The M1A1 SA Abrams, confirmed to have arrived in Ukraine, is a 67.6 ton tank. This makes the Abrams much, much heavier than Soviet era thanks like the T-72B3 or the T-64 BM in use by the Ukrainian and Russian Armies, both of which weigh only 45 tons.
There is an assumption by some analysts that due to muddier conditions in Ukraine during the fall, winter and spring seasons, that the Abrams will struggle to handle the lighter terrain, and that lighter Soviet tanks will enjoy superior off-road mobility.
In reality, there is very little reason to believe this to be the case, as the Abrams enjoys a superior power-to-weight ratio, better traction, and superior weight distribution—the main things that go into off road mobility in muddy conditions. Indeed, the Abrams was essentially designed for a fight in conditions that can be expected in Zaporizhzhia in winter.
The Abrams tank began as an effort by NATO allies to develop a common Main Battle Tank (MBT) platform in the 1970s to counter a powerful new Soviet MBT then rumored to be about to enter service, which turned out to be the T-72.
This joint effort by the United States and West Germany, called the MBT-70, ultimately failed. West German and American militaries had different ideas for what they wanted from the new tank, and the need to appease both sets of requirements spiraled costs out of control.
German designers took their lessons learned to create the highly regarded successor to their Leopard tank, the Leopard 2. American designers ended up with the M1 Abrams tank, which entered service in 1980.
At that time, American planners were focused on the possibility of a major armored invasion by the Soviet-led Warsaw Pact into Western Europe through what’s known as the Fulda Gap, considered the most likely route of advance by a Soviet armored invasion force.
Both NATO Allies and Soviet forces deployed a large proportion of their forces opposite each other in this area of central Germany, and American weapons were designed with this central European battlefield foremost in their minds.
The Abrams tank very much reflects this focus.
Fortunately for Ukraine, the climate and weather of Tokmak, and more broadly Southern Ukraine, are extremely similar to Fulda, Germany. Tokmak and Fulda are both quite dry climates, with both only averaging about 2 inches of rain a month. Tokmak gets 9.2 days of rain/month, while Fulda gets 8.7. Both experience relatively mild winters with average highs rarely dipping below freezing for any length of time.
Fulda does not suffer weeks-long muddy seasons like Eastern or Northern Ukraine in fall or spring, but neither does southern Ukraine. Both will get mud during winter rainy months, but neither experience the muddy morass seen in battlefields around Kupyansk or Bakhmut. As such, in a typical fall or winter, the level of mud should be comparable to the Central European battlefields anticipated by the Abrams’ designers.
Thus, despite the fact the Abrams is over 50% heavier than Soviet tanks like the T-72 or T-64, it can actually perform better in mud because of
- its wide tracks that distribute weight over a wide area and give it superior traction, and
- Its powerful engine gives it a high power-to-weight ratio.
While many assume that its 70 tons will immobilize an Abrams tank in mud, particularly compared to lighter Soviet (or even other NATO) tanks, what actually matters isn’t the total weight of the tank, it’s how much ground pressure per square inch the weight pushes into the ground.
Think of it this way—put a 100 lb weight atop a thin metal pole, that weight will drive that pole into soft muddy ground. But add 100 lbs on a wide platform the size of a football field, that weight will barely put any pressure on the ground at all.
For example, the average person’s foot will exert about 16 psi on the ground. An average passenger car exerts more pressure, around 35 psi. But a road bike’s thin wheels exert a whopping 90 psi of ground pressure. Guess which one suffers most in mud.
Here’s the big one—the ground pressure of an M1A1 Abrams? Just 14.4 psi, less than that of a person walking on the ground. Due to its greater length and its wider tracks, the Abrams distributes its nearly 70-ton weight over a much wider area, thus the Abrams and the T-80 (13.1psi) have negligible differences in ground pressure.
Furthermore, the Abrams sports a powerful 1,500 hp Honeywell AGT 1500 gas turbine engine. It is a thirsty engine, consuming 1.5~3 gallons of fuel per mile (gallons per mile, not miles per gallon) depending on conditions. It consume almost as much fuel even when idling. And it runs most efficiently on jet fuel, rather than more commonly available gasoline or diesel. It is, quite simply, logistically demanding.
But it wasn’t for nothing that the Abrams designers chose this monstrously powerful engine. Tank mobility is largely a function of its power-to-weight ratio.
For example, Ukrainian tankers mostly rely on the T-64 BM on the battlefield. It is a fine and agile tank, well suited for the Ukrainian battlefield. It sports a 850hp engine on a 45-ton tank, or a 18.9 hp/ton power-to-weight ratio.
The M1A1 SA is a much, much heavier tank at 67.6 tons. But thanks to its 1,500 hp engine, it sports a superior power-to-weight ratio of 22.2 hp/ton. With tank treads that offer almost 50% more contact with the ground compared to the T-72, this combination of powerful engine and broad tank treads gives the Abrams greater traction.
As such, the Abrams is arguably better in muddy conditions than Ukraine’s smaller, lighter Soviet-era tanks.
The Abrams is not a wonder-weapon that will simply blow Russian defensive lines around Tokmak to smithereens. Like any other tank, it can be immobilized by land mines, aerial threats like Lancet drones and Ka-52 attack helicopters, and anti-tank guided missiles.
What can it do?
It can accurate strike enemy targets in day or night from close to the visual horizon. Its most advanced munition, the new M1147 Advanced Multi-purpose round, it can punch through 20 centimeters (8 inches) of solid concrete. The Abrams should make quick work of Russian bunkers and fortified positions, and its high explosive mode should be able to strike reinforced Russian trench positions with terrifying accuracy.
As Ukraine heads into the rainier fall and winter seasons of the South, analysts like George Barros at the Institute for the Study of War predict that Ukraine will continue to employ the same assault tactics it has employed in the past months.
That would be platoon size infantry groups attacking Russian positions, supported by artillery and a couple of infantry fighting vehicles and/or western tanks providing long range fire support. You can see that exact tactic in action in this video:
RUSI has noted that these tactics reduce the impact of landmines on Ukrainian assaults, minimizing risks to valuable western armored vehicles, while making use of their long range accuracy. They are low-risk, low-reward tactics aimed at inflicting maximal Russian losses, while minimizing Ukrainian losses—at the expense of faster, larger breakthroughs.
The Abrams will be extremely well suited for this kind of fighting. Its high mobility design will help with Ukraine’s hit and run tactics, but greater range and lethality will allow it to offer such support even further back from the main assault than the Soviet tank seen on the video above. And while Ukraine hasn’t made great use of Western night vision equipment thus far, the Abrams superior night-time optics will hopefully get put to greater use. Russia has far less ability to defend in the dark.
And if called upon, the Abrams will protect its crew thanks to its superior tungsten-reinforced Chobham armor (compared to say, the Leopard 2A4 which only has heavy tungsten reinforced armor on its front). There are plenty more Abrams in storage to replace battlefield losses. Tank crews are indispensable.
Ukraine’s grinding attritional attacks will be boosted considerably by the Abrams. Hopefully, more will be on the way in short order.
