Classification
- Incident Type: Structural Failure
- Severity: High
- Evidence status: The U.S. Coast Guard Marine Board identified construction, weather, and loading as material factors in the hull-girder failure.
Vessel Details
| Field | Value |
|---|---|
| Vessel Name | Fort Mercer |
| Vessel Type | Tanker |
| Flag State | |
| IMO Number | |
| Official Number | 24881 |
| Gross Tonnage | 10266 |
| LOA (m) | 153.30 |
| Breadth (m) | 20.73 |
| Bollard Pull (t) | |
| Power (kW) | |
| Owner/Operator | Trinidad Corporation |
| TEU | |
| Year Built | 1945 |
| Crew Size | 43 |
Incident Details
| Field | Value |
|---|---|
| Date | 1952-02-18 |
| Location | Approximately 27 miles east of Pollock Rip Light Vessel, off Cape Cod, Massachusetts, United States |
| Coordinates | 41.6808, -69.9533 |
| Region | Atlantic Ocean |
| Fatalities | 5 |
| Injuries | |
| Missing | 0 |
| Cargo Loss | Oil leakage from the No. 5 tank; quantity unresolved |
| Direct Damage | Hull girder failure broke the tanker into bow and stern sections; the bow later sank. |
| Economic Damage | |
| Insured Loss | |
| Salvage/Cleanup Cost |
Key facts
- Fort Mercer was carrying a full cargo of No. 2 fuel oil and kerosene from Norco, Louisiana, toward Portland, Maine when the hull began cracking during a severe storm.
- The official Marine Board timeline records cracking and oil leakage at approximately 08:10, further failures at approximately 10:30 and 11:40, an SOS at 11:58, and complete hull failure at approximately 12:05.
- The hull failed near frame 59 in way of No. 5 cargo tank. Nine people were on the bow and 34 on the stern; five bow crew members died and four were rescued by Coast Guard cutter Yakutat.
- The Marine Board attributed the casualty to brittle fractures associated with construction and welding, low-temperature notch sensitivity, heavy seas, and loading that increased sagging stresses. It found no contributing incompetence, misconduct, or regulatory violation by the master or crew.
Narrative
Fort Mercer, a 10,266-gross-ton T2-SE-A1 steam tanker built in 1945, was carrying No. 2 fuel oil and kerosene from Norco, Louisiana, to Portland, Maine. On 18 February 1952 the tanker was approximately 27 miles east of Pollock Rip Light Vessel, off Cape Cod, in gale-force winds and heavy seas. The vessel had 43 persons aboard.
The Marine Board report records a sharp crack and oil leakage at approximately 08:10. Further cracking occurred around 10:30 and 11:40, with oil escaping from the starboard side near No. 5 cargo tank. At 11:58 the tanker sent an SOS reporting that its hull was splitting. At approximately 12:05 the hull girder failed near frame 59, and the tanker broke into bow and stern sections.
Nine people were on the bow and 34 on the stern. The stern section remained operable and ultimately made port safely after assistance and towing. The bow section became increasingly dangerous as it rode low at the after end. One crew member was washed overboard while the bow crew moved toward the forecastle, and four others were lost during the attempted rescue. Coast Guard cutter Yakutat and its boats and rafts rescued the remaining four bow survivors. The official casualty accounting is five fatalities and 38 survivors, with no persons left unaccounted for.
The Marine Board identified construction and welding features, low temperature, heavy seas, and the loading distribution as material factors. Low temperature increased the steel's notch sensitivity, while empty or nearly empty end tanks and heavier weight amidships increased sagging stresses. The Board found that the vessel was properly manned and that the master followed good seamanship. The stern was towed to port, while the bow was later sunk by gunfire on 20 February because it was a navigation hazard. The quantity of oil spilled and the economic and environmental losses were not established in the reviewed sources.
Sequence of events
| Date/time | Event |
|---|---|
| 1952-02-18 08:10 | A sharp crack and oil leakage were observed near the No. 5 cargo tank. |
| 1952-02-18 10:30 | Further cracking occurred as the tanker remained in severe weather. |
| 1952-02-18 11:40 | A third major crack was heard and oil was seen escaping from the starboard side. |
| 1952-02-18 11:58 | Fort Mercer sent an SOS reporting that the hull was splitting. |
| 1952-02-18 12:05 | The hull girder failed near frame 59 and the tanker broke into bow and stern sections. |
| 1952-02-19 | Coast Guard operations rescued the four surviving members of the bow section; the stern survivors were assisted and the stern was taken in tow. |
| 1952-02-20 16:50 | The bow section was sunk by gunfire because it was a navigation hazard. |
Contributing factors
| Factor | Evidence status | Description |
|---|---|---|
| Brittle fracture associated with construction and welding | Confirmed finding | The Marine Board identified brittle fractures beginning near a defective weld and propagating through the hull structure around frame 59. |
| Low temperature and heavy seas | Confirmed finding | The Board found that low temperature increased notch sensitivity and that the severe storm and heavy seas materially aggravated the structural stresses. |
| Loading distribution and sagging stresses | Confirmed finding | Empty or nearly empty tanks at the ends and heavier weight amidships increased buoyancy differences and sagging stresses during the storm. |
Investigation
The United States Coast Guard Marine Board of Investigation reviewed the casualty and issued findings in September 1952. It concluded that the hull-girder failure involved brittle fractures associated with the vessel's construction and welding, low-temperature notch sensitivity, heavy seas, and loading distribution. The Board found the vessel properly manned and the master compliant with good seamanship, with no incompetence, misconduct, unskillfulness, or regulatory violation contributing to the casualty. It recommended further study of T2 loading and ballasting, additional crack arrestors and longitudinal strength members, and an emergency ladder arrangement near the bridge.
References
- U.S. Coast Guard Marine Board report: Fort Mercer structural failure
- U.S. Coast Guard cutter Yakutat history
- U.S. Coast Guard Gold Lifesaving Medal record
- U.S. Coast Guard history timeline
- Second Circuit decision involving Fort Mercer claims
- Naval Institute: Triumph and Tragedy off Cape Cod
- Cleburne Times-Review contemporary report