Great Western Coffee Shop

For a few years now coaches A and B on down 8 coach HST's are not unlocked at Camborne due to 'short platforms' and departing passengers are advised to move back to coach C, however coaches A and B appear to be always completely platformed. The best answer for this situation that I can get, from the station staff, is that 'A and B may not be platformed' from which I can only assume that there is a concern that HST's might overshoot the station? - Unless anyone knows otherwise? I'm also wondering if there's any other stations where a similar situation arises?:o

The sectional Appendix says that P2 at Camborne is 184 m long. It also says:

Now seven cars plus the power car is 7x23+18=179 m, so you can't get coach A in. The wording does suggest that 7+2 should not cause a problem, without being explicit.

The expected accuracy of stopping at that point - which I don't know - might dictate that B could not be platformed reliably in practice, as suggested. I note that there is "a location of known low adhesion" just outside the station. That's actually on the Up Main, but does suggest this is not the easiest place to stop exactly where you want to.

Often see this at Thatcham. On the down platform, if the HST stops in the right place, at least 6 coaches are clearly platformed.

In my experience the doors are usually only opened on 5, although it does seem to vary. One TM told me that is because of the curve in the platform and the ability to observe all doors that are open.

You'd think there would be an SOP by Station.

This also the case at westbury on the up, only 6 coaches should be released if the signal is on(20m from said signal).So you have to position yourself at the rear of coach c, if signal is off then all doors can be released.

The SDO system on FGW HSTs seems to vary from train to train. Here at Hanborough we have a 3 car platform. Some HSTs can stop with coaches A, B & C, doors unlocked. However some only allow the doors on two coaches to be unlocked. I am told that this is because on some trains the door unlocking is contolled for pairs of coaches and on such a train unlocking the doors of coach C would also mean unlocking the doors of coach D which would be off the end of the platform.

As I understand it the SDO system is fairly complex and only certain combinations of doors may be opened, depending on the last use of the SDO system. I'm sure somebody familiar with the system might be more familiar with it.

The way the XC SDO system works on HSTs is all down to the location of the SDO panels within the train, generally of all the door control panels throughout the train only two per-side are SDO.
You have the option of opening the whole lot, doors in front of you (as you face the panel) or doors behind you.
As the Trailer Standard vehicles are all pretty similar and interchangeable you may find that they've been swapped round during maintenance over time, altering the exact position of door panels therefore affecting what doors are open at SDO stations, though the usual positioning allows for a five or two coach release.

The Camborne situation I believe is all to do with not blocking the level crossing as the traffic builds up quickly.  In normal formation public doors for coaches A/B are usually platformed, TGS/Guards door is not.  The door panel to open between A & B is situated by the door in Coach A, so if the train is slightly past the stop-board you'll be unlocking an un-platformed door, and then you'd have to run back to B/C to open.

Of course if the train is in reverse, then the front passenger will definitely be off, and the risk again for the next set of doors still exists.

As readytostart says, door panel locations can change the situation too.  Where the emergency doors are in the buffet, there are no door panels, so heading towards London in the normal formation, then it was impossible to open 5 coaches (back in the day of 3 first/5 standard ;)).  Of course a mini-buffet has panels, so you can open 5.  Somewhere like Yatton which will easily take 5 coaches could see 4 or 5 being opened purely dependant on the buffet type.  A coach the wrong way round in a formation may cause no panels be available between two coaches, so reducing the number available.

There is a SDO master-guide to tell TM's how many coaches each platform will fit, and then it's up to their discretion/operating decisions on the day to implement.

As for the FGW SDO technology, there is also a SDO-HOLD option.  "Basic" example.  As a TM, if you leave Newbury from the rear door, you are sending a door lock signal down the train.  When you arrive at Hungerford and only open the front 6 coaches because of the short platform, when you select doors AHEAD (facing what you are opening), that lock signal from the back of the train is still active, as it is not being cancelled by the doors being opened.  As a result, the front doors will open and when the TM removes their key, the doors will lock back-up again as the lock signal from Newbury is still active.  However, by selecting HOLD, those forward doors unlocked will stay unlocked and the key can be removed.  The TM MUST return to the panel where HOLD was selected to lock the train and dispatch.

However, if when leaving Newbury the TM locks from coach F, the lock signal is then sent from there.  So on arrival at Hungerford, they can open the doors ahead from coach F, and remove key and dispatch further down as the lock signal is then cancelled.  I would then lock from coach C at Hungerford, as 3 coaches at Bedwyn is next allowing me to open the 3 and move down, but by locking from D/E/F would then require HOLD to be used at Bedwyn.  Hopefully that explains a bit of the operating side of it, or just caused more confusion!  :D

Many thanks for posting an obviously very interesting and complex question, Kernowman - and may I offer you a warm welcome to the Coffee Shop forum.  :)

Chris from Nailsea. (Another relatively short platform).  ;) :D ;D

Firstly thanks for the responses.


- Very True, at Camborne there is a small gap between the level crossing and the start of the down platform but keeping the crossing clear is important.
Spot on about coaches A and B, thankyou - only the TGS/Guards door is not platformed - it usually stops around the platform ramp leaving all public doors platformed. The down platform is on a down gradient and an HST would have to overrun the stop board by at least two thirds of a coach length in order for the rear door of coach A to be off the platform.
I appreciate the complexities of SDO operation, when it comes to selective door opening, but I still say that if an eight coach HST, in correct formation that stops where it should at Camborne, shouldn't need any doors to be kept locked as the only door not platformed is the front of the TGS which is usually not for public use anyway.  

Km :o ;)

4 coaches  ;D

As well as the problems with panels being on hold, there's also the added complication with the panel at the end of the coaches with mini-buffets which is set up so you have to think twice as it is different to all the rest as it is backwards compared.  Caught at least one TM out when Platform 7 at Reading was temporarily shortened.

Interestingly, I did the 16.06 Pad - PZ 8 coach HST throughout at the end of last week and although the TM announced that coaches A and B would be kept locked at Camborne he actually (safely) unlocked All doors at Camborne.  :o 

There is a similar situation at Totnes on the down platform, normally the rear coach of First Class remains locked - the rear door can sometimes be just off the platform. However the whole set can fit JUST depending on where the driver stops compared to the stop board, when all doors are platformed normally all doors are released as the train manager can see from where he is to do the SDO.

A bit off topic but short platforms that are short.

I had not realised until this year's Tall Ships event that Falmouth Town station could only take two cars.

For the event the Maritime line ran two 3 car trains which could not stop at Falmouth Town station.

I believe this station is recycled as it was previously Perranporth Beach Halt on the line from Chacewater to Newquay.

That is correct, the station is indeed the former Perranporth Beach Halt platform. Its a pre-fab structure if you have a close look.

The only document I can find about the lengths of platforms isn't exact, and each station is colour coded for 0-50m, 51-100m etc.

http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDMQFjAD&url=http%3A%2F%2Fwww.networkrail.co.uk%2Fbrowse%2520documents%2Frus%2520documents%2Froute%2520utilisation%2520strategies%2Fgreat%2520western%2Fgreat%2520western%2520rus%2520baseline%2520information%2F05.%2520stations%2520and%2520toc%2520depots%2Fplatform%2520lengths.pdf&ei=q2adVOfANKWu7gaRgIHgDg&usg=AFQjCNFfuGNWXzTZu937dbPVPUR01tYJgA

The Timetable Planning Rules here:

http://www.networkrail.co.uk/browse%20documents/Rules%20Of%20The%20Route/Viewable%20copy/roprhome.pdf

give the lengths for all platforms on the network in section 5.4 of each region's document.  All sorts of other fascinating information can be found in other sections.

Did another down 8 coach HST at Camborne the other day and All doors were unlocked (safely) without passengers being told to move back.


The summer saturdays Falmouth - Paddington used to stop there in the late 70's but that was a different era and a different railway...


Edit note: Quote marks fixed, for clarity. CfN.  :)