulic lifts between the two levels into the well between the bogies. I believe there was a fatal loading accident with them with a car driven over the edge when the lift was at the bottom, after which the lower level was not used again.

Were any Freightliners ever articulated? As far as I'm aware they were bar-coupled into sets of five, therefore indivisible in service, but each flat had two conventional bogies.

 

[Taunton]

Am I long-term mistaken? It's indeed a valid point, that articulation doesn't gel with axleload limits for loading heavy containers each side.

 

[edwin_m]

Am I long-term mistaken? It's indeed a valid point, that articulation doesn't gel with axleload limits for loading heavy containers each side.

Indeed, even if containers are lighter than some loads the axle loads are probably a critical issue, especially with small wheels. Cars are one of the lightest loads relative to volume, and articulation maximises the volume available for them.

 

[Clarence Yard]

Weren't the Cartics on the same articulated chassis/running gear as the first Freightliner sets, which were also air brake? These began in 1965 and developed quite rapidly. Air braked Mk 2a passenger stock (with converted Mk 1 refreshment vehicles) came in 1967; I presume the dual braked Mk 1 conversions discussed above were done before that.

I believe both the MGR and the Freightliner were Gerry Fiennes idea, both picked up and developed with money obtained by Beeching from the Ministry after the two of them talked it through.

The 1972 listing I referred to above also lists 9 Cartic quads in the passenger series, built 1964-7, air braked, I presume just for Motorail. They are numbered next to the 14 2-tier car vans built for the ER in 1961-2, which had internal hydraulic lifts between the two levels into the well between the bogies. I believe there was a fatal loading accident with them with a car driven over the edge when the lift was at the bottom, after which the lower level was not used again.

The fatal accident to TCV E96291E (iirc) occurred when a lift failed, crushing an MGB and, unfortunately, the person loading it. They had to recover him by going in through the side, which afterwards had a patch in it to denote exactly where they went in. The lifts were immediately taken out of use but after a couple of years, when a modification was made to the locking arrangement, they were re-instated but the TCV's reputation with the staff never really recovered and they were eventually withdrawn.

Articulated Freightliners? I think they were just fixed formation sets with two FL1 bogies per vehicle, as mentioned above. The idea for Liner Trains actually came from Ralph Wilson, an ex LNER cartage manager (and enthusiastic supporter of the previous generation of railway containers) and Gerry Fiennes put a young Peter Keen (from LT) in charge of the project. Both the Liner Trains and MGR projects effectively saved rail freight on BR.