The VDDCSS-CON allows simple shear to be performed in two directions, rather than the standard single. This is achieved by having a secondary shear actuator that acts at 90 degrees to the primary shear actuator.

The VDDCSS-CON also allows the application of a confining pressure to the sample. The sample carriages are encased within an acrylic pressure cell. The application of confining pressure also allows back pressure to be applied to test specimens. This allows specimens to be back-pressure saturated, with excess pore pressures directly recorded during simple shear tests. When used as a variable direction machine, the secondary shear axis can be used independently of the other shear axis or in conjunction, therefore simple shear may be performed in any horizontal direction.