Specifying breaker power

When looking to purchase a new breaker, how are customers to compare one against another when manufacturers use a number of different classification methods? D&Ri asked Atlas Copco's Peter Bigwood for his take on the situation.

“This is a complex issue, and somewhat controversial, particularly in the USA,” says Mr Bigwood. “The Mounted Breaker Manufacturers Bureau (MBMB) wrestled for 10 years before producing the AEM tool energy rating system. I was chairman of the MBMB shortly after its introduction and experienced the whole range of reactions it provoked among the market, but mainly among the manufacturers. What became clear, sadly, was that there was still room for interpretation - there still seemed to be ways for manufacturers to present their results in the best light.”

“Some manufacturers felt that they were being put in an impossible situation, and some key players decided not to publish those ratings. Ultimately it proved too difficult to keep everybody on the same page. In addition, the market, in the USA at least, had been educated to think in the ft/lb class, and that is a very elastic and subjective approach.”

He continued: “Ultimately, to be blunt, I think it does the market a disservice that we were unable to come up with something that could be used as an industry standard. The situation we have today is that fewer and fewer people are publishing the AEM numbers and we will probably end up with a ft/lb class arrangement. We at Atlas Copco are currently discussing what we will do. In Europe, the main approach is to talk about hammers in terms of the weight of the breaker and the weight of the carrier it goes on, and this seems to work. Generally people in the USA ask, for example, for a 500 lb hammer. What they mean of course is a 500 ft/lb class hammer and that can cover a multitude of sins.”