What is considered dunnage?
Dunnage is a commonly used term by industrial packaging technicians in the shipping industry. While transporting manufactured goods, dunnage is an inexpensive material that helps to load and secure all the items transported by ship, road, or rail. Dunnage is made up of various materials such as plastic, foam, wood, corrugated paper, etc.
There are primarily three types of packaging:-
Kit packs (components packs): They are used to hold all the parts of a specific item or product in place. Such packaging helps in reducing the number of containers used to hold individual parts.
Custom dunnage: Custom dunnage is used when the customer demands a specific requirement for packaging.
Multi-material varieties: As the name suggests, it is made up of multiple materials for better protection and safe transportation of goods.
What is the purpose of dunnage particularly in the ship's cargo?
Dunnage may be a small but vital part of the packaging process as it helps in protecting practically all types of cargo during the loading and transportation of goods. From filling the void spaces securely, positioning the goods so that it remains intact to protecting the sensitive cargo from moisture and ensuring that it holds its place while in transit, one cannot ignore the importance of dunnage in logistics.
Why Is Dunnage Used?
When the cargo is stored in a sorting facility or trucks, ships, and or other vehicles, it is likely to face certain tough environmental factors. Dunnage bags help the goods remain in place and act as a shock absorber to protect sensitive items.
Listed below are three main advantages of using dunnage:-
Damage Protection: Dunnage prevents the packages from falling out of a truck, ship, or train. Proper dunnage will barely cost you much, protecting your valuable and fragile items from any serious harm.
Moisture Protection: Sometimes, electronic gadgets can get damaged due to exposure to moisture. But proper dunnage in place will prevent such kind of sensitive items from getting spoiled.
Shock Absorption: When a cargo slides across in a ship, it can undergo shocks and vibrations. If these cargos contain delicate items, they are likely to get damaged. Dunnage helps avoid these mishaps.
When to use dunnage?
Dunnage can be used in the following cases:-
- To prevent cargo items from shifting
- To secure containers
- To block off broken stowage and fill void spaces that cannot be filled with cargo
- To prevent water or other liquids from entering the cargo
- To provide air passages for effective ventilation
- To provide spaces for air circulation in refrigerated places
- To evenly distribute weight
- To separate cargo
Benefits of dunnage
In a business, dunnage is as important as the shipment itself. Here are three benefits of the proper implementation of dunnage:-
Protecting your goods: The primary use of dunnage is to protect your goods from any damage they are likely to receive while moving from factories to warehouses to endpoint customers. During these transits, products are loaded onto trucks or trains, stacked, sorted, etc., so there are higher chances of them getting damaged. Dunnage limits these damages by absorbing the shocks, keeping the goods moisture-free, and ensuring their place intact while being transported. Proper dunnage saves your goods while on the move.
Protecting your revenue: Damaged goods tend to impact your goodwill in the market. If your goods get harmed during shipping, you will have to give a refund or replace the damaged products. Proper dunnage will protect the cargo and in turn contribute to higher sales. This will be because the shipment will be delivered without any damages.
All the more, dunnage is generally cost-efficient as it is made from reusable materials, making it a good packaging investment.
Reducing labor cost: A specific dunnage usage guidance given to the packaging team can go a long way in helping the labor force work efficiently, who in turn will churn out more packages each day. This eventually will result in a better return of investment, thus reducing the labor cost.
How do dunnage bags work?
Dunnage is placed between the cargos and then inflated, thus pushing the cargo on the sides of the compartment. It is crucial to decide the size of the dunnage bag, depending on the void of the spaces between the cargos. Bigger spaces would require wider bags. An improper decision about the size of the dunnage bags will lead to unwanted movement of the cargo, resulting in damaged goods.
How is dunnage calculated?
Calculating the dunnage for steel coils
- Dunnage wood is of good quality with no cracks
- Dunnage is 60 inches long (1500 mm) since it will extend over two frames under the tank top
T= Thickness of dunnage material (in inches) W = Width of dunnage material (in inches)
Permissible Load = 0.15 x T x W x W (Metric tons) which is per dunnage material
Example 1: For the dunnage material of dimension (T x W) of 2 (inch) x 8 (inch), Permissible Load = 0.15 x 2 x 2 x 8 = 4.8 tons per dunnage unit Suppose, we have a 20 ton coil, then,
Required dunnage units = (20 x1)/4.8 = 4.16 So, 4 dunnage units will be needed.
Example 2: Dunnage dimensions (T x W) : 75 mm x 75 mm Dunnage dimensions (T x W) : 3 inch x 3 inch Permissible Load = 0.15 x 3 x 3 x 3 = 4.05 tons
Required dunnage units = (20 x 1)/4.05 = 4.94 So, 5 dunnage units will be needed.
Dunnage sizes and permissible load per dunnage unit:
Types of Dunnage
The types of dunnage can be classified as per the kind of materials used, which is as follows:-
- Solid Plastic
- Bubble Wrap
- Air Pillows
- Kraft Paper
- Corrugated Paper
- Custom Dunnage Solution
Solid Plastic: This type of dunnage is mostly found in industrial or high-value shipping. These materials provide high protection but are also costly.
Bubble wrap: Bubble wrap is the most commonly used dunnage material for fragile items like glass. It can be reused until the bubbles pop.
Wood: Wood is used to separate and protect goods that are strong and heavy.
Air Pillows: Air pillows ensure minimum movement of goods and also offer maximum protection so that the articles do not move at all during transit.
Kraft Paper: Kraft paper is commercially cheaper, economical, and can be reused, making it an effective dunnage material for packing. It is crinkled often because of its reusability.
Foam: Foam is mostly useful in safeguarding electronics. It is also highly effective in protecting fragile articles during transit.
Steel: Steel is one of the most expensive dunnage materials. It helps in protecting the lighter/fragile materials from the heavier materials.
Corrugated Paper: This dunnage material can protect goods against moisture. It is found to be a sustainable protection material that can carry a wide range of weights.
Custom Dunnage Solution: When the customer requires packaging of a specific dimension, a mix of dunnage materials can be made so that the safety of the articles is ensured.
Difference between Dunnage, Cribbing & Bracing
It is a packaging material that is used to protect the shipment from moisture and contamination during transit. Dunnage is also used for shifting and chaffing.
It is a packaging material that blocks a particular area or space to help increase the bearing height and area. Cribbing is used to stack uniform blocks to create a sturdy structure that can support heavy loads.
It is a packaging material that is used to eliminate or reduce the vertical movement of the shipment. Without bracing, the shipment can fall off and the articles can get damaged. Bracing holds the cargo in one place and thus helps protect it.
FAQs on Dunnage
1. Why do you need dunnage for refrigerated cargos?
Dunnage is needed to protect the shipment from the moisture that is accumulated on the sides of the ship.
2. How do you use dunnage on different deck cargo?
The application of dunnage can be done in various ways. In the case of cargo ships, floor dunnage is used to safeguard goods against moisture. For the delicate/fragile shipment, double layers or crisscrossed dunnage are used. It is most commonly applied to containers. Top dunnage is used to contain the condensation that gathers over the shipping containers.
3. What kind of wood is used for dunnage?
Rough wood like pine, hemlock, spruce, etc. are the common wood types for dunnage.
4. What is the reason behind using cargo dunnage for loading goods?
- It helps in a comparatively easy loading process for a shipment
- It helps protect goods against moisture and contamination
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