The History of Tribology Part 4: The Modern World, 1915-2000

In the last instalment of the History of Tribology series, we learned that the Second Industrial Revolution (1870-1914) was defined by innovations in steel production, railway expansion, electrification, the rise of the internal combustion engine, and advancements in the chemical industry.

The 20th century is filled with amazing advances in technology and science, and spans over both world wars, the space race, and modern computing! Think about the cars from the 1920s, or the tiny computer parts from the 1990s, to parts of space shuttles! Even though these changes might seem very different, there’s a common theme behind them: tribology.

The impact of tribology was felt profoundly during World War I, which was the first truly mechanised and industrialised total war. Innovations in military tech included the very first tanks, and these heavy machines imposed enormous demands on materials, especially in the interactions of their tracks and treads with the ground.

The challenge was not only in ensuring efficient movement (which was achieved with the invention of caterpillar tracks) but also in ensuring that the parts wouldn’t wear down quickly. Tanks during the First World War were notoriously unreliable, and at the Battle of Flers-Courcelette in 1916, only 25 of the 49 tanks used in the attack were able to move forward!

Engineers at the time had to develop tread grease for the tracks, work on keeping engines running smoothly in incredibly harsh conditions, and engineer new power-trains to move such heavy machinery through mud!

In the inter-war period, the world witnessed a boom in the automotive industry. Cars became more than just luxury items; they began serving as a primary mode of transportation for the masses and goods, with around 5 million motor cars in use in the USA in 1918! As vehicle numbers surged, so did the need for longer-lasting and more efficient engines.

Much of the advancements in the longevity and efficiency of engines can be attributed to the field of tribology. For example, the development of synthetic oils by companies such as Mobil and AMSOIL in the early-to-mid 20th century drastically reduced engine wear and tear, allowing for extended periods between maintenance, enhancing fuel efficiency, and promoting sustainability!

AMSOIL would also go on to be heavily involved in developing synthetic oils for use in the aviation industry…

The jet age began with the development of the first commercial jet airliner, the De Havilland Comet, in the late 1940s. The field of tribology played a crucial role in making these marvels of engineering feasible. From bearings in propellers to more efficient fuels and oils, tribology and aviation have always been linked!

Ensuring low friction while maintaining structural integrity at high altitudes and freezing temperatures demands specialised lubricants, oils and fuels, and without such advances, commercial jet travel and military advancements in jet technology would have remained a distant dream.

As mentioned before, one pioneering group in this area was AMSOIL. Born in 1924 in Duluth, Minnesota, Albert J. Amatuzio founded AMSOIL after a notable career as a fighter pilot. Inspired by the synthetic oils he saw being used successfully in jets, he developed and commercialised synthetic oil for cars. In 1972, AMSOIL’s product was the first synthetic oil to get an official approval, leading to the tagline “The First in Synthetics.”

Tribology didn’t just stop it’s impact in-atmosphere though, and during the Space Race of the 1960s and 70s, tribology played an incredibly important role. Outer space presented unique challenges: extreme temperatures, vacuum conditions, and a lack of atmosphere. Lubricants needed to be designed to withstand the most extreme environments, and external machinery had to be designed with no expectation of being able to replace parts.

The Apollo moon missions and the subsequent space shuttles had moving parts that required lubrication – without which, the wear and tear would have been catastrophic. Some of the most important scientific equipment in mankind’s history is heavily dependent on tribological knowledge, for example the the Solar Array Drives of the Hubble Space Telescope were reliant on tribological knowledge to work, and to keep the solar arrays (panels) pointing towards the sun!

As the 20th century approached its final decades, the digital revolution took hold. Computers transitioned from being room-sized behemoths to personal devices, and at the heart of this transformation was the hard drive. Disk drives were commonly built with the platter (the things that look like disks), sitting on a support structure which itself was supported by ball bearings! These bearings were designed within miniscule tolerations, as any wobble of the platter could lead to damage and the loss of data!

In fact, most hard disc drives rotate at 7200rpm. That’s 120 revolutions a second, 10.3 million a day, and a whopping 3.8 billion a year!  Most hard disk drives are designed with a “mean time between failures” of 100,000 hours or more (sometimes up to 1,000,000 hours). That’s around 11 years, or about 40 billion revs of the platters! The bearings within disk drives are designed so precisely, that often the ultimate failure of the drive will be nothing to do with the bearings, but some other failure in the mechanism or electronics.

Tribology in the 20th century also played a role in our own health and wellbeing, especially in the field of joint replacement! The first full-hip replacement surgery (or hip arthroplasty) ever was performed by Sir John Charnley at Wrightington Hospital in 1962, and the continued success of joint replacements has been heavily dependent on tribological research.

Tribology guided everything from the choice of bio-compatible materials for implants (ensuring minimal wear and increased implant longevity), to the design of hip replacements that closely imitate natural joint motion. Furthermore, understanding natural joint lubrication spurred the development of biologically friendly lubricants for artificial joints, and tribological testing methods were used to evaluate the wear resistance of materials used in hip implants, ensuring their durability.

In retrospect, the 20th century was a period of rapid technological advancement and global change, and where tribology truly started to take the form that we know it as today. Influencing design decisions in everything from aeroplanes and cars, to joint replacements and space travel, the importance of tribology in the 20th century can’t be overstated!

If you’d like to read the previous posts in this series, follow the links below!

Keep an eye out for the next instalment of our History of Tribology series, coming soon