London Power Tunnels 2 (LPT2), New Cross site

An internship with an engineering company allowed me to be a part of this vital project. Following on from London Power Tunnels 1, which spanned north London, these new pipes will connect the dots of south London, replacing old oil-filled pipes in a decaying power network with the latest technology. The westerly shaft sits at Wimbledon, the easterly shaft at Hurst. New Cross site is the midpoint and main office.

My sketch shows a section at the centre of the site. The middle silo contains sodium silicate – used to increase concrete’s durability, by filling its pores via a chemical sealing process. Four of the larger ones contain cement and one contains bentonite – a gel that swells in water. It both waterproofs the concrete and exerts a hydrostatic pressure on the tunnel during construction, making the structure less likely to collapse.

[Not all silos can be seen on the sketch.]