Abstract: A mooring device having a pivotal joint which is subjected to shear strain or stress at a pin when in use. The pin is provided with at least one region having a cross section with a diameter smaller than that of the bearing surface of the pin. At least one pair of strain sensors is mounted in this region, and these are connected in an electrical circuit capable of indicating shear strain due to force applied to the pin. The pin is provided with means for keeping the plane of action of the strain sensors aligned substantially in the direction of any resultant applied force which produces the shear strain or stress.