Máy single line token trong railway signalbox

This is a model of a single line token machine from a UK railway signal box (though similar designs were used elsewhere). These were machines which were placed in signal boxes on each end of a single line section (where there was only one railway track rather than two) and allowed tokens to be taken out under certain circumstances. These tokens were then given to train drivers as permission to enter the section. The key task of a token machine was communicate with the other machine and ensure that only one token was taken out at a time. This was done with a telegraph wire, and the needle at the top of the machine showed the signals on the wire, and the bell on the right-hand side of the machine allowed bell signals to be sent.

This specific model is a replica of a Great Western Railway Tyers No 9 token machine. My modelling (in Fusion 360) was based on the photo below. I haven't replicated absolutely everything, but the key parts are there. I have included a flat grey part which can be stuck to the front of the machine to more closely replicate the prototype but I decided not to use it as I didn't like the look so much.