Outer Continental Shelf National Center of Expertise (OCSNCOE)

OCS-Related Accidents, Investigations and Safety Alerts

This page consolidates information pertaining to OCS-related accidents, investigations and safety alerts/lessons learned. Use the tabs above to view the following categories:

1) U.S. Coast Guard Investigations;

2) National Transportation Safety Board (NTSB) Marine Accident Reports and Marine Accident Briefings; and

3) USCG Safety Alerts and Lessons Learned (with access to additional USCG and Bureau of Safety and Environmental Enforcement (BSEE) alerts).

Additional information is also available on dedicated pages for the following incidents:

• DEEPWATER HORIZON/Macondo Well Blowout, April 20, 2010; and

• FPS AUGER Lifeboat 6, June 30, 2019.


U.S. Coast Guard Investigation Reports for OCS-Related Casualties

The U.S. Coast Guard prepares and publishes reports of investigation that present the findings of fact, results of analysis, conclusions, and recommendations of the Coast Guard's investigation of marine casualties, outer continental shelf (OCS) casualties, and commercial diving casualties. This page lists USCG reports that are OCS-related, ordered from newest to oldest (by accident date). Additional investigation and casualty analysis reports are available on the Office of Investigations & Casualty Analysis (CG-INV) Marine Casualty Reports page.

Click on the accident date to open the document (opens in a new window).

Accident Date Vessel/Unit Type Subject and Summary
30Jun2019 Floating OCS Facility Shell AUGER TLP Lifeboat No. 6 Inadvertent Hook Opening with Loss of Life and Injury at Garden Banks 426 on the U.S. OCS in the Gulf of Mexico - Report is currently under review at USCG HQ with Commandant Actions to be determined. Release date is unknown.
View the AUGER LB 6 tab (above) for information related to this incident.
31Dec2012 MODU Multiple Related Marine Casualties and Grounding of the MODU KULLUK
MODU Explosion, Fire, Sinking and Loss of Eleven Crewmembers aboard the MODU DEEPWATER HORIZON at Mississippi Canyon Block 252 in the Gulf of Mexico
View the DWH - Macondo tab (above) for additional information.
07Apr2004 OSV Vessel Fire on the OSV SEABULK NEW JERSEY in the Gulf of Mexico
30Jun2003 OSV: Liftboat Sinking of L/B SUPERIOR CHALLENGE at Eugene Island Block 193-A in the Gulf of Mexico
04Mar1996 MODU Commercial Diving Accident aboard CLIFF'S DRILLING RIG NO. 12 with Loss of Life
15Dec1988 MODU Capsizing and Sinking of MODU ROWAN GORILLA I in the North Atlantic Ocean
15Feb1982 MODU Capsizing and Sinking of MODU OCEAN RANGER in the Atlantic Ocean with Loss of Life
10May1979 MODU Collapse and Sinking of MODU RANGER I at Block 189L offshore Galveston, TX with Loss of Life
15Apr1976 MODU Capsizing and Sinking of the OCEAN EXPRESS (Drilling Unit) in the Gulf of Mexico (under tow) with Loss of Life
28May1970 Platform Explosion and Fire on the CHAMBERS AND KENNEDY PLATFORM 189-L, southeast of Galveston, TX in the Gulf of Mexico, with damage to the M/V CARRYBACK and Loss of Life
13Mar1968 MODU Capsizing and Sinking of Drill Rig DIXILYN 8, JULIE ANN at Eugene Island Block 276 in the Gulf of Mexico
24Oct1967 Platform Explosion and Fire on CONTINENTAL Oil COMPANY PLATFORM 43-A, Grand Isle Block in the Gulf of Mexico
21Sep1960 MODU: Drill Tender Explosion and Fire onboard the M/V S-21 at Grand Isle Block 26 in the Gulf of Mexico with Loss of Life
26Jul1959 Platform Explosion and Fire onboard OFFSHORE PLATFORM SOUTH TIMBALIER BLOCK 134-D1, Gulf of Mexico, with Loss of Life
15Oct1958 Platform Fire on OFFSHORE DRILLING PLATFORM 45-E, West Delta Block in the Gulf of Mexico, with Loss of Life
17Apr1957 MODU Capsizing of DRILLING BARGE MR. K in the Gulf of Mexico with Loss of Life
10Aug1956 MODU Capsizing of SEDCO NO. 8 - RIG 22 at Avondale, LA with Loss of Life (under construction, afloat and nearing completion)


NTSB Marine Accident Reports (MARs) and Marine Accident Briefs (MABs)

National Transportation Safety Board Accident Reports "provide details about the accident, analysis of the factual data, conclusions and the probable cause of the accident, and the related safety recommendations". This page lists NTSB Marine Accident Reports that are OCS-related, ordered from newest to oldest (by accident report number). Additional accident reports and information are available on the NTSB's Accidents Reports page.

Click on the report number to open the document (opens in a new window).

Report Number Accident Date Vessel/Unit Type Subject and Summary
Preliminary Report DCA21MM024 13Apr2021 OSV: Liftboat

Capsizing of the Liftboat Seacor Power (report released 18May2021; investigation is ongoing)

About 1541 local time on April 13, 2021, the US-flagged 175-foot-long liftboat Seacor Power capsized off the coast of Port Fourchon, Louisiana. Nineteen personnel were aboard the vessel, including nine crew, two galley staff, and eight offshore workers. Vessels in the area reported heavy rain, winds exceeding 80 knots, and building seas at the time of the accident. Search and rescue efforts were hampered by 30–40-knot winds and 10–12-foot seas that persisted throughout the evening and into the next day. Six personnel were rescued by the Coast Guard and Good Samaritan vessels, and the bodies of six fatally injured personnel were recovered. Seven remain missing.

MAB-20/36 08Sep2019 OSV: Liftboat

Overturning of the Liftboat KRISTIN FAYE

Summary: On September 8, 2019, about 1015 local time, the liftboat Kristin Faye overturned while preparing to conduct work alongside a platform in the Gulf of Mexico, in Main Pass Block 64, located about 18 miles east of Venice, Louisiana. All three crewmembers abandoned the vessel and were rescued. One person suffered minor injuries during the evacuation. An estimated 120 gallons of diesel fuel were released. The vessel was declared a constructive total loss at an estimated $750,000.

MAB-19/36 08Oct2018 OSV: Crewboat

Fire aboard OSV GRAND SUN

Summary: On October 8, 2018, about 0215 local time, the offshore supply vessel Grand Sun was transiting the Chandeleur Sound in the Gulf of Mexico, about 15 miles from the Chandeleur Islands, Louisiana, when the vessel caught on fire. The four crewmembers aboard attempted to fight the fire but were unsuccessful. They remained on the stern of the vessel until they were rescued by the US Coast Guard. The fire burned itself out, and the vessel was later towed to port. No pollution or injuries were reported. The vessel, valued at $1.6 million, was deemed a constructive total loss.

MAB-19/27 18Nov2018 OSV: Liftboat

Overturning of the Liftboat RAM XVIII

Summary: On November 18, 2018, about 0200 local time, the liftboat Ram XVIII overturned in the Gulf of Mexico, in West Delta block 68, located about 15 miles south-southeast of Grand Isle, Louisiana. Five crewmembers and ten offshore workers abandoned the vessel and were rescued. Three personnel suffered minor injuries during the evacuation. An estimated 1,000 gallons of hydraulic oil were released. The vessel was declared a constructive total loss at an estimated $1,140,000.

MAB-15/16 24Aug2014 OSV

Collision of OSV GLORIA MAY and Fishing Vessel CAPT LE

Summary: The offshore supply vessel Gloria May collided with the uninspected fishing vessel Capt Le in the Gulf of Mexico about 2040 on the evening of August 24, 2014. As a result of the collision, the hull of the Capt Le was breached and the vessel flooded and sank; the bow of the Gloria May suffered minor damage. Three crewmembers from the Capt Le abandoned their sinking vessel into a liferaft and were recovered by the crew of the Gloria May. No injuries resulted from the accident. Total damage was estimated at $225,000.

MAB-16/06 02Mar2015 OSV: Crewboat, Liftboat

Collision between Passenger Vessel DIAMOND EDGE and Liftboat B.W. HALEY

Summary: On March 2, 2015, at 1027 local time, the passenger vessel Diamond Edge and the liftboat-configured offshore supply vessel B.W. Haley collided while under way in dense fog about 55 miles south-southwest of Lafayette, Louisiana. As a result of the collision, the hull of the Diamond Edge was breached and the vessel partially sank. There were no significant injuries or pollution reported. Estimated damage exceeded $1.75 million for both vessels combined.

MAB-16/03 23Jan2015 OSV

Allision of OSV CONNOR BORDELON with Unmanned Platform South Timbalier 271A

Summary: On January 23, 2015, at 0432 central standard time, the offshore supply vessel Connor Bordelon struck the unmanned natural gas platform South Timbalier 271A, which was located about 5.25 miles south of the jetty channel entrance at the vessel’s home port of Port Fourchon, Louisiana. The allision caused the pipelines attached to the platform to rupture and the natural gas and oil inside the pipelines to ignite. After the allision, the pipelines were shut down, and three good Samaritan vessels in the area applied water to put out the fire. The allision also caused a breach in the Connor Bordelon’s hull below the waterline, and the vessel began taking on water. The captain contacted the US Coast Guard to report the accident, and the Coast Guard released the Connor Bordelon from the accident area and allowed it to continue to Port Fourchon while the crew addressed the flooding. None of the 24 persons aboard the vessel were injured.

MAB-15/18 18Feb2014 OSV

Allision of OSV TRISTAN JANICE with Natural Gas Platform

Summary: About 0712 local time on February 18, 2014, the US-registered offshore supply vessel Tristan Janice allided with a natural gas production platform in the northern Gulf of Mexico, about 54 miles south-southwest of Houma, Louisiana. No one was injured and no water pollution resulted from the allision. However, the vessel and the platform sustained about $545,000 in total damage, and a substantial amount of natural gas escaped into the atmosphere from a ruptured supply pipe.

MAB-15/15 17Nov2014 Platform, Pipeline

Subsea Pipeline Damage by Tug and Barge VALIANT/EVERGLADES

Summary: The articulated tug and barge (ATB) unit Valiant/Everglades lost propulsion and drifted to within about 20 yards of the East Cameron (EC) 321A production platform in the Gulf of Mexico, forcing the shutdown of the platform and evacuation of its 35 crewmembers about 0600 on November 17, 2014. The captain of the Valiant ordered the anchor dropped to slow the vessel until propulsion was restored, and in the process of backing away, the anchor ruptured a subsea pipeline, causing an estimated $2 million in damage and the release of a total of about 249,800 mcf of natural gas. Neither the platform nor the vessel was damaged, and no one was injured.

MAB-15/02 28Nov2013 OSV: Dive Support

Fire on Board Saturation Diving Support Vessel OCEAN PATRIOT

Summary: A fire that broke out in the forward machinery space of the saturation diving support vessel Ocean Patriot while under way in the Gulf of Mexico on the evening of November 28, 2013, was brought under control by the vessel’s fixed fire suppression system without serious injury, and no pollution resulted from the accident. Damage to the Ocean Patriot was estimated to be $9.8 million.

MAB-15/01 14Jun2013 OSV: Crewboat

Allision and Sinking of Offshore Supply Vessel CELESTE ANN

Summary: The offshore supply vessel Celeste Ann was receiving passengers from West Delta oil platform 73 about 20 nautical miles southeast of Grand Isle, Louisiana, when the vessel allided with the platform about 0836 on June 14, 2013. The allision punctured the hull, and the Celeste Ann subsequently flooded and sank. All passengers and crew evacuated to another vessel, and no one was injured.

MAB-14/01 30May2013 OSV

Sinking of Offshore Supply Vessel RICKY B

Summary: On May 30, 2013, at 0702 central daylight time, the offshore supply vessel Ricky B sank in the Gulf of Mexico about 24 nm south of Marsh Island, Louisiana, while being towed. The three crewmembers had abandoned the Ricky B earlier and boarded a good samaritan vessel, from which they were subsequently transferred to a nearby manned oil platform. No one was injured. The Ricky B was later refloated. Its damage was estimated to be $520,000.

MAB-13/14 16Jan2012 OSV: Liftboat

Fire On Board and Sinking of Liftboat MAKO

Summary: About 0503 on January 16, 2012, the US liftboat Mako caught fire while supporting oil drilling operations about 6 miles off the coast of Nigeria, Africa. No one on board was injured, but the Mako was a total loss in the accident.

MAB-13/13 02May2012 MODU

Collision of Oil Tanker FR8 PRIDE with MODU ROWAN EXL I

Summary: On May 2, 2012, at 0718, the oil tanker FR8 Pride collided with the mobile offshore drilling unit (MODU) Rowan EXL I in Aransas Pass, Corpus Christi, Texas. No one was injured in the collision, but the two vessels sustained an estimated $16–17 million in damage.

MAR-13/01 08Sep2011 OSV: Liftboat

Liftboat TRINITY II, Personnel Abandonment and Loss of Life

Excerpt from abstract: This report discusses the September 8, 2011, accident involving the U.S. Liftboat Trinity II. Ten persons were on board. Because of severe weather and boarding seas associated with Hurricane Nate, the elevated liftboat’s stern jacking leg failed and the onboard personnel abandoned the vessel. Four of them died.

MAR-89/06 15Dec1988 MODU

ROWAN GORILLA I, Capsizing and Sinking

Excerpt from abstract: This report explains the sinking of the mobile offshore drilling unit ROWAN GORILLA I on December 15, 1988, in the North Atlantic Ocean. The safety issues discussed are the vessel's design and stability, vessel towing, weather, lifesaving equipment stowage, survival capsule design, survival training, and manning and licensing requirements.

MAR-86/03 15Jan1985 MODU

GLOMAR ARCTIC II, Explosion and Fire

Excerpt from abstract: On January 15, 1985, the U.S. semi-submersible mobile offshore drilling unit (MODU) GLOMAR ARCTIC II was conducting well testing operations 130 nautical miles east-southeast of Aberdeen, Scotland, in the North Sea. About 2030, the drilling unit experienced an explosion in the port pontoon pump room. The chief engineer and third assistant engineer were killed in the blast. Damage to the drilling vessel was estimated to be $2.3 million dollars.

MAR-85/11 14Sep1984 MODU

ZAPATA LEXINGTON, Explosion and Fire

Excerpt from abstract: About 1230 on September 14, 1984, the U.S.-flag mobile offshore drilling unit (MODU) ZAPATA LEXINGTON suffered an explosion and fire while moored and conducting drilling operations in 1,465 feet of water in the Gulf of Mexico. The accident occurred while procedures were being employed to evacuate a gas bubble from the subsea blowout preventer stack on the sea floor. Instead, gas trapped in the blowout preventer entered the base of the marine riser, rose to the surface, and escaped into the atmosphere, expelling a large volume of drilling mud out of the riser. The gas infiltrated the areas above and below the drill floor at the base of the derrick and was ignited. The explosion and fire that followed resulted in the deaths of four persons and severe injuries to three persons. Sixty-four persons abandoned the MODU using two survival capsules and three inflatable liferafts. The gas fire burned itself out about 30 minutes after the rig was evacuated. The cost of repairs was estimated at $12 million.

MAR-87/02 25Oct1983 MODU: Drillship

GLOMAR JAVA SEA, Capsizing and Sinking

Excerpt from abstract: About 2355 on October 25, 1983, the 400-foot-long United Stated drillship GLOMAR JAVA SEA capsized and sank during Typhoon LEX in the South China Sea about 65 nautical miles south-southwest of Hainan Island, People's Republic of China.  Of the 81 persons who were aboard, 35 bodies have been located, and the remaining 46 persons are missing and presumed dead.  The GLOMAR JAVA SEA currently is resting on the bottom of the sea in an inverted position in about 315 feet of water; its estimated value was $35 million.

MAR-83-2 15Feb1982 MODU

OCEAN RANGER, Capsizing and Sinking

Excerpt from abstract: About 0300 on February 15, 1982, the U.S. mobile offshore drilling unit OCEAN RANGER capsized and sank during a severe storm about 166 nautical miles east of St. John's, Newfoundland, Canada; 84 persons were aboard.  Twenty-two bodies have been recovered, and the remaining 62 persons are missing and presumed dead.  The OCEAN RANGER currently is resting in an inverted position in about 260 feet of water; its value was estimated at $125 million.

MAR-79-5 15Apr1976 MODU

OCEAN EXPRESS, Capsizing and Sinking

Excerpt from abstract: About 1100 c.s.t. on April 14, 1976, the self-elevating drilling unit OCEAN EXPRESS departed a drilling site in the Gulf of Mexico under tow for a new drilling site about 33 nm away.  The OCEAN EXPRESS arrived at the new drilling site about 2330, but was not set in place because of adverse seas.  Three tugs held the OCEAN EXPRESS in position awaiting better weather, but the seas continued to increase.  On April 15, 1976, one tug's starboard reduction gear failed, and another tug's towline broke.  With only one effective tug remaining, the OCEAN EXPRESS turned broadside to the wind and seas, drifted, grounded, capsized, and sank about 2115.  Thirteen persons drowned in a capsized survival capsule.


Safety Alerts and Lessons Learned

This page lists U.S. Coast Guard Safety Alerts and Lessons Learned that are OCS-related or pertain to systems that are onboard vessels and units that are conducting OCS activities, ordered from newest to oldest (by date). Additional safety alerts from the USCG and BSEE can be viewed at the following pages:

Office of Investigations and Casualty Analysis (CG-INV) Safety Alerts and Lessons Learned

Bureau of Safety and Environmental Enforcement Safety Alerts

Click on the safety alert number to open the document (opens in a new window).

Number Date Released Vessel/Unit Type Subject and Summary
04-21 08Jul2021 All Verify Your Wire Rope Terminations: Incorrect Terminations Can Lead to Catastrophic Failure
05-20 06Jul2020 All Electrical Issues Spark Major Concern - Addressing Hazardous Area Electrical Installations Knowledge Gaps
03-20 05Feb2020 Floating OCS Facility; All Check Your Lifeboat Cables: Damaged Control Cables can Contribute to the Unintended Opening of a Hook
View the Auger LB6 tab (above) for additional/related information.
13-17 19Dec2017 All Fixed CO2 Fire Extinguishing Systems: When your hoses aren't right you might lose the fight.
10-16 16Aug2016 OSV: Crewboat; All Iron Mike will steer straight but you control your fate! Avoid Auto-Pilot Induced Casualties
02-16 04Apr2016 All Worn Thin: Vibration Abrasion, a "Short" Summation
11-15 09Nov2015 All Dried not Fried; Laundering Safety Issues
06-15 27May2015 All Fire Extinguishing Systems Ready: Are you sure?
01-15 24Feb2015 OSV; DP Vessels BSEE/USCG Joint Safety Alert: Dynamic Positioning System Failures on Offshore Supply Vessels Engaged in Oil and Gas Operations in the U.S. Outer Continental Shelf
15-14 12Nov2014 All Accidental Release of CO2 System! Importance of Design and Testing of Emergency System Controls
LL-02-14 09Jul2014 All Battery Weight Varies: Use proper replacement parts on all Emergency Equipment
LL 01-14 09Jul2014 OSV; All It's the Seemingly Minor Items... that sometimes can create a catastrophe
08-14 20May2014 OSV; DP Vessels BSEE/USCG Joint Safety Alert: Dynamic Positioning System Failures on Vessels other than Mobile Offshore Drilling Units (Vessels)
08-13 30Aug2013 All Confined Space Entry Dangers: Understanding Hazards
05-13 17Jun2013 MODU  Recent Failures of Dynamic Positioning (DP) Systems on Mobile Offshore Drilling Units
03-13b 30Apr2013 All Surge Protective Devices onboard Vessels
01-13 21Mar2013 All Counterfeit Portable Fire Extinguishers
02-11 14Feb2011 All Air Receivers and Relief Valves: A reminder that shouldn't be necessary!
01-11 31Jan2011 All Inspection of Quick-Closing Valves [Fuel Valves]
10(b)-10 21Dec2010 All Simple Failures Render CO2 System Inoperative [Fixed CO2 Fire Suppression System]
10(a)-10 21Dec2010 All Wrong Directions: A Recipe for Failure [Fixed CO2 Fire Suppression Systems]
02-03 23Mar2003 Fixed Platforms; FOFs Joint MMS/USCG Safety Alert: Deck Openings
02-98 16Jun1998 All Wire Rope Failures


AUGER Lifeboat No. 6

This incident occurred on FPS AUGER, a Tension Leg Platform (TLP) at Garden Banks Block 426 in the Gulf of Mexico, on June 30, 2019 and resulted in the untimely deaths of two personnel and injury to a third person. The incident occurred when Lifeboat 6 released from the fall cables during recovery after a routine launch and perceived U.S. Coast Guard requirements. Our condolences go to the families of those crewmembers that lost their lives during this incident.

The USCG formal investigation has been completed and endorsed by the District Commander, Coast Guard District Eight, but is still under review for Commandant actions at USCG Headquarters. The information on this page is associated with USCG Safety Alert 03-20 that was issued as a result of findings/concerns during the investigation, until such time that the Report of Investigation for this incident is made available to the public.

Safety Alert Summary

Photo of damaged control cable with broken conduit and linerSafety Alert 03-20 was published on February 5, 2020, after observations and testing revealed that a damaged/compromised hook control cable could fail in a manner that would allow a hook to open, essentially defeating the safety features that are incorporated into the design of a lifeboat release gear system. Prior failures with these types of control cables were assumed to be 1) a seized cable or 2) a severed cable. Shell Offshore, Inc. and USCG investigation team members observed that another failure mode was possible, as summarized in the safety alert:

"During post-incident laboratory testing the Coast Guard observed that if a control cable, similar to that shown in the image above, is damaged all the way through the outer layers, leaving the traveling inner member exposed, forces applied directly on the separated outer layers can cause the traveling inner member to pull on each of its ends. As the separated outer layers pull apart, the cable’s end rod at the hook can move, which in turn can rotate the locking shaft inside the hook. If the locking shaft rotates enough, the hook can release, even without an operator touching the release handle or overriding the interlocks. The Coast Guard has no indication that a damaged control cable alone can cause a hook to release or open on-load. However, the Coast Guard believes that damaged control cables pose a significant safety risk and should be replaced before attempting to launch a boat that incorporates control cables into the on-load release capability of a hook release system."

Presentation and Videos

Safety Alert 03-20 and the observations from CG-testing were presented during the September 30, 2020 National Offshore Safety Advisory Committee (NOSAC) meeting (video teleconference). The presentation and individual videos (mp4 format) are available below. Note that the presentation is a large file size (30mb), as the videos are embedded within the presentation, but can also be downloaded separately. Microsoft PowerPoint or a compatible viewer will be needed to view the presentation.

  • Introductory Video: Separated Cable Conduit (2.5mb)
    • This video shows what happens if the conduit is extended between the fixed connections at the release unit and the hook. See the graphics below for details on the various control cable conditions and the related effects on the hook.
  • Video #1: Conduit/Liner Separation (4.2mb)
    • Testing video 1 documents U.S. Coast Guard testing and the observations upon conduit liner separation.
  • Video #2: Subsequent Cycling (after conduit/liner separation; 5.6mb)
    • Testing video 2 documents the observations of open and close cycling of the release unit after the control cable conduit (and liner) have separated.
  • Video #3: Effect of an Increasing Load (12.3mb)
    • Testing video 3 documents the effect of additional loading to a hook with the locking shaft in a partially-closed (i.e., almost-open) position due to a compromised control cable/separated conduit. As shown in the video, additional load can force the locking shaft to open and release the hook, but it has to be very close to the open position to be forced open. USCG testing showed that if the compromised control cable leaves the locking shaft in a position closer to the fully closed position, the locking shaft will not be forced open under increasing load.

Discussion of Observations and Findings

Please note that testing was conducted on Schat-Harding LHR-series release gear. As such, the descriptions of components and operation relate to that make and series of release gear. Other manufacturer's release gear designs, functions and component terminology could vary, but the ​control cable is the area of focus in these findings.

Generally, the system works in the following manner:
When closing or resetting a hook, an operator positioned at the release unit pulls up on the safety lock and pushes forward on the control handle, locking it into place. Consequently, the end rod on the hook extends. This extension causes the hook's locking shaft to rotate to the closed or locked position. When opening the hook, the opposite actions and forces apply.

A previously unknown vulnerability in the system was identified during the course of the investigation that was referenced in Safety Alert 03-20: if all three layers of the conduit of a hook cable separate or break during a reset, the locking shaft may not return to the fully-closed position. Rather, the locking shaft may come to rest at an "almost-open" position (see the various positions on the following graphics). In such a position, the hooks can support the weight of the boat and its occupants during retrieval. However, testing has revealed that an additional load can cause the locking shaft to rotate to the open position, releasing the hook.

Release Mechanism Arrangement

A typical dual-fall/hook release mechanism is comprised of two hooks, a hook release unit (located inside the lifeboat adjacent to the helm), a hydrostat unit, and three control (push-pull) cables. One control cable connects the hook release unit to the aft hook, the second control cable connects the release unit to the forward hook, and the third control cable connects the release unit to the hydrostat unit.

Graphic depicting a typical dual-fall lifeboat release gear arrangement

Closed/Reset Position

This graphic shows the positions of the control cable and the hook when the release unit handle is in the closed, or reset, position.

Open/Released Position

This graphic depicts the actions of the control cable and the hook when the release unit handle is moved into the open, or released, position.

Closed/Reset Position with compromised cover and steel layers

With the conduit cover and steel reinforcement compromised but the liner still intact, the system continues to function. In this condition, the liner is subjected to compression and tension forces that correspond to the open and close motions of the release handle that is transmitted through the control cable.

Closed/Reset Position with separated conduit (broken liner)

The conduit tends to separate after the liner breaks. This separation causes the conduit to lengthen and results in the inner member moving the locking shaft arm toward the open position. During testing, it was observed that the:

  • liner separated during the closing motion of the release handle (the liner is under tension during this motion);
  • locking shaft stopped rotating toward closed when the liner separated and remained in a partially-closed position; and
  • conduit separated during the remaining closing action of the release handle (less resistance require to separate the conduit than to rotate the locking shaft).

Effects of Increasing Load with a separated conduit

Testing confirmed that the locking shaft can be in a partially-closed position that will support the weight of the boat and occupants, but can rotate to the open position with an increasing load/additional weight (such as the additional load that can be imparted to the hooks as a boat is pulled against the davit bumpers).

Close/Reset Position with separated conduit after additional cycling

Additional cycling (opening and closing) of the release handle during testing showed that the cable conduit would separate before any rotation was transferred to the locking shaft. This condition leaves the hook in an open position that will not support any weight.

USCG Recommendations

Based on these observations, the USCG strongly recommends the following in Safety Alert 03-20:

  • Conduct thorough inspections of control cables between the release handle station and release hooks;
    • Inspect any other similar cables communicating between the release station and the hydrostatic interlock, if installed, and
    • Look for current damage and for potential hazards or other conditions that might compromise the cables in the future;
  • Photo showing an in-service (at the time it was taken) control cable with a compromised conduit (outer layers)Replace cables that show signs of wear or damage to any layers (photo to the right shows a release mechanism control cable that was in service (at the time the photo was taken) with a compromised conduit);
  • Implement an inspection regime that allows for cable damage to be identified and replace cables identified to need replacement in a timely manner.
  • Consult the lifeboat and release mechanism operations manual(s) prior to conducting launch and recovery drills.

The safety alert also noted that:

  • Photo of a Palfinger Marine Safety pins (photo to the right shows a Palfinger Marine "Training Lock" installed in a LHR-series hook) can be used during drills to prevent the hook-locking shaft from rotating, when they are approved as part of the release mechanism;
  • Although safety pins may provide an extra level of safety during drills and training, operators should ensure that lifeboats are stowed in the "ready to launch" condition without safety pins in place; and
  • Operators should ensure that lifeboat crews understand that safety pins will prevent a lifeboat from releasing from the fall wires during a real emergency if they are not removed after routine training evolutions or maintenance.