Breaker Power: Searching for industry-wide standards
25 March 2008
When looking to purchase a new breaker, how are customers to compare one against another when manufacturers use a number of different classification methods? Atlas Copco'sPeter Bigwood was forthright concerning the situation in North America.
“This is a complex issue, and somewhat controversial, particularly in the US,” said 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 US at least, had been educated to think in the ft/lb (impact energy) classification, and that is a very elastic and subjective approach.”
He continued, “Ultimately, to be blunt, I thinkit 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 US 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.”
Smallest in the range, the H35Ds is designed for use on carriers weighing from 1.1 to 2.4 tonnes and is a new model with an impact energy of 204 Joules, while the H45Ds, with an impact energy of 408 Joules, replaces Cat's H45/45s hammers and is designed for use on 1.5 to 3.2 tonne machines. The H65Ds is also a new product class for Cat, completing its line-up of compact breakers at the top end. It is intended for use on 3 to 6.5 tonne machines and has an impact energy of 950 Joules.
These hammers feature another design trend to be seen in the sector, with -50% fewer parts than the H45/H45s that is being replaced by the H45Ds. As manufacturers aim to reduce downtime and simplify maintenance, the latest breakers frequently are designed with the need for fewer components very firmly in mind. But it is not just for ease of maintenance that this is a desirable feature–it also helps in minimising sound generated by the breaker.
The SC6 and SC50 are the latest breaker models from Montabert in its compact Silver Clip range. The former weighs in at 65 kg and is for carriers weighing from 0.7 to 1.2 tonnes. The SC 50 weighs 500 kg and is intended for use on 7 to 14 tonne carriers. iC