The second-generation mobile construction vehicle (abbreviated as MCV) was the heart of every battle force, regardless of faction, during the first and second iterations of the Third World War.
MCVs were armoured vehicles that could deploy into Allied, Soviet or Yuri construction yards and vice-versa. They were defenseless and slow, so they had to be escorted at all times. Despite their bulky appearance, their armour was quite weak.
In Red Alert 2 (through modding) and Yuri's Revenge version 1.000, mind-controlled mobile construction vehicles could be deployed. However, since this control was tied to the mind-controlling unit (in regular cases, only the Yuri's Revenge version of Yuri Prime could do this), if that unit was killed, the MCV could vanish if the construction yard was being undeployed. In Yuri's Revengepatch 1.001, mind-controlled MCVs were prevented from deploying and construction yards from undeploying - except if the mind control is done by a psychic dominator (as the controlled vehicle is not "bound" to any mind-controlling unit) to fix this bug.