The restoring force exerted by gravity acts in a vertical line from the centre of gravity; and the length of its lever arm is the horizontal distance between this vertical line and the outer rail.
In addition, it also helps to minimize offset errors and MRU lever arm effects on the bathymetry data.
For upgrades and where internal space is at a premium, a lever arm rotary damper can be adopted.
This involved changing from lever arm dampers with coil springs to telescopic dampers and torsion bars.
From consideration of the rigid triangular frame described above, it is clear that the " overturning " force acts horizontally from the centre of gra'Vity, and that the length of its lever arm is, at any instant, the vertical distance from the centre of gravity to the level of the outer rail.
