A PSV was working alongside an installation and had successfully completed a discharge of oil based mud (OBM) to the installation via the mud hose. The vessel was subsequently required to deliver base oil (BO) using the same (OBM) delivery hose.
In order for the hose to reach the BO manifold onboard, the vessel would be required to re-position the OBM hose from the forward hang off pin to the aft hang off pin. This was to be executed utilising the platforms crane. The OBM hose was connected to the crane pennant and was lifted clear from the forward hang off pin in the usual manner. It was then transferred aft and re-positioned to one of the hang off pins adjacent to the BO connection. Once the hose was in the required position the hang off sling was placed over the pin.
The ABs noticed that the hose hang off sling was displaying signs of wear and tear / damage during the re- positioning of the hose from the forward to the aft pin. They however continued with the operation and as a precautionary measure they decided to secure the hose with a piece of rope as a backup.
A breakdown in communications between the AB’s followed and the hose was disconnected from the platform crane before it was made completely secure with the rope to the vessels bulwark.
At approximately the same time as the hose was disconnected from the platform crane a combination of the sea lifting and dropping and with the vessels rolling motion, the weight of the hose came onto the damaged hang off strop which resulted in it parting. Subsequently the hose slid up over the vessels crash rail and landed in the sea.
- The hose was fitted with a capped Avery hardoll fitting and no pollution was reported by the hose falling overboard
- Although the weather was suitable for the work being carried out the vessel was rolling in the seaway which in turn was allowing the hang off strop to ’chaffe’ on the hang off pin
- The vessel had been pumping OBM for 7+ hours prior to the hose being repositioned
- The hang off strop was reported by the AB’s on duty as being in a ‘good’ condition when initially delivered to the vessel
- The AB’s had just completed a rest period and returned to duty. Although reported as being experienced they were on their first tour of duty together
- Although ‘rope’ was being used in this case to ‘assist securing’ the hose, it is not normal practice for rope to be used for securing purposes due to the risk of hose damage
- Rope is still widely used on all PSV’s to tie hoses in place but these are not ‘load bearing’ securing arrangements
- During the transfer of the hose from forward to aft the damaged hang off strop was not reported to the bridge by the AB’s and there was no ‘stop the job’ initiated
- The Master, AB’s and crane operator are reported to have worked well together and retrieved the hose quickly and safely
SUGGESTED ONBOARD ACTIONS:
- Where the system of hang off strops is employed (with the permission of the company involved ) it is recommended that there be robust measures in place on the platform/rig to regularly inspect the strop and replace if required.
- All hang off pin areas on the vessels bulwarks should be inspected to ensure there are no sharps / snags which could cause damage to the hang off strops. Any sharps / snags should be attended to prior to pin use.
- Communications between the AB’s and the bridge should be verified as acceptable. (Suspect equipment should be reported immediately and when required ‘Stop the Job’ should be enforced). If doubts arise a ‘Time out for Safety’ should be held onboard and the importance of communications highlighted.
- When possible, and if considered safe to do so, hang off strops should be visually inspected during use onboard the PSV to ensure that there is no chaffing taking place.