Hi you all !
Funnily enough, there are two mechanical signals on the AMTP although there was none on the TPT neither on the other French two-footers, I think. Only three-footers got a few of them. The first one is a danger signal that has been salvage from a well known French three-footer the chemin de fer du Blanc- Argent that still partly exists nowadays. It's located at the far end of Pithiviers station and concerns the westbound trains to Bellébat. It is intended to avoid a " cornfield meet" with an on coming eastbound train. When that signal is "on" you can see a square iron plate painted in white and red check that is at right angles to the track. It means STOP and it's an absolute signal of course . When the signal is "off" the iron plate is parallel to the track and you can't see the painted face and then it means proceed if the go- ahead signal has been given by the Pithivers station agent. At night the danger signal shows two red lights when it is "on" and a green one when it is"off". In French such a signal is called "un carré" a square. I'm going to tell you about the other mechanical signal, a round one, later on.
By the way go visit my fb page, every week I post AMTP photos, hopefully you can see those signals, and follow me on the AMTP trip down memory line. Explanations and pic captions are in English too. See you soon !