0 a person who operates railway signals. -- เจ้าหน้าที่ให้สัญญาณรถไฟ
1 a person who sends signals in general -- คนให้สัญญาณ
He is a signalman in the army.
In my experience as a former railway signalman, farm trucks, horses, pedestrians and high-speed trains do not make an especially safe mixture.
What should be the degree of differential, and what are the relative skills of the engine driver, the signalman, the fireman and so on?
In many places, the only indication that the driver of the train has of his whereabouts is the fog signalman showing his light.
Stationmasters, porters and signalmen in my area are looking for this sort of modern outlook on transport.
Improved communication between train drivers and signalmen will improve passenger security, as will the phasing out as quickly as possible of non-corridor compartment carriages.
It is sometimes thought that a signalman is simply somebody who waves flags.
However on one occasion, the signalman got the signal wrong and the train hit the sheep.
It is important to remember this background in considering the present unofficial action by a minority of all railway employees, indeed a minority of signalmen.