A shipping container (1, 2) locking system (10u, 10b) comprising: an actuating unit housed in an interior space of an upper corner fitting of a shipping container, said actuating unit comprising a compression plate and a vertical return means, said compression plate and vertical return means configured to move in a generally vertical direction and rotational direction within said interior space of the upper corner fitting; a locking mechanism at least partially housed in an interior space of a lower corner fitting of the shipping container, said locking mechanism comprising an internal locking leg and a body, each having a slot formed therethrough, said locking mechanism also comprising a locking leg shaft having a cylindrical section protruding through said slots of said internal locking leg and body and being connected to a locking leg having an elongated base; a coupling linkage, said coupling linkage connecting said actuating unit with said locking mechanism; a return means, said return means communicating elastically between said locking leg shaft and said internal locking leg and body, wherein a force can be applied about a central axis of the cylindrical section of said locking leg shaft; wherein a compressive force can be applied to said actuating unit to cause a generally vertical movement of said actuating unit; wherein a torsional force can be applied to said actuating unit to cause rotation of said actuating unit; wherein the rotation of said actuating unit imparts a tension force on said coupling linkage; wherein the tension force on said coupling linkage causes a movement of said coupling linkage; wherein the movement of said coupling linkage imparts a torsional force on the locking mechanism; and wherein the torsional force on the locking mechanism causes rotation of the locking mechanism. an actuating unit housed in an interior space of an upper corner fitting of a shipping container, said actuating unit comprising a compression plate and a vertical return means, said compression plate and vertical return means configured to move in a generally vertical direction and rotational direction within said interior space of the upper corner fitting; a locking mechanism at least partially housed in an interior space of a lower corner fitting of the shipping container, said locking mechanism comprising an internal locking leg and a body, each having a slot formed therethrough, said locking mechanism also comprising a locking leg shaft having a cylindrical section protruding through said slots of said internal locking leg and body and being connected to a locking leg having an elongated base; a coupling linkage, said coupling linkage connecting said actuating unit with said locking mechanism; a return means, said return means communicating elastically between said locking leg shaft and said internal locking leg and body, wherein a force can be applied about a central axis of the cylindrical section of said locking leg shaft; wherein a compressive force can be applied to said actuating unit to cause a generally vertical movement of said actuating unit; wherein a torsional force can be applied to said actuating unit to cause rotation of said actuating unit; wherein the rotation of said actuating unit imparts a tension force on said coupling linkage; wherein the tension force on said coupling linkage causes a movement of said coupling linkage; wherein the movement of said coupling linkage imparts a torsional force on the locking mechanism; and wherein the torsional force on the locking mechanism causes rotation of the locking mechanism.