Unauthorised firing of rocket line
- Safety Flash
- Published on 10 September 2026
- Generated on 11 September 2026
- IMCA SF 16/26
- 2 minute read
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What happened?
A vessel was preparing for the connection of a tow wire for pulling back a tanker. The vessel was manoeuvring astern, approx. 10m from the tanker stern to receive heaving line and messenger line. The tanker was stopped on DP, bow to current and weather.
The agreement was that the vessel bridge crew would communicate via VHF radio when it was ready to receive the heaving line. The heaving line method was the approved method for passing the messenger rope.
Without warning or agreement, Line Throwing Apparatus (LTA) was discharged by the tanker deck crew, splitting into two parts. The apparatus malfunctioned; one part of the rocket struck the upper spooling winch, the line detached and returned to deck.
There were no injuries to the crew or vessel damage.

Example of rocket line used.
What went wrong?
- The tanker crew used the LTA without prior notification to, or agreement with, the crew of the company vessel.
- There was ineffective communication between the vessels and lack of confirmation before starting operations.
- There were procedures that were not followed by the tanker crew: a heaving line should have been used, not the LTA.
- The LTA malfunctioned due to inadequate maintenance or improper handling.
- There was no defined and documented vessel operational interface protocol, verification and approval process.
Yellow circle – where rocket struck
Lessons to learn
- Better ways of working together:
- A mandatory pre-transfer checklist should be signed by both vessels
- Clear communication protocols and procedural compliance verification are critical for safe operations
- Pre-job planning and confirmation of methods reduce risk of unsafe acts and behaviours
- Stop-work authority is effective in preventing escalation.
- Check equipment to make sure it works, and/or to make sure it is still “in date”.
Related Safety Flashes
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IMCA SF 13/12
11 December 2012
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IMCA SF 30/19
17 December 2019
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IMCA SF 08/19
25 April 2019
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IMCA SF 24/18
30 October 2018
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