The first signalmen, originally called Railway Policemen (leading to the nickname of 'Bobby'), were employed in the early 19th century and used flags to communicate with each other and train drivers.
)[citation needed] In South Africa, a local rail signaller named Jack achieved some fame for the unique distinction of being a chacma baboon.
In many cases, a switch, button or computer command is used to alter the lie of points and control signals.
In busy locations, signalling can be very challenging and stressful, in a manner similar to air traffic control.
Following protracted industrial action from unions and, much more recently, detailed studies on fatigue and ergonomics in the rail industry,[3][4] prudent operators implemented strict guidelines relating to the length and number of consecutive shifts permissible for safety-critical workers, including signallers.
At some locations, a Station master or Porter performs signalling duties in addition to other work such as selling tickets and cleaning.
On busy railways such as the Midland, it was at times very difficult for signalmen to keep track of train movements and make optimal traffic regulation decisions whilst operating signalling equipment.
Moreover, there was no-one with specific responsibilities relating to the efficient, economical use of rolling stock in traffic, which made it difficult to manage the contingencies of underutilisation, wastage and allocation of inappropriate locomotive power.
In the face of rising costs, operating economies were particularly important to the private British railway companies in the early twentieth century.
If the signalman required directions, he simply lifted the receiver and spoke to the train controller on the omnibus circuit.
This led to delays for signalmen waiting for their turn to speak on the omnibus circuit, making the role of the train controller somewhat self-defeating.
Secondly, signalmen were often in a better position to make train working decisions by virtue of their experience and by being on the spot, but were prevented from doing so by bureaucratic procedures.