5 Landmark Offroad Vehicles

Look at the history of land transportation and such vehicles as Henry Ford’s Model T or Richard Trevithick's pioneering steam engine are sure to make the list. But some impressive engineering has been devoted to developing vehicles meant for offroad transportation. That’s due in no small part to the use cases for these machines: They must operate in uncontrolled conditions or carry impossibly heavy loads.

Here are five offroad vehicles that have achieved landmark status as awarded by ASME, which has designated more than 280 engineering landmarks over the last 50 years.
 

Lombard Steam Log Hauler

Logging operations must go deep into roadless forests to harvest trees. Sending in the loggers is easy, but bringing out the timber without roads can be a challenge, especially in winter when rivers (often used for floating logs) are iced over. At the turn of the 20th Century, several existing technologies, such as steam engines, large farm machinery, and continuous belts, were brought together by Alvin Orlando Lombard, a blacksmith from Waterville, Me. Lombard patented and built log haulers that resembled large, steam-powered snowmobiles. They featured a boiler similar to a small steam locomotive with tracks in the back for gripping snow and dirt and a set of skis in front for steering. (One member of the four-person crew had the unfortunate job of sitting at the front and operating the skis.)

A single hauler could pull a dozen or more sleds loaded with logs from the wilderness to the mill. One account states that a single hauler once pulled 24 sleds extending more than a quarter of a mile.

For more info: Lombard Steam Log Hauler
 

Holt Caterpillar Tractor

Engineers had developed steam tractors in the 19th Century, but steam power was tricky for farmers and other laborers to master. The gasoline-fueled internal combustion engine was a boon for automobiles (there’s a reason why the Stanley Steamer didn’t pan out) but it took time to develop engines powerful enough for agricultural and industrial transportation. The first practical demonstration of a gasoline-powered, continuous-track tractor—essentially the forerunner of machines like a bulldozer or other heavy earth-moving equipment—was conducted in 1904 by Stockton, Calif.-based Holt Manufacturing. Some of the first production units, manufactured between 1980 and 1913, were used in the building of the Los Angeles Aqueduct, while others towed howitzers in Europe during World War I.

For more info: Holt Caterpillar Tractor
 

Alligator Amphibian

While the term “offroad” is usually applied to land vehicles, the “Alligator” vehicle designed by Donald Roebling—a descendent of the family that designed and built the Brooklyn Bridge—could operate at sea as well. After a 1928 hurricane devastated communities near one of the family’s homes in Florida, Roebling set to work designing a hybrid vehicle that could do the job of both a boat and a truck. Instead of building it with separate propulsion systems for either water or land, Roebling developed a paddle-wheel track system. By adding cleats to a standard caterpillar-style track, the Alligator could crawl over land but use the cleats as paddles when floating.

Roebling continually improved the design of the Alligator over the course of the 1930s and then landed a large customer for his vehicle: The United States Marine Corps, which was looking for an amphibious assault craft that could ferry Marines from ships to shore. Vehicles based on the Alligator design saw combat in the Pacific during World War II and are still used by the Marine Corps.

For more info: Alligator Amphibian
 

Crawler Transporters

The Apollo program was marked by many firsts and records, but the crawler transporters are some of the most amazing. They met the challenge of how to move the Saturn V rocket, which needed to have its enormous components assembled in a controlled environment, to a launch site safely isolated in case of accident. The solution was a pair of 6 million-pound tractors with eight separate tracks to bear the weight of the machine and the 12-million-pound rocket. Both vehicles are 131 feet long and at the time they were built, they were the largest self-propelled vehicles in the world. The two crawler transporters are still in use and are expected to carry the Artemis 2 mission to the launchpad in late 2024.

For more info: Crawler Transporters of Launch Complex 39
 

Thrust SSC Supersonic Car

Black Rock Dry Lake in Nevada is extremely flat and featureless, perfect for vehicles attempting to set land speed records. In 1997, Thrust SSC broke more than a record—it broke the sound barrier. The 54-foot-long needle-nosed car is powered by two Rolls-Royce Spey turbofan engines, the type used in the Royal Air Force’s F-4 Phantom II jet fighter. On October 15, 1997, Thrust SSC achieved an average speed of 763 mph over a mile-long course. While the vehicle was optimized for speed, it is decidedly a gas guzzler: By one calculation, its fuel economy during its record-setting run was 0.05 miles per gallon.

For more info: Thrust SSC Supersonic Car

Jeffrey Winters is editor in chief of Mechanical Engineering magazine.