Sir, Following your recent report on harnesses in platforms (Scaffold and Access, July 14), I feel it would be prudent to highlight some issues worth considering when selecting personal protection equipment.
Most boom lifts have their anchorage points at the side of the control console, which makes it difficult to restrain the user from a rear anchor point on a harness, simply because, if you were to adjust a restraint lanyard short enough to stop you being able to climb or fall out of the bucket, you would have to crouch down.
It becomes less of a problem when you have a front chest anchor point as you can make an uninhibited connection from harness to anchorage point.
If you need a safe connection from a rear anchor point then you would need to anchor the lanyard to the bucket's floor.
If you can climb out of a bucket when connected via a lanyard then you are not restrained. If this happens when using a restraint lanyard then one of two things could happen after a fall: you pull out the anchorage point from the bucket; or you will put a massive amount of force through your spine because restraint lanyards are not shock-absorbing.
When manufacturing fall arrest equipment we have certain design parameters we must adhere to, we cannot allow the forces generated during a fall to exceed 6 kN.
This loading only applies to shock absorbing lanyards ? if you were to fall on a restraint lanyard there is no device to absorb the forces, so potentially you could put up to 1.5 tonnes-worth of force through your body.
Michael Horrocks Technical services manager Capital Safety Group Northern Europe Runcorn Cheshire