Ventilation Requirements & Guidelines for Cargo Ships

Cargo ships are a deceptive breed of vessel: while their design and purpose may seem simple at first, there’s a lot more moving parts and interconnected designs than you might expect.

A good example of this is the ventilation system. While proper air flow and purification is a must on any boat, especially one built for long-term trips with below-deck cabins and accomodations, cargo ships must be more careful than many other vessels due to the presence of goods onboard, often perishables or chemicals, that must be stored properly on their long journeys.

Don’t worry, though, it isn’t as complicated as it sounds. Several guidelines and requirements are in place to help monitor and regulate the temperature and airflow on cargo ships, and while they might seem a little overwhelming at first they’re easy to understand once you get the lingo down. If you want to better understand the use of ventilation in cargo ships, here’s a few requirements, terms, and guidelines to remember:

Understanding the difference between types of cargo
One of the easiest ways to start understanding the need for cargo ventilation is to understand the types of cargo that can be carried on a vessel. This can be a lot of things, as you’ve surely seen in your time working on the water, but most cargo can be broken down into one of two types: hygroscopic and non-hygroscopic.

Hygroscopic cargo is any product that contains natural moisture, typically grains or other agricultural products. Depending on the surrounding atmosphere and the environment they’re being transported from, to, or in, these cargoes can absorb or release moisture along the way and may require additional regulation to keep them fresh. On the other hand, non-hygroscopic cargoes don’t contain natural moisture and are generally any solid non-perishable product; however, these products are very susceptible to temperature and humidity changes, which can lead to stricter ventilation guidelines and storage requirements.

Preventing ‘cargo sweat’
For vessels carrying non-hygroscopic products, ‘cargo sweat’ or ‘ship sweat’ can be one of the leading causes of damage. As vessels travel between areas of varying temperatures and humidity levels, the air inside the vessel can become saturated with moisture and begin to leave condensation throughout the ship, potentially damaging the cargo. Understanding the causes of cargo sweat and how to prevent it will be critical to making sure your cargo arrives safely to its destination.

Always monitor inside and outside temperature
A great way to prevent your cargo from being affected by moisture in the atmosphere is to monitor the temperature and humidity levels both within the cargo area and immediately nearby. Install thermometers and ‘hygrometers’ (a device used to measure humidity and atmospheric moisture in an area) to be constantly aware of the temperature and air conditions around any potentially sensitive cargo.

Know when to ventilate the air
When it comes to the actual ventilation of the cargo, a lot of people think you can just ‘set it and forget it’ and leave the ventilation system running constantly, but this may actually cause more damage in the long run. Ventilation should primarily be used when the cargo area’s relative humidity begins to exceed recommended guidelines, if the ship is passing through a particularly humid area due to temperature or sea conditions, or if external temperatures are significantly lower than the temperature inside the cargo vessel, particularly at night when the temperature discrepancy can be at its highest in many parts of the globe.

Maintain records whenever possible
In order to maintain proper environmental conditions, and to keep track of any potential damage to cargo along the way, records must be kept of all environmental conditions while the vessel is in transit to help pinpoint the cause of any potential issue and better regulate temperature along the way. Along the way, keep active, accurate track of weather conditions outside the vessel as well as conditions in the cargo area and make adjustments as needed.

If you have been injured while working on a cargo ship, contact the maritime lawyers of O’Bryan Law immediately for a case consultation. You may be able to seek compensation for your hardships under the Jones Act.