What is this outside the exchange?

I’ve always been curious why there’s a lamppost outside my local exchange with a metal basket on top instead a lamp. The blueprints for the exchange state it’s a lamppost and there’s only 1 sub level which consists of a cable chamber and a heating chamber, but someone once told me the exchange was 7 stories deep and it made me wonder if this lamppost was an air vent for the sub levels below.

Google Street View

Pretty sure that's a vent for some ductwork, to prevent any pressure issues or contanimation.

Look like a sewer vent pipe to me.

It'll be down to the basement where the cables come in, visited my local exchange on work experience.

The building once housed pre digital exchange equipment, TXS ( Strowger ) , TXE2/4 ( electronic ) TXC ( crossbar ) or a mixture of these old technologies, before the change to TXD ( digital exchanges , System X and System Y ) these old style exchanges had battery rooms with lead acid cells that required maintenance , because of the potential build up of explosive gasses these battery rooms were vented , battery rooms effectively became redundant with the introduction of TXD exchanges as the UPS were sealed units , much smaller and housed within the exchange racks not in a separate room , the power requirements much reduced with digital technology….that’s probably the vent for the now empty battery room.

Edited by Iniltous (Tue 21-Jan-25 14:36:57)

Vents any gas from the exchange manhole to stop it entering the exchange and going bang.

In reply to a post by FibreBubble:

Vents any gas from the exchange manhole to stop it entering the exchange and going bang.

What FB said