While using the many different rugged computers and servers on the market, you may have encountered three categories of ruggedisation: semi-rugged, fully rugged and ultra-rugged.

For example, we at Trenton Systems offer fully rugged servers and workstations, and we are currently working on an ultra-rugged embedded computer, the COM Express Type 7.

But what do each of these categories even mean and why is it important to know the difference?

Before we move on, however, it’s important to note that these categories are not standardised by any organizational body.

A device that one rugged computer hardware manufacturer says is fully rugged may be considered semi-rugged or even ultra-rugged by another. Therefore, we have based our definitions on how the industry commonly uses these terms.

If a server, workstation, mini PC or laptop has a rugged design, it has been stress-tested to endure, function and perform in extreme environments, usually according to military and industrial standards such as MIL-STD-810, MIL-STD-461 or D0-160.

When a rugged device is placed in a harsh environment – this could be a location that receives extremely high or low temperatures or a place with lots of moving parts such as a factory floor – the ruggedisation process ensures the survival of not only the device’s chassis or outer casing but also its internal components.

Rugged computers are used in a variety of industries, including defence, space, aviation, aerospace, big data, industrial automation, healthcare, entertainment, agriculture, energy and telecommunications.

It is important to note, however, that not every rugged device has been certified to military or industrial standards. It is possible to purchase a rugged device that has undergone some form of stress testing but not the standardisation and certification process, which is desirable and necessary if the device is intended to support an important military or industrial application in a harsh environment.

If you are looking for a device with legitimate rugged design – one that will perform in the face of many different environmental conditions such as high humidity, high or low temperatures, vibration, mechanical shock, among others – certifications are the golden ticket of ruggedisation. They are what make a rugged computer truly rugged.

A rugged device could be used by the military to support mission-critical weapons, radar and communications systems or by industries to support assembly line automation and collect field data.

Any program or application that requires durability and powerful performance can benefit from the introduction of a rugged computer or device. Not to mention, the possibilities are endless, especially with the advent of edge computing.

One example of a rugged device in use is a processor board installed on a United States Air Force fighter jet.

In 2009, the airforce needed a customised processor board for use in the heads-up display (HUD) of one its fighter jets. The board had to be able to withstand hot temperatures on the tarmac and cold temperatures at high altitudes.

Looking to the rugged computing industry for help, the airforce was able to secure a MIL-STD-810-temperature-certified processor board offering more than enough durability to support the HUD. In fact, the airforce went on to purchase 600 of these processor boards for use with its other aircraft. A consumer-level processor board simply would not survive the hot and cold temperatures specific to this program.

A semi-rugged device is commonly seen at the consumer level supporting law enforcement and business-related applications and projects. It is helpful to think of a semi-rugged device as commercial-off-the-shelf computer complemented with limited rugged features.

Semi-rugged devices are typically equipped with a few parts that have undergone stress testing or certification to military and industrial standards. For instance, a semi-rugged device may have a hard drive that is resistant to mechanical shock or an outer covering that can withstand some rain.

One example of a semi-rugged device is a police computer, which may be dropped, impacted during a high-speed chase or exposed to rain and extreme temperatures.

Unfortunately, semi-rugged devices are likely to suffer if pushed too far. In other words, if the environment becomes too harsh, a semi-rugged device could experience a significant performance decline or stop working altogether.

Fully rugged and ultra-rugged devices do not suffer the same fate as all their components and hardware have been designed to both endure and perform no matter the severity of the environment.

Fully rugged devices are commonly seen supporting military and industrial applications in riskier environments than the semi-rugged device. Simply put, they are more durable than the semi-rugged device but less ruggedised than the specialised ultra-rugged device.

Depending on their certifications, fully rugged devices can be dropped, impacted, exposed to extremely high or low temperatures, withstand high levels of humidity, endure heavy rain and direct sunlight exposure for prolonged periods, and the list goes on.

An example of a fully rugged device is a military computer or a rugged blade server and its electronic components.

Fully rugged devices will not suffer from a performance decline in extreme environments. This makes them ideal for mission-critical applications, which require continuous operation.

Trenton Systems specialises in fully rugged servers, workstations, storage, mini PCs, processor boards and backplanes.

Ultra-rugged devices are a little pricier than fully rugged devices, but they go the extra mile in terms of durability. They are designed to endure the harshest conditions the world has to offer.
Ultra-rugged often refers to a fanless, sealed, conformal-coated device, one that could even survive being submerged in water.

These devices are stress-tested beyond the requirements of the semi-rugged and fully rugged devices. If you are looking for a device that can be literally frozen, left out in the desert run or dropped from three feet onto a cement floor, the ultra-rugged device is the right choice.


To recap:

  • A semi-rugged device is often seen at the consumer level supporting business and law enforcement applications and projects. Semi-rugged devices are usually just commercial-off-the-shelf computers with additional but limited rugged features.
  • A fully rugged device is often seen supporting military and industrial applications in riskier environments than the semi-rugged device. They are more durable than the semi-rugged device but less ruggedised than the specialised ultra-rugged device.
  • An ultra-rugged device is designed to endure the absolute harshest conditions the world has to offer. The industry often refers to them as indestructible due to their enhanced durability.

If you are unsure about which category your rugged device falls under, ask the manufacturer. Do not take a chance on uncertified rugged devices.