BS EN 1804-1-2020 Machines for underground mines一Safety requirements for hydraulic powered roof supports Part 1: Support units and general requirements.
4.1.6 Lifting sad pulling points
Support units shall have hftrng and pulling
Lifting and puUing ponLs shall be suitable for their intended purpose. They shall be designed to have a calcu1ted mininiuni factor of safety of 4 on ultimate breaking load In reLation to their intended load carryrng capacity, They shall be L’learIy and permanently marked with their load carrying capacity. e.g. by welding
4.2.7 Fcsrcpollng devices
Forepoling devices shall not lead to damage to other parts of the support unit when loaded with the rated toe.
4.2 Stability and alignment requirements
42.1 TUt-reslstaace
When handled In accordance with the manufacturers lnstrucbons support units in a rrestaiidlng state shall be ct.Ile over their whole ac)lustrncnt 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
42.2 Alignment
With support units for use in inclined seams with gradients of more than 30°, the alignment fi,ecr (push or pull) of a support unit which is set shI he greater than the btrral wright component olthree adjacent support units which are not set if these support units are no longer stable in the freestanding 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. Doting convergence the rated rorre 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 Iowenng,
4.32 Behaviour when overloaded
Support components Including face spriags shall be designed so that no failure occurs by bending. tension and compression when they are loaded up to 12 tImes the yield foece 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. eg. it the canopy is in contact with the coot on one side only.
4.3.4 Loading resulting from caving or stowing
Support units shIM be capable ol withstanding the caving or stowing forces resulting from over upping when operated on a gradient when working an over tipped face. The forces and the gradients to 1w expected are normally 1w provided by the user (see introduction. last paragraph).BS EN 1804-1 pdf download.