Underground boring is set to start on a £100m project in Glasgow to create Scotland's largest storm water tunnel.
The Shieldhall Tunnel will run 3.1 miles from Craigton to Queen's Park and handle sewage and excess rainfall.
Scottish Water will take delivery of a 1,000 tonne, 180 metre-long tunnel boring machine in the coming weeks.
Due for completion in 2018, the tunnel will be big enough to fit a double-decker bus inside and more than five times as long as the Clyde Tunnel.
Scottish Water chief executive Douglas Millican said the project was the biggest investment in waste water infrastructure in Glasgow for more than a century.
"Much of the Greater Glasgow area's existing waste water infrastructure was built in Victorian times and the modernisation of the system and construction of new underground assets, such as the Shieldhall Tunnel, will protect the natural environment, reduce the risk of flooding and meet the needs of growth, economic development and regeneration," he said.
The tunnel will be constructed using a specially designed tunnel boring machine, and will follow a route from Craigton industrial estate to Queen's Park.
It will run under Bellahouston Park, Pollok Park, along Titwood Road to Queen's Park, where it will tie in to the existing sewer network.
It is part of a £250m, five-year programme of work aimed at improving the waste water network in the Glasgow area.
The main shaft for drilling the tunnel has already been prepared and Infrastructure Secretary Keith Brown was given a tour of the site on Monday.
"This is a massive undertaking - at more than £100m it will be Scotland's largest sewer," he said.
"This project is just one part of a massive investment programme to upgrade Glasgow's sewer network to make it fit for the 21st century."
I've been following this with interest, the route of the tunnel finishes in my neck of the woods. Queen's Park has been a hive of activity recently, there are a few voids from mining works which are being filled to prevent the tunnel boring machine from going off course.
There's a fly past of the route the tunnel will take on Scottish Water's youtube channel: