Zeebrugge Ferry Disaster is the 18th episode of Seconds from Disaster explaining how did the ship capsized in 90 seconds.
The British car ferry M/S Herald of Free Enterprise departs the port of Zeebrugge in Belgium. The crew have left the bow doors open and water splashes into the car deck. So much water pours in that the car ferry capsizes, taking the lives of 193 passengers and crew.
How it all happenedEdit
BackgroundEditOn the day the ferry capsized, the Herald of Free Enterprise was working the route between Dover and the Belgian port of Zeebrugge. This was not her normal route and the linkspan at Zeebrugge had not been designed specifically for the Spirit class vessels: it used a single deck, preventing the simultaneous loading of both E and G decks, and the ramp could not be raised high enough to reach E deck. To compensate for this, the vessel's bow ballast tanks were filled. However, the ship's natural trim was not restored after loading. Had the Herald survived, she would have been modified to obviate this procedure.
Before dropping moorings, it was normal practice for the assistant boatswain to close the doors. However, the Assistant Boatswain, Mark Stanley, had returned to his cabin for a short break after cleaning the car deck upon arrival, and was still asleep when the harbour-stations call sounded and the ship dropped its moorings. The First Officer, Leslie Sabel, was required to stay on deck to make sure the doors were closed. Sabel was seriously injured in the disaster and the court concluded that his evidence that he thought he saw Stanley approaching was inaccurate. It believed that under pressure to get to his harbour station on the bridge, he had left G deck with the bow doors open in the expectation that Stanley would arrive shortly. The court also described the attitude of Boatswain Terence Ayling, believed to have been the last person on Deck G, as most unfortunate. Asked why he didn't close the doors given there was no one else there to do it, he said it wasn't his duty. However the court praised his work in the rescue.
Captain David Lewry could only assume that the doors had been closed since he could not see them from the wheelhouse owing to the ship's design, and had no indicator lights in the wheelhouse.
The ship left its berth in Zeebrugge inner harbour at 18:05 (GMT) with a crew of 80 and carrying 459 passengers, 81 cars, 3 buses and 47 lorries. She passed the outer mole at 18:24 and capsized about 20 minutes later.
When the ferry reached 18.9 knots (35.0 km/h; 21.7 mph) 90 seconds after leaving the harbour, water began to enter the car deck in large quantities. The resulting free surface effect destroyed her stability.
In a matter of seconds, the ship began to list 30 degrees to port. The ship briefly righted herself before listing to port once more, this time capsizing. The entire event took place within 90 seconds. The water quickly reached the ship's electrical systems, destroying both main and emergency power and leaving the ship in darkness.
The ship ended on her side half-submerged in shallow water 1 kilometre (0.5 nmi; 0.6 mi) from the shore. Only a fortuitous turn to starboard in her last moments, and then capsizing onto a sandbar, prevented the ship from sinking entirely in much deeper water, which would have resulted in an even higher death toll.
Crews aboard a nearby dredger noticed the Herald's lights disappear, and notified the port authorities. The alarm was raised at 18:26 British time (or 19:26 Belgian time). A rescue helicopter arrived within half an hour, shortly followed by assistance from the Belgian Navy who were undertaking an exercise within the area.
The disaster resulted in the deaths of 193 people. Many of those on board had taken advantage of a promotion in The Sun newspaper for cheap trips to the continent. Most of the victims were trapped inside the ship and succumbed to hypothermia because of the frigid (3 °C) water. The rescue efforts of the Belgian Navy limited the death toll. Recoverable bodies were removed in the days following the accident. During the rescue the tide started to rise and the rescue team was forced to stop all rescue until morning and the last of the people on board who were not rescued died of hypothermia. Only a few families survived all together.
Investigation and inquiryEdit
A public Court of Inquiry into the incident was held under British Lord Justice Sheen in 1987. It found the sinking was caused by three main factors--Stanley's failure to close the bow doors, Sabel's failure to make sure the bow doors were closed, and Lewry leaving port without knowing the bow doors were closed. While the court determined the immediate cause of the sinking was Stanley's failure to close the bow doors, it was very critical of Sabel for not being in a position to prevent the disaster. "Of all the many faults which combined to lead directly or indirectly to this tragic disaster that of Mr. Leslie Sabel was the most immediate. This Court cannot condone such irresponsible conduct."
The fact that Stanley was asleep at the time of departure led Sheen to examine the working practices of Townsend Thoresen, which concluded that the poor workplace communication and stand-off relationship between ship operators and shore-based managers was the root cause of the sinking, and identified a "disease of sloppiness" and negligence at every level of the corporation's hierarchy. Issues relating to the breaking of waves high on the bow doors while under way and requests to have an indicator installed on the bridge showing the position of the doors were dismissed; the former because of the attitude that ships' masters would come and "bang on the desk" if an issue was truly important, and the latter because it was thought frivolous to spend money on equipment to indicate if employees had failed to do their job correctly.
The design of the Herald was also found to be a contributing 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 Seaspeed Dora and Hero 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.
In October 1983, the Herald's sister ship The Pride of Free Enterprise had sailed from Dover to Zeebrugge with the bow doors open, after her assistant boatswain fell asleep. It was therefore believed that leaving the bow doors open alone should not have caused the ship to capsize. However, tests by the Danish Maritime Institute after the accident found that once water began to enter the vehicle deck of a RORO, the vessel would likely capsize within 30 minutes, while other tests showed that the lack of watertight subdivision common on other vessels allowed the weight of water to flow freely and increase the likelihood of capsizing.
Another factor that contributed to the capsizing was the depth of the water. When a vessel is under way, the movement under it creates low pressure, which has the effect of increasing the vessel's draft. This effect is known as ship "squat". In deep water the effect is small but in shallow water it is greater, because as the water passes underneath it moves faster and causes the draft to increase. This reduced the clearance between the bow doors and water line to 1.5 metres. Although the bow doors were open and 1.5 metres above the water, it was still not enough to cause the ship to capsize, so the investigators looked at the height and volume of water produced by the bow wave.
After extensive tests, the investigators found that when the ship travelled at a speed of 18 knots (33 km/h), the wave was enough to engulf the bow doors. This caused a "step change": if the ship had been below 18 knots and not in shallow water, people on the car deck would probably have had time to notice the bow doors were open and close them.
In October 1987, a coroner's inquest jury into the capsizing returned verdicts of unlawful killing. Seven individuals involved at the company were charged with gross negligence manslaughter, and the operating company, P&O European Ferries (Dover) Ltd, was charged with corporate manslaughter, but the case collapsed after Justice Turner directed the jury to acquit the company and the five most senior individual defendants (for a discussion of the legal issues, see corporate manslaughter). It did, however, set a precedent that corporate manslaughter is legally admissible in English courts. The disaster was one of a number that influenced thinking leading to the Public Interest Disclosure Act 1998.