Lightering operations - Important and demanding

The transfer of liquid or solid cargo from ship to ship at sea is an important link in the transport chain in many parts of the world. MARINTEK, together with companies in the lightering business, is planning an R&D program, the objective of which is products that will improve the safety and economy of lightering operations: Better numerical models for simulator training, user friendly shipboard simulators and decision support and warning systems.

The first model test programme has now been completed as part of this R&D. Below is shown the mean rudder angle required when a 136 m vessel is closing in on a 224 m vessel.

	To the left is a situation where the small vessel is aft relative to the large vessel. Negative rudder angles are required to avoid the aftship of the small vessel colliding with the large vessel.
	To the left is a situation where the small vessel is forward relative to the large vessel. Only small rudder angles are required to control the small vessel on a heading parallel to the large vessel.