An armoured train is a railway train protected with armour. Armoured trains usually include railroad cars armed with artillery, machine guns and autocannons, some also had slits used to fire small arms like pistols and rifles from the inside of the train, this feature was especially prevalent in earlier versions of armoured trains. For the most part they were used during the late 19th and early 20th centuries, when they offered an innovative way to quickly move large amounts of firepower. Most countries discontinued their use – road vehicles became much more powerful and offered more flexibility, and train tracks proved too vulnerable to sabotage as well as to attacks from the air. However, the Russian Federation used improvised armoured trains in the Second Chechen War of 1999–2009.