In Ukraine, landmines have once more proved to be the most common cause of armored vehicles being lost. The mines don’t destroy the tanks, they damage its track-laying mobility system, rendering the tank unable to move. As any experienced tank user will tell you, the major cause of tank losses is the loss of mobility in combat. The track-laying system is essential for mobility but also a major vulnerability. Even when not in combat, a tank driver can drive through broken terrain and encounter an obstacle like a tree stump or similar items that if not avoided, will cause the tank to “throw a track”. That means the tracklaying system on one side of the tank fails and a track detaches from the running wheels that keep the tracks, and the tank, moving. The crew will then have to get out and manually reattach the track to the road wheels. Sometimes this requires undamaged tracks to replace damaged ones. Tanks usually carry some spare tracks and one or more road wheels on the outside of the tank.
Repairing a thrown track is one of the more tedious and unpopular jobs for a tank crew. Doing this in combat is generally impossible. Unless your forces push the enemy away from where disabled tanks are, the immobilized tanks are not going to get fixed. Another issue is the durability of tank tracks and how long they will last. Sets of tank tracks are generally good for over 2,000 kilometers before replacement is needed. Track life can be reduced by the kind of terrain the tank is moving across.
Over the last two decades more durable and easier to refurbish tracks have been developed. This is important because there are not always enough tank transporter trucks available to move immobile tanks long distances.
Lighter armored vehicles, like the American M-2 IFVs (Infantry Fighting Vehicle) also run on metal tracks that have rubber pads attached to save wear and tear on roads and give better traction. Naturally, the rubber pads, as well as the entire track, wear out. Normally, a heavily used M-2 might need a new set of tracks once a year. In 2003 there were nearly 700 M-2s in Iraq, and many needed new tracks every few months. A set of tracks is normally good for 1,300-1,600 kilometers of travel. To keep the M-2s in Iraq supplied with replacement tracks, the army's only depot that refurbishes worn tracks, with about 80 percent of the track reused, had had to go from one shift a day, five days a week, to 24/7 production. Even at that, stocks worldwide were nearly depleted by the end of the year. That was one reason for the rush to get more armored Humvees over to Iraq. These don't have tracks and were nearly as resistant to Iraqi attacks as the M-2s are. Actually, in many cases, the M-2s were used in low-risk situations because they are the only combat vehicle available. Meanwhile the army had to face the fact that a larger war, calling on more of the 6,000 M-2s in U.S. service would not be practical.
The first combat for the M-2 was in 1991, but that lasted less than a week and gave the impression that all was well. In Iraq, the fighting went on for years and the M-2 got heavier. Eventually the M-2 was found to have a serious weight problem. When the vehicle first appeared in the early 1980s it weighed 25 tons. By 2006 M-2s weighed about 36 tons, which was about what most World War 2 tanks weighed. The increase comes from added equipment and, especially, armor. This makes the M-2 RPG proof, but the extra weight has been hell on the M-2’s most vulnerable component, the tracks it runs on. By the time 2003 rolled around, additional weight meant that a set of tracks lasted about 1,400 kilometers. But still more weight was added (more armor), and it got to the point (in 2006) where tracks had to be changed after only 700 kilometers. This meant that M-2s in combat might need several new sets of tracks a year. Changing tracks is hard, sweaty work, especially in tropical Iraq. The crews do most of the work, and they don't like it. By 2006, the army had designed a new set of tracks that was good for about 4,000 kilometers. The refurb included new tracks, as well as replacing other worn out or damaged equipment, and adding new items, usually electronics.
By 2011 the army had decided to replace most of the M-2s with wheeled armored vehicles like Stryker, MRAPs and armored Humvees. At that point the army was also undergoing a reorganization, which included converting some mech brigades that normally use M-2s with Stryker wheeled armored vehicles. There were proposals to equip some combat brigades with MRAPs on a permanent basis but that never happened. Thousands of MRAPS were put into storage, just in case. The Strykers and armored hummers were deemed adequate for peacetime training and the initial stages of a war. Most importantly the Strykers cost half the $2.4 million cost of an M-2 and the armored hummers were cheaper still.