Modelling GWR Slip Coach operation -

[Stevelewis]

Thinking  further   about  the  Slip  Coaches,  and perhaps  this  is  off topic* a bit   but  maybe  someone  fron  one  of  the  manufacturers  may  jsut  read  it.

 

To make a model slip  coach  function  prototypically  it  would  have  to  be  very  free  running  and  inevitably, many layouts  would  not  have  sufficient  length  of  run to  make  it, detach  and  glide to  a  halt in  the  platform.

 

So  if  a  digitaly controlled uncoupling slip coach  was  produced,  why not  go  the  whole  hog  and  fit  a  powered  bogie, obviously  this  system  would  need DCC to  work,  and  it  would  depend on  the user  to be  able  to  synchronise the  speed  of  the train loco and  the  slip  coach,  obviously  the  Slip coach  would  have  a different  digital address to  the  train loco, so that  when slipping  was  due, the coupling  would be disengaged and the coach  would be brought to a halt in the  station under digital  control

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*Should any Mod reading this  wish to move   to  another  section please do  so*.

[phil_sutters]

Or they had them along the roof on clerestories, yes. They still only had a limited amount of vacuum to play with. And it doesn't give more braking power, just the same braking power for longer, allowing the brake to be modulated.

 

Adrian

Like this one my father took at Didcot in 1935.

 

 

 

Whether slips were slipped outside station limits and had to be collected or arrived in the platform under their own momentum, they would still have to be shunted when empty, or added to local trains. So there is more potential action than just the 'slip'.

I can just remember being 'slipped' at Westbury (I think) and can even remember the repeated gentle application of the brakes. I would only have been around twelve at the time, so it is odd to remember that particular sensation.

 

Later - within an hour of finding and reading this thread, I picked up a Railway Modeller from a pile I found while sorting out the garage this week. What should be in it - the March 2011 edition - but Brian Gillespie and Brian Kingett's article on 'Great Western slip coaches' and their description, with scale drawings, of making a 4mm radio controlled Diagram F23 slip coach. What a coincidence! I hadn't even remembered stashing the magazines away, let alone being aware that there was a slip article.

Edited October 8, 2016 by phil_sutters

[scratcher]

Anybody happen to know which diagrams of slip coach were slipped at Princes Risborough in the 1930s ?

[Adrian Wintle]

Anybody happen to know which diagrams of slip coach were slipped at Princes Risborough in the 1930s ?

 

In the 1938 workings it is shown as a slip coach plus a third (only the slip coach on Mondays) slipped from the 7.10pm Paddington to Shrewsbury. The presence of the third suggests a single-ended slip with a gangway at the other end, but based on the list of slip coaches and other slip workings there were only two coaches that were available and met those criteria, 7101 or 7102 (Dia F14). There were significantly more double-ended slip coaches available. The working does not show a non-gangwayed indicator, so it was not diagrammed specifically for a double-ended slip.

 

I would suggest an F14 (single ended) or an F15 (double ended), but it could just as likely have been an F10, F7, F11, F12, or F22 *(all clerestory diagrams, F10 is double-ended, the others single-ended and non-gangwayed) as they were mostly still in service at the time. They were unlikely to be either of the 70' diagrams (F13 or F21) or F23 (built 1929 for the Riviera). F24s were built in 1938.

 

*Edit: see my post below for coaches available in Sept 1937.

 

Adrian

Edited October 14, 2016 by Adrian Wintle

[81C]

I've a F15 PC kit to build would one of them have been slipped at any point west of Exeter in the late 1930's , I have done a detailed research on this and can not find any photo's on the subject unless Chrisf knows of any.

[chrisf]

I've a F15 PC kit to build would one of them have been slipped at any point west of Exeter in the late 1930's , I have done a detailed research on this and can not find any photo's on the subject unless Chrisf knows of any.

 

Pass.

 

Chris

[Coach bogie]

I've a F15 PC kit to build would one of them have been slipped at any point west of Exeter in the late 1930's , I have done a detailed research on this and can not find any photo's on the subject unless Chrisf knows of any.

 Late Thirties, most of the images I have looked at appear to be F23 and F24. The paneled slips are noticeable by their absence.

 

Mike Wiltshire

[Adrian Wintle]

I've a F15 PC kit to build would one of them have been slipped at any point west of Exeter in the late 1930's , I have done a detailed research on this and can not find any photo's on the subject unless Chrisf knows of any.

 

As far as I know there were no slip workings west of Exeter.  Certainly there were none in the 1937/1938 coach workings.

 

The listed workings were:

Down trains, all originate at Paddington

8.55 am, coach slipped at Stoke Gifford**

9.10 am, coaches slipped at Banbury and Leamington

10.30 am, coaches slipped at Heywood Road Junction and Taunton (double-ended slip and F23 respectively)

11.15 am, coach slipped at Didcot***

2.10 pm, coach slipped at Banbury

4.5 pm, coach slipped at Bicester

5.15 pm, coach slipped at Taplow

6.10 pm, coaches slipped at Bicester and Banbury

7.10 pm, coach slipped at Princes Risborough

7.40 pm, coach slipped at Taplow

7.55 pm, coach slipped at Stoke Gifford*

 

Up trains

7.10 am Weston, coach slipped at Didcot*

8.52 am Oxford, coach slipped at Reading

6.50 am Weymouth, coach slipped at Reading (Mon, Thurs, Sat) (this is the double-ended coach off the Riviera)

8.35 am Plymouth, coaches slipped at Westbury* and Reading (Reading slip is a double-ended 70' coach conveyed to Plymouth as a regular coach)

8.21 am Frome, coach slipped at Reading (Tues, Wed, Fri) (this is the double-ended coach off the Riviera)

11.45 am Malvern Wells, coach slipped at Reading***

4.35 pm Weston, coaches slipped at Swindon and Reading** (Swindon slip is a double-ended 70' coach that returns to Weston via Bristol as a regular coach)

 

Notes:

The slip from the Riviera at Taunton was an F23 (6962, 6963, or 6964), carried onward to Ilfracombe and returned to Paddington the next day.

* this is a double-ended 70' slip coach, two of them used to make this (two day) circuit

** this is a double-ended 70' slip making the circuit in a single day

*** this is a double-ended 70' slip making the circuit in a single day

The other coach types are not explicitly called out in the slip coach workings, but more information may be gleaned from the individual train workings.

 

Note that the F24s were built in 1938 and so wouldn't have been in any of these workings as originally scheduled.

 

Adrian

[Adrian Wintle]

The list of available slip coaches from September 1937 is as follows:

 

Single-ended with a gangway at the other end:

6962-6964 F23 (61' Collett)

7101-7102 F14 (57' Toplight)

 

Single-ended with no gangway

7237 F7 (58' Clerestory)

 

Double-ended 70'

7685-7699 F13 (Concertina)

7990-7993 F21 (Toplight)

 

Double-ended

7087-7088 F10 (58' Clerestory)

7094 F10 (58' Clerestory)

7096-7100 F10 (58' Clerestory)

7103-7109 F15 (Toplight)

7994-8000 F15 (Toplight)

 

Adrian

[81C]

My fears were confirmed about not being used west of Exeter still the bogie's which are first class moulding can go on a Siphon G the rest of the parts can go in the spares box long to be forgotten. 

[Adrian Wintle]

My fears were confirmed about not being used west of Exeter still the bogie's which are first class moulding can go on a Siphon G the rest of the parts can go in the spares box long to be forgotten. 

 

It could stand in for the 70' slip that was conveyed to Plymouth as a regular coach and then slipped at Reading on the way back.

 

Adrian

[81C]

It could stand in for the 70' slip that was conveyed to Plymouth as a regular coach and then slipped at Reading on the way back.

 

Adrian

Thanks for that idea It did cross my mind maybe if I build the coach it might give me "food for thought" mingled in with a Toplight or two the GWR did throw everything into the summer excursion season, the jury is now out. 

Edited October 15, 2016 by 81C

[Adrian Wintle]

Thanks for that idea It did cross my mind maybe if I build the coach it might give me "food for thought" mingled in with a Toplight or two the GWR did throw everything into the summer excursion season, the jury is now out. 

 

The formation for the 1:40 am Paddington to Penzance (1937) is quite interesting (gangwayed coaches unless indicated):

 

To North Road

Third

70' double-ended slip (no gangways)

 

To Penzance

Brake Van (Toplight, Collett*, or ganwayed Dean)

Compo

Third

Van Third (van trailing)

 

To Kingswear

Siphon G

 

To Taunton

70' News Brake Van

Dining Car (presumably a positioning move)

 

*not a K40 as these were specifically called out as 60x9 Brake Vans

 

Adrian

[dibber25]

Reading was 'standard' in so far as the meaning of Slip Distants was concerned although they were not a widespread fitment (there were particular reasons at Reading which related to the possibility of Main Line East having its signals at danger and the fact that the slip took place at the entrance to the platform) but I think Reading was probably the last place to have them.  The Reading Slip Distants were in fact a splitting pair so in theory slipping could also take place on the Up Main Through Line although as far as I'm aware it certainly wasn't booked to take place there in later years (and would have been a right nuisance if it did.

 

There were also copious Instructions regarding the need to stop instead of slipping as a stop could happen for all sorts of reasons (e.g. defective slipping coupling) or even a train stopping for water when it was not booked to do so.

 

There is a nice piece by Adrian Vaughan about the Reading slip (I just Googled slip coaches). He says the train was routed through the up main platform (No. 5 in those days?) at 20mph and the coach slipped at the approach end of the platform. I would have thought such an operation would be possible in model form without a powered slip coach. Provided the uncoupling was friction-free, a modern model coach should roll fairly realistically for a short distance, bearing in mind most model platforms will be shorter than scale length anyway. (CJL)

[Ian G]

I have a similar challenge for our MRC layout Okehampton 7mm (OK not GWR), the Meldon Quarry engineers coach was un-coupled near its siding in Okehampton and a type of air motor was used to send the coach down into its siding. there is a gradient drop to the buffers on the real thing.

I have thought of having a working braking system on the coach.

Motorising the chassis.

mini bearings for free running

my best thoughts are, is to use a small coreless motor in place of the dynamo to a pully on the coach wheel. and mini bearings on all axles.

 

Going back to the model slip coach idea, if my memory serves me right, the coupling hook was a disk with a 2 slots cut out one for the coupling the other for the release mechanism.

Using a servo this can be achieved, and a read switch to activate it or dcc.

 

Ian G

[DCB]

With modern free running stock in 00 the problem is more likely to be stopping the coach rather than keeping it running.  I have a small S gauge radio control car which I have plans to use for a slip coach. With both steering and drive motors arranging one to lift the coupling hook and the other to apply a sort of brake "shoe" to one of the wheels or axles.

My previous attempt had metal Hornby Dublo bogies with Lima wheels insulated one side and Romford pin point bearings which picked up power from the track.  When it passed over a dead section the coupling hook raised and uncoupled it.   It was powered by a capacitor which discharged through the lift solenoid when power was removed.   It worked and stopped in a reasonable distance in a sort of LMS Coronation arriving at Crewe at 114 MPH sort of manner, but I never had a station to operate it at.  1 didn't have platforms on the through road, the other was on a down gradient and the damned coach picked up speed instead of slowing.    The dead section had a switch which was thrown just after the loco passed, (hopefully)

 

I can't see a flywheel helping the momentum, the losses in the gearing would be horrendous, but if a powered slip coach is required maybe a Micro scalextric drivetrain on one axle might produce a nice fairly free running coach which could be powered and braked to glide smoothly into the platform.    Accelerating it out of a bay platform to catch and couple up to an express could be a nice set piece for the last half hour of an exhibition.

[Gordon A]

Have you carried out any trials using a coach fitted with a remote uncoupling system?

A lot would depend on the approach speed of your train to the station along with other factors already mentioned.

 

Gordon A

[DCB]

I

Have you carried out any trials using a coach fitted with a remote uncoupling system?

A lot would depend on the approach speed of your train to the station along with other factors already mentioned.

 

Gordon A

My uncoupling system worked really well and was just a dropper arm on a solenoid, the end engaged with a standard coupling and simply lifted to release.

It could equally twist laterally to release which is my plan to use the S scale car motor and R/C equipment, powered by button cells as used.

Using R/C instead of track power will decrease the rolling resistance of the coach compared to my old system, but I believe a Hornby Hawksworth brake compo

which is as near as I know to a RTR slip coach will run away on a 1 in 100. I would suggest testing a coach by taking the couplings off your Thomas

the Tank engine and propelling the coach at test speed and stopping the loco dead. In my case it coasts right through the station and disappears into the

hidden siding. Going the other way you can propell it out of the hidden sidings into the station with your hand after a train has passed but it

then rolls back into the sidings down the gradient, hence the need for brakes....

the slight gradient.

[unclebobkt]

        I write availing of a very amnesic memory as we are going back to the fairly early days of WW2..

 

  Our prep. school was evacuated from Bognor Regis, (Sx.), to near Truro, in Cornwall.

 

  Back then the pre-war editions of GWR. themed books for 'Boys of all ages.', issued by the GWR. Publicity Dept.,  were still available from the WH. Smith's bookstall at Exeter.

  In one of those books - probably the one dealing with the '10.30. Limited.' - were drawings of the slip-coach couplings together with how the slip-coach's Guard operated the mechanisms and brought the coach to a stop just where it needed to be.

  Memory suggests that for 'Slipping.' the optimum speed of the main part of the train was 60MPH., (?),  and based on that figure there were line-side boards to shew the Guards when to operate the slipping mechanism.

 

  Maybe these books, or their later re-prints, are available from 2nd, hand book shops etc. etc.?

 

       E&OE..       

[Miss Prism]

http://www.railwaywondersoftheworld.com/slip-coaches.html

[Joseph_Pestell]

Reviving this theme, we have been discussing slips on my recently started Haddenham theme and I am looking for what kits are available.

 

I see that Worsley Works have a kit of a toplight brake third that can be made into an F20. When would they have been withdrawn?

[rprodgers]

I recall that a working ex GWR slip coach was recreated on a model based on Wellington Shropshire using a powered bogie

An article on this layout appeared in MRJ at the time

R

 

 

Edit layout was by a David Amias

https://www.shropshirestar.com/news/local-hubs/telford/wellington/2017/09/14/davids-model-on-track-for-show/

Edited March 14, 2018 by rprodgers

[chrisf]

Reviving this theme, we have been discussing slips on my recently started Haddenham theme and I am looking for what kits are available.

 

I see that Worsley Works have a kit of a toplight brake third that can be made into an F20. When would they have been withdrawn?

 

Harris does not give the number series for F20 and there is no photo in Vol 2 of the Russell appendix.  This does make it a bit difficult to answer the question.  What may help is the following list from the Railway Observer of operational slips still extant in 1957: 7069-74 [F24, built 1938], 7685/8 [Concertina, F13, built 1906] 7898/9, 7900 [F23, Riviera stock, built 1929], 7991/2/3 [F21, 70 ft, built 1916].

 

Chris 

[Ravenser]

In terms of how this could be done - the idea of trying to deconsist a moving train under DCC seems to me unworkable . A theoretical concept, but not something you could actually do successfully with a moving train.

 

I'm driven back on the off-the-wall idea that a DCC controlled coupler could be used - such things exist, and that the act of uncoupling would somehow act as a switch, switching in an auxiliary motor on the coach. This would draw on a very limited but rechargeable on board power source, so the motor would rapidly run down and stop . Almost on the lines of a "stay-alive" capacitor but with a bit more grunt.

 

The trouble with this is that the coach would need to be free running when hauled by the train, but geared to the motor when uncoupled.....

[Donw]

On 19/03/2013 at 17:48, ozzyo said:

Hello all,

 

Steve and myself were talking about slip coaches a few days back. One of the questions that we asked ourselves was at say Reading with through roads.

1], would the train run through the platform to slip the coach.

2}, run through on the through road and the station pilot pick up the slip coach from the through road.

3], the main train runs through on the through road, then the point is changed (along with the F.P.L and put back) and the slip coach runs into the platform.

 

Number 1, sounds OK but it will slow down the main train, but not as much as stopping.

Number 2, would seem the most logical, it may take a bit longer for the passengers, but it would still be quicker than getting the slow train.

Number 3, this one just sound all wrong. having to do at least three point moves ( F.P.L. out point thrown F.P.L. in) in front of a moving passenger train (the slip coach).

 

Can any one say for certain, what would have happened.

 

For the slip coach (we were talking about 7mm and DCC) power the coach and make the coupling work something like the real thing using one of the DCC functions. So it would be something like a clam shell for the hook.

 

OzzyO. 

 

According to my Father in law the coach he was in glided into the platform unassisted. However he did not say whether the main train had gone through the platform road or the centre road. A lot depends on whether the interlocking would allow the signalman to change a turnout between the train passing though. I imagine the signalman might be able to throw the levers quick enough especially if an economical FPL (i.e only one lever) was used. However I think changing a turnout in front of a moving coach would not be acceptable. What if it jammed. Of course from my Father in Law's point of view the Express would have cleared either the platform or the centre road before the Slip was close enough to see. This was at Reading with a Slip off the up Torbay Express not sure if he mentioned the date but it would have been before 1942 when he joined the RAF to become a Lancaster ground crew member.

 

If you build one using DCC. You need to set the acceleration CV so there is no delay in reaching speed (or else the coach will appear to speed up)  and iff using say the Zimo immersive drive where it will coast and you press F2 to break it will be a close replica of dribving the real coach by using the break. Sounds fun.

 

Don

 

PS Staionmaster Mike may have a better idea if the interlocking would have allowed the turnout to be changed with an approaching coach.

 

 

PPS this had been flagged up to me by the system as something was updated  I didn't notice the date. I see Mike did give a clear answer about slipping distants.

Edited January 24, 2021 by Donw
adding post script