Uwe-Peter Schieder.
Humidity Management in Cargo Transport
By James Brewer
Waterborne cargo can contain too much of something that can ruin it – and that is, water. Close attention must be paid to the humidity thresholds that are crucial for the high-quality transport of goods.
This is the message from Capt Uwe-Peter Schieder, loss prevention manager at the Gesamtverband der Deutschen Versicherungswirtschaft (GDV), the Berlin-based German Insurance Association. The GDV is the federation of private insurers in Germany and has some 460 member companies.
Humidity management is so important that Capt Schieder devoted the whole of his 25-minute presentation to the topic at the 2016 annual meeting in Genoa of the International Union of Marine Insurance.
He said: “I am always surprised to see how much water is transported in one voyage. The less water that is in the cargo, the easier water management will be.”
As an example, Capt Schieder posed a quiz question to the underwriter delegates. How much water is contained in 24 tonnes of green coffee beans that are in a suitable condition for transport? The answer, in graphic terms, is 13 bath-tubs full.
In one instance, 80 litres of water was ascertained from 20 tonnes of cocoa in a shipping container. “A few bags of desiccants are not going to solve the problem of humidity. The result was mouldy cocoa,” said Capt Schieder.
He said that the variation between day and night temperatures produced the danger of condensation. Ships passed through different climate zones, and air and water temperature could change quickly, affecting the microclimate in the container.
The objective should be “container-dry” Ø a term included in the IMO/ILO/UNECE Code of Practice for Packing Cargo in Transport Units (CTU Code2014/2015). This is a non-mandatory code of practice for the handling and packing of cargo transport units for transport by sea and land. Container-dry refers to the specific water content at which transport of goods can be considered safe depending on the route and the time of year.
“You cannot dry cargo in the hold like laundry in a breeze. The container is a closed space which has its own climate,” said Capt Schieder, who is a member of the IUMI loss prevention committee.
The use of desiccants outside sealed packaging made little sense. It required specialist skill and must be done properly. “If you pull off the packaging you will have condensation immediately.” Active ventilation helped to prevent condensation, but had its limitations.
Damage from excess moisture could be avoided. “The water content of the cargo is the key to success. If no moisture has come from the outside, then internal moisture has caused the damage. The correct water content is a quality characteristic of the cargo.”
The factor regulating moisture in a container is the water content of the goods. Mould could grow at a relative humidity of 75% or more. Consequently, the water content must be chosen in such a way that the relative humidity cannot rise above 75%, the most important humidity threshold for the purpose of container transport.
“Mould and so on do not generally represent transport damage. Rather they are a problem with the cargo itself. Using the CTU Code, insurers can help their clients to achieve loss-free transport,” said Capt Schieder.
