Secure and safe

01 Jul 2004

Though the prime cause of the accident was the vessel?s grounding, the tragic capsize of the 28,100 DWT bulk carrier Rocknes off Bergen in January this year, with the loss of a number of lives, highlighted once again the dangers inherent in poor cargo stowage arrangements. More recently in April, the Malaysian cargo ship Genius Star VI sank in heavy seas between Haldia and Kolkata in the Bay of Bengal with the loss of two lives, though 15 were saved. The vessel was carrying 6,000 tonnes of logs, secured by chains, from Malaysia to Kolkata. Apparently one of the chains, which was old and rusty, snapped and the logs rolled to one side of the cargo hold, breaching the shell plating and causing the ship to list and subsequently sink.

A problem with timber
The particular problem with timber as a cargo was investigated by the UK?s Marine Accident Investigation Branch (MAIB) in 2003 following a number of accidents involving timber deck cargoes reported to the MAIB since it was set up in 1989. These accidents did not give cause for particular concern until 2002, when several occurred in quick succession.
As a result, eight accidents that involved timber deck cargoes, and which came to the attention of the MAIB in the years 2001 and 2002, were examined. All concerned vessels loaded with sawn timber travelling from a Baltic or north Russian port and destined for ports in Great Britain or Ireland, or were passing Britain en route to the Mediterranean. All the incidents occurred in heavy weather and most during the autumn. Each case involved a transverse shift of the timber deck cargo; however there is no evidence that longitudinal movement of timber cargo posed a problem.
All of the incidents related to the shifting of packaged timber deck cargoes and, perhaps surprisingly, none concerned the carriage of logs. All involved the consequences of transverse movement of cargo in heavy weather. In the large majority of cases, the initial movement was caused by waves hitting the stow, and this was exacerbated by the movement of the vessel in rough seas. In each case, a failure in the methods of stowing and lashing the cargo was identified as contributory.

A Dutch solution
The Dutch company MaxCargo BV is a specialist in cargo securing with particular expertise in short-sea and deep-sea shipping carrying break-bulk cargoes, forest products such as timber and paper rolls, and Ro-Ro vessels. It has a background in ship operations and management and this expertise has enabled it to develop and improve a range of cargo-securing systems that are certified according to IMO and class requirements. Its lashing systems are supplied with class certificates from, for example, Lloyds Register, Germanischer Lloyd, Bureaux Veritas, ABS, DNV etc.
MaxCargo produces a variety of specialised cargo securing products for different applications:
l For break-bulk: AirMax dunnage bags, slings for timber, paper rolls etc., as well as AirMax dunnage tubes for reefers
l For bulk: SealMax inflatable seals for moveable bulkheads, and airbags for void spaces
l For RoRos: RoRoMax trailer lashings and car lashings
l For timber cargoes: TurtleMax timber deck cargo web lashings up to 500kN
l Lifting: SlingMax lifting slings with SWL of up to 300 tonnes.
According to MaxCargo, it is a fact that the lashing and securing of cargoes, and particularly deck cargoes, can become a matter of trial and error, which is not a professional way of safeguarding cargo. Those responsible for cargo securing must have a fundamental knowledge of lashing systems under different loads. It is essential that all who are directly engaged in the transport of goods on ships should understand the fundamental principles of ship movement and accelerations.
Hence the company has introduced its Cargo-Care training centre, which covers all aspects of cargo-handling and securing, including knowledge of lashing systems, a ship's motions, working with a ship's loading computer, etc.
One particularly important aspect is an understanding of the forces on a ship in a seaway and the forces working on the cargo securing systems. To provide a better understanding, MaxCargo has also developed SafetyMax, a system which visualises real-time accelerations and calculates the forces working on ships, cargoes and lashing systems. The system is able to predict the accelerations when no action is taken. Monitoring assists the ship's management team to compare the calculated GM with the actual in order to determine stability problems at a very early stage.
Another of the company?s products is OrangeMax, a portable measurement system and data-logging system to monitor accelerations, motions and conditions during the handing and transport of vulnerable and/or valuable cargoes

Automated loading
system for Terra Marique The multi-purpose pontoon heavy lift barge Terra Marique, built for UK operator Robert Wynn and Sons and described in our June issue, is fitted with a ShipLoad system with several unique add-ons, that has been developed by the Norwegian company Lodic AS. Lodic is one of many new spin-offs from the high-tech cluster formed by the SINTEF Group and the NTNU (University of Technology and Science) in Trondheim.
Terra Marique is a unique vessel, being a Ro-Ro vessel equipped with an elevating driveway, but also able to handle float-on/float-off cargo or daughter vessel. This feature is complemented by an advanced monitoring and control system that can control the three driveway panels individually, will compensate for tidal movements during Ro-Ro operations, and will operate the water ballast (WB) system automatically. The latter function is handled by a ShipLoad unit that is interfaced with the WB control and monitoring system.
A measure of the complexity of this task, and how essential this system is, can be seen in a typical cargo operation. During the loading of a single trailer from the quay to the onboard roadways, a total of 20 to 30 WB operations may be required in order to keep the vessel within the floating position envelope specified by the operator. In the case of a corresponding manual operation would have required a great number of loading conditions and steps to be calculated by the barge master.
In addition to the automated WB handling feature, Lodic AS has also delivered an integrated sea-fastening module with the ShipLoad. This enables the barge crew to rapidly compute basic data for the lashing requirements, and hence also keep the lashing work to the absolute minimum under the prevailing rules and regulations.

Developed from
technical research
The developer, Lodic, originates from the Norwegian Marine Technology Research Institute (MARINTEK). Ever since the 1970s, MARINTEK has made software for hydrostatics and stability calculations for ships and floating offshore structures. These applications have been both pure onboard solutions (Loading Instruments) as well as design/analysis tools for design studies and preparation of documentation for class or statutory approval.
As MARINTEK is primarily a research and development institution, the commercial potential of the products could not be properly exploited within the system. It was thus decided to spin off the department handling the software development and related services to a new company ? Lodic AS ? which continues to develop MARINTEK products and provide high quality software and services. n

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