Fighting in a tank
has never been the easiest job in the world. When first developed in WWI
, tanks were noisy, dangerous, and difficult to operate. (And that was before they even engaged the enemy
.) One of the most difficult tasks was aiming and firing the guns of the tank with any accuracy
In a tank that is standing still, it is relatively easy to aim and fire its guns, but that is an inadequate solution. Since a tank is basically a huge sign saying "fire everything you have at me", it is important that a tank stay in motion, as its speed and maneuverability are its primary survival tools. However, a tanks moving over any terrain rougher than a parade field will buck, wallow, dive, and roll as it moves. This makes firing very difficult. Tactics primarily involved moving to a firing point, stopping just long enough to shoot, and moving on.
After WWII, a number of vehicles, such as the British Centurion 5, were equipped with gyrostabilized gun mounts, which used a gyroscope to help steady the gun in a manner similar to "anti-shake" systems in video cameras. Such a system is a significant improvement over a free-floating gun in that it helps keep the gun steady in the gunner's hands. There was room for improvement, as the system did not compensate for target motion. (Thanks to The Custodian for reminding me of this important fact.)
The first electronic systems to aid the gunner were simple aiming aids like improved optics to more accurately point the gun at the target, and laser designators to precisely determine the target range. When electronic turret stabilization was first introduced at the end of the 20th Century (one of the first to have such a system was the M1 Abrams tank), it created a significant operational advantage over every other tank on the field. By using an electronic gyroscope as a stability reference, a computerized system can keep the barrel of the tank’s main gun steady and directed at the target, no matter what the tank is doing at the time. This meant for the first time a tank could fire on the move with a reasonable certainty that it could hit its target with the first shot.
Considering that the killing range of an armor-piercing fin-stabilized discarding-sabot tank round (APFSDS) is over 5,000 meters, this means that a tank on broken terrain with an electronic aiming and stability system (the Abrams increases this accuracy with a little wind sensor on the turret that helps it also calculate the windage) can hit anything it can see all the way to the horizon.
locke baron pointed out that it is worth noting that similar stabilization is also used in modern naval artillery - not so much for anti-ship fire, as for AA work. This is extra important for 57mm and 76mm weapons that can also act as a CIWS in addition to their more typical heavy-AA use.