Ukraine Is Getting Bridge-Laying Patton Tanks—Here’s Why They Didn’t Receive the Abrams Version
As part of a $400 million military assistance package announced on March 3, the United States is supplying Ukraine with its first M60 Pattons, a classic American Cold War tank. But while regular M60s were built to slug it out with Soviet T-55 and T-62 tanks, the unarmed version Ukraine is receiving an undisclosed number of might as well bear a sign that says “Do tread on me.”
That’s because they’re Armored Vehicle Launched Bridges (AVLBs) designed to unfold bridges over narrow water obstacles and large trenches and ditches—a process that takes just three minutes for M60 AVLBs. The bridge-launching vehicle then detach so that accompanying armored vehicles can roll across, likely somewhere the enemy doesn’t want or expect them to be. When the fording is complete, the AVLB can pack up its bridge on the other side (which may take 10 minutes) and rejoins the column.
Confirmation that the AVLBs mentioned by the Pentagon were M60s was reported by the The Drive’s Joe Trevithick. Most of the M60s AVLB’s turretless hull is occupied by hydraulics and batteries for deploying/undeploying the bridge; the crew two is nestled in the center hull.
Originally, the 53-ton M60 AVLB carried a 14-ton aluminum scissor bridge 18 meters long by 3.8 meters wide designed to support 60-ton vehicles. However, latera second 70-ton class bridge was developed to support the heavier M1 Abrams tank, though with restrictions (see below). This was followed in the 2010s by an even stronger 85-ton class bridge which may allow more flexible use.
Though heavily armored like a regular M60, AVLBs are unarmed, but can generate a smoke screen and launch smoke grenades to shroud their position. A sub-variant called the M60 AVLM can launch a 100-meter-long cable full of plastic explosives (line charges) to rapidly clear minefields.
Bridge-layers in Ukraine
AVLBs were first adopted during World War II, typically converted from Sherman, Churchill and Panzer IV tanks so that bridge-layers shared parts in common with those widely-used fighting vehicles.
While AVLB bridges can’t span larger rivers, they did, and still do enable tank and mechanized infantry to hop across smaller tributaries, or over broken spans of bridges in a matter of minutes, retaining the momentum of their advance, and potentially bypassing well-defended bridge crossings. And thanks to being, well, tanks, they were more likely than engineers riding soft-skin trucks to survive artillery fire directed at a fording point.
Rivers, marshes and trench warfare have substantially shaped Russia’s invasion begun in 2022. Ukraine is also notorious for its extremely muddy Spring and Fall weather (rasputitsa), and thus bridging over theoretically traversable shallow waters and mud can spare valuable heavy armored vehicles from bogging down, taking them out of the fight as surely (if not as permanently) as an anti-tank missile.
Ukraine began 2022 with a few dozen AVLBs based on the Soviet T-55 tanks (the MT-55 and MTU-20) and T-72 (the MTU-72). Kyiv’s forces also captured 16 truck-based TMM-3 bridge layers from Russia bearing 10.5-meter segments that can be linked together, and has received nine of 16 Bibers (“Beavers”) from Germany based on the fast but lightly armored Leopard 1 tank also entering Ukrainian service, that can lay 22-meter long bridges.
Unfortunately, those all were designed to accommodate 50-60 ton tanks, not better armored 60-75 ton Western main battle tanks Ukraine is receiving.
Even M60 AVLBs equipped with 70-ton class bridge have to observe restrictions for M1 tanks, including reducing gap-crossing distance to 15 meters, forbidding stopping or turning while on the bridge, and using stabilizing pins, cribbing and approach ramps to reduce stress on the bridge.
This article from the 1990s describes the challenges an Army engineers faced arranging a crossing for Marine M1A1 tanks in an exercise in Korea. However, with planning and rehearsals, the engineers managed to build the bridge, cross the tanks, and then pack up the bridge in less than in an hour.
Why Ukraine got bridge-laying Pattons instead of Abrams
The M60 was the last in the lineage of Cold War-series Patton tanks stretching back to the mid-1940s. From 1963-1967 an initial batch of M60 hulls were converted into AVLBs at the Anniston Army Depot in Alabama. A second run of M60A1s and M60A2s was converted 1987-1996. These vehicle saw combat use in Iraq in 1991 and 2003.
Israel used its own M60 AVLB—known as ‘Tagash’—in the Yom Kippur War and conflicts in Lebanon in 1982 and 2006. These remain in service, modified with track components from its indigenous Merkava tank, and option for the alternate Tzmedtandem-bridge system.
Portugal, Singapore, Spain and Pakistan also retain small M60 AVLB fleets.
Ukraine has received a menagerie of diverse military equipment from international donors—a situation increasingly true of its tank fleet, which will include German-designed Leopard 1 and 2s, American M1A2 Abrams, Slovakian M55S ‘super T-55s’, and British Challenger 2s.
But while Kyiv will gladly accept any weapons it can, Western analysts often bemoan the diversifying ‘zoo’ because each new type requires a separate pool and logistics pipeline of spare parts, and new training programs for crew and maintainers. That usually results in lower equipment readiness rates and a huge headache for logisticians.
So in theory, seeing as the U.S. is providing Ukraine with newly rebuilt M1A2 tanks, one would expect it to furnish Abrams-based bridge-laying tanks too. After all, the U.S. wants to replace its own M60 AVLBs because their maximum speed of 30 miles per hour meant they couldn’t keep up with Abrams (45 miles per hour or more) and Bradley vehicles (35-40 miles per hour), and because their bridges could only accommodate M1s moving at slow speeds.
Indeed, in the 1990s, an Abrams-based bridge layer called the M104 Wolverine Heavy Assault Bridge was developed, mounting mounted two segments for the 26-meter-long Leguan bridge, also mounted on some German Leopard 1 and 2 tanks. The bigger, two-part bridge could be deployed in 5 minutes and removed in 10.
The Army began procuring Wolverines in 2003, but only received of 44 of the planned 465 vehicles, as it was deemed too costly to maintain and operate—and willingness to invest in heavy armor capabilities was lacking in the War on Terror era.
Ultimately, the Army instead decided in 2016 to procure 337 new M1074 Joint Assault Bridge System (JABS) based on the M1A1 tank but with enhanced armor and engines, equipped with a shorter 18.3-meter bridge that can deploy in three minutes and support up to 95 tons.
However, according to The Military Balance 2021 the U.S. still had 230 M60 AVLBs on inventory and just 54 of the new M1074s. So the M60 AVLBs end up being what the U.S. could readily give to Ukraine without removing the newest equipment from its operational units.
To be fair, Ukraine is also receiving eight M88 Armored Recovery Vehicles for towing damaged tanks, also derived from the M60’s hull, and thus with some commonality with the M60 AVLB, including its 750-horsepower diesel engine. Washington could expand on Ukraine’s M60-based fleet by donating M728 Combat Engineering Vehicles armed with demolition guns and other devices to breach obstacles under enemy fire.
Kyiv could also theoretically go bargain hunting for regular M60 tanks, thousands of which remain in inventories around the world.
Like baking soda in cake, unarmed AVLBs are an a key ingredient of amore impressive whole—in this case mobile, mechanized warfare that can rapidly exploit gaps in enemy lines, forcing them to withdraw to avoid destruction or capture. That’s the kind of ambitious combined arms maneuver campaign Kyiv hopes it can wage this Spring to liberate swathes of Ukrainian territory occupied by Russian forces.
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