MS Herald of Free Enterprise was a roll-on/roll-off (RORO) ferry which capsized moments after leaving the Belgian port of Zeebrugge on the night of 6 March 1987, killing 193 passengers and crew.

[1] The eight-deck car and passenger ferry was owned by Townsend Thoresen, designed for rapid loading and unloading on the competitive cross-channel route between Dover and Calais.

The ship left harbour with her bow door open, and the sea immediately flooded the decks; within minutes, she was lying on her side in shallow water.

Since the disaster, improvements have been made to the design of RORO vessels, with watertight ramps, indicators showing the position of the bow doors, and the banning of undivided decks.

[4] To remain competitive with other ferry operators on the route, Townsend Thoresen required ships designed to permit fast loading and unloading and quick acceleration.

The assistant boatswain, Mark Stanley however, 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 her moorings.

[14] It is 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.

[17] 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.

[18] Crew aboard a nearby dredger noticed Herald of Free Enterprise's lights disappear, and notified the port authorities.

[23] Wolfgang Schröder [de], the German captain of a nearby ferry (M/V Gabriele Wehr),[24] was commended by Prime Minister Margaret Thatcher and received a medal from King Baudouin of Belgium for his heroic efforts in rescuing passengers.

[15] The fact that Stanley was asleep at the time of departure led Sheen to examine the working practices of Townsend Thoresen, from which he concluded that the poor workplace communication and stand-off relationship between ship operators and shore-based managers was the root cause of the capsizing,[12] and identified a "disease of sloppiness" and negligence at every level of the corporation's hierarchy.

[30] 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.

[31] 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 capsizing.

Tests by the Danish Maritime Institute after the accident, however, found that once water began to enter the vehicle deck of a RORO, it was likely that the vessel would capsize within 30 minutes, while other tests showed that the lack of watertight subdivision (which was common on other vessels) allowed the weight of water to flow freely and increase the likelihood of capsizing.

This caused a "step change": if the ship had been sailing at less than 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.

The operation included parbuckling and was successfully concluded in late April 1987, allowing the remaining bodies trapped underwater to be removed.

The ship was towed to Zeebrugge, and then across the Western Scheldt to the yard of De Schelde in Vlissingen (Flushing, Netherlands), where her fate was decided.

[37] The voyage was interrupted for four days when the ships encountered the Great Storm of 1987 off Cape Finisterre, where Herald of Free Enterprise was cast adrift after its tow rope parted,[38] resuming on 19 October 1987.

The hull began to disintegrate while off the coast of South Africa on 27 December 1987, and had to be towed into Port Elizabeth on 2 January 1988 to undergo temporary repairs to allow her to continue her voyage.

[40] The capsizing of Herald of Free Enterprise caused the highest death count of any peacetime maritime disaster involving a British ship since the sinking of HMY Iolaire on 1 January 1919 near Stornoway, Isle of Lewis, when at least 205 perished of the 280 aboard.

New International Maritime Organization (IMO) regulations are in place that prohibit an open (undivided) deck of this length on a passenger RORO vessel.

The former Spirit of Free Enterprise was extended to increase her cargo capacity during her time under the P&O flag in a stretch and total rebuild operation and scrapped in 2012.

Australian businessman Maurice de Rohan, who lost his daughter and son-in-law in the tragedy, founded Disaster Action, a charity which assists people affected by similar events.