Complex sentence: After the weights were calculated the ship showed a substantial trim by the stern; the two 100 mm turrets mounted on the quarterdeck were deleted and the height of the armor belt abreast the rear turret was lowered in a effort to reduce the trim.
Split into simpler sentences: After the weights were calculated the ship showed a substantial trim by the stern. So the two 100 mm turrets mounted on the quarterdeck were deleted, the height of the armor belt abreast the rear turret was lowered in a effort to reduce the trim.