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Dead man anchor supplied unfit for purpose

A clump weight was sent to a member’s dive ship with the intention of it being used as a dead man anchor (DMA). The offshore manager correctly rejected the weight as not being fit for purpose for diving works on the grounds that it was unstable because of the limited steel base of the weight, in relation to its height.

This type of weight or ‘pill’ is part of a much bigger 50 tonne DMA, which is used for wire initiation. Its main frame holds four pills and is lowered to the seabed empty; thereafter each 11 tonne pill is inserted into the main frame. The steel frame on the bottom of each single pill is used for transportation purpose only and is not intended to act as sub-sea stability for the weight itself, which is lifted from the transport frame before being deployed on the sea bed.

The member advises that under no circumstances should this type of weight or other types which have an inadequate base size to height ratio, be used as a DMA; and that inspection of equipment to ensure its fitness for purpose is essential during the planning phase of a project.

Safety Event

Published: 1 October 2001
Download: IMCA SF 11/01

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