Signal 52 at Par railway station in Cornwall controls trains going from the Newquay branch line onto the 'up main' towards Plymouth. The subsidiary disc signal allows shunting moves when the line might otherwise be occupied.
<a href="//commons.wikimedia.org/wiki/User:Geof_Sheppard" title="User:Geof Sheppard">Geof Sheppard</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>