Safety has priority – extraction companies underline this again and again. Holcim South Germany at the location Dotternhausen shows how construction machinery and equipment with corresponding features can contribute to this. Recently a new off-road hauler, type Cat 772, was commissioned in the Plettenberg quarry (Fig.). Together with two other handling units, the heavy-duty lorry transports the blasted limestone, which is brought down to the valley by wagons via an endless-rope haulage system to the Dotternhausen cement factory. The daily capacity amounts to 5000 t. One of the 67 wagons is able to load 1.3 t. Thus, about 300 t are brought down to the valley every hour. So as to fully utilize the loading capacity, the side plates of the body was raised. The construction machinery and equipment operate on three floors of 47 ha at an altitude of 980, 960 and 940 m. The floors are continuously changed during the extraction. “This is to homogenize the raw material quality. The higher you are, the higher the content of calcium oxide, which is so important for cement production”, said Andreas Junginger, who has been the manager of the extraction sites of Holcim South Germany from 1 August 2013.
Except a period of four weeks for the revision, the extraction was carried out continuously in two-shift operation. “There is no bad weather, only bad equipment”, as slogan of outdoor manufacturers, could also be the motto for this operation, because the winter can be severe in the Zollernalb area. The new Cat 772 will be equipped with snow chains so that the driver will be able to deliver the load of the 50-t lorry safely to the crusher and that the material transport will not slide due to the slippery ground surface. The chains are part of the equipment for the safety of the staff like the widened wings. The latter are to prevent splashes from getting onto the rear mirrors. Dirt would affect visibility of the road surface as well as of the loading and discharging point. Labour safety was also taken into account concerning another aspect. A four-way spring suspension is intended to protect the driver and his lumbar vertebrae as well as to relieve strain on the spinal discs. “Thus vibrations are noticeably reduced in the cabin”, explained the Quarry Master Joachim Haag.