BS EN 1804-1 pdf free download
BS EN 1804-1-2020 pdf free download.Machines for underground mines — Safety requirements for hydraulic powered roof supports Part 1: Support units and general requirements.
4 Safety requirements
4.1 General requirements
4.1.1 General
Hydraulic powered roof support that is constructed in accordance with this document shall also satisfy the requirements stipulated in the other parts of EN 1804.
Machinery shall comply with the safety requirements and/or protective/risk reduction measures of this clause. In addition, the machine shall be designed according to the principles of EN ISO 12100:2010 for relevant but not significant hazards which are not dealt with by this document.
4.1.2 Walkway
The walkway through the support unit shall ensure the minimum dimensions of 0,6 m in width and 0,4 m clearance height (permissible tapering on the corners, see Figure 1).
The walkways shall be designed to minimize slipping hazards, e.g. by the use of ribbed plates.
4.1.3 Protection against dust
Support units shall be designed in such a manner that appropriate equipment for dust control can be installed.
Support units should be designed in such a manner that they seal the walkway against dust ingress from the roof and goaf.
4.1.4 Protection against ejected fluids
Support units shall be designed that no hydraulic elements are damaged when used as intended.
4.1.5 Protection against face material spalling
Support units having a maximum extended height of 2,5 m or more shall be fitted with devices to which sprags can be attached.
The sprags shall be positively lockable when in the retracted position.
4.1.6 Lifting and pulling points Support units shall have lifting and pulling points. Lifting and pulling points shall be suitable for their intended purpose. They shall be designed to have a calculated minimum factor of safety of 4 on ultimate breaking load in relation to their intended load carrying capacity. They shall be clearly and permanently marked with their load carrying capacity, e.g. by welding.
4.1.7 Forepoling devices Forepoling devices shall not lead to damage to other parts of the support unit when loaded with the rated force.
4.2 Stability and alignment requirements 4.2.1 Tilt-resistance When handled in accordance with the manufacturer’s instructions support units in a freestanding state shall be stable over their whole adjustment range on all sides on a gradient of up to 15°. In addition, they shall be stable in operation, e.g. with external stabilizing means.
4.2.2 Alignment With support units for use in inclined seams with gradients of more than 30°, the alignment force (push or pull) of a support unit which is set shall be greater than the lateral weight component of three adjacent support units which are not set if these support units are no longer stable in the free-standing state.
4.3 Design requirements
4.3.1 Yield capability Support units shall be designed for yielding to absorb convergence between the roof and the floor. During convergence the rated force shall not be exceeded by more than 20 %. Support units should be designed in such a way that their function is impaired as little as possible by caved waste when lowering.
4.3.2 Behaviour when overloaded Support components including face sprags shall be designed so that no failure occurs by bending, tension and compression when they are loaded up to 1,2 times the yield force of their respective actuators.
4.3.3 Eccentric loading Support units shall be designed in such a way that their ability to function is not impaired in the presence of eccentric loading, e.g. if the canopy is in contact with the roof on one side only.
4.3.4 Loading resulting from caving or stowing Support units shall be capable of withstanding the caving or stowing forces resulting from over tipping when operated on a gradient when working an over tipped face. The forces and the gradients to be expected are normally be provided by the user (see introduction, last paragraph).BS EN 1804-1 pdf download.
