SEDCO Helen (1970/01/31)
800m SE Petrel 1 well, Petrel Field, Bonaparte Gulf
In January 1970 a large oil well blow out led to an attempt to drill a relief well nearby. The SEDCO Helen was positioning mooring buoys for floating drilling rig SEDCO 135G when the propeller fouled the buoy cable and the buoy punctured the ship’s hull, flooding the engine room and causing it to sink in minutes with the loss of 9 lives. A large scale search was carried out using RAN patrol boat HMAS Assail, RAAF Neptune aircraft A89-281, tugs Rode Zee and Super Tide and oil rig supply boat Cookshore. The bulk ore carrier Musgrave Ranger bound from Darwin to Japan also turned back to join the search. The Rode Zee picked up the 11 survivors. Salvage divers used a diving bell (famously used in the RMS Niagara gold salvage during World War II and reconditioned for the work) to assess the possibility of salvaging the SEDCO Helen but it was considered too dangerous.
The wreck was relocated by Santos Ltd using side scan sonar survey in June 2010.
Shoalest depth 82m, seafloor depth 320 ft/ 97m
Ship Built
Owner SEDCO
Country Built Australia
Port Built Newcastle
Port Registered Panama
When Built 1969
Ship Lost
Gouped Region North-West
Sinking Holed and sunk
Crew 20
Deaths 9
When Lost 1970/01/31
Where Lost 800m SE Petrel 1 well, Petrel Field, Bonaparte Gulf
Latitude -12.830947
Longitude 128.479558
Port From Darwin
Port To Petrel Field, Bonaparte Gulf
Minimum Depth of site 82.00
Length of site 69.00
Ship Details
Length 61.00
TONA 837.00
Museum Reference
Unique Number 1129
Sunk Code Foundered
Protected Not protected Federal
Found Y
Inspected N
Confidential NO