Classification
- Incident Type: Tow capsize
- Severity: High
- Region: North Sea
Vessel Details
| Field | Value |
|---|---|
| Vessel Name | Ikar |
| Vessel Type | Tug |
| Flag State | Poland [PL] |
| IMO Number | 6519302 |
| MMSI | 261000620 |
| Call Sign | SPG 2521 |
| Gross Tonnage | 171 |
| LOA (m) | 29.97 |
| Breadth (m) | 7.54 |
| Bollard Pull (t) | 15.37 |
| Power (kW) | 882 |
| Owner/Operator | Jan Stępniewski i Ska Sp. z o.o., Gdynia |
| Year Built | 1966 |
| Crew Size | 6 |
Siebengebirge was a German passenger and car river ferry built in 1969 for service on the Rhine. It was unmanned during the tow.
Incident Details
| Field | Value |
|---|---|
| Date | 2017-04-30 |
| Location | North Sea west of Texel, Netherlands |
| Coordinates | 53.1142, 4.5627 |
| Region | North Sea |
| Fatalities | |
| Injuries | |
| Missing | |
| Economic Damage |
Key facts
- Ikar departed Rotterdam with the unmanned Siebengebirge at 15:55 on 29 April 2017, bound for Hanko, Finland.
- The crew observed the ferry heeling to starboard and trimming by the bow early on 30 April.
- Siebengebirge capsized at 06:25 and was fully submerged by 07:40 at 53°06.85′ N, 004°33.76′ E.
- The report identified flooding of bow compartments and water on the foredeck as the cause of the capsize and sinking.
- Ikar sustained no damage apart from loss of the towline; Siebengebirge was lost.
Narrative
Ikar arrived in Rotterdam on 26 April 2017 to tow the former Rhine ferry Siebengebirge to Hanko, Finland. Contractors removed its loading platforms, closed openings left by the work, secured wheelhouse windows, and fitted chain bridles. An insurer's consultant inspected the towing arrangement and issued a Towage Approval Certificate after the bridles were load-tested to about 19 tonnes. The certificate set limits of 12 m/s wind and 1.5 m significant wave height. The investigation later found that this certificate did not replace required voyage documentation or port permission. (PKBWM Final Report 24/17, printed pp. 14-16, 20-24)
The unit left the berth at 15:55 on 29 April with a pilot and assisting harbour tug. The harbour tug was released at 18:10, the pilot disembarked after Hook of Holland at 19:10, and Ikar continued at about five knots with 140 metres of towline. Early the next morning, the crew noticed that Siebengebirge was heeling to starboard. Ikar reduced speed and notified the Dutch Coast Guard, then turned toward Den Helder. Daylight showed a pronounced bow trim. At 06:25 the ferry capsized; at 07:40 it sank in about 20 metres of water. Ikar cut the towline at 08:30 and remained near the wreck as directed. (PKBWM Final Report 24/17, printed pp. 4, 16)
The Commission found that Siebengebirge had been designed for closed and inland waters. Its external closures were only splash-proof, leaving paths for water to enter internal spaces. The ferry's stability had not been checked before departure, despite stability documents being available aboard. The report also questioned the declared draught and noted that the interior was not inspected after the bridle load tests. (PKBWM Final Report 24/17, printed pp. 17-26)
In the Commission's simulations, deck water alone, or flooding a single bow compartment with deck water, did not capsize the ferry. Flooding compartments 1 and 3 together with about 33 tonnes of deck water produced capsize in the model. This was a modeled scenario rather than an established measurement of the actual flooding, and the simulations excluded pitching and rolling. The investigation attributed the loss to flooding of bow compartments and water on the foredeck; its reconstruction described progressive flooding through leaking closures after capsize. Authorities later permitted Ikar to leave the wreck area, and it reached Gdynia on 4 May. (PKBWM Final Report 24/17, printed pp. 4, 16-17, 26, 47-50)
Sequence of events
| Date/time | Event |
|---|---|
| 2017-04-29 15:55 local | Ikar and Siebengebirge departed the Rotterdam berth. |
| 2017-04-29 19:10 local | The pilot left after Hook of Holland and sea towage began. |
| 2017-04-30 early morning | The crew observed starboard heel and increasing bow trim and turned toward Den Helder. |
| 2017-04-30 06:25 local | Siebengebirge capsized. |
| 2017-04-30 07:40 local | The ferry was fully submerged. |
| 2017-04-30 08:30 local | Ikar cut the towline. |
| 2017-04-30 08:55 local | Ikar anchored near the wreck as directed. |
| 2017-04-30 | Authorities permitted Ikar to leave the wreck area after document checks; the report gives conflicting release times. |
| 2017-05-04 11:35 local | Ikar berthed in Gdynia. |
Contributing factors
| Factor | Evidence status | Description |
|---|---|---|
| Water ingress | Confirmed finding | Ineffective closures allowed bow compartments to flood while water accumulated on the foredeck. |
| Vessel suitability | Confirmed finding | The inland ferry was not adapted for an exposed sea voyage. |
| Stability assessment | Confirmed finding | The ferry's stability was not checked before towage despite documents being available. |
| Voyage authorization | Confirmed finding | Required documentation and Rotterdam towing permission were absent; the Towage Approval Certificate was treated as authorization. |
Investigation
The Polish State Marine Accident Investigation Commission published Final Report 24/17 in February 2019. It recommended that Ikar's operator issue instructions requiring masters to hold the necessary towage documents and require agents to provide applicable port rules and permission requirements. (PKBWM Final Report 24/17, printed pp. 50-51)
References
Related
- Ikar
- North Sea
- Tug Incident Classification
- Polish State Marine Accident Investigation Commission