Classification
| Field | Value |
|---|
| Incident Type | Other |
| Severity | Low |
| Investigation Body | DMAIB |
Vessel Details
| Field | Value |
|---|
| Vessel Name | Amber II |
| Vessel Names | Amber II; Sea Worker |
| Vessel Type | Tug |
| Flag State | Malta [MT] |
| IMO Number | |
| Gross Tonnage | |
| LOA (m) | |
| Breadth (m) | |
| Other Involved Vessels | Sea Worker, manned jack-up platform |
Incident Details
| Field | Value |
|---|
| Date | 2016-01-27 |
| Region | North Sea |
| Location | North Sea, about 6 nautical miles west of Jutland |
| Coordinates | 56.5000, 7.8000 |
| Fatalities | 0 |
| Injuries | 0 |
| Missing | 0 |
| Direct Damage | |
| Economic Damage | |
Key facts
- Amber II departed Frederikshavn on 24 January 2016 towing Sea Worker toward Esbjerg.
- The tow was struggling to make speed because of wind, waves and current.
- The towing pennant broke on 27 January, three days after departure.
- Amber II did not succeed in reconnecting with the platform using the emergency towing equipment.
- Sea Worker's 15-person crew was evacuated before the platform grounded; no casualties were reported.
Narrative
Amber II departed Frederikshavn on 24 January 2016 towing the Danish manned jack-up platform Sea Worker toward Esbjerg. The tug was an oceangoing anchor-handling tug operated by Polskie Ratownictwo and had 12 crew members. On 27 January, the tow was in the North Sea about six nautical miles west of Jutland and was struggling to make speed in wind, waves and current. At about 00:30, the towing wire between Amber II and Sea Worker became slack and the crews established that the tow connection had broken. Amber II attempted to reconnect using the emergency towing arrangement, but the effort did not succeed. As Sea Worker drifted uncontrollably toward shore, its 15-person crew prepared to abandon the platform because remaining aboard during the grounding sequence was considered dangerous. The crew entered a life raft and were transferred to the rescue boat, with additional evacuation by rescue boat and helicopter. Sea Worker grounded after the evacuation. DMAIB found it likely that the towing pennant broke because of sudden overload at an unfortunate angle for the wire-rope end. Wind, waves, current, the tug heading into the weather, high waves with short roll periods and constant engine power all contributed to the loading. The emergency towing equipment was not successfully deployed, and the report notes that the arrangement and procedures were not suited to quickly restoring control. The reviewed source records zero fatalities, injuries and missing persons and does not provide normalized hull particulars or a monetary loss estimate.
Sequence of events
| Date/time | Event |
|---|
| 2016-01-24 | Amber II departed Frederikshavn towing Sea Worker toward Esbjerg. |
| 2016-01-27 about 00:30 | The towing pennant broke in the North Sea west of Jutland. |
| 2016-01-27 | Amber II failed to reconnect using the emergency towing arrangement. |
| 2016-01-27 | Sea Worker's crew was evacuated before the platform grounded. |
Contributing factors
| Factor | Evidence status | Description |
|---|
| Heavy weather and current | Confirmed finding | Wind, waves and current made it difficult for the tow to maintain speed and increased towing loads. |
| Sudden overload at the towing-pennant end | Confirmed finding | DMAIB found it likely that the pennant broke because of overload at an unfavourable angle. |
| Emergency tow not established | Confirmed finding | Amber II's attempt to reconnect with the emergency towing equipment did not restore control of Sea Worker. |
Investigation
The Danish Maritime Accident Investigation Board investigated the loss of tow. Its report identifies the broken towing pennant as the main accident event and considers sudden overload, caused by the weather, sea state, current, tow movements and constant engine power, the likely reason for the fracture. The report also examines the emergency towing arrangement and the failure to reconnect before Sea Worker drifted ashore. It confirms that the platform crew was evacuated without fatalities, injuries or missing persons and does not provide a monetary loss estimate.
References
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