Tank desant
Tank desant is a military combined arms tactic, where infantry soldiers would ride into an attack on tanks. They dismount to fight on foot in the final phase of the assault. Desant is the Russian word for airborne or parachute drops, but it can be used more generally, describing amphibious landings or "tank desant".
This is very dangerous and inefficient; soldiers riding on a single tank are very vulnerable to machine gun and high explosive fire, and of course a tank would draw enemy fire. Smoke and covering fire may be used to reduce the hazards, but this tactic is mostly used by forces with a shortage of motor transport or armoured personnel carriers, and a low regard for their own soldiers' lives.
The tactic was institutionalized by the Soviet Red Army during the Second World War. Tank desant troops (tankodesantniki) were specialist infantry, trained in the technique. From WWII until the 1970s, Soviet tanks were built with hand-holds for this purpose.
Almost universal mechanization has rendered this tactic obsolete; most infantry rides inside special-purpose armoured personnel carriers or infantry fighting vehicles into battle.
Riding armoured vehicles
Other military forces, including U.S. troops in Vietnam, Soviets in Afghanistan, and Russians in Chechnya have chosen to ride atop their carriers while on patrol or routine movement, rather than inside them. In contrast to the offensive Soviet tank desant tactics of the Second World War, these were troops who wanted to get away from their vehicles in case of real ambush.
Fearing land mines and RPGs widely used guerillas, these servicemen refused to stay inside the personnel carriers—contravening normal standing orders. The reasons were the following:
- Explosive concussion inside the personnel compartment, caused by an RPG grenade or the land mine hitting the armour, was said to be more dangerous than enemy fire on the personnel mounted outside. It must be noted that most of these soldiers were wearing body armour, which reduced their fear of the enemy's firearms.
- Wounded and dead soldiers stuck inside were very unlikely to be extracted safely, especially if the vehicle was on fire.
The aluminum armour of U.S. M113 carriers was reputed to be highly flammable, although this reputation was likely due to the gasoline engine of the earliest version. Some American soldiers went as far as to improvise controls allowing the driver to be raised up out of the vehicle. See M113 modifications.
Soviet troops also adopted the tactic of riding the roofs of their BTRs (armoured personnel carriers), BMPs/BMDs (infantry fighting vehicles) and, rarely, tanks. Recently, during the Chechen war and other local conflicts of post-Soviet era, the units of the Russian Army and law enforcement acquired the tactic, making it a routine. However, riding the vehicles outside is still prohibited by Russian army doctrine, so it is not used during training and manoeuvres.