PURPOSE: To introduce a fixed quantity-shipping system which, when a tank truck is loaded with a specified quantity of oil, prevents the load from overflowing the hatch and makes the shipment accurate in quantity.

CONSTITUTION: A shipment device for loading a tank truck with oil is equipped between an oil-feeding main 2 and a loading arm 5 with a flow-rate detector 3 and a flow-rate control valve 4. In a quantity control device 6 which takes in as input signals a flow-rate signal from a flow-rate detector 3, a liquid-level signal from a liquid-level detective means which detects the quantity of the liquid below the hatch of the tank truck, and a contact signal from a start-stop switch 7 attached close to the loading arm 5 standards for judgment to keep the oil from overflowing the hatch are provided. The flow-rate control valve 4 is opened or closed by the use of an interlock which, when there is oil remaining below the hatch, forbids the start of the fixed quantity-shipping operation.