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

A close up of the junction signal at Dyce, about 10 km north-east of 
Aberdeen (Scotland).  Note the individual signal numbers.  DY3 controls
the main (highest speed) route, and DY6 a diverging route to the right. 
DY7 is a "calling on" arm for shunting manoeuvres.  These signals
were installed around 1970 and are stil going strong; the signal box that 
controls them was built in 1880!  

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