A self contained mobile assembly capable of use for remote area maintenance and repair of unwanted damage to a wall of a confined space tanks. The assembly comprises an undercarriage carriage including a wheel base, a housing mounted above the wheel base and defining an internal space capable of receiving and retaining repair and maintenance equipment for repairing said tank. The equipment includes a defouling kit, equipment for desealing and resealing of an interior of the confined space tank, equipment for decontamination of air in the tank; and a breathing kit for a wearer to safely access the internal space and repair the unwanted damage from the inside of the confined space.