As given in Watercraft Philately by Andre Laffut the vessel depict in the Berendrecht Lock, Antwerp is not the MAIN ORE as given in Stanley Gibbons Collect Ships on Stamps but a container vessel.
The stamp was issued to commemorate the opening of the Berendrecht Lock on 1 October 1989.
The lock has a length of 500 meter between the doors, and is 68 meter wide with a depth of 17 meter, at that time the largest lock in the world.
The first vessel to enter the lock was the bulk carrier MAIN ORE , built in 1975 with a deadweight of 26.4999 tons wand a length of 335 meter, beam 52 meter and a draught of 11 meter, to enter the lock she was assisted by four harbour tugs.
The vessel depict is an artist conception and is not identifiable. When you click on the stamp to enlarge the stamp, you can see that she is not a bulkcarrier but a container vessel.
On Belgium 1990 10f sg 3027, scott 1353.