They are digging up the orad to reline one of the water mains (as is typical here, there are several down the road and the paperwork describing which house is connected to which one is somewhat ancient and lacks accuracy)
Why? This is a 5 inch main, and a good part after 100 years in the ground. The more scaly parts are very much sclerosed. They are scraping out the scale and painting the inside with epoxy to preserve it for longer.
DSC_6276 by
David Martin, on Flickr
Where these chinks have been lifted out to allow access for the cleaning process they have replaced them with nice coated ductile iron pipes.
DSC_6282 by
David Martin, on Flickr
The stub on the right is a capped off old 4" lead pipe.
Then it is time to get the air out.
DSC_6285 by
David Martin, on Flickr
DSC_6291 by
David Martin, on Flickr
"Don't take any pictures of that - the boss will have me for leaving it that far open"
After slowing down the water flow the air came out.
DSC_6293 by
David Martin, on Flickr
DSC_6294 by
David Martin, on Flickr
Apparently the epoxy cures in 20 secs. They heat it then run it into a spray head which is dragged through the pipe by a tractor at a constant rate, enough to get a ca 1mm coating on the inside of the cleaned pipe. This was a branch main off one of the 8 inch ones. Good job all round.
