Rusted Steel: 5 Worst U.S. Tanks In Military History

Key Points and Summary: This analysis identifies the author’s picks for the five worst tanks involving US development, highlighting design flaws and performance issues.

-The list includes: the cancelled US/German MBT-70 (#1) plagued by complexity and cost; the M3 Stuart light tank (#2), outgunned and cramped; the M551 Sheridan airborne tank (#3), which suffered from thin armor and recoil problems despite its intended role; the M3 Lee/Grant medium tank (#4), known for its awkward, high-profile design; and the primitive Disston Tractor Tank (#5), an underpowered and slow 1930s concept.

-These examples showcase significant historical missteps in American armored vehicle design.

5 Worst U.S. Tanks Ever 

They can be rolling coffins, trapping their crew inside in a deathly inferno. They can have inferior armor or an underpowered gun. They can break down easily with difficult maintenance. I am talking about “bad news” tanks. The US Army and its allies have rolled around with some stinkers that are American-made.

Let’s examine the five worst U.S. tanks of all time.

The Disston Tractor Tank

The Disston Tractor Tank was a rolling bucket of bolts that should never have been built. William D. Disston created it in the mid-1930s. Disston owned companies that made saws and had an idea to build a tank on a six-ton tractor. He and other designers decided that a Caterpillar-made tractor chassis would do the job.

Despite their good intentions, they built a problem child.

The tank was actually just a basic metal box that could fit three crew members on top of the tractor. This metal box served as a turret with a 37mm gun and a .30 caliber machine gun. This thing was underpowered, with only a 4-cylinder engine that pushed out a paltry 47 horsepower.

The turtle-like tank had a terrible speed of only 6.5 miles per hour. It would have been destroyed easily. The Disston was presented to export customers, and they all balked at this hunk of junk except for Afghanistan, and several of them were still in storage in Kabul as of 2003.

The M3 Lee/Grant    

The M3 Lee/Grant was another dubious design that caused all sorts of problems for crews and maintenance workers. It was known as the Grant by British users. The M3 was used during World War Two. It did have a more powerful 75mm gun on the right side and a 37mm gun on the turret, so those armaments were a plus. However, it was difficult for the crew to man the guns due to tight quarters and aiming problems. 

The M3 also had a high silhouette, making it easy for the Germans to see even when hiding. The light armor made it susceptible to destruction by Nazi tanks and other anti-tank defenses. Still, the British used them in North Africa; some were even sent to the Soviet Union.

But hits by enemy shells caused rivets to break in the armor, rendering it useless. The M3 only served as a stopgap tank for the United States until the much better M4 Sherman was produced in numbers.

The M551 Sheridan

First, the M551 Sheridan was a budget boondoggle. The Army spent a total of $1.3 billion on its development and manufacture. The idea was a good one: Provide a light tank to paratroopers for better protection of dismounted troops. This would allow airborne forces to take control of airports and other critical infrastructure more easily. 

M551 Sheridan. Image Credit: Creative Commons.

The problem was the chassis was too light, and when the gun fired, the tank lifted off the ground, which could hurt the crew. The turret was also thin and had a lightweight aluminum hull. Making it droppable by parachute required lightweight, but this necessitated thin armor.

The aluminum hull could burn easily if hit. The M551 also had a low rate of fire – just two rounds a minute. The Sheridan was used in Vietnam without much success and even served until the 1990s, there just wasn’t another light tank to take its place.

M551 Sheridan. Light Tanks.

The M3 Stuart

The British used the American M3 Stuart light tank during the Lend-Lease program of World War Two. They quickly found out that the Germans outgunned them. The updated version deployed by the US Army was an attempt to fix the problem, but rounds still penetrated it from Nazi tank fire.

So, the best mission the M3 Stuart could do was reconnaissance. It had to stay on the flanks to ensure no German tanks could sneak around the main element.  

While deployed in the Pacific, the tank’s tall silhouette made it easier for the Japanese to track and blow up. When the revolving turret was engaged, the crew had no room to do their jobs. Despite the problems, the M3 Stuart was actually popular on the export market and fought many engagements around the world, but those pesky drawbacks kept it from being effective.

The MBT-70

The MBT-70 “super tank” was a dual project from the Americans and West Germans during the Cold War in the 1960s. It had some interesting innovations but ultimately failed due to problems with the language barrier during its design.

Engineers couldn’t speak much German, and the Germans couldn’t speak English that well. They had different ideas on what would make a great tank. The MBT-70 was also expensive and delayed for a significant amount of time.

However, the MBT-70 had a remote-controlled autocannon, which was considered a newfangled addition to tank warfare. All the crew served in the turret, which was lowered to increase survivability. Unfortunately, this design led to soldiers getting motion sickness.

The armor was not effective, and it didn’t test well during evaluation periods. The MBT-70 was finally canceled, but some of its innovations were used by future main battle tanks.

About the Author: Dr. Brent M. Eastwood

Brent M. Eastwood, PhD is the author of Don’t Turn Your Back On the World: a Conservative Foreign Policy and Humans, Machines, and Data: Future Trends in Warfare plus two other books. Brent was the founder and CEO of a tech firm that predicted world events using artificial intelligence. He served as a legislative fellow for US Senator Tim Scott and advised the senator on defense and foreign policy issues. He has taught at American University, George Washington University, and George Mason University. Brent is a former US Army Infantry officer. He can be followed on X @BMEastwood.