[jhouis]

I'm Jacques. I am translating a fascinating new French novel written by a TGV driver, about a TGV driver- 3/4 of it in free verse. I'm over a hundred pages in, and for the first time I am stumped by a technical term for which I cannot find an English equivalent. The term is "Clé de chauffage". A literal English translation "heating Key" sounds misleading. It is used to turn off/on voltage from the locomotive to the cars. Does anyone know the proper English term? Here is a taste of the book, for fun. In it, our narrator is just starting out as a driver:

"I relive the arrival at the Nanterre Préfecture station, diving into the darkest tunnel while the valiant headlights try to identify its contours. Under a closed signal, by switching, I go from twenty-five thousand volts to one thousand five hundred continuous, I must remain vigilant while maintaining the controller at three quarters braking, deceleration without pause between thirty and forty kilometers per hour, taking the slope into account, to avoid needing help, and to arrive at the head of the platform under thirty. The prowess involved, I did not know at the time, would become commonplace.
I think I’m God, master of the doors, I allow myself to let people enter my train or stay on the platform. As a lance, whose origin is a branch of the World Ash, I have a pigtail with which I direct the opening. Left side, right side, toward the platform rather than toward the tracks (Hell). I am the master of chance, of the missed train, of space-time and the encounters it sows, of crossings made and unmade, and of the children who will be born, or not.
To those who run, who pant against their sad fate, I reopen the doors. Some humans know and give thanks through the camera, others ignore me and believe in providence. I observe the platform with the help of mirrors or screens that sometimes only afford a glimpse of vague shadows. To those who drag their feet I am without pity. In my kingdom one’s place must be earned. I lock it down rather than see its rules tarnished. Merciful, however, a look is enough for me to grant forgiveness, as much as I am able, and allow the penitent to climb aboard Heaven".