TDD Trenchless Technology Specialists Our Services Directional Drilling duel main comprising 1 No.  355mm and 1 No. 180mm across the A406 at Edmonton, as part of our ongoing works on the Thames Victoria Mains Renewal programme.  Our team of operatives have successfully installed in excess of 120 kilometres of main on the VMR programme using trenchless technology. Butt-fusion welding Electro-fusion welding Mains connections Pipe Bursting