Single Line brass Tablet DALMENY - FORTH BRIDGE NORTH number 10. Special configuration for converted Tyers No 1 machine, introduced in 1896 for the double line section across the famous Forth Bridge. There were 'scissor crossings' each end of the bridge and single line working could be introduced quite simply should week-end or any other time engineering works were introduced. The signal boxes controlling this section were closed on 13th May 1979 and control for such workings today, are from Edinburgh SC.