In their place, Network Rail are to reopen the Montrose North signal box which has been closed for the last four years.

The signal boxes are part of a major change in signalling operations which includes northbound trains now stopping on the upline or platform one at Montrose station to enable wheelchair-bound persons to alight or board more easily.

New power operated points are also being introduced in place of old mechanical ones.

Eight permanent signalmen plus four relief men work at Montrose South and Usan. Some of them are retiring or leaving to go to other jobs.

There will be no compulsory redundancies, with the majority of the workers being redeployed by Network Rail.

The Montrose North signal box which is being recommissioned is a listed building. The Montrose South and Usan boxes will be demolished.

Montrose South opened on March 1, 1881 and Usan in 1906. The Usan box was introduced to shorten the section between Montrose and Lunan Bay.

The signalmen were joined at Montrose South last week by James T. Egan, mobile operations manager and Ross Moran, local operations manager.

Mr Moran said the signalling changes take effect from February 1.

He said: "These guys have put in a lot of hard work, working in difficult conditions while doing the resignalling work. The men gathered here today have over 250 years of service between them."

Montrose to Usan is the only stretch of single line between Kings Cross and Aberdeen.