by Doc
I had no idea about these but was led towards finding out more by a desire to festoon a newly built carriage with all the possible extra bits and pieces. It seems that, in a vacuum braking system there needed to be some way to tell which carriage had put the brakes on. Often that meant which drunken yobbo had pulled the emergeny cord but in any case it was important to see at a glance where the problem was. A system of 'Tell-tales' was fitted to each carriage end with a pipe leading from the vacuum hose to what were effectively flags protruding from the sides near the roof.
Now, although I have a couple of books about carriages, namely 'British Railway Carriages of the 20th Century' by David Jenkinson Vol 1 1901-22 and G.M Kichenside's Rauilway Carriage Album, both found in secondhand book shops, those people who took the photographs were more or less concentrating on full side on views and few show the carriage ends in any detail. However, one or two shots seemed to show that a central pipe rose from behind the vac hose below the bend and went more or less vertically to a rectangular junction box with a chamfered top, centrally mounted. From this box,rods ran to the sides, ending at half round 'blocks'. The actual 'tell-tales' seem to have been horizontal flat plates, similar to door handles in appearance. These normally present a slim profile to a guard looking down the train but, once activated and turned through 90 degrees, they would have been quite obvious to him.
Another research problem is that most pictorial references are of much bigger standard gauge coaches but perhaps that allows us a certain licence. If it looks pleasing, it's OK?
A day after knocking up this first attempt, I went to my nearest railway preservation outfit. I don't like them one little bit, as it happens. They have a pile of derelict junk, mostly unattractive and modern,. Worst of all, their attitude to prospective new members is truly awful so I have never joined. It's a club seemingly dedicated to renovating and restoring the glories of the permanent way but not as we know it, Jim. Snotty is not the word. However, they do have a coach, a full luggage brake, with tell tales and they did grant me permission to take a snap with my mobile phone but not that closely.
You can see that the vertical pipe is quite thick, maybe even as thick as the vac pipe it connects to and the horizontal activating rods are simple iron rods no more than an inch in diameter, perhaps three quarters of. The central activating chamber is not very big and certainly not much bigger than the end supports the nearest one of which is obviously missing.
The blades resemble door handles to some extent but project backwards more than that. My thoughts went to a certain sort of putter head, for those into golf.
So, armed with this new insight and with another caoch to fit out, I had a major rethink about the construction method. I decided to play around with plasticard to make the indicator blades and I realised that I ought to reduce the thicknerss of the activating rods. Here is the outcome
By adding a base plate to the central box, I think it looks more as uif it has a mnechanism inside. The indicator blades are the right shape.
How I made the tell tales
Because the middle end step of these Brandbright coaches is designed to be mounted centrally, I was unable to run a simple straight piece of wire upwards and had to fiddle with it to take detours. I could have cut the wire or even filed a groove in the back of the step fitting. I made the three blocks that hold the horizontal wire from plastruct rectangular profile rod. First I drilled the holes into which the rod would be glued then shaped around those until I had two almost identical half rounds and a suitable central block.
Here are the constituent parts prior to assembly. The centre block is drilled across and from the bottom. The half round blocks have been drilled and the holes widened to permit the horizontal wire to fit from inside and the indicator blade legs to slide in from outside. I would quite like to thicken up the vertical bleed pipe somehow. Thicker brass wire would be harder to bend to the shape needed to sit neatly under the step and appear to connect to the vac pipe.
I suppose I could sleeve it in heat shrink?
