Ground movement detectors

[Jack Barry]

I have seen on Facebook mention of detectors for earth tremors the one mentioned was Holborn Piccadilly, anymore known.

 

[Peter Mugridge]

There are ground movement detectors at most locations in Central London; I believe they were put in place ahead of the Crossrail works starting in case of any subsidence problems.

 

[Jack Barry]

There are ground movement detectors at most locations in Central London; I believe they were put in place ahead of the Crossrail works starting in case of any subsidence problems.

I understand with something like Crossrail there would be lots of detectors but the ones I am on about are permanent and not at sites where construction is going on well not that I'm aware of.

 

[Peter Mugridge]

Do you have a picture of the one(s) you have seen?

 

[sharpley]

I assume these are what we're talking about. Think they're called a Total Station https://en.wikipedia.org/wiki/Total_station Used to measure tunnel movement around construction sites like Crossrail. London Bridge had loads when the Shard was being built. Think Crossrail had them outside on buildings as well. Not sure about Piccadilly but Crossrail runs through Holborn

 

[Jack Barry]

Do you have a picture of the one(s) you have seen?

No photos but I see Sharpley has put one of a more modern one.

 

[rebmcr]

The ones pictured are called Autotheodolites and are accompanied by a constellation of reflectors in their lines of sight. The Crossrail-related reflectors are quite small and have a 50p-sized orange-coloured lens which is extremely shiny; they can be found anywhere from underground platforms, passages, escalator shafts, and on the outside of surface structures.

They were detailed heavily in an episode of The £15billion Railway.