Cargo Stowage Solutions Enhance Payload Capacity


  • MacGregor has retrofitted 100 container ships and offers Cargo Boost service designed to improve the earning potential of existing container ships by offering higher cargo stacking.
  • DP World and SMS group created ‘High Bay Storage system’ where containers are stored in a 11-story rack, creating 200% more capacity and will be unveiled at Jebel Ali Terminal 4 in Dubai Expo 2020.
  • Hoppe Marine’s ‘Flume roll-damping system’ is designed to boost the efficiency of loading and unloading containers and consists of an anti-roll tank installed across 48 ships in its fleet and controlled by software.
  • The software adapts to changes in load and operational conditions and counteracts the roll of the ship by changing the liquid level of the tank and reduces a vessel’s roll by up to 50%.

An increasing number of container vessels are being retrofitted to increase carrying capacity and revenue.

Retrofits on the rise

As operators seek to monetize their ships and boost the amount of cargo stowed, so the number of container vessels undergoing retrofits of their cargo stowage systems has increased.

MacGregor is one company that is benefiting from this trend, having noticed a “big boom” in the need for greater payload capacity, translating into earning potential. It is currently retrofitting vessels with innovative solutions to improve the number of containers that can be carried on board. To date, MacGregor has retrofitted 100 container ships, varying in size from 6,800 TEU to 19,200 TEU.

Cargo Boost service

The company offers a Cargo Boost service, part of its PlusPartner concept, which is designed to improve the earning potential of existing container ships. The upgrades include an individual plan for each vessel, with a focus on improving earnings and efficiency and decreasing emissions per transported unit.

At the heart of the system is the cargo handling arrangement, which said the company, must be looked at holistically along with all elements of the system – the lashing bridge, lashing system, and hatch covers – to create the most efficient and effective cargo system.

Late 2017 and early last year MacGregor carried out its Cargo Boost service on 11 10,000 TEU container vessels owned by Seaspan, known as ‘SAVER 10000s’.

Retrofit enhances flexibility

Seaspan explained the motivation behind the retrofit as the one and the only purpose of a containership is to transport containers, so the cargo system must be considered at every stage of the design process, starting from day one up until delivery and commissioning of the vessel. Thereafter it should be monitored in service to ensure that it remains effective as market conditions change

The market conditions are vitally important to provide vessels with minimized fuel requirements and flexible cargo loading systems, which allow for maximum cargo intake of the available cargo. One must also keep in mind that the cargo profiles are continuously changing, so flexibility is key.

Higher stack weights

MacGregor also deployed its Cargo Boost service on systems on board seven Hapag-Lloyd C-class (Samsung 9,300 TEU series) container vessels in 2018. Key to the project was enabling higher stack weights for 40 ft containers; a sector identified as holding revenue potential.

MacGregor senior naval architect Kari Tirkkonen said the company is focused on improving cargo efficiency and has been looking at ways to allow ships to carry a mix of 20 ft boxes and 40 ft boxes together. Previously they would be carried in separate slots but more and more 40 ft containers are being carried, especially high cubes, and this has created a pressure for cargo systems to be retrofitted to allow the carriage of high cubes/40 ft containers.

Holistic approach

MacGregor’s holistic approach is also applied to newbuilds, with Mr.Tirkkonen noting that the loading system for each vessel should be completed before the building stage to get the best possible configuration. The company is keen on creating the best arrangements for each vessel, lashing bridges, hatch covers, and lashing systems each need to be configured into the system as a whole.

Mr.Tirkkonen advised that container ship operators should not go by the nominal capacity of a vessel when it came to cargo loading. Vessels may have a nominal capacity of say 8,000 TEU, but when loaded they may not reach that number of containers – and not even be close. But if the actual cargo carried is taken into consideration in the software that we use at the design stage, accounting for the size and weight of the cargo and optimizing the vessel’s cargo system to fit this, then utilization rates can be much higher.

Mr.Tirkkonen commented that another benefit of this approach is that loading and unloading in port are also easier. If the cargo-carrying capabilities of a ship are more flexible, then you can reduce re-stowage and moves when in port. If the cargo is not stowed flexibly enough then it might have to be re-stowed during loading/unloading, which is inefficient and time-consuming. There is pressure for cargo systems to be retrofitted to allow the carriage of high cubes/40 ft containers.

Crew and cargo planners to be trained

MacGregor highlights that for the cargo stowage system to be as efficient as possible, the crew on board and the personnel ashore using it must be well trained.

MacGregor master mariner Tero Sairanen said: “Crew and cargo planners really must be trained by MacGregor so that they can use the system properly, explain to other personnel how to operate it and use it wisely to get the maximum benefit from it.”

Revolutionsing technology – High Bay Storage system

A joint venture (JV) between DP World and industrial engineering specialists SMS group has resulted in new technology which will ‘revolutionise’ the way that containers are handled in ports, according to the JV.

The High Bay Storage system was originally developed by SMS group subsidiary AMOVA for round-the-clock handling of metal coils that weigh as much as 50 tons each, in racks as high as 50 m.

Instead of stacking containers directly on top of each other, the system places each container in an individual rack compartment. Containers are stored in an 11-story rack, creating 200% more capacity than a conventional container terminal, effectively enabling the same storage capacity in less than a third of the space, according to the JV.

Chief executive Dr.Mathias Dobner said: “This new container handling technology allows cities to use their expensive and sensitive land and waterfront areas more effectively. Our system will significantly increase the productivity of handling ships on the quay. This means that quay walls can be shortened by a third. [It] will greatly improve the financial performance of container ports, and well as their overall appearance“.

Thanks to the rack’s design, each container can be accessed without having to move another one. The new, container storage system will be applied for the first time at Jebel Ali Terminal 4, in time for the Dubai Expo 2020 world fair.

Reduce roll to increase stowage

Reducing the roll of a vessel can have a direct impact on cargo stowage. Hoppe Marine’s Flume roll-damping system is designed to boost the efficiency of loading and unloading containers and consists of an anti-roll tank that is usually placed behind or below the deckhouse. Its software allows the system to adapt to changes in load and operational conditions and counteract the roll of the ship by changing the liquid level of the tank. This can reduce a vessel’s roll by up to 50%, according to Hoppe Marine sales manager Bastian Marquardt. Hoppe Marine’s Flume roll-damping system can reduce the roll of a vessel by up to 50% Maersk Line has installed the system across 48 ships in its fleet.

Mr.Marquardt explained that the system allows the lashing forces on containers to be reduced, giving more flexibility to where the containers are stowed and allowing more containers to be carried.

He said, “Heavier containers used to be placed deep in the vessel, but with the Flume system they can be placed higher up as the lashing forces are still ok“.

This is of benefit when loading and unloading in port, as there are options to place containers for an earlier port stop higher up, saving both time and money.

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Source: MPropulsion


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