A very cold assignment

During the cold Russian winter of 2005 and 2006 Aarsleff Pipe Technologies was facing a very challenging project in the middle of Moscow. In temperatures down to minus 20 degrees we inspected, cleaned and renewed the 300 m long and 50 years old DN 1400 mm Savinsky wastewater siphon that runs under the Moscow River.

We set up a site on the western bank of the river. Here, we established a 5 m deep launching pit in order to expose the pipe. We also established mobile and roofed production facilities right next to the pit. Similarly, we opened a pit to expose the inverted siphon on the opposite bank – in Gorky Park. The production facilities were heated to 20 degrees even though it was minus 20 degrees outside.

We carried out the actual renewal of the siphon by using a double relining system. After taking the siphon out of use we first installed a 300 m long closed and sealed liner. By means of a wire attached to a winch in Gorky Park we pulled the liner through the still water-filled inverted siphon. The liner was suspended freely in the inverted siphon, the end was opened for installation of the relining. Via conveyor belt the impregnated liner was guided to the top of a 2 m high scaffold tower placed above the pit. From here it was pushed into the pulled-in liner by means of water. This process lasted no less than 38 hours.

When the liner was in place we cured it by heating 460m3 of water in hoses that we had pulled through the inverted siphon at an earlier stage in the process. The process of curing the liner lasted another 40 hours.

We were able to complete the entire project without any disruption to river or road traffic.