Brake continuity test on vacuum braked stock

[The Johnster]

If you are missing anything it is that there is rarely a setter at both ends of the rake, and even then you are only testing the brake's continuity as far as the setter, and the action of the setter; there is still a bogie at the end of the coach past the setter's position that is not tested for continuity and you have no idea if the brake on it is operational or operable.

 

Once the system is coupled up and the continuity tested, you can leave it all day so long as the continuity is not broken; detach anything and you need another test.

Edited July 21, 2018 by The Johnster

[johnb]

Many thanks Johnster, can understand that now. I was just thinking of a bit of plain pipe terminating in the vac hose.

I really appreciate your explanation

regards

John

[The Johnster]

There are junctions in the pipe, where the branch pipe goes to the setter and the gauge, and of course for each separate vacuum cylinder.  So a false continuity that appears to show the brake working properly could, in theory, be established which isolates sections of the pipe between the setter/gauge and the ejector, and of course if something bad can happen in theory, experience shows that sooner or later it will in practice.  

 

The vacuum brake system (as originally devised by Westinghouse back in the 1880s I believe) has stood the railway in good stead over many years, and is still a perfectly effective and efficient brake; it is in daily use on heritage railways which are subject to the same regulations as any other.  It is not foolproof, but if used properly and according to the regulations, is as close to foolproof as makes no difference.  So is the air brake, but both must be used properly and according to the regulations.

Edited July 21, 2018 by The Johnster

[russ p]

For the life of me I fail to understand why a continuity test can't be carried out on every run round on a preserved railway?

You have to go to the back to put the tail lamp on so what do guards have to do which prevents them spending about two minutes doing a safety test.

Mind some railways now guards and station staff are covered in gold braid and name badges their weight with all this on probably stops them getting back on the platform, and it stops them talking loudly outside the buffet about outlandish stories which never happened before the war!

[Boris]

For the life of me I fail to understand why a continuity test can't be carried out on every run round on a preserved railway?

You have to go to the back to put the tail lamp on so what do guards have to do which prevents them spending about two minutes doing a safety test.

Mind some railways now guards and station staff are covered in gold braid and name badges their weight with all this on probably stops them getting back on the platform, and it stops them talking loudly outside the buffet about outlandish stories which never happened before the war!

Don't forget all the enamel loco badges, or that they will get that nice clean uniform dirty.  Too many railways seem to measure the competence of their staff in terms of how well they dress/how shiny they are rather than how well they actually do the job these days.

 

Seriously though if you were to go round the preserved railways I suspect there would be a direct relationship between the average age of the Guards and where the continuity test is performed from.  Several of the same railways no longer expect Guards to shunt (split/join not just parking) either but have C&W or other staff who do it on the behalf of the guard.  Mind you I can think of a number of preserved railways where Guards only brake test the last 2 coaches or start the day with a continuity test from the rear and every other test is done from the setter.

[russ p]

I bet hardly any of them these days have a dust coat.

When I worked up there as a volunteer all those years ago there was some quite scruffy f###ers but they were good guards and I learned a lot from them ,a good grounding for my future career.

If it was my local railway nowadays I would learn nothing for my career unless my chosen path was an arrogant, surly cake shop owner as more time is spent in the buffet with similar types each trying out do each other in the importance stakes!

The thing is these types aren't really interested in railways at all just the fact that they have retired here and once had a train set!

[jim.snowdon]

From a technical perspective, the purpose of the brake pipe continuity test is to confirm that all of the flexible connections between the vehicles have been connected and, in the case of air brakes, the angle cocks have been opened. It isn't to check the integrity of the fixed piping under each vehicle. That is down to engineering and the examiners who are responsible for signing vehicles back into service. Flexible connections between vehicles that are permanently coupled, ie where uncoupling them is a workshop job.

 

The key requirement is that the test is carried out from the rearmost vehicle (or permanently coupled set of vehicles) so that it includes all of the flexible connections that are routinely made and broken during operations. On passenger vehicles, that can be done from the brake valve in the guard's compartment if it is the last vehicle, or the rearmost unit in a multiple unit train. Only if the last vehicle is not equipped with a brake valve does it become necessary to test the brake pipe continuity by opening the brake pipe at the rear of the train, or the fitted portion thereof in the now historic practice of running partially fitted goods trains. Specific rules would have applied to situations for trains with a locomotive at each end.

 

Jim

[russ p]

If there is a loco at the rear that loco should have its exhausters isolated and the driver of it should place his brake valve to emergency and observe a full brake application is applied on the bogie brakes