Byford Dolphin

Byford Dolphin was a semi-submersible, column-stabilised drilling rig operated by Dolphin Drilling, a subsidiary of Fred Olsen Energy. Byford Dolphin was registered in Hamilton, Bermuda, and drilled seasonally for various companies in the British, Danish, and Norwegian sectors of the North Sea. In 2019, Dolphin scrapped the rig. The rig was the site of several serious incidents, most notably an explosive decompression in 1983 that killed four divers and one dive tender, as well as critically injuring another dive tender.

Infobox

Name

Byford Dolphin Deep Sea Driller (1974–1978)

Owner

Byford Dolphin Pte. Ltd. (Fred. Olsen Energy)

Operator

Dolphin Drilling

Port of registry

Singapore Panama (1974–2005) Bermuda

Builder

Aker Group

Yard number

Aker Verdal A/S (695)

Laid down

31 October 1972

Completed

1 February 1974

Out of service

2016

Identification

Call sign: 9VDG7 DNV ID: 09092 IMO number: 8750584 MMSI no.: 563601000

Fate

Beached Aliağa and scrapped 2019

Class & type

DNV class: 1A1 Column-stabilised Drilling Unit UKVS

Tonnage

11,792 GT 3,538 GT

Length

108 m (355 ft)

Beam

67 m (221 ft)

Depth

36 m (120 ft)

Speed

4 kn (8 km/h)

Capacity

Variable Deck Lo: 3,021 t Liquid Mud: 3,981 bbls (534 m3) Bulk Mud/Cement: 547 t / 270 t

Crew

102 berths

Tables

Byford Dolphin specifications · Description

Crew quarters

Operating deck load

Crew quarters

3,025 tonnes

102 persons

Operating water depth

Operating deck load

Operating water depth

3,025 tonnes

460 metres (1,500 ft) maximum

Derrick

Operating deck load

Derrick

3,025 tonnes

49 m (160 ft) Shaffer top compensator

Mooring system

Operating deck load

Mooring system

3,025 tonnes

12-point

Blow-out preventer

Operating deck load

Blow-out preventer

3,025 tonnes

Hydril 476 mm (18 in), 10,000 kPa (1,500 psi)

Sub Sea Handling System

Operating deck load

Sub Sea Handling System

3,025 tonnes

Christmas tree

Deck cranes

Operating deck load

Deck cranes

3,025 tonnes

2 × 40 tonnes

Operating deck load	3,025 tonnes
Crew quarters	102 persons
Operating water depth	460 metres (1,500 ft) maximum
Derrick	49 m (160 ft) Shaffer top compensator
Mooring system	12-point
Blow-out preventer	Hydril 476 mm (18 in), 10,000 kPa (1,500 psi)
Sub Sea Handling System	Christmas tree
Deck cranes	2 × 40 tonnes

References

navalmarinearchive
https://navalmarinearchive.com/sbh/highvalueships/offshoresemisubmersibles.html
MarineTraffic
https://www.marinetraffic.com/en/ais/details/ships/shipid:726704/mmsi:310715000/imo:8750584/vessel:BYFORD_DOLPHIN
Byford Dolphin
http://vesselregister.dnv.com/vesselregister/details/09092
"Byford Dolphin"
http://www.fredolsen-energy.no/?aid=9048931
Energy Voice
https://www.energyvoice.com/oilandgas/norway/540650/byford-dolphin-diving-incident-casts-long-shadow-40-years-on/
The American Journal of Forensic Medicine and Pathology
https://doi.org/10.1097%2F00000433-198806000-00002
Byford Dolphin
https://web.archive.org/web/20110607125608/http://www.rigzone.com/data/rig_detail.asp?rig_id=102
"Byford Dolphin"
https://web.archive.org/web/20110720154005/http://www.fredolsen-energy.no/arch/_img/9073113.pdf
North Sea Divers - a Requiem
https://books.google.com/books?id=lPp68NAoUF0C&pg=PA168
Norges Offentlige Utredninger
https://urn.nb.no/URN:NBN:no-nb_digibok_2013081906099
Rules for certification of diving systems, 1982
https://search.worldcat.org/oclc/9287902
"Historiens verste dykkerulykke"
https://web.archive.org/web/20110605103112/http://www.dagbladet.no/tekstarkiv/artikkel.php?id=5001080047056&tag=item&words=byford%3Bdolphin
The Times
http://www.timesonline.co.uk/tol/news/world/europe/article3613778.ece
Byford Dolphin
http://cdiver.net/news/norwegian-government-finally-pays-out-for-1983-byford-dolphin-diver-death/#more-3678