The invention relates to an offshore drilling vessel comprising a main deck, a moonpool, a firing line hoist system having a tower, a BOP transport system and a pivotally supported U-shaped working deck. The U-shaped working can be pivoted between an active position, in which it extends in a substantially horizontal direction such that it covers a portion of the moonpool, and a non-active position, in which it extends in a substantially vertical direction such that it provides room for a BOP to be moved by the BOP transport system from a storage position adjacent the moonpool into a launch position above the moonpool, in which launch position the BOP is located between the tower and the working deck.