Summary
On 28 December 2015, the Maltese registered general cargo Hagland Borg berthed at the port of Karlshamn in Sweden. The vessel had to discharge a cargo of timber, which was loaded from Helland, Norway and then load grain for Ventspils in Latvia.
By 2015 on 28 December, the discharge of timber had been completed and at 2200, the crew members were making the necessary arrangements to move the portable dividing bulkhead in the only cargo hold fitted on the vessel.
The bulkhead was fitted with a wheel arrangement on port side and another one on starboard side at the top edges (Figure 1). Two recesses were fitted to the portable bulkhead, which provided access to hydraulic jacks to be fitted (Figure 2).
Figure 1: Bulkhead wheel arrangement (in the open position)
The jacks exerted hydraulic pressure against the bulkhead, creating a resultant upward force which lifted the bulkhead. With the bulkhead clear from the tank top, the wheels could be rotated outwards and locked in position on the hatch coaming (Figures 1 and 3).
Figure 2: Hydraulic jacks in position to lift the bulkhead
Figure 3: Wheels locked on the cargo hold coaming
With the wheels fitted and locked in position, the jacks’ hydraulic pressure could then be released and both jacks removed. The bulkhead would remain suspended on the wheel arrangements, which therefore, took the full weight of the bulkhead. In this position, the clearance of the lower part of the bulkhead from the tank top would be in the region of about 5 cm. The portable bulkhead is transferred to the desired position along the length of the cargo hold, by connecting a link to the cargo hold hatch covers (Figure 4). Once the portable bulkhead reaches the desired position, it is locked by side securing bolts. Hydraulic jacks are used again to lift it and retract the wheels. The hydraulic jack pressure is then bled in a controlled manner so that the bulkhead will eventually rest on the tank top in the cargo hold.
Figure 4: Link between the hatch cover and the portable bulkhead wheel arrangement
On this particular occasion, the bulkhead was raised as per normal procedure and the wheel arrangements extended on both sides. The hydraulic jacks were removed and the shifting operation initiated. Initially, after the wheel arrangements were linked to the cargo hold hatch cover, the system could not move and the crew members decided to use the on board compact loader (Bobcat), to move the hatch covers.
The intervention was successful and the cargo hatch covers were moved, hence shifting the portable bulkhead. However, the bulkhead was only shifted by a few metres, when the system came to a halt.
A closer inspection of the system revealed that the wheel on the port side of the portable bulkhead had slipped of its shaft. As a result of this, the bulkhead dropped by about 3.5 cm. It was also observed that the bulkhead was not at right angles to the tank top but was slightly tilted towards the direction of movement.
Seeing this, the crew members decided to lift the bulkhead again with the hydraulic jacks. The plan was to provide enough clearance to allow them to reinstall the wheel. In order to get the bulkhead in an upright position, the compact loader was used. At the same time, the AB was operating the hydraulic jack.
The bulkhead was eventually lifted to create enough clearance for the wheel to be reinserted. At this stage, without any warning, the bulkhead tilted backwards and fell from the hydraulic jack. The hydraulic jack was also displaced and the bulkhead landed on it and consequently it toppled on the AB’s foot (Figure 5), although bearing partial weight of the bulkhead.
Figure 5: A crew member showing how the injury happened (during the accident, the portable bulkhead fell on the hydraulic jack)
Cause of the Accident
The immediate cause of the accident was the tilting of the bulkhead at a vulnerable time when the structure was being supported by the hydraulic jacks and not secured by its securing bolts. The operation of the hydraulic jacks necessitated at least one crew member to be in close proximity of the hazard.
At the time of the accident, the portable bulkhead was not secured because it was in an intermediary position. This was considered to be a barrier system which was missing during a high risk operation.
Actions Taken
- Inspections routines on the portable bulkhead were implemented as part of the Company’s electronic maintenance system;
- Prior to rectification of defects which would necessitate shifting the bulkhead, the crew members are being instructed to ensure that it was upright and that there were no external moments acting on it before the shifting operation was commenced;
- Routines for risk assessments on board Company vessels were enhanced;
- A new procedure has been introduced which requires that in cases of similar damages to the wheels and when it is not possible to prevent the bulkhead from moving, a shore crane is hired to lift the moveable bulkhead in a safe manner.
Recommendations
Taking into considerations the actions taken by the Company, no recommendations were made as a result of the safety investigation
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Source: Transport Malta
