Looks like a run of cables we have on quite literally every single street in the country... Put on a high viz jacket and you could lift the access cover there and do whatever you want to all those cables carrying super secret data.
Hi viz. There's your problem... totally solved by a private underground secret room just metres away.
The drawings show that a single concealed chamber will sit directly alongside fibre-optic cables transmitting financial data to the City of London, as well as email and messaging traffic for millions of internet users.