Rope team may be used in the event of a crevasse accident, e.g. to make a Swiss pulley in order to rescue a fallen climber. For larger groups of about four people or more, recovering a fallen man is most easily done using a team pull. When "walking on a rope", the fall of one person - for example, into a crevasse - must be broken by the rest of the rope team members. So there is a danger that such a fall can endanger the entire team. On steep firn or ice-covered mountainsides, where possible and appropriate, the rope must be
Block and tackle blocks. Frictional losses also mean there is a practical point at which the benefit of adding a further sheave is offset by the incremental increase in friction which would require additional force to be applied in order to lift the load. Too much friction may result in the tackle not allowing the load to be released easily, or by the reduction in force needed to move the load being judged insufficient because undue friction has to be overcome as well. A block which is open or can be opened to engage with a bight, without the necessity to thread the