Longman Dictionary of Contemporary English
signal box
noun
EXAMPLES FROM CORPUS
▪ A class D9 No. 6028 departs southwards, seen from the signal box.
▪ A typical branch line country station complete with signal box has been created.
▪ Approaching the signal box he mounted the steps, the hand-rail creaking as he used it for support.
▪ Between the years 1902-1902, there was actually a signal box situated well inside the Woodhead tunnel.
▪ He walked along Platform 2 and noticed smoke coming from the signal box.
▪ Terror gripped the two men as they ran as fast as they could away from the ghostly train towards Elsham signal box.
▪ There is a signal box at each end, East and West also the Breakdown Vans, ready when they are wanted.
▪ With the modernisation of the railway system, Brooke End signal box was abandoned, its structure left to stand forlorn.
Wiktionary
signal box
n. A building, typically adjacent to or spanning a railway line, from where signals, points and (sometimes) level crossings are controlled.
WordNet
signal box
n. a building from which signals are sent to control the movements of railway trains
Usage examples of "signal box".
Beyond the lights of the signal box I could see flares burning, silhouetting the huge shapes of the tractors and snow ploughs trying to clear the main road from the city, with a line of trucks crawling in their wake.
He entered an alley comprised of control rooms for the cranes, each like a modern signal box, each with green levers and big windows.