Full brake vans

[Masboroughlad]

Why were full brake and guard vans only ever built in mk1 design?

No mk2, 3 or 4 versions?

 

[Llanigraham]

Why were full brake and guard vans only ever built in mk1 design?

No mk2, 3 or 4 versions?

Because now all passenger trains are fully and through braked.

 

[43096]

Why were full brake and guard vans only ever built in mk1 design?

No mk2, 3 or 4 versions?

You might argue that the Mark 3 and 4 DVTs are as close to a full brake as you can get. No Mark 4 BG simply because BR had gone for push-pull operation.

 

[Bevan Price]

BGs were most useful when there was lots of parcel trafic. A BSO or BSK was more useful in terms of passenger space per ton when parcel traffic had largely ceased. In the absence of parcels, a BG was just 30+ tons of deadweight just to carry a guard + brake gear.

 

[jopsuk]

there were very few Mark 3 brake vehicles at all- just the DVTs and 3 BFO (now with the Cornish sleeper fleet)- as for most Mark 3 loco hauled work a mark 1 or mark 2 brake vehicle sufficed (and for HSTs the power cars take on that function) and there were (as far as I can find out?) ~2000 of those built (including over 1000 Mark 1 BG)

 

[nat67]

In Ireland on the loco hauled services they use a Mk3 full brake.

 

[43096]

In Ireland on the loco hauled services they use a Mk3 full brake.

It’s a train heating generator van, not a full brake.

 

[ChiefPlanner]

It’s a train heating generator van, not a full brake.

Long gone surely - they had them on Rosslare - Waterford in the last century ? (maybe in the heritage fleet , but I doubt it)

 

[nat67]

Long gone surely - they had them on Rosslare - Waterford in the last century ? (maybe in the heritage fleet , but I doubt it)

No they are still used with the GM's on the Emerald Isle Express or what ever they are called.

 

[43096]

Long gone surely - they had them on Rosslare - Waterford in the last century ? (maybe in the heritage fleet , but I doubt it)

No - a handful have been retained for use on the Dublin-Belfast “Enterprise” service. They are used to both save fuel (the 201s are very thirsty when supplying ETS, much like a 67 is) and for maintenance reasons (the 201s had a spell of unreliability and this was in part attributed to use of the ETS). With the Cork line Mark 4s also having generator vehicles, the 201s have had their train supply connections plated over.

 

[Spartacus]

Why were full brake and guard vans only ever built in mk1 design?

No mk2, 3 or 4 versions?

Decline in parcels and other sundry goods traffic from local stations meant there was no need to ever build any more, with existing ones being refitted for higher speeds as needed (as high as 110mph), or simply using newer designs with smaller 'goods' carrying capacity.

 

[Ken H]

BG's were part of the trains for the west coast until they had Mk3 DVT's. They were modified to run at 110mph to run with 110mph Mk3 sets Evidently a BG was capable of a 110mph mod but Mk2's weren't.
The DVT's were built as vans because after the Polmont disaster, when a Mk2 DBSO (Driving Brake Second open) hit a cow while being propelled and had a brief career as an aircraft, carrying passengers in leading vehicles over 100mph was banned.

 

[Spartacus]

They were modified to run at 110mph to run with 110mph Mk3 sets Evidently a BG was capable of a 110mph mod but Mk2's weren't.

Parcels don't complain about the ride or spilling tea down their shirt Sure, you could probably maintain a Mk2 to do 110mph all day without said problems, but the maintenance costs to keep it like that might skyrocket.

 

[30907]

Parcels don't complain about the ride or spilling tea down their shirt Sure, you could probably maintain a Mk2 to do 110mph all day without said problems, but the maintenance costs to keep it like that might skyrocket.

Quite. And don't expect air-conditioning
More seriously, while you could use surplus Mk1s on short passenger workings, they rarely needed a full brake and there were loads of BSKs to play with.

 

[43096]

BG's were part of the trains for the west coast until they had Mk3 DVT's. They were modified to run at 110mph to run with 110mph Mk3 sets Evidently a BG was capable of a 110mph mod but Mk2's weren't.

The reason was very simple: they didn’t need any Mark 2s 110mph rated as West Coast could form up full sets of Mark 3s. It was only the lack of Mark 3 brakes that forced the Mark 1 upgrade, and there were additional maintenance requirements as a result.

 

[edwin_m]

The reason was very simple: they didn’t need any Mark 2s 110mph rated as West Coast could form up full sets of Mark 3s. It was only the lack of Mark 3 brakes that forced the Mark 1 upgrade, and there were additional maintenance requirements as a result.

I recall reading in Modern Railways at the time that Mk2 stock couldn't be upgraded to run at more than 110mph but no reason being given. It couldn't have been to do with the bogies as the same B4 (possibly B5) design was fitted to the Mk1 BGs that were rated at 110mph to run with the Mk3 sets. There were also 100mph rakes formed of late series Mk2s which were used mainly on West Midlands services (Oxley based). I don't recall if these had Mk1 BGs or Mk2 brake coaches.

 

[43096]

I recall reading in Modern Railways at the time that Mk2 stock couldn't be upgraded to run at more than 110mph but no reason being given. It couldn't have been to do with the bogies as the same B4 (possibly B5) design was fitted to the Mk1 BGs that were rated at 110mph to run with the Mk3 sets. There were also 100mph rakes formed of late series Mk2s which were used mainly on West Midlands services (Oxley based). I don't recall if these had Mk1 BGs or Mk2 brake coaches.

Brake force might be the reason, as the B4/B5 type had conventional tread brakes but Mark 3s have disk brakes.

 

[dubscottie]

Brake force might be the reason, as the B4/B5 type had conventional tread brakes but Mark 3s have disk brakes.

And the cost/fire risk. Its why the E&G Mk2s were fitted with disc brakes. IIRC BR would need to employ 6 staff just to change brake blocks had they kept tread brakes.

Saying that, there were numerous reports of Deltics + a/c Mk2 stock doing 120 mph+ in the last days of their use on the ECML.

 

[Ken H]

And the cost/fire risk. Its why the E&G Mk2s were fitted with disc brakes. IIRC BR would need to employ 6 staff just to change brake blocks had they kept tread brakes.

Saying that, there were numerous reports of Deltics + a/c Mk2 stock doing 120 mph+ in the last days of their use on the ECML.

but E&G hammers brakes, esp on the incline in the tunnel approaching Queen St.

 

[edwin_m]

Brake force might be the reason, as the B4/B5 type had conventional tread brakes but Mark 3s have disk brakes.

As far as I'm aware the 110mph BGs had the same tread brakes as the standard Mk2s. So having a Mk2 BSO in place of a Mk1 BG wouldn't have changed the brake force of the train significantly or made any difference to the brake pad life or the likelihood of fire (though more passengers would have been at risk if a passenger coach had caught fire).

Also, unlike HSTs, I don't believe loco-hauled Mk3s were allowed shorter braking distances so 110mph would have required longer signal spacings than 100mph and a whole train of tread-braked 110mph BGs would have been safe to run at 110mph.

 

[Ken H]

As far as I'm aware the 110mph BGs had the same tread brakes as the standard Mk2s. So having a Mk2 BSO in place of a Mk1 BG wouldn't have changed the brake force of the train significantly or made any difference to the brake pad life or the likelihood of fire (though more passengers would have been at risk if a passenger coach had caught fire).

Also, unlike HSTs, I don't believe loco-hauled Mk3s were allowed shorter braking distances so 110mph would have required longer signal spacings than 100mph and a whole train of tread-braked 110mph BGs would have been safe to run at 110mph.

I think the 110mph running on WCML was done on the very cheap. doubt they did any expensive signalling changes.

 

[Ken H]

while on the subject of vans on the WCML, some motorail vans (GUV's?) were sometimes attached to london-glasgow trains. So you could have on a southbound train, DVT, MK3's Cl87 or 91, then the vans. Northbound, loco, Mk3's DVT, vans. Dunno about the speed with GUV's. NPA sub type were 110mph.

 

[43096]

Also, unlike HSTs, I don't believe loco-hauled Mk3s were allowed shorter braking distances so 110mph would have required longer signal spacings than 100mph and a whole train of tread-braked 110mph BGs would have been safe to run at 110mph.

There were two reasons why HSTs had better braking performance than what went before. One was the ability to propagate the brake from both power cars using the E70 (or DW2) brake pipe pressure control unit, which means rather than the delay in getting a brake application was over 8 vehicles, it was effectively 4, which meant a faster application - obviously this does not apply in the West Coast scenario. Second, disc brakes are inherently better than tread, and it is this that allowed the 110mph upgrade.

 

[edwin_m]

I think the 110mph running on WCML was done on the very cheap. doubt they did any expensive signalling changes.

There were two reasons why HSTs had better braking performance than what went before. One was the ability to propagate the brake from both power cars using the E70 (or DW2) brake pipe pressure control unit, which means rather than the delay in getting a brake application was over 8 vehicles, it was effectively 4, which meant a faster application - obviously this does not apply in the West Coast scenario. Second, disc brakes are inherently better than tread, and it is this that allowed the 110mph upgrade.

The tables in GK/RT0075 is used to derive signal spacings. It give the same braking distance on level track for standard passenger trains from all line speeds between 100mph and 120mph, and the 125mph distances are only a little longer. So I think you are right that the 110mph trains must have relied on having better braking to achieve the same stopping distance as standard trains from 100mph (as the HSTs do from 125). These are the current tables but it's the sort of thing that doesn't change much.

However the tables for trains with 9%g braking give shorter distances, which suggests that the braking of a 110mph Mk3 formation is not as good as that of modern multiple units. There's probably an instruction somewhere that says how many tread-braked vehicles are allowed in a 110mph formation.

 

[Ken H]

The tables in GK/RT0075 is used to derive signal spacings. It give the same braking distance on level track for standard passenger trains from all line speeds between 100mph and 120mph, and the 125mph distances are only a little longer. So I think you are right that the 110mph trains must have relied on having better braking to achieve the same stopping distance as standard trains from 100mph (as the HSTs do from 125). These are the current tables but it's the sort of thing that doesn't change much.

However the tables for trains with 9%g braking give shorter distances, which suggests that the braking of a 110mph Mk3 formation is not as good as that of modern multiple units. There's probably an instruction somewhere that says how many tread-braked vehicles are allowed in a 110mph formation.

I used to enjoy a 110mph thrash with an 87/90 up front as a passenger. happy days....
What could have been with a decent 125mph Co-Co...

 

[zn1]

there is a British rail research film on youtube concerning brake block composition

 

[supervc-10]

Am I right in thinking that DMU stock won't suffer issues with brake propagation? As each car is effectively it's own unit?

 

[Ken H]

Am I right in thinking that DMU stock won't suffer issues with brake propagation? As each car is effectively it's own unit?

this is the point of EP brakes on EMU's

In the old days the air was released only at the drivers brake valve

An electro pneumatic brake had valves operated electrically down the train so the brake pipe lost pressure quicker.

The 4EPB units were so designated because they had Electro Pneumatic Brake.

I dont think modernisation plan DMU had electric actuated braking - they were vacuum braked anyway.

Do later DMU have electric actuated braking? I am thinking sprinters and subsequent.

 

[hexagon789]

Why were full brake and guard vans only ever built in mk1 design?

No mk2, 3 or 4 versions?

Mk2d and Mk3 versions in Ireland, when IÉ still operated such trains.

In Ireland on the loco hauled services they use a Mk3 full brake.

Mk3 Electric Generator Vans on the De-Dietrich push-pull sets used on the cross-border Enterprise. Mk4 DVTs with generator sets on select Dublin-Cork.

It’s a train heating generator van, not a full brake.

Now probably yes, as I don't think any luggage or bicycles are stored in them these days but when IÉ still operated loco-hauled Mk3s sets on InterCity services they definetly got used for storing bikes and things.

Also, unlike HSTs, I don't believe loco-hauled Mk3s were allowed shorter braking distances so 110mph would have required longer signal spacings than 100mph and a whole train of tread-braked 110mph BGs would have been safe to run at 110mph.

The E70 brake unit on HSTs speeds up the brake propagation rate so they can stop using a combination of disc brakes and faster acting brake applications to stop from 125mph in the distance a traditional train could from 100.

If an E70 fails then the train is limited to 110mph as it can't stop from faster speeds within the same distances anymore.

this is the point of EP brakes on EMU's

In the old days the air was released only at the drivers brake valve

An electro pneumatic brake had valves operated electrically down the train so the brake pipe lost pressure quicker.

The 4EPB units were so designated because they had Electro Pneumatic Brake.

I dont think modernisation plan DMU had electric actuated braking - they were vacuum braked anyway.

Do later DMU have electric actuated braking? I am thinking sprinters and subsequent.

Second Generation DMUs have Electro-Pneumatic braking, mostly Westcode 3-step energise-to-release.

 

[Ken H]

Second Generation DMUs have Electro-Pneumatic braking, mostly Westcode 3-step energise-to-release.

Thanks for that.