This sign at Old Oak Common Depot is on the Heavy Maintenance Facility and can be seen from passing Great Western Railway trains on their way in and out of London Paddington.
<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>