British Electricity Authority Under the bridge carrying the Fenchurch Street Railway over Bow Common Lane is this signage from the long defunct BEA (not the airline!)that still helpfully reveals the location of an underground high voltage cable.
<a rel="nofollow" class="external text" href="https://www.geograph.org.uk/profile/28736">Peter Thwaite</a>
From <a rel="nofollow" class="external text" href="https://www.geograph.org.uk/photo/1176643">geograph.org.uk</a>