In the world of shipping, profit maximization for carriers and shippers is greatly dependent on how well utilized cargo space is. Ideally a cargo space should be utilized as much as possible. This principle applies to both break bulk and containerized cargo.
Broken Stowage is lost cargo space as a result of not being fully utilized due to the shape of the vessel, cargo design and quantity, or material that is used to secure the cargo in place.
This article aims to highlight the main reasons behind broken stowage, share how broken stowage is calculated and also discuss some of the best ways to mitigate or in some cases completely avoid it.
What Causes Broken Stowage?
There are various reasons why broken stowage can occur that range from dunnage and lashings to the shape of the vessel and insufficient cargo that can be loaded. Let’s take a closer look at the causes and reasons for broken stowage.
- Dunnage – Depending on the type of cargo and how they are stowed, dunnage is used to keep the cargo secure by minimizing movement during transportation. Dunnage can include bubble wrap, airbags and even crates, which also result in broken stowage as this space is not allocated for cargo.
- Ladders – Similarly common objects such as ladders are part of the vessel design, which cannot be temporarily moved. Ladders are an essential tool to allow access to various compartments of the vessel.
- Lashings – Lashings are mainly seen in containerized cargo, to ensure that pallets or loose cargo don’t topple over during transit and unloading. While lashings help to secure the cargo in place, they also occupy room, which counts as broken stowage.
- Stanchions – Stanchions are guiding structures that are designed to secure the cargo and prevent it from sliding or moving around during transit. They’re also known as ‘stoppers’ and are commonly used when transporting pipes or similar cargo.
- Vessel Shape – The shape of a vessel is not uniform and can therefore have storage compartments and areas that don’t allow for maximum cargo utilization. Areas where cargo cannot be loaded into is often also counted as broken stowage (such as curved walls or cargo bays).
- Cargo Shape – Goods come in different shapes and sizes. Certain cargo (for example odd-shaped or round items) may naturally cause broken stowage as they don’t allow for stacking due to their shape. Therefore, goods and packaging are often designed with transportation in mind.
- Insufficient Cargo – From time to time, shippers or exporters encounter various issues that don’t allow for the intended cargo quantity to be loaded. The empty space that arises from the missing cargo is also counted as broken stowage or deadfreight.
Broken Stowage Formula
Broken stowage calculates to what degree cargo space is underutilized. In essence it’s a measurement of how much of the total space is not loaded with cargo.
Broken Stowage = Used Cargo Space ÷ Total Cargo Space
Broken stowage is often expressed in a percentage value (of total cargo space that is lost because it can’t be filled with cargo). If the total cargo space is 150 CBM and can only be filled with 120 CBM worth of cargo, the broken stowage is 20% or 30 CBM.
Broken Stowage Example
Let’s take a closer look at two case studies in which we’ll calculate and further illustrate the concept of broken stowage. One scenario will be covering containerized cargo, while the other scenario will be about break bulk.
Broken Stowage: Container
Broken stowage in a container is calculated as the amount of space that is not used by cargo. Let’s take for example a 40’ high cube shipping container that has a capacity of 76 cubic meter (CBM).
A shipper is loading round paper rolls and is stacking them on top of each other. The cargo is loaded by hand and fills the container until the door. However, as the paper rolls are round, some space is wasted as no cargo is able to be filled in between the gaps.
After loading, it was calculated that the cargo made up about 55 CBM, which means that the broken stowage inside the container, also referred to as unused cargo space, is 18% or 12 CBM.
Oftentimes, broken stowage also occurs if only a fraction of the cargo can be loaded due to various reasons. In this case, the cargo is short shipped.
Broken Stowage: Break bulk
In our example of broken stowage for break bulk shipments, an exporter is shipping 500 tons of sand to his customer. The vessel that was chartered has a capacity of 400 CBM.
However, due to the walkways within the cargo bays and shape of the vessel only 370 CBM is usable. Subsequently the vessel gets loaded with 500 tons of sand until the maximum cargo capacity is reached.
As only 370 CBM of cargo space is usable, there is a broken stowage of 30 CBM or 7.5%. Therefore, when shipping break bulk, it’s crucial to understand how much broken stowage a vessel has, so that cargo utilization can be calculated in advance.
In actual practice, the exporter and shipowner have a charter agreement (charter party) which clearly outlines the vessel’s available cargo space and the cargo volume that’s being shipped.
Ways to Minimize and Avoid Broken Stowage
There are several ways to minimize and potentially even avoid broken stowage. Some of these practices range from selecting the right vessel or container type and size to reducing dead freight. Let’s explore some of these causes in more detail.
- Selecting the Right Equipment – It’s important to ensure that the right container is selected when it comes to shipping general cargo. Underutilizing container space unnecessarily increases freight costs.
- Selecting the Right Vessel – Similarly, the right vessel type and size should also be selected for break bulk shipments, in order to minimize broken stowage.
- Minimizing Dunnage & Lashings – There is no debate that safety during transportation is always the highest priority. At the same time, adding an excess amount of dunnage and lashing can lead to increased broken stowage.
- Setting Order Quantities – Assuming that sales are in larger qualities, accepting orders in batches to fill a 20’ or 40’ container ensures that the cargo utilization in a container is always optimized and no cargo space is wasted.
- Calculating Stowage Factor in Advance – Understand how calculating the stowage factor is able to give you insights on how to maximize loads for your cargo. It’s always best to calculate this in advance.
- Optimizing Packaging – Ensure that packaging is optimal for transportation and stacking. For example square or rectangular boxes are easier to stack and store then round or odd-shaped cartons. They also allow for maximum container space utilization.
- Optimizing Product Design – Similarly, the product design could also be optimized to facilitate stackable packaging. The more products and packaging are optimized for efficient stacking and loading, the more freight costs can be saved due to cargo maximization.