202536 Diminishing magnet strength for pilot ladder anchors

Pilot/Accommodation ladder magnets may reduce in strength over time

A tanker in ballast and with a freeboard of 15.4m was about to leave port. Two pilots joined from the vessel’s sea side and inspected the pilot and accommodation ladder arrangements while boarding. On their suggestion, the pilot ladder was adjusted about three steps higher but otherwise was found to be acceptable.

Departure and outbound voyage were without incident but at the pilot disembarkation area the vessel was rolling so heavily that the magnets for the accommodation platform released from the hull. The disembarkation of the pilots was postponed to re-secure the ladder. The magnets were re-attached to the vessel’s hull, the accommodation ladder was secured, and one pilot disembarked safely to the pilot boat. The second pilot could not disembark as the magnets were again dislodged from the hull due to rolling. The disembarkation of the second pilot was postponed and the vessel headed towards an area where the weather conditions were deemed more suitable for disembarkation.

The Master subsequently ordered new magnets for the vessel.

Lessons learned

Pilot and accommodation ladder magnets, like any magnet, will lose their strength over time. Various factors contribute to the loss in magnetic strength, depending on the type of magnet, including among others:

• High temperatures.
• Physical damage: Impacts or vibrations.
• Electromagnetic interference: High levels ofelectromagnetic fields generated by strongelectrical currents can reduce a magnet’s strength.
• Corrosion: Magnets made of iron can rust if not coated or protected. Over time, corrosion can compromise their structure and reduce their magnetism.
• Keep ladder magnets in a protected environment and if possible one with stable temperature control.
• Maintain ladder magnets by eliminating rust and protecting them from impacts.
• When in doubt, since judging magnet strength is difficult under operational conditions, replace old pilot/accommodation ladder magnets with new ones.