The robot has been in the development stage for the past two years, and is unique to the water industry as it does not require water to propel itself through pipes. Its introduction should lead to the replacement of the current cleaning method which is essentially to blast a sponge along the main using water pressure. This technique has been very effective in the past but requires a large amount of water for its operation, which proves especially difficult in certain areas. The initial prototype of the crawler, using a 12-in diameter version of the robot, was tested in Sheffield in February, 2001. Following the testing, Yorkshire Water engaged DPT to produce a 36-in machine capable of cleaning with reduced volumes of water. The crawler design is such that, once in the pipe, it is controllable, can cope with varying pipe dimensions and surfaces, and can inspect the cleaned main immediately. This will provide Yorkshire Water with further savings through reductions in downtime and set-up costs. The production of the larger robot is currently under way, and Yorkshire Water will test it in some of its largest mains in Bradford which, at present, are difficult to clean.