starting signal

Noun

(rail transport) A railway signal controlling the starting of trains from a station or some other location, nowadays usually a colour-light signal. / (sports) A signal to begin a race.

Japanese Meaning

鉄道：列車の発進を制御する信号（通常はカラーライト信号） / スポーツ：レース開始の合図となる信号

What is this buttons?

The engineer waited for the starting signal before releasing the brakes and moving the train out of the station.

Google Translation / DeepL Translation

運転士は発車信号機が出るのを待ち、ブレーキを解除して列車を駅から発車させた。

Details

Sense（1）

As it happened, however, it was clear enough, when the platform starting-signal was lowered, for the signalman in box No. 5 to see his advance-starting signal, and he was therefore justified in allowing the train to go forward, and it was not until it had passed his box that, upon looking out, he saw that it had disappeared into the bank of fog, which had by that time hidden the advanced starting-signal from his view.

Google Translation / DeepL Translation