The film illustrates the safety rules for the repair of water tanks and tanks. Experienced sailors are selected for cleaning the tanks, who are familiar with the signaling by means of the safety end. The mechanic gives instructions before starting work. The water tank is dried, a ventilation pipe is lowered into it. The ventilation works during the entire period of repair work. Before descending into the tank, the repairer puts on a safety belt, a protective mask with forced air supply, takes work tools and a rechargeable flashlight. His partner at the top holds a safety rope, he helps the worker at the bottom. Protective equipment lies near the observer: a helmet, a safety belt and a rechargeable flashlight. To carry out electric and gas welding works in a tank, the ship's captain signs a special permit. The mechanic gives out a rubber mat with galoshes. The repairman conducts welding work in the tank. Painting the tank with a roller, brush and from a spray gun in a protective mask with forced air supply in special clothing and footwear that meets sanitary rules. The observer at the top signals with a rope that it is time to rest (every hour for 15 minutes). The repairman goes upstairs. The mechanic takes the job inside the tank.