200555 Tanker Loading Arms

We need the opinion or advice from The Nautical Institute, IFSMA, sea going officers and terminal operators on the relevance of painting or displaying the limits of metallic loading arms operating envelope on the jetty of marine oil terminals or displaying it on the loading arm itself.

Some of the marine oil terminals paint the limits of the envelope of metallic loading arms on the dockside in accordance with International Safety Guide for Oil Tankers and Terminals (ISGOTT), 4th. edition, sections 5.1.1 and 5.1.2 which require a terminal operator to pass this information to the tanker. The reason for passing this information to the Master of a tanker is implicit and not explicit in ISGOTT.

We mariners rarely complain about many deficiencies in the port facilities but there is a difference in perception of the terminal staff. They think that, as long as the limit line alarm has not been activated, they can continue with the transfer of liquid bulk. If the alarms come on, the loading arm has reached its limit, and the transfer operation should be stopped and resumed only when the tanker is fully aligned. As no tanker master would like to stop the cargo operation, he does not let the tanker surge forward or aft to the extreme limits. In my experience, the deck crew adjust the forward and after springs to keep the vessel aligned to the centre line of the longitudinal envelope of the loading arm using the visible/displayed envelope on the jetty or loading arm as a reference.

In some terminals, the berth operators do not want to paint the limit lines. They feel limit line alarms are adequate. They do not realize that painting the envelope provides a means of passing information to the master at the pre-transfer conference stage and fulfils the spirit of ISGOTT 5.1.1 and 5.1.2. The painted or displayed envelopes complement the information passed to the tanker and provide a visible reference to the crew to keep the tanker in position.

Having done this the tanker crew member on watch in the manifold area uses the painted envelope as a reference. He judges whether the ship is in position aligned to the loading arm or has moved forward or aft. If the vessel moves any substantial distance, he alerts the deck watch to adjust the forward or after springs as the case may be, to bring the tanker in alignment with the centre line of the envelope. The crew do not want to wait for the limit line alarms to come up before they respond but to observe all precautions listed in ISGOTT Section 6.7.8.

Having said this much, I would like to have the views and opinions of Masters and terminal operators on the use of (a) Information of limiting envelopes of the loading arm passed to the vessel at pre transfer conference and (b) The importance of visible limits of the envelope of the loading arms to the vessel's crew. Will the absence of visible limit line envelope make the berth an 'unsafe berth' for transfer operation?

Feedback please to [email protected]

Feedback 1

We concur completely with the argument that having painted lines showing limits of loading arm travel on the pier allows the ship's crew to be proactive in monitoring the ship's position. We have also experienced terminals that do not want to paint lines and unless the ship's crew is vigilant in monitoring the ship's position relative to the loading arm (painted mark on pier, flag on handrail, or similar marker), we end up shutting down on limit-of-travel alarms. We rarely have good information passed regarding limits of travel at terminals without painted lines. We have experienced a couple of terminals that insist their arms cannoy permit deviation of even half a metre but the company keeps using them, despite costs incurred by frequent and unwarranted shutdowns.