The "Derbyshire" Story

The Derbyshire sank in September 1980 in the Pacific about 350 miles south east of Japan. The sea is about 4200 metres (2½ miles) deep at this point. 44 people died -.42 crew and the wives of two of the officers.

She was an enormous oil/bulk/ore carrier (0.B.0) and could carry about 160,000 tons of oil, iron ore, coal, grain or other bulk cargoes.

What makes the story so important is that she was, and still is, the biggest British registered merchant ship ever to have been lost. 294 metres (1000ft) long - almost three times the length of a football pitch. 44 metres (150ft) wide - as wide as a six lane motorway - wider even than the Titanic. The ships were so enormous that they built them in sections and then joined them together. Her loaded draft was 18.5 metres (62 feet). She had one 30,400 hp diesel engine driving a single propeller.

The Derbyshire was delivered in June 1976. She was the last of six sister ships all of which were built by Swan Hunters.

In the 1980s about 17 ships like the Derbyshire were. being lost each year. The figures for the last ten years (1993-2002) is 108 ships. The loss of The Derbyshire was extraordinary because she .was only 4 years old; she was British owned and manned by a competent and experienced Master and crew; she was built by a British shipyard - Swan Hunters; she was fully classed Al by Lloyds Register of Shipping; all her surveys and certificates were up to date.

On her final voyage she left Fos sur Mer, France on 23rd June 1980 for New York. She. arrived on 5th July to take on fuel oil bunkers. She got to her loading port - Sept Isles, Canada on 10th July and left on 11th July after loading 157.447 tonnes of iron ore concentrates bound for Japan. It was raining when she arrived in Sept Isles. This might have been significant because iron ore can shift in a seaway if it is too damp, but It was clear that the moisture content of the ore was within acceptable limits.

She sailed for Japan via Capetown where she took on stores. After leaving Cape Town the charter party (the legal agreement under which the vessel had been hired) required the ship to comply with recommendations from a weather routing organisation called "Oceanroutes". It would advise on course and speed, according to expected weather conditions, to minimise fuel consumption. The ship sent messages to Oceanroutes every two days giving her position and speed. On 3 Sep the Master increased the ship's speed to 12.5 knots to pass ahead of a tropical depression which he had learnt about from a Japanese weather fax. Oceanroutes confirmed the existence of the tropical depression and recommended that the ship take a northerly course to clear it. On 5 Sep Oceanroutes told the Master that his route was still valid and that the tropical depression would reach storm intensity by the following day. On 6 Sep the ship reduced speed to 10 knots as the tropical depression had apparently subsided. But during the course of that day typhoon Orchid developed close to the tropical depression. Some 20 years later Oceanroutes was criticized for not warning the ship about Orchid.

The Derbyshire's last message was to her owners on 9th September 1980 it read.

"9 September 0930 GMT; Now hove to due to severe tropical storm; estimated time of arrival Kawasaki 14th hopefully"

This was the last known message sent by the ship No MAYDAY (distress message) was heard. This was most unusual.

On 13th September 1980 the ship owner asked the Japanese authorities to search for the Derbyshire. On 15th September the Japanese authorities and other ships in the area commenced searching. An oil slick was found and a sample was sent ashore for analysis. This showed that the oil was of the same type as that used by the Derbyshire. The search was interrupted on 17 September due to another typhoon. It resumed on 18 September but was called off on 21 September as nothing had been found.

The UK Government refused to hold a formal investigation because there was no evidence, and an investigation would be unable to find out why she had disappeared.

The Department of Transport instead asked two independent bodies to undertake some research into bulk carrier losses.

In March 1982 one of the Derbyshire's sister ships; the Tyne Bridge, encountered severe weather in the North Sea and her deck plating started to crack just forward of the bridge in an area known as Frame 65. Ships' frames are numbered from aft and the Derbyshire had over 300 frames. It was found that the damage was caused by a defect in the Frame 65 area. The four other remaining sister ships were contacted. Each one in turn found similar damage in the same location as shown in the sketch above.

It was later found that the last five of the six sister ships, including the Derbyshire, had been modified in this area and that the shipyard had mislaid the plans of the modification. The modification resulted in a massive longitudinal girder being cut at the bulkhead by Frame 65 - instead of penetrating the bulkhead to maintain strength. The modification sought to maintain longitudinal strength by means of a fore and aft bulkhead. Not only was this much weaker than the massive girder but was out of line with the bulkhead by as much as 35 mm (1½ inches). This modification was the result of a change in International Rules for ship construction - and was not done at random by the shipyard. But even though the first sister ship - the Furness Bridge - had been built to plan she also suffered cracks in the same area.

Peter Ridyard, the father of the 4th Engineer Officer on the Derbyshire was a very experienced ship surveyor. He was convinced that a ship like the Derbyshire should not have sunk and he started to collect information about the damage to her sister ships in the Frame 65 area. He sent this data to the Department of Transport (DOT) in September 1982 but received no response. He sent it again in June 1983 but once again no response.

In July 1985 the.DOT issued a draft report based, presumably, on the research done by the two independent bodies (British Ship Research Association and Brunel University) and on Peter Ridyard's data. The report tended to agree that the Derbyshire. could have been lost due to damage in front of the bridge in the region of frame 65. However, the underwater investigation in 1997 proved that the ship had -not been lost in this way. -

The Derbyshire families were angered when, in March 1986, the DOT published the report in a much modified form - saying that the loss of the ship could have been due to various other reasons. The Government said that the draft report had been changed in the light of new evidence but even, when challenged in the House of Commons, they would not say what the new evidence was.

Then on 18th November 1986 the Kowloon Bridge, one of the Derbyshire's sister ships, developed severe deck cracking at Frame 65 whilst crossing the North Atlantic in severe weather. In view of the connection with the Derbyshire the Department of Transport's inspectors boarded the Kowloon Bridge on 20th November in Bantry Bay, Eire where she lay at anchor.

But on 22nd November she broke away from her anchor and, to be safer, put to sea again. She then lost her rudder and on 24th November went aground on Stag Rock off the south coast of Ireland. On 25th November, after grounding, she broke her back; the break occurred near Frame 65. It was learnt that cracks in the Frame 65 area of the Kowloon Bridge had been repaired in April 1982 and that massive girders had been welded over the deck there to prevent further cracking.

Following the loss of the Kowloon Bridge, and the growing suspicion that the Derbyshire could have been lost because of a failure at Frame 65, the Government agreed to hold a formal investigation into the loss of the Derbyshire. This took place between October 1987 and March 1988 in Church House, Westminster, under a Wreck Commissioner, Gerald Darling QC. The investigation was the longest of its type ever to have been heard. It took the Wreck Commissioner 10 months to reach a conclusion which was in any case inconclusive. The conclusion was announced on 18th January 1989 (almost nine years after the loss of the Derbyshire).

"For the reasons stated in this Report the Court finds that the Derbyshire was probably overwhelmed by the forces of nature In Typhoon Orchld, possibly after getting beam on to wind and sea of Okinawa in darkness on the night of 9th/10th September 1980 with the loss of 44 Iives. The evidence available does not support any firmer conclusion."

The Wreck Commissioner gave these reasons for his condusions:

1. Even under the weight of severe seas the ship would not have fractured amidships. As the Frame 65 area was stronger than amidships it is unlikely that failure occurred there
2. Fatigue cracking was unlikely to have caused the total loss of the ship whether amidships or at Frame. 65
3. Failure of the.hull at Frame 65 due to brittle fracture was extremely unlikely
4. Although flooding of the bosun's store and the chain locker could have caused loss of freeboard by the bow, followed by sequential damage and failure to No. 1, 2 & 3 hatch covers, it was thought unlikely that this caused the loss of the ship

The government felt that a search for the Derbyshire was impossible as her whereabouts was not known and there was no technology to obtain clear photographic evidence at a probable depth of 4,200 metres.

In June 1990 Tyne Tees Television took up the fight through the "Northern Eye" program - a half hour long documentary about the Derbyshire.

On 29th May 1994 a U.S organisation - Oceaneering Technology - commenced a search for the Derbyshire This cost £350 K and was organised and paid for by the International Transport Federation (ITF). An off-shore support vessel called Shin Kai Maru was used from which the Ocean Explorer 6000 a unique dual channel side scan sonar was used to search for the wreck. On board the Shin Kai Maru was a team from Channel 4 TV who later broadcast an excellent documentary. During the days following the loss of the Derbyshire in September 1980, oil had been seen bubbling to the surface, by helicopter, and the positions noted. Based on this it was estimated that she would lie somewhere within an area of 200 square nautical miles. It was more likely that she lay within an area of 90 square nautical miles. Against all odds the wreck was discovered only 23 hours after the search had commenced. Deteriorating weather delayed a more detailed examination and the time that the ITF had paid for was running out. Nevertheless, Oceaneering Technology donated the use of its Magellan 725, a remotely operated vehicle, to obtain video evidence to identify the wreck. The bow and stem were found more or less intact but the rest of the wreckage was spread over a large area of about 1500 x 1500 metres (2.25 sq. Km). The cargo holds had imploded (opposite to exploded) due to the enormous water pressure that was exerted on the ship as she sank to the bottom.

Now that the wreck had been found the Government was forced to take action and Lord Donaldson was appointed to assess what further steps were needed to obtain evidence about the loss of the Derbyshire. He concluded that a second expedition to the ship was essential not only to establish why she sank but also for the benefit of ship safety in general.

Three Assessors were appointed to oversee the expedition and prepare a report. Two underwater remotely controlled vehicles would be used Argo to obtain a broad view of the wreckage and Jason for a more detailed inspection. Although the wreckage was distributed over a wide area the Assessors were surprised that it was as localized as that considering the depth of water. The technical achievements of the survey were exceptional, 135,774 Individual electronic photographic stills were obtained of over 98% of the entire wreckage field. The stills were then joined up to make larger pictures. Some 2500 separate items of wreckage were identified and some 200 hours of video were taken. The Assessors had a lot of work to do before they could come to a conclusion and it took them almost 11 months to publish their report in March 1998.

The Assessors' conclusion was that the lid to the hatch leading to the bosun's store on the fore deck had not been secured. Their evidence for this was that they could see a mooring rope trailing from it. They also noted that the wing nuts, which should have secured the hatch, were not fully tightened. The open store hatch had allowed water to fill the void spaces in the fore part of the ship. The bow of the ship had then sunk deeper into the momentous seas which soon damaged the hatch on No I hold causing It to collapse and the hold to fill with water. This made the bow go down even further with the result that the same thing happened to No 2 hatch and No 2 hold flooded. And so, one by one, under the same circumstances the remaining holds flooded and the vessel sank. The assessors did not know how long this sequence of events took - it could have been just a few minutes! The Assessors also said that Frame 65 had not caused the loss of the ship.

The conclusion that the bosun's hatch had not been property secured implied serious negligence on the part of the crew.

0n 17th December 1998 the Government announced that there would be a full re-opening of the Formal Investigation in the High Court. The hearing commenced on 5th AprIl 2000 and lasted for 54 days. Evidence was taken from a number of experts. The Court decided that the cover to the bosun's hatch had not been left open by the crew.

The Court concluded that the cover to the bosun's hatch had probably been destroyed when one of the massive windlasses on the fore deck was dislodged. Evidence about the alleged unsecured hatch to the bosun's store was given by a previous Chief Officer of the Derbyshire. He explained that on leaving port the forward mooring ropes would be stowed away in the bosun's locker. Before, lowering them into the locker the end of each one would be lashed to the following one. Then, to make it easier to get them out of the locker when they were next needed, the end of the final rope to be stowed would be lashed to a special bracket on the underside of the hatch cover. It was the end of this rope which the Assessors saw protruding from the store hatch that caused them to draw the wrong conclusions.

This Chief Officer also explained that the hatch dogs had a nasty habit of working loose, especially when heavy seas, landing on top of the lid, compressed its rubber seal. He knew that the ship's carpenter habitually secured the lid with a "cat's cradle" of rope to prevent the dogs from working loose and it was most unlikely that the "cats cradle" was not in place.

The Court learnt from weather hindcasts (backward looking weather forecasts) about the sea conditions that the Derbyshire probably encountered during Typhoon Orchid.

Before making its decision the court heard the results of tests on a model of the Derbyshire which were conducted at the MARIN Research Institute, Wageningen, Netherlands. These were designed to measure the forces exerted by heavy seas on the forward hatches under different conditions of trim and wave heights. It was established that if the Derbyshire had been bow on to the very high waves, and if the wave length was similar to the length of the vessel (about 1000 metres) then, she could have pitched down into the trough of successive waves. Before the bow had a chance to rise back to the horizontal, it would have been submerged under the next wave crest.

On the basis of the condition of the wreckage, the model tests done by MARIN and the weather hindcasts, the Court believed that the initiating cause of the, loss was .the destruction of the ventilators and air pipes on the foredeck by continuous green water loading over many hours on the 8th and 9th September 1980. The seas then flooded the bosun's store and the forward ballast tank causing the ship to trim down by the bow and eventually sink. This trim was not perceptible from the bridge because it would have been obscured by the extremely poor visibility that was likely at the time due to driving wind and spray. Also the bridge was over 260 metres (850 feet) from the bow. The sea started crashing onto No I hatch cover as the bow dropped lower in the water. No I hatch cover was not designed to withstand such enormous pressures and eventually gave way. This caused No I hold to flood and so the bow went down even more. The same thing then happened to the other hatches, one after the other, until each hold filled with water and the ship finally sank. The Court also concluded that it was most unlikely that the ship had been lost due to any other cause - including faults at Frame 65! The Court believed that it was most unlikely that she ever went beam on to wind and sea as was suggested in the Formal Investigation held in 1987-1988.

The Court made a number of significant recommendations to improve ship safety which are gradually being implemented.