Transit cases lead hard lives. They bang together in the backs of trucks, are often dropped, and take knocks from all directions. Yet, users expect them to shrug off this abuse, protect their delicate contents and be as light as possible. Case designers tackle these conflicting requirements in three ways. Continue reading
Understanding Transit Case Rotomolding
Rotational molding, or rotomolding, is a cost-effective way of making large, joint-free polymer containers. “Rotationally Molded Transit Cases: 8 Advantages” discussed what makes this process so useful. Here, we’ll dive deeper into the details of the process. Continue reading
Protecting Electronics from Vibration (Part 2)
A transit case uses isolating mounts to protect electronic payloads from vibration. These mounts are chosen with a natural frequency of vibration significantly different from the expected excitation frequency. This helps ensure the minimum of vibration is transmitted to the payload. However, there are challenges: Continue reading
Protecting the Payload from Vibration (Part 1)

Vibration is bad for electronic devices such as radio transmitters and computers. Screws can work loose and cards and cables can come unplugged. As a result, equipment is sometimes inoperable after a long journey. Fortunately, that kind of damage is usually easily repaired, unlike the harm caused by resonance. Continue reading
Verifying How Much Shock Protection a Transit Case Provides
Electronic systems need transporting with care. Sudden impacts, as if dropped from the back of a truck, can pop IO cards out of their slots, disconnect cables, and damage hard drives. That’s why you’ll often see acceleration or g-force limits called-out in specification documents for many electronic products. Continue reading
Consider a Cut and Weld Case for Odd-Sized Payloads
Study the Sierra Cases website and you’ll see transit cases come in many sizes. Sometimes though, a standard case doesn’t work well for the item or payload to be moved. Perhaps you need to transport something long and thin, like an antenna. In those situations you can end up buying a much larger, and more expensive case, and wasting a lot of the interior volume.
If it Needs Connecting, it Needs an I/O Panel
Something first-time transit case buyers often overlook is adding an I/O panel for easy cable connection. Without it, the case is little more than a storage box, albeit one providing protection from temperature extremes, dust, humidity and shock impact. Using the equipment inside means either taking it out of the case or running with the case open and cables fed in. Either option negates the purpose of the case. Continue reading
Does Your Transit Case Need A Load Spreader?
A load spreader does exactly what its name implies. It distributes a load over a larger area. Engineers might recall load, divided by area, as the definition of stress. So, a load spreader reduces stress on a load-bearing material or structure. Continue reading
Case Color and Internal Temperature

Leave a transit case in the sun and the interior can get hot enough to kill electronic components. Inlets and outlets for convection mitigate the problem if the ambient air is cool enough. But, they may draw in dust and moisture. Active cooling – thermoelectric or air conditioner – is an alternative but incurs installation, weight and extra costs. Continue reading
Cases That Protect Against EMI: Part 2

Electromagnetic Interference (EMI) can affect electronics, disrupting timing circuits and corrupting signals. If sufficiently powerful – perhaps a pulse from a nearby radar installation – it can induce damaging voltage surges in wiring. There’s even evidence of EMI damaging the read/write heads of hard drive storage units. Continue reading
Electrical Shielding and Transit Cases: Part 1

Modern electronics are very vulnerable to Electromagnetic Interference (EMI), sometimes called Radio Frequency Interference (RFI). It’s not just lightning strikes, whose destructive potential is well known. Radar pulses, radio and microwave emissions, cellphones, wireless routers, and the humble microwave oven can affect microprocessor-based systems. It disturbs timing and corrupts data. Continue reading
Choosing the Right Cooling for Your Application

Any time you’re buying a case to hold powered-up electrical equipment, cooling should be a top concern. Without it, signals degrade and electronic components are likely to fail. Convective airflow (letting cool air in at the bottom and warm air leave from the top) might be appropriate for low ambient temperature, dust-free conditions. But most applications need a more sophisticated solution. Continue reading
An Overview of Foam Materials
In my last two postings I reviewed equipment fragility and the influence of handling and transport on packaging design. The most common approach to protecting equipment within a carrying case, transit case or shipping case is to use foam cushioning. In this posting, I’ll provide an overview of foam materials. Continue reading
How Handling and Transport Influence Case Performance
If you are looking for a carrying case, transit case or shipping case to protect your equipment, you should be able to relay the performance expectations to your packaging professional. That’s so he / she can adequately address your requirement. If you do not set these expectations, you run the risk of having inadequate protection with potential equipment damage and nobody to blame. Continue reading
Sealing A Transit Case
An IP-rated transit case has a water and air-tight seal between lid or cover and body. That seal must be maintained in the face of relative movement caused by rough handling, pressure differentials between interior and exterior, and temperature extremes. That seal is formed by an O-ring. Continue reading
6 Reasons for Choosing Thermoelectric Cooling

For shipping and transit cases, traditional refrigeration technology is giving way to thermoelectric cooling. Here’s why: Continue reading
Lifting Limits Reduce Back Injuries

According to the Bureau of Labor Statistics (BLS), back pain is one of the leading reasons for workplace absence. The data reveals many of these injuries occur while lifting. That’s why it’s important to not lift too much and minimize twisting while lifting. Continue reading
Choosing the Right Humidity Indicator

In the desert, relative humidity levels may be as low as 5%. In the tropics, 100% is possible. Anything over 40% is generally considered humid. Humidity causes metal to corrode and mold to form. Lower humidity is a problem too, as drops in temperature cause condensation. If that happens inside a transit case or shipping container, the contents can be damaged or completely ruined. Continue reading

How Desiccants Manage Moisture in a Transit Case

You can’t prevent moisture from entering an enclosure. It’s in the sealed-in air. It’s in the enclosed materials. It even permeates through the walls and seals of the enclosure. And, when a transit case is equipped with a breather for pressure equalization, air will be drawn in from outside, too. Continue reading
How Humid Can it Get
When warm air meets a cold glass of beer, condensation forms on the surface. The resulting drips may be annoying, but they won’t ruin your beer. Should condensation occur inside a transit case, it’s another story. Continue reading