Travelling Post Office, how slow can you go?

[73c]

Hi all. I'm wondering what would be the minimum safe speed an exchange could take place at?

An example being if there were a temporary speed restriction in place that included the exchange equipment within that section.

Would such information be contained in railway regs, drivers having to maintain a certain low speed or would it be just the postal side ie ' Can't do a drop at X because of travelling to slow ' 

I'd be interested to see any written documentation, if there's any about.

Thanks in advance for any help with this.

[Welchester]

Not written information, I'm afraid, but the GCR occasionally gives demonstrations of TPO operations, for which I believe the minimum speed is 30 mph.

[The Stationmaster]

Just about the only thing which does not appear in the relevant Instructions is any mention of train speed!  Diversions, trains running in two parts, trains cancelled, method of warning (to Post Office staff at the ground apparatus) of a TPO train approaching and so on are all covered but there is nothing at all about train speed.

[73c]

The one person I thought would have the answer!

[The Johnster]

Thinking of the mechanics of the operation, picking up leather pouches full of mailbags or dropping them into heavy nets, the thing could probably be done at quite low speeds.  It is more likely that there was a limit to the top speed for picking up; this is well depicted in ‘Night Mail’ as the heavy pouch is hurled across the coach.  I can picture excess speed resulting in coach rocking violently enough to be out of gauge or even going beyond the tipping point and derailing.  

[73c]

I'd have said something around 40mph would be the slowest, otherwise you wouldn't get a clean exchange, bags wouldn't be deposited inside the coach properly and pouches could catch the ground net, ripping it out. Top speed I've been told was around the 60mph mark, weight of pouch and post inside is about 50lb's max, 20lb pouch + 30lb post.

[kevinlms]

5 hours ago, 73c said:

I'd have said something around 40mph would be the slowest, otherwise you wouldn't get a clean exchange, bags wouldn't be deposited inside the coach properly and pouches could catch the ground net, ripping it out. Top speed I've been told was around the 60mph mark, weight of pouch and post inside is about 50lb's max, 20lb pouch + 30lb post.

Welchester above, said the GCR manage at 30mph, which I believe is the maximum speed allowed on most preserved lines.

Surely the correct answer is a determined range of speeds depending of site arrangements. Although I can see why there has to be an upper limit, just imagine modifying an HST to enable the process at full speed. The pouch would fly across the coach, through the sheeting and never to be seen again!

[Edwin_m]

6 hours ago, kevinlms said:

Welchester above, said the GCR manage at 30mph, which I believe is the maximum speed allowed on most preserved lines.

Surely the correct answer is a determined range of speeds depending of site arrangements. Although I can see why there has to be an upper limit, just imagine modifying an HST to enable the process at full speed. The pouch would fly across the coach, through the sheeting and never to be seen again!

Preserved railways are normally 25mph maximum.  The GCR can run non-passenger trains at higher speeds, subject to various conditions including closing any foot crossings on the lines in question.  The TPO runs on the Down line at Quorn, which only has a foot crossing on the Up.  

[Pete the Elaner]

6 hours ago, kevinlms said:

Welchester above, said the GCR manage at 30mph, which I believe is the maximum speed allowed on most preserved lines.

Surely the correct answer is a determined range of speeds depending of site arrangements. Although I can see why there has to be an upper limit, just imagine modifying an HST to enable the process at full speed. The pouch would fly across the coach, through the sheeting and never to be seen again!

 

I saw a demo at the GCR back in 2017 & asked a staff member about this.

He responded that it doesn't work very well below 40mph but would not give an answer about what speed the train was actually moving.

I was too busy trying to get good photos to even think about marking out a distance to time it.

[Michael Hodgson]

2 hours ago, Edwin_m said:

Preserved railways are normally 25mph maximum.  The GCR can run non-passenger trains at higher speeds, subject to various conditions including closing any foot crossings on the lines in question.  The TPO runs on the Down line at Quorn, which only has a foot crossing on the Up.  

That foot crossing gives convenient access to the island platform from the car park.  In BR days, I doubt it was there - passengers would have been required to use the staircase from the road overbridge like most of the stations on that line.  It might be useful to revert to that and remove thet foot crossing, but I doubt that would be acceptable under modern disability access rules, short of providing a lift.   

[The Stationmaster]

2 hours ago, Edwin_m said:

Preserved railways are normally 25mph maximum.  The GCR can run non-passenger trains at higher speeds, subject to various conditions including closing any foot crossings on the lines in question.  The TPO runs on the Down line at Quorn, which only has a foot crossing on the Up.  

The GCR has authority to run non-passenger trains at speeds up to 60mph as its line is used for rail vehicle testing etc.  With that facility available the GCR effectively has the answer in its own hands and really needs only to do the necessary in order to do the job at a suitable speed for the process. to work as it should.

[Compound2632]

The Didcot demonstration is, I gather from their website, currently mothballed for lack of suitably-trained volunteers. But I can't see theirs ever having been run at 30 mph let alone 40 mph+!

[phil-b259]

 

I understand the GCR do their demonstrations at 40mph  - which means the train cannot be in passenger service as they only have authorisation from the ORR to carry passengers at 25mph. In addition....

 

• The foot crossing at Quorn MUST be closed before the train departs Loughborough
• The block section must be empty and signals must be cleared from Quorn to Rothley BEFORE the train is permitted to depart Loughborough (i.e Double block working is in force)
• All personal (staff and visitors) at Quorn MUST be kept a specific distance away from the equipment in case it goes wrong and the mail bags go flying.
• If the specified minimum speed is not achieved at Quorn then the drop off / pick up MUST be aborted.

Its an impressive sight and one that does prove popular when they do it at Galas - but its certainly not feasible to do it routinely.

[phil-b259]

2 hours ago, Compound2632 said:

The Didcot demonstration is, I gather from their website, currently mothballed for lack of suitably-trained volunteers. But I can't see theirs ever having been run at 30 mph let alone 40 mph+!

 

I don't think the Didcot gear has been used for over a decade - and in todays litigious / H&S conscious world it may well be that the legally required risk assessment would come down against restarting them even if volunteers could be found.