Driving van trailers

[Foden]

Never seen any in cab footage riding in a driving van trailer, what were they like from a driver’s perspective? A lot like a coach with a forward facing window I’d have thought!?

 

So were they generally the preferred end of the train to drive from? Something to look forward to if an outward leg was in a loco? A nicer ride and a little more peace and quiet perhaps?

[Talltim]

I’d have thought the cab interiors looked much like, but not identical to, their respective locos, i.e. the Mk3 DVT like the 90 and the Mk4 like the 90

[Wickham Green too]

The passenger ride in the front end of a 4TC+4TC+4REP unit could be 'interesting' at times - if the driver was a little heavy-handed and the motive power caught up with the rest of the train, so to speak.

[hexagon789]

6 hours ago, Foden said:

Never seen any in cab footage riding in a driving van trailer, what were they like from a driver’s perspective? A lot like a coach with a forward facing window I’d have thought!?

 

So were they generally the preferred end of the train to drive from? Something to look forward to if an outward leg was in a loco? A nicer ride and a little more peace and quiet perhaps?

 

Mk3 DVT - like a 90, same style power controller, 7-step brake, speedset

 

Mk4 DVT - like a 91, same style power controller marked out 0-10 but fully variable, 7-step brake, speedset

 

Other driving trailers:

 

Mk2f DBSO - like a 1970s EMU crossed with a loco, four-notch power controller, normal twin-pipe air-brake controller.

 

Class 489 GLV - like an EMU, four-notch power controller, Auto-Air/EP brake controller

 

 

One thing I have often wondered is how the DBSO were set up with 86s, anyone know?

[DY444]

16 hours ago, Wickham Green too said:

The passenger ride in the front end of a 4TC+4TC+4REP unit could be 'interesting' at times - if the driver was a little heavy-handed and the motive power caught up with the rest of the train, so to speak.

 

And if power was shut off with the REP at the back, particularly when it was accelerating hard, you'd get a brief surge at the front of the train as the small amount of compression unwound which was then straight away arrested by the couplings.  A very odd sensation which I don't recall having ever noticed on the 47/7 or AC electric propelled formations.

[frobisher]

4 minutes ago, DY444 said:

 A very odd sensation which I don't recall having ever noticed on the 47/7 or AC electric propelled formations.

 

Probably because there's a lot more mass hence inertia in a loco than the motor cars of the REP.

[Pete the Elaner]

18 hours ago, hexagon789 said:

 

One thing I have often wondered is how the DBSO were set up with 86s, anyone know?

 

It was very common for it to snatch quite violently when setting off running DBSO first.

Not sure if this is relevant?

[Bomag]

I was with RCE Anglia just before the DBSO were moved there and one of the S&T engineers who was checking immunisation etc on them in testing mentioned that the rolling stock lot were complaining (among a many things) about the 'give' in the couplings and buffers on the 86/2s we had at the time being more that expected. However, given that the coach sets on GEML were twice the length of EG services and as only the DBSO has disk brakes (well most had) snatching was seen as not much of an issue. We were more concerned about the ongoing mullering the track was taking from the axle hung traction motors.

 

The worst for snatching and shunting were the Class 91 and HST. Going southbound from Newark and Grantham could be quite lively in the TGS as drivers could open it up straight off and not have to keep it down over pointwork etc.

[Foden]

Was there ever any concern with drivers in DBSOs and DVTs of being propelled at upwards of 100mph in a lighter carriage? After the awful events of Polmont, was it something that some drivers didn't particularly like for these reasons?

[hexagon789]

7 hours ago, Pete the Elaner said:

 

It was very common for it to snatch quite violently when setting off running DBSO first.

Not sure if this is relevant?

 

Thanks all the same but I was more meaning how the control system was set up. I had someone very kindly explain how the 47/7s were set-up with the DBSO in terms of what each power notch in the DBSO gave, and I know that with DVTs the TDM would demand a proportion of power and tap-changer locos (86/

87s) would simply set a proportional equivalent of taps but I wondered what happened with DBSOs and 86s.

 

In other words what did each of the 4 power notches demand from/give with the 86? Did they set a proportion of power similar to how an ac EMU of the period was set-up:

 

OFF

Notch 1 - shunt 

Notch 2 - half power

Notch 3 - full power 

Notch 4 - weak field

 

 

It couldn't be exactly that as 86/2s have no weak field taps, only 86/1s do by virtue of effectively being 87s.

 

So some modification of that set-up must have been used. Unless it was more like the 47/7s and you got about 10%, 25%, 60% and 100% power with each respective notch?

 

I've never managed to find out and I've always wondered.

[DY444]

18 hours ago, frobisher said:

 

Probably because there's a lot more mass hence inertia in a loco than the motor cars of the REP.

 

Not convinced it's mass.  The REP motor coaches weighed 52 tons and there were two with the whole 4 car unit weighing in at 170-ish tons.   Your average AC Bo-Bo was about 80-ish tons.

[DY444]

On 14/05/2020 at 22:48, hexagon789 said:

 

Thanks all the same but I was more meaning how the control system was set up. I had someone very kindly explain how the 47/7s were set-up with the DBSO in terms of what each power notch in the DBSO gave, and I know that with DVTs the TDM would demand a proportion of power and tap-changer locos (86/

87s) would simply set a proportional equivalent of taps but I wondered what happened with DBSOs and 86s.

 

In other words what did each of the 4 power notches demand from/give with the 86? Did they set a proportion of power similar to how an ac EMU of the period was set-up:

 

OFF

Notch 1 - shunt 

Notch 2 - half power

Notch 3 - full power 

Notch 4 - weak field

 

 

It couldn't be exactly that as 86/2s have no weak field taps, only 86/1s do by virtue of effectively being 87s.

 

So some modification of that set-up must have been used. Unless it was more like the 47/7s and you got about 10%, 25%, 60% and 100% power with each respective notch?

 

I've never managed to find out and I've always wondered.

 

The DBSOs were changed from FDM to TDM for use with the AC electrics so the system is the same as with a DVT.  A tap changer locomotive translates the power demand set on the controller to a specific tap and runs the tap changer up or down as necessary to set that tap.

Edited May 16, 2020 by DY444

[hexagon789]

4 hours ago, DY444 said:

 

The DBSOs were changed from FDM to TDM for use with the AC electrics so the system is the same as with a DVT.  A tap changer locomotive translates the power demand set on the controller to a specific tap and runs the tap changer up or down as necessary to set that tap.

 

I understood that the push-pull system employed changed, but I still don't understand how it worked with the four-notch power controller under TDM control with 86/2s

[DY444]

21 hours ago, hexagon789 said:

 

I understood that the push-pull system employed changed, but I still don't understand how it worked with the four-notch power controller under TDM control with 86/2s

 

It's exactly the same as any other TDM equipped driving vehicle and locomotive.  The TDM equipment on the driving trailer transmits a message to the locomotive containing information about the power controller setting.  The locomotive TDM equipment translates that message into a setting for its traction equipment and applies it.  In the case of a tap changer locomotive that translation is a target tap changer position.  The tap changer is then run up or down as appropriate from the current tap position to the target tap position.  

 

If you're asking for a definition of what data the DBSO TDM equipment transmits for each power controller position and the algorithm the Class 86/2 TDM equipment uses to translate that data into a target tap changer position then I don't know.  I used to visit Plessey at Sopers Lane frequently during my BT days and was given a set of Push Pull TDM technical documentation around the time it was being developed, unfortunately I mislaid it years ago and can't remember any of the details now.

Edited May 17, 2020 by DY444

[Catkins]

21 hours ago, hexagon789 said:

 

I understood that the push-pull system employed changed, but I still don't understand how it worked with the four-notch power controller under TDM control with 86/2s

I can't answer this question, but I guess what Hexagon is trying to get at is how each notch on the DBSO equalled the power crontroller position in an 86.

I know the DBSOs were refurbished before they were deployed to the Anglian Main-line, dit the cabs get refitted at the same time?

[47513]

Along the same lines, I am curious as to the set up when Freightliner 86’s work in multiple via the TDM cables. Is the leading loco directly transmitting the driver’s notch up/down etc actions to the trailing loco or is there a translation into a traction demand that is translated back to notches in the trailing loco?

[hexagon789]

2 hours ago, DY444 said:

 

It's exactly the same as any other TDM equipped driving vehicle and locomotive.  The TDM equipment on the driving trailer transmits a message to the locomotive containing information about the power controller setting.  The locomotive TDM equipment translates that message into a setting for its traction equipment and applies it.  In the case of a tap changer locomotive that translation is a target tap changer position.  The tap changer is then run up or down as appropriate from the current tap position to the target tap position.  

 

If you're asking for a definition of what data the DBSO TDM equipment transmits for each power controller position and the algorithm the Class 86/2 TDM equipment uses to translate that data into a target tap changer position then I don't know.  I used to visit Plessey at Sopers Lane frequently during my BT days and was given a set of Push Pull TDM technical documentation around the time it was being developed, unfortunately I mislaid it years ago and can't remember any of the details now.

 

I do appreciate you typing this believe me, but it's still not quite what I meant sorry.

 

This is exactly what I meant as Catkins so succinctly put:

1 hour ago, Catkins said:

I can't answer this question, but I guess what Hexagon is trying to get at is how each notch on the DBSO equalled the power crontroller position in an 86.

 

Because of the limitations with having only four power settings in the DBSO, I was curious as to which levels of power these corresponded to on the 86s.

Edited May 17, 2020 by hexagon789

[DY444]

17 minutes ago, hexagon789 said:

 

I do appreciate you typing this believe me, but it's still not quite what I meant sorry.

 

This is exactly what I meant as Catkins so succinctly put:

 

Because of the limitations with having only four power settings in the DBSO, I was curious as to which levels of power these corresponded to on the 86s.

 

As I said I can't remember the details.  I do remember the design having a separate module for interfacing the TDM equipment in the locomotive to the tap changer and I believe that this also monitored motor current so that the rate of running up the tap changer could be automatically regulated to avoid excessive current at low speeds.   If I had to guess then I'd say the taps would probably be something like 9, 18, 28 and 38 for a 4 position controller.    

[DY444]

1 hour ago, 47513 said:

Along the same lines, I am curious as to the set up when Freightliner 86’s work in multiple via the TDM cables. Is the leading loco directly transmitting the driver’s notch up/down etc actions to the trailing loco or is there a translation into a traction demand that is translated back to notches in the trailing loco?

 

The latter I believe.

[EddieK]

On 13/05/2020 at 20:11, hexagon789 said:

 

Mk3 DVT - like a 90, same style power controller, 7-step brake, speedset

 

Mk4 DVT - like a 91, same style power controller marked out 0-10 but fully variable, 7-step brake, speedset

 

Other driving trailers:

 

Mk2f DBSO - like a 1970s EMU crossed with a loco, four-notch power controller, normal twin-pipe air-brake controller.

 

Class 489 GLV - like an EMU, four-notch power controller, Auto-Air/EP brake controller

 

 

One thing I have often wondered is how the DBSO were set up with 86s, anyone know?

Was a GLV a Driving Trailer? I thought that they retained the motor bogie of the donor EMU vehicle.

[Wickham Green too]

34 minutes ago, EddieK said:

Was a GLV a Driving Trailer? I thought that they retained the motor bogie of the donor EMU vehicle.

No ......... and yes !

[m1a2lt]

For the interior of a MK4 DVT, go to 4:22 and they have some interior video:

 

https://www.youtube.com/watch?v=map-6zN1fKI

[russ p]

There was also a driving trailer that was converted from a BSK I believe in the 60s for some trials.

It ended up with the structure gauging train.

If I remember rightly it had a 45 controller and an EP brake controller.  I was blue star multiple working but also worked with those RTC 47s

[keefer]

 QXX RDB 975076, formerly BSK 34500.

http://www.departmentals.com/departmental/975076

(Details given in the comments)

Edited May 25, 2020 by keefer

[russ p]

10 minutes ago, keefer said:

 QXX RDB 975076, formerly BSK 34500.

http://www.departmentals.com/departmental/975076

(Details given in the comments)

 

Shame its going to be rebuilt as a standard BSK, would have been nice to have seen it restored as DT with two or three coaches through wired.

WSR doesn't seem to know what certain coaches are for with it and the Dartmouth railway using DMU trailers to cram more passengers in.

A driving trailer with a loco enables railways to run services without having boxes open for run rounds 

Mind with the  current financial situation of the railway hopefully it will be sold to somewhere more appreciative of what it is