The Eimco Rocker Shovel

As a result of the rapid closure of pits in the North East in the 1990s, the Eimco Rocker Shovel coal loader was donated to Bowes Railway for exhibition in our 'Coal Gallery' in the Tub Shop. The machine was renovated by one of our volunteers, Alf Gascoigne, and this is his account of the job:

After painting the BoBo locomotive in the old exhibition room I turned my attention to the Rocker Shovel. With numerous nooks and crannies filled with coal dust and dirt on the machine I decided that the best I could do would be to just tidy it up, in other words just slap a coat of paint on it and hope for the best, after all it was an insignificant machine a bit like a bulldozer. Then chance led me to a Web Site entitled Eimco Rocker Shovel, and indicating that an almost identical machine built in 1938 had been designated as a National Landmark in the United States and was preserved at Miners Plaza , Old Park City , Utah . So obviously a bit more care was required and a bit of research.

The first patent for the Rocker Shovel was issued in 1938 and assigned to EIMCO (Eastern Iron Metals Co). A worker on a step on the side of the machine used two controls to operate the Loader, one lever for the wheels, and another one for bucket travel. It was operated by compressed air. The operator would drive the bucket into the rubble and then operate the lever to raise the bucket upwards and rearwards into the tub behind. It was the first successful mining device to replace human labour in removing rubble from underground hard rock mining.

The bucket drive motor exerted a force upon the rocker pull chain attached to the outer end of the arms. The rocker arms rolled the bucket upwards towards the rear of the machine maximising the lift force on the bucket. As the bucket rose, the vertical force reduced and the horizontal velocity increased until the rocker arm struck the shock absorbing stops on the frame and the contents were thrown into the attached mine tub. The machine was designed to emulate the movements of a human shoveller pushing a shovel into the pile of “muck” and throwing the shovelful of material over his shoulder and behind him.

Licenses were issued to various countries for the production of the machine and our machine was built in Gateshead in 1958. Various modifications had been made to the original design including the ability to move the bucket sideways. The machine has not been used for several years and yet the bucket can be moved sideways very easily, so much so that I have had to wedge it to prevent young children from moving it. The design is brilliant and so simple that I have no doubt that it would work fully if a supply of compressed air was available. At least 28000 were built since the first one in 1932. Many of them were left underground and it would be interesting to find out how many are still left in this country and if any are still working. Perhaps some Industrial Archaeology student may find it an interesting project.

Rocker shovel and trailer
© A Gascoigne

The Web site is ….. www.asme.org/history/h212.html

This page last updated 11th April 2007