Classification
| Field | Value |
|---|
| Incident Type | Hydrodynamic Interaction |
| Severity | Medium |
| Investigation Body | Federal Bureau of Maritime Casualty Investigation (BSU) |
Vessel Details
| Field | Value |
|---|
| Vessel Name | WILHELMINE |
| Vessel Type | Tug |
| Flag State | Germany [DE] |
| IMO Number | 8007133 |
| Gross Tonnage | 207 |
| LOA (m) | 26.39 |
| Operator | Petersen & Alpers |
Incident Details
| Field | Value |
|---|
| Date | 2008-04-04 |
| Location | Tollerort, Port of Hamburg |
| Region | Germany |
| Coordinates | 51.8676, 12.5786 |
| Fatalities | |
| Injuries | |
| Missing | |
| Direct Damage | WILHELMINE sustained denting and deformation at the stern, with water ingress; PAVEL KORCHAGIN sustained scratch marks to its port bow. |
| Economic Damage | |
Key facts
- At 20:26 local time on 4 April 2008, WILHELMINE broached ahead of the Russian general-cargo ship PAVEL KORCHAGIN while its hawser tripping line was being hauled up.
- The tug struck PAVEL KORCHAGIN's bow slightly aft of amidships on its port side, listed heavily to starboard and took water over the deck and through port engine-room ventilators.
- An engineer went overboard during the event, held a tyre fender, and reboarded with assistance; he was subsequently taken to hospital as a precaution.
- The BSU calculated the vessels' speed through the water at about 9.2 knots during the line-connection attempt.
Narrative
On 4 April 2008, WILHELMINE had been ordered to act as the forward tug for the Russian general-cargo ship PAVEL KORCHAGIN, which was bound for shed 62 in Hamburg's Südwesthafen. The tug approached the ship's bow from starboard to establish the towing connection. A trainee helmsman manoeuvred under the tug master's supervision while the engineer worked on the stern deck to connect the tripping line.
At 20:26 local time, as the tripping line was being hauled up, WILHELMINE came extremely close to the ship. A Full Ahead manoeuvre and counter-steering did not prevent the tug from broaching across PAVEL KORCHAGIN's bow. The ship made contact with WILHELMINE's port side slightly aft of amidships. The tug heeled heavily to starboard, its deck was flooded, and two people on the bridge were knocked down. The engineer went overboard from the stern but held onto a tyre fender until the crew recovered him by ladder. He was taken to hospital as a precaution.
WILHELMINE subsequently came clear, righted itself and moved to PAVEL KORCHAGIN's port side. The ship's engine was stopped to avoid more serious damage. The initial line connection was released; tug BUGSIER 14 later took the tripping line and the towing connection was completed. BSU recorded scratch marks on PAVEL KORCHAGIN's port bow. On WILHELMINE, the port stern bulwark and internal structures were dented or deformed, and water had entered through port engine-room ventilators. The tug later received permission to proceed to Rendsburg for repair.
Sequence of events
| Date/time | Event |
|---|
| 2008-04-04 20:22 local | WILHELMINE approached PAVEL KORCHAGIN's bow from starboard and caught the heaving line. |
| 2008-04-04 20:25 local | Radar recorded PAVEL KORCHAGIN at 8.2 knots over ground shortly before the contact. |
| 2008-04-04 20:26 local | As the tripping line was being hauled up, WILHELMINE broached ahead of PAVEL KORCHAGIN and was struck by its bow. |
| 2008-04-04 20:27 local | WILHELMINE had moved to the ship's port side after coming clear. |
Contributing factors
| Factor | Evidence status | Description |
|---|
| Hydrodynamic interaction | Confirmed finding | The BSU found that the tug was operating close to the ship's bow in a restricted waterway, where interaction effects were pronounced and could draw the tug across the bow. |
| Speed through the water | Confirmed finding | The BSU calculated a speed through the water of about 9.2 knots. It considered that speed extremely high in shallow water, where interaction forces and moments can be substantially greater. |
| Limited manoeuvring margin | Confirmed finding | At the reported speed, WILHELMINE had little force reserve to maintain separation from the ship during the line-connection manoeuvre. |
| Exact initiating manoeuvre | Suspected | The BSU could not establish whether a manoeuvring error, excessive speed, or insufficient available steering force initiated the loss of separation because no detailed manoeuvre recording was available. |
Investigation
The Federal Bureau of Maritime Casualty Investigation investigated the serious marine casualty in Investigation Report 149/08. It found that WILHELMINE broached during the hazardous line-connection phase near PAVEL KORCHAGIN's bow, in conditions where hydrodynamic interaction was significant. The investigation could not conclusively reconstruct the immediate initiating manoeuvre. BSU recommended that Hamburg port pilots and tug operators review their procedures and risk management, assess operating speeds, and improve communication about where and at what speed towing connections should be made.
References
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