Hand operate concrete crunching is now widely used by Denver Drilling Services to quickly, quietly and with no vibration, break up walls, stairwells and in situ floor slabs up to 350mm thick. They are often employed in conjunction with diamond cutting techniques. The unit (shown opposite) operates using high pressure hydraulic technology. A built in hydraulic ram opens and closes special alloy jaws to give crushing loads of 30 tonnes of more, which is normally sufficient to break the strongest of 300mm thich reinforced concrete walls. Hand operated crunchers used in confined working space areas are now in many cases the modern day alternative to noisey and dusty breakes. Also with no hand arm vibration, they can also eliminate any potential HAVS problems.