Scottish wire-and-chain semaphore signals for the 21st Century... 

A splendid junction signal at Dyce, about 10 km north-east of Aberdeen (Scotland). 
The taller left-hand arm controls the main (highest speed) route, and the 
lower arm on the central post controls a diverging route to the right.  
There was once another arm to 
control a second diverging route on the right-hand side.   Below the main arm
on the left-hand post is a minature "calling on" arm for controlling shunting 
or low speed manoeuvres.  I do not believe it has been used for quite a few years... 
The white diamond shape half way down the main post indicates that track circuits
are in operation and the driver does not need to leave the train to inform the 
signalman of the train's presence. 

These fine signals will hopefully be around for many years to come, as the signal box 
was recently refurbished.   Note the south-facing solar panels on the right-hand 
side of the track to power the signal lights. 

For a fantastic web site on British signalling, visit http://www.signalbox.org

Photo by Bill Harrison (bill.harrison@dsl.pipex.com)   3 March 2007