Fly system By trimming the lift lines, loads are more evenly distributed to them. Turnbuckles are moused (secured against free rotation) to prevent the jaws from slowly unscrewing over time due to vibrations incurred during normal use. Counterweight lift lines typically connect to the tops of arbors with shackles. A block is a pulley used to support and direct lift and operating lines. A block consists of a grooved wheel, known as a sheave (pronounced "shiv"), steel side plates, spacers, shaft, flange bearings, mounting angles and clips, etc. Blocks are sized based on anticipated live loads, operating speeds, line type and other
Lifting Operations and Lifting Equipment Regulations 1998 indicate safe working loads; ensuring that any equipment is positioned and installed so as to minimise risks; that the equipment is used safely ensuring that work is planned, organised and performed by a competent person; that equipment is subject to ongoing thorough examination and where appropriate, inspection by competent people. The regulations define lifting equipment as "work equipment for lifting or lowering loads and includes its attachments used for anchoring, fixing or supporting it". The regulations involve anything which involves the lifting of goods or people at work. Equipment covered would include lifts, cranes, ropes, slings, hooks, shackles, eyebolts, rope