Searching for the Derbyshire

Moreover the Derbyshire was only four years old, built by Swan  Hunter's of the river Tyne a well-regarded British shipbuilding company was launched in 1976 at their Haverton Hill yard on the river Tees, being the last in the class of six sister ore/bulk/oil (OBO) ships.

The earliest indication that Derbyshire’s death was extremely sudden was the puzzling absence of a "Mayday" call or any sort of distress signal. By September 13, four days after their last radio communication, the owners Bibby Brothers & Co were sufficiently concerned by the absence of contact to request a search by the Japanese Maritime Safety Agency (MSA). MSA regulations on missing ships dictated that the search could not begin until September 15, 24 hours after Derbyshire was expected to arrive in Kawasaki.

On the 15th, with two patrol boats and two reconnaissance aircraft combing the seas, one of the aircraft spotted an oil slick that was about a kilometer wide by 2 kilometers long.

The following day, a patrol boat directed to the slick confirmed that oil was bubbling up from the ocean in a location approximately 40 miles from Derbyshire‘s last reported position. Although the search was temporarily suspended for a day because another tropical storm was threatening the area, a third observation of "upwelling" fuel oil was made by an MSA aircraft on the !9th. No other sign of the ship or her crew was made and, on September 20th, the search was terminated. Any remaining hope of saving the 42 British officers and crew and two wives on board Derbyshire was extinguished.

Six weeks after the sinking, one of Derbyshire's life boats was sighted by a Japanese tanker nearly 700 miles to the west-southwest of the search area. The empty life boat showed clear evidence of having been wrenched with great force from its davits on the ship, further suggesting that the sinking was rapid.

Reaction to Derbyshire's loss was immediate and intense. In the public and in the shipping industry, the same questions were asked: How could such a large and seemingly invincible ship be lost almost without a trace?

Derbyshire had been equipped with the latest electronic equipment capable of transmitting a May Day call at the push of a button. What possible catastrophe would leave the crew on the bridge with so little time to react in saving the ship and their own lives?

Eighteen months after the loss, one of Derbyshire's sister ships, the Tune Bridge, was forced to return to port because of cracking of the deck plate in an area just forward of the superstructure known as Frame 65. In port, the severity of the cracks was alarmingly apparent. On the starboard side there was a 19 foot crack: on the port side an I 11 foot crack (Ramwell and Madge. 1992).

Prompted by LIoyds Register two sister ships Casi Kittiwake Casi Kittiwake and Sir Alexander Glen —were inspected in the summer of 1982 and were both found to have identical problems with the design and workmanship of critical structural members around Frame 65. The common defect in all three ships invoked a pair of longitudinal bulkheads (girders) that nearly run the length of the ship and serve as main strength members. Contrary to the originally intended design, the two longitudinals were terminated at Frame 65 and butt-welded to the transverse bulkhead that marks the end of the line of cargo holds. Furthermore, the longitudinal bulkheads forward and aft of Frame 65, which should be precisely aligned to preserve continuity and maximum hull strength, were misaligned by 25 to 45 millimeters.

A research study commissioned by the U.K. Department of Transport (Bishop, eta!., 1991) concluded that overall "field stresses" along DerbyDerbyshire's hull would be at a peak near Frame 65. such that the combination of field stresses and high local stresses resulting from probable termination and misalignment of longitudinal members is likely to have resulted in rapid crack propagation and catastrophic structural failure of Derbyshire's hull.

A formal investigation (F!) into Derbyshire's loss was finally conducted in 1987. Unfortunately. the Bishop study was excluded from consideration by the wreck commissioner and the authors were never called to testify. Even more surprising, evidence from the Knowloon Bridge another sister ship whose sinking and subsequent fracture all around Frame 65 was the incident that initiated the inquiry—was essentially ignored Ironically citing the lack of factual evidence the Fl report published in 1989 concluded that Derbyshire was probably overcome by the forces of nature in Typhoon Orchid (Anon.. 1989).

The impact of Derbyshire mysterious sinking on the shipping industry was great, but nowhere was it more personal than in Liverpool where the ship made her home port and where 17 members of Derbyshire's crew lived. For many of the surviving wives, children, and parents, the grief has been prolonged b the lack of a body to bury and distrust in the 1987 formal investigation. Ultimately. the common loss shared by the family members led them to form Derbyshire Families Association (DFA) and to persistently campaign for a true accounting of Derbyshire's loss.

At least 273 crew died in these sinkings. Including the 99 crew that have perished in the worst three of this year’s bulk carrier losses, it is estimated that 750 seafarers have lost their lives since 1988. In response to proposals by the DFA and two U.K. transport unions—the RMT and NUMAST the International Transport-workers’ Federation (ITF) ambitiously decided to fund a search for Derbyshire and to produce the first factual evidence of her sinking. Among its objectives, ITF wanted to focus attention on maritime safety and the plight of seafarers and to expose the practice of attributing mysterious sinkings force majeure.

The ITF’s selection of Oceaneering Technologies to perform the search was based largely upon the firm’s reputation, unique experience, and capabilities in the conduct of deep ocean searches and marine accident investigations. In addition to its well-known track record in major air crash inquiries (Air India 747, Challenger, SAS 747, United Airlines cargo door, Itavia DC9). the company was developing a further specialty in the location and photo/video investigation of sunken ships. In 1990, Oceaneering Technologies made a major investment in this specialty by fielding the first state-of-the-art "teamed system" that combined a dual-frequency side-scan sonar with a work-class ROV system for the deep ocean up to 6000 meters.

The system was first used in solving the mystery of the freighter Lucona for an Austrian court that was hearing a famous insurance fraud and murder case. Since this introduction, Oceaneering Technologies has used the teamed systems frequently on a variety of shipwreck insurance investigations and special salvage projects.

Like all searches. Derbyshire search began with a very thorough collection and analysis of the known loss data, of six reported sightings of oil slicks and debris, only three were felt to be reliable and accurate. The major uncertainty in these positions was the lateral displacement the oil bubbles would experience during their 4.210 meter rise to the surface. Although some studies suggested that displacement could be as great as 10 nautical miles away from the wreckage. our analysis indicated a worst case displacement of 3 miles.

Another vital clue came from the Japanese Hydrographic Office who provided current doppler data that showed a prevailing southerly current, refuting the conventional wisdom of a north westerly Kuroshio Current.

Using the principles of modern probability analysis (Discenza and Greer. 1994), an overall search area of 75 square nautical miles was estimated with a high probability zone of roughly 90 square miles. The search plan to cover this area relied on seven 14-mile lines running 1000 280~ where the ocean floor slopes off the Daito Ridge at 70 towards a basin more than 5.200 meters deep (Davies. 1994).

Following mobilization of Oceaneering Technologies’ teamed Ocean Explorer 6000 side-scan sonar and Magellan 725 ROV systems on board the survey vessel Shin Kai Mart,, and transit to the search area, the sonar was launched at 1405 hours on May 29 to begin the search. By 2152, Ocean Explorer’s wide swath sonar (33 36 kH,) was on-line and sweeping a 4.8-kilometer swath of ocean floor in search of Derbyshire's wreckage.

On the third line, less than 23 hours from the start of the search pattern, the sonar detected a large and dense area of high backscattcr. Although promising and a definite candidate for a high-resolution pass. this sonar contact did not match the expected large single target of the presumed intact hull.

As the search progressed, other contacts were found on overlapping lines in the area of the earlier promising contact, increasing the crew’s hope. With no other likely contacts found, the search plan was ultimately modified to run over the promising contact on a high-resolution puss (simultaneous 33/36 kHz and !20 kHz) of 1.2 kilometers.

At 0123 hours on June 3, the color monitor displaying Ocean Explorer’s sonar imagery began revealing a scene of immense destruction and fragmentation that could not be attributed to anything other than the obliterated remains of the bulk carrier Derbyshire.

For detailed photo/video documentation work, the Magellan is typically outfitted with a 35mm still camera (stereo and 750 frame options) and strobe lights; a wide-angle black & white SIT camera; a color camera with zoom capabilities; and a bank of variably controlled flood lights. Video options include a three-chip camera for the highest broadcast quality and a boom deployed small-diameter camera for internal penetrations. This range of high quality photo/video configurations as available to ensure that Magellan’s visual evidence is clear to lay people and is defensible in a court of law.

Due to time limitations, Magellan was deployed in the wreckage field for just six hours. The initial scene that greeted her was one of thousands of bright, sparkling reflections from the tons of iron ore particles that had escaped the cargo holds and settled on the seabed. It wasn’t long before the first piece of fractured shell plating was found. Thereafter. large pieces of wreckage were videotaped in unusual contorted angles lying next to lengths of bent piping and other small debris. Finally, a very large section of the ship sitting upright but deeply buried within an impact crater was recognized as the bow. Maneuvering high above to visualize the widest view of wreckage possible, the bow appeared to be fractured straight across at Frame 339. Moving past the large spare anchor that was still lashed to the deck, Magellan closed in to observe the last five letters on the name on the port side: SHIRE," which had not been seen for nearly 14 years.

Before leaving the wreck, Magellan performed one final act, gently placing a bronze plaque bearing words of remembrance for Derbyshire families on the bow as a final memorial to the 44 who died.

Further detailed analysis of the sonar imagery following the search mission has yielded another significant finding: the identification of a sonar target believed to be the stern section just forward of the superstructure in the suspected weak section around Frame 65. This location of the stern, in addition to the confirmed fracture of the bow and the presence of hundreds of relatively small pieces of wreckage. indicates an extremely violent breakup that must have occurred over a very short period of time, perhaps only seconds or minutes. The extensive shattering of the hull clearly visible in the high resolution sonar image has raised new questions about what forces came to bear on the Derbyshire in the moments just before, and after, her sinking.

In the view of the ITF and many other supporters, this spectacular scene of destruction is new and important evidence that invalidates the conclusion of the 1987 formal inquiry that Derbyshire was probably overcome by the forces of nature in Typhoon Orchid." As calls for a fresh public inquiry and a new expedition to gather more information from the wreckage field mounts, the U.K. Marine Accident Investigation Branch has been asked by the minister of transport to assess this new evidence and report to him MAIB’s recommendations.