Mole The process of 'trenchless' technology allows the installation or renewal of underground pipes, ducts and cables minimalising the need for excavation. The use of such methods can reduce environmental impact, social costs and at the same time provide economic alternatives to traditional open cut methods. Essential to the success of such methods are training, thorough site survey, planning, material and equipment choice. The mole is operated by compressed air and with its unique reciprocating chisel head assembly makes its way accurately through the ground creating a borehole in all compressible soil ready for the installation of new services and cables. The technique is often referred to as 'thrust bore' and the equipment used as a 'mole'. Essential Water Services Ltd more commonly uses a 45mm mole for installation of 1" services or cables but on occasions a 75mm mole is used to install larger services up to 2" in diameter.
The piston strikes onto the chisel head assembly, which is propelled forward as the piston accelerates and impacts against the rear of the chisel. The piston then strikes onto the casing pulling it into the previously created borehole. This process is repeated creating a hammer motion forcing the mole through the ground.