iv) a 250 m range smoke grenade launcher assembly which fires automatically if the laser warning device is activated to lay down a thermal sight defeating smoke screen, v) additional armour on the glacis to improve protection against some SABOT round types and ATGW. The weight penalty is considerable and can affect vehicle handling if the engine has not been upgraded. vi) improved engine and track suspension features to enhance crosscountry mobility and offset increased vehicle weight vii) thermal sleeve for the main armament. Subsequently it was found that the modernisation programme had in fact been undertaken on a much wider scale in a number of the then Warsaw Pact nations and included a number of local variations. The modified T-54/ T-S5 vehicles serve with the Bulgarian, CIS, Hungarian, Polish and Russian armies, They were also used by the former East German army (including the AT-10 equipped Russian T-55AM2PB and Czechoslovakian T-55AM2B models).
Known variants of the T-54/55 modernisation programme include: T-B4AM2 - Czechoslovakian Army rebuild of T-54 command tank with Kladivo fire control. T-54AMK - Czechoslovakian Army rebuild of T-54K command tank with Kladivo fire control. T-55AM - Czechoslovakian built T-55AM with Kladivo fire control system. Also used by Hungarian Army. T-55AM1 - Czechoslovakian Army rebuild of T-55 with Kladivo fire control system. Also Russian T-55A(M) with laser rangefinder and armoured side skirts. Also used by Bulgarian Army. Also Polish Army rebuild of T-55 with locally developed Merida fire control system instead of the Klavido. T-55AM2 - Russian T-55A(M) rebuild with full armour upgrade package, laser rangefinder and upgraded fire control system. Also used by Bulgarian Army. Also Czechoslovakian T-55 rebuild with Klavido fire control system and new engine. T-B5AM2B.- Czechoslovakian T-55 rebuild with full armour upgrade, Kladivo fire control system and integration of
the AT-10 Stabber laser beam-riding ATGW with its associated 1K13 day/night sighting system. T-55AM2P - Polish version of T-55AM2B using locally developed Merida fire control system in place of Klavido. T-5SAM2PB - Russian version of T-55AM2B using own Volna fire control system in place of Klavido. T-55AM2K - Czechoslovakian T-55K commander's tank rebuild with Kladivo fire control system and new engine. T-55MV - Russian T-55M upgraded with explosive reactive armour package. T-55AMV - Further improved Russian T-55MV with the addition of a new commander's periscope, the use of T-72 running gear components and replacement of the 12.7 mm DShK AA machine gun by a 12.7 mm NSV model. The use of the ERA package increases the armour protection by 25% but adds another 1500 kg or so to the total combat weight. NOTE: All the former Czechoslovakian Army modified T-54/55 tanks mentioned above are used by the Czech Republic and Slovakian Republic.
