In the wood packaging world, crate and container design often relies on rules-of-thumb and previous experience. What has worked in the past will work today – until it doesn’t.
Some wood packaging providers rely on military specifications that may lead to overdesign because military crates and containers are usually purpose-built for extreme situations. This can result in unnecessary packaging costs for a typical supply chain. Others, especially large producers with access to testing labs, are using more testing and design to develop wood crates and containers that are purpose-built for each application based on sound design principles. Regardless of your approach, being aware of common pitfalls can only make your decisions better.
As global supply chains push heavier, taller, and more sensitive equipment into longer and more complex shipping routes, the margin for error in crate design has narrowed considerably. Failures today are rarely the result of a single bad board or weak fastener connection. Instead, they stem from fundamental design oversights that repeat themselves across the industry.
Based on recent discussions with Dr. Laszlo Horvath, director of the Center for Packaging and Unit Load Design, and Dr. Dan Hindman, professor of wood engineering at Virginia Tech, five mistakes stand out as the most common – and most damaging – errors wood crate and container manufacturers continue to make.
Virginia Tech offers a short course to help packaging designers develop more stable, cost-effective crates and containers. The next class will be in the fall of 2026.
1. Ignoring the Load Path
If there is one concept that separates engineered crate design from trial-and-error construction, it is understanding the load path. Simply put, loads do not magically distribute themselves evenly through a crate. If designers do not intentionally guide forces from the product down through the structure and into the base, the load will find its own path – usually with destructive consequences, often through the weakest part of the crate.
Many failures occur not because components are undersized, but because loads are transferred to the wrong locations. Machinery weight ends up bearing on unsupported panels, headers are bypassed, or skids are placed where they never see the forces they were meant to carry. Over time – or sometimes in a single hard bump – members bend, fasteners withdraw, and components fail.
As Dr. Dan Hindman suggested, designers must mentally trace the load from the top of the product all the way to the floor. Every beam, column, and connection in between must be part of that design. When the load path is unclear, performance becomes unpredictable.
2. Underestimating Fasteners – and Using Them Incorrectly
Fasteners are often treated as an afterthought, yet they are among the most common failure points in wood crates. Nails, in particular, are frequently underestimated. Even when the correct number of fasteners is used, improper placement can negate their effectiveness entirely. You want to make sure that fastener spacing is adequate to support the load and the crate itself.
Dr. Laszlo Horvath noted, “The majority of the problems really happens for sidewalls of the crates. Nails are always a problem because they have a tendency to come out, even if they are clenched or, penetrated with like a helical nail.”
One recurring issue involves nails driven into end grain, where withdrawal resistance is minimal. Another involves torque-related failures, where fasteners closest to pivot points experience the highest forces and are often installed in orientations that reduce holding power. In some cases, nails bend during installation, eliminating their withdrawal strength altogether.
Dr. Laszlo Horvath explained, “Some designs underestimated torque. For example, a vertical member in the crate is nailed to a horizontal member forming a header, then it would pivot as vibration forces act on the crate. The nail that was farther from the pivoting point that had the highest torque actually bent into the entry. As a result, it had no withdrawal properties. Nails were pulling out and components got detached completely compromising load protection.”
While screws and bolts typically perform much better, they are not immune to problems. Vibration during transport can loosen carriage bolts, allowing equipment to rock inside the crate. Once movement begins, damage accelerates rapidly. The lesson is clear: fastener selection, placement, spacing, and orientation matter. Also, screws and bolts are much more expensive, which can add unnecessary costs to some designs.
If designers do not intentionally guide forces from the product down through the structure and into the base, the load will find its own path – usually with destructive consequences, often through the weakest part of the crate.
3. Failing to Control Product Movement
Many crate designs focus almost exclusively on vertical loads—how much weight the structure can support. What gets overlooked is lateral movement. In real-world shipping environments, crates are bumped, jolted and subjected to repeated side-to-side forces.
Tall or top-heavy equipment is particularly vulnerable. Even small amounts of sway at the top of a product generate significant moments at connection points, pulling fasteners loose and stressing members far beyond their design limits. This is where internal bracing and proper blocking become critical.
Securing the product at the correct attachment points – and assuming more movement than intuition suggests – can prevent costly failures. As Horvath notes, most designers underestimate how much motion actually occurs in transit, especially during handling rather than long-haul transport.
4. Poor Bracing and Column Design
Open crates, while economical and flexible, present unique structural challenges. Long, slender columns without intermediate bracing are prone to buckling, even under modest loads. Capacity does not decline gradually as column length increases – it drops off dramatically.
Simple fixes are often overlooked. Adding mid-height bracing, introducing side-to-side restraints, or building up columns into T-shaped sections can significantly increase strength without dramatically increasing material usage. Yet many crates continue to rely on long, unbraced members that are structurally inefficient and failure-prone.
This mistake is especially common when designs are scaled up from smaller crates without reconsidering proportions. What worked at one size may be structurally unsound at another.
Hindman focused on the importance of bracing. He said, “Especially for open crates, if your columns are too long, then they’re just not able to carry much load. But if you simply run a brace halfway through, you can really increase the strength of that whole structure.”
Kristen DeLack, principal software engineer for the NWPCA, explained, “CDS is able to design crates that meet all major international crating standards…CDS provides the ability to fully customize the crate but does adhere to these industry standards by default. In essence, it designs the crate for you based on your desired dimensions and weight capacity among other broad design choices.” (Screen shot of CDS, image courtesy NWPCA)
5. Designing in a Vacuum
Perhaps the most subtle mistake is designing the crate without fully considering environmental and dynamic loads. Shock, vibration, wind, moisture, and even resonance can all influence performance, particularly for sensitive or high-value equipment.
Horvath explained, “During the short course, we did talk about adding shock absorbing feet under the crates or foam inside. These enhancements can eliminate shock and then tune out vibrations, which can be important for sensitive electronic equipment. We put the designs on a vibration table and ran experiments. What we found is that you need to know a lot about the natural frequency of the product to be able to isolate vibrations. For example, you need to know the resonance of the vibration of a server tower.”
While military specifications provide a conservative baseline, they are often overbuilt for commercial applications. Many companies either follow them blindly – adding unnecessary cost – or abandon standards altogether and rely solely on experience. Neither approach is ideal.
Understanding when deflection matters, how vibration can loosen connections, and when supplemental materials like foam or isolation pads are warranted requires more than rule-of-thumb knowledge. It requires engineering insight – and, increasingly, testing or simulation.
One of the best pieces of advice may be to join the upcoming Virginia Tech Wood Crate Design Short Course, scheduled for early fall 2026. It is a great way to learn from experts and peers while discussing real-world challenges. See page 48 for more information.
Virginia Tech’s Wood Crate Design Short Course Returns in Fall 2026
For wood crate and container manufacturers looking to move beyond experience-based design, Virginia Tech’s Wood Crate Design Short Course, scheduled for early fall 2026, offers a rare opportunity to blend theory with hands-on application.
Now entering its third year, the course brings together packaging engineers, wood scientists, and industry professionals for an intensive program focused on real-world crate design challenges. Participants do not simply review standards—they build crates, analyze load paths, evaluate fastener performance, and observe failures firsthand.
A key addition for the 2026 course is the new Crate Design System (CDS) software developed by the National Wooden Pallet & Container Association (NWPCA). CDS includes state-of-the-art graphics that allow immediate visualization of the design principles taught during the crate design course.
The course also emphasizes practical optimization – learning when military specifications make sense, when they don’t, and how National Design Specification (NDS) principles can be adapted to wood packaging applications. In the past, these courses have filled up quickly, and with the new CDS software being launched soon, even more people may want to attend this year. You can find out more information by visiting https://tinyurl.com/43vuafjv or sign up to receive updates about short courses.
Key Benefits of the New Container Design System
The new Container Design System developed by the NWPCA will be utilized in upcoming Virgina Tech short courses.
Why is this software such a game changer? Kristen DeLack, principal software engineer for the NWPCA, explained, “CDS is able to design crates that meet all major international crating standards. It has been developed using public domain crate design details that are known to work in the industry.
CDS provides the ability to fully customize the crate but does adhere to these industry standards by default. In essence, it designs the crate for you based on your desired dimensions and weight capacity among other broad design choices.”
In the past, most companies had to either draw their crates by hand or use an expensive, cumbersome, and labor-intensive CAD software package that wasn’t purpose-built for the packaging industry. CDS is geared to the way the industry thinks and builds crates. Developed in collaboration with members of NWPCA, the software is tailored to how the industry actually thinks and builds. Over forty years of wood science and engineering know-how from the Pallet Design System has been rolled into CDS. Design details can be included in drawings with just a few mouse clicks.
Users can quickly add fastener positions, corner designs, lid drainage, skids, rubbing strips, and numerous other features to their drawings with precision and ease.
What are some of the advanced features that will be deployed in CDS. DeLack commented, “CDS is built on a fully modern software platform that is truly cutting edge. This allows the user to interact with the graphical interfaces extremely fast. As fast as you can move the mouse! Exploded views and views with ghosted components can be instantly generated to illustrate how a complex crate goes together.”
CDS allows CAD models to be imported into the software enabling CDS to generate professional drawings, specification documents, component lists and production orders. For more information, visit https://tinyurl.com/4e2czj4a.
