Signal W111, a filament-bulb four-aspect signal installed in the 1980s. It controls movements in the up direction from platform 3. Straight ahead is the route via Trowbridge to Bristol (or Swindon); the right-hand 'feathers' are for trains heading east towards London. There are two 'stencils' to give more specific route information above the two small lamps of a calling-on signal which gives permission for shunting moves.
<a href="//commons.wikimedia.org/wiki/User:Geof_Sheppard" title="User:Geof Sheppard">Geof Sheppard</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>