Update on Crossrail monitoring

Update from the char of the BA:

Update on Crossrail monitoring

Following the note I sent last week about Crossrail monitoring on the estate, I've now had an email from the coordinator to say that they will after all be drilling into the concrete to place the prisms and sockets. The explanation is as follows:

"We have reviewed the clamp installations and the potential for any damage to the concrete columns. The clamp we proposed was stainless steel and when it was installed put in a rubber tube to limit any damage to the rough finish of the concrete. Due to the length of time the installation will be in place (up to a year) we cannot guarantee that the rubber tubing will not deteriorate. So we will carry on with the installations as per the Listed Building consent, which is drilling for both the prisms and the sockets.

To reduce the impact of this we are proposing that the socket installed is slightly different from the one I showed you. We intend to install the socket in the same place as shown on the photomontages but instead of being installed at a height of 1.5m above ground level these will be much nearer the ground within approx. 300mm and then a socket (rawl plug ) installed and a longer monitoring point screwed in so that the instrumentation is then put on top of this. This is then unscrewed once the readings have been done.

I am sorry about changing all of this but we are trying to ensure that there will be no damage to the Barbican and also trying to reduce the impact of the installations. Also to reinstate the hole left from drilling for the socket or prisms is easier and more successful than it would be if there was any damage from the clamp."

3 March 2014

Chair, Barbican Association