Abstract: A mobile tank for storing a liquid includes a bottom part, a top part and side walls extending from the bottom part to the top part to form a liquid reservoir. A safety rail is pivotably connected to an upper surface of the top part, which safety rail is pivotable from a laid down position into a raised position, and vice versa. The safety rail includes two, and only two, support legs positioned at a first distance from each other and extending in a flat plane. The safety rail further includes a rail part connected to upper ends of the support legs, which rail part extends in the plane and in a direction transverse to the support legs over a second distance being larger than the first distance of the support legs, the safety rail includes one, and only one, connector by which the safety rail is connected to the upper surface, and each of the support legs is at a lower end thereof pivotable coupled to the connector.