Bremerhaven logistics student investigates shock loads during container handling

Accelerometers provide information on load safety

In order to choose the right form of load securing, companies need to know what accelerations act on the goods during transport. Failure to do so can result in serious damage to the means of transport and the cargo. The respective acceleration values are known for lorries, trains and ships. But what loads act on the goods during container handling? This was investigated by Bremerhaven student Bennet Krause during a project. To do so, he equipped a container with special measuring devices.

When transporting goods, acceleration forces always act on the cargo. The fact that it is not yet sufficiently known how high these forces are during container handling can be a safety risk. Although the cargo is secured in such a way that it can withstand the expected acceleration values of the means of transport, this securing could be too low for loading in the harbours. The danger: ‘The cargo can shift unnoticed in the container if it is not adequately secured. If it is then transported by a lorry, for example, and the lorry brakes, this can lead to serious accidents,’ says Bennet Krause, who is studying transport/logistics in Bremerhaven. As part of a voluntary project for the Loss Prevention Conference 2024, he looked into the question of how much stress a container is actually subjected to during transport.

At the 20th Loss Prevention Conference 2024, he looked at the question of how much stress a container is actually subjected to during transport.
Bennet Krause analysed the impact load that occurs during container handling using reach stackers. This is a crane-like vehicle that is very manoeuvrable and can therefore park the containers in a particularly space-saving manner. The student worked with data loggers, i.e. electronic measuring devices with which various measured values can be recorded simultaneously. These include the accelerations, which are decisive for the impact loads. ‘The transport loads that are to be expected during handling using a reach stacker are caused by the typical movements of the means of transport, for example turning, braking and starting, setting down the container and movements when driving over uneven ground,’ explains Bennet Krause. The accelerations differ in terms of direction: when turning, accelerations occur in the transverse direction, when braking and starting in the direction of travel and when setting down the container in a vertical direction. On uneven floors, accelerations occur in all horizontal and vertical directions. As the data loggers know in which direction they are travelling, it is easy to trace the movements that caused the measured acceleration values. They can also be located via GPS so that the values can be assigned to a specific location on the transport route. 

The data logger recordings show that the transport loads during transshipment by reach stacker are above the values that are included in the calculation of the necessary load safety. The direction is relevant here. ‘When handling containers, the highest accelerations are usually measured when the container is set down. However, a data logger has recorded the highest accelerations in the horizontal direction. This poses a higher risk for load securing, as containers are secured against fewer g-forces in the longitudinal and transverse directions than in the vertical direction.’ 

In order to better categorise the collected data, Bennet Krause drew on the results of a student project from 2021, which his supervisor Prof. Dr Dieter Heimann made available to him. The students analysed the container's journey from Bremerhaven to Busan, during which it was handled several times. The data loggers recorded the measured acceleration values throughout the entire period. The result: ‘As expected, there were no high accelerations during transport by ship and lorry. However, the situation was different during container handling. At one point, even eighteen times more acceleration was measured than the load should actually be subjected to. This could damage the safety of the cargo,’ says Bennet Krause. However, he also has an explanation for these values: ‘The container was handled in the harbour with a container gantry crane. Not only are these more difficult to operate than a reachstacker, but time is always of the essence in ports. If things have to move quickly, the containers are not handled as gently.’ 

Even if the measured data provides an initial impression of the acceleration values that companies can expect during container handling, it is not yet truly conclusive. Numerous further test series would have to be carried out for this. For Bennet Krause, however, the project was a great opportunity to deal with a current topic in logistics outside of his lectures. He learnt a lot, including about working with data loggers. ‘Data loggers have an integrated coordinate system and therefore know in which direction they are recording. You have to document this precisely, otherwise you end up with negative values. That's probably the most important thing when working with data loggers.’ He presented the results of his work to an expert audience at the 2024 Loss Prevention Conference. ‘When Prof Dr Dieter Heimann presented the topic, I was immediately interested. I also knew that I would have to give a presentation at the end. That was a bit of a challenge for me and took me out of my comfort zone. The whole experience was very interesting for me,’ concludes Bennet Krause.

The Bachelor's degree programme in Transport/Logistics is unique in the logistics sector with its technical-engineering focus and Bachelor of Engineering degree. The programme is deliberately designed to be interdisciplinary and application-oriented in order to train students to become logistics generalists. This enables them to deal with all aspects of logistics and become competent contacts for all specialised disciplines of practical logistics.

The application phase for the 2025 summer semester is currently underway, with four Bachelor's and eight Master's degree programmes, including the university's logistics degree programmes, accepting new students. The application deadline is 15 March 2025. Further information can be found at www.hs-bremerhaven.de/study.