The design of "Herald of Free Enterprise" was also found to be a contributory cause of the sinking. Unlike other ships, which are subdivided into watertight compartments, the vehicle decks of RORO vessels are normally contiguous: any flooding on these decks would allow the water to flow the length of the ship. This issue had been identified as early as 1980, following the losses of and in June and November 1977 respectively. The need to adjust the ship's bow trim to use the port facilities at Zeebrugge and failure to readjust before departure was another factor in the sinking.