Near-miss: Potential fall when TMS protection gate came loose
- Safety Flash
- Published on 4 September 2012
- Generated on 13 October 2025
- IMCA SF 09/12
- 2 minute read
A Member has reported a near miss potential fall and dropped object incident in which a protection gate on a Tether Management System (TMS) was almost lost.
What happened?
The incident occurred when crew were working on the top on of an ROV, using cut-out holds on the TMS protection gate itself. The two dogs on top of the protection gate became dislodged from their receptacles; whilst the gate was still secured by bolts and ‘R’ clips at the bottom, it fell into the inside of the TMS. The personnel working managed to hold onto one of the main load bearing posts of the TMS. Full harness and fall arrestor equipment was being used and a permit to work for working at heights had been issued. There were no injuries or damage to equipment.
Our Member’s investigation revealed the following:
When downward force was applied to the gates via the cut-outs, the gate became dislodged.
Members are encouraged to make a careful check of this kind of TMS protection gate to ensure they are secured by the top pins. If they tend to come out while downward force applied, then the top pins should be changed immediately. The top pin which is secured to the gate can be modified such that it won’t dislodge easily.
TMS protection gate showing ‘cut-outs’ which are used as foot-holds
TMS protection gate showing ‘cut-outs’ which are used as foot-holds
Bottom of TMS protection gate showing fixing brackets with bolts and ‘R’ clips which remained secured
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