The shear vane test is a method of measuring the undrained shear strength of a cohesive soil. The test is carried out with equipment consisting of a rod with vanes mounted to it that is inserted into the ground and rotated. A gauge on the top of the rod measures the torque required to cause failure of the soil and provides a conversion to shear strength. The equipment has been in use since at least 1948. The equipment has also been used since at least 1967 to assess the shear strength of packs of snow at risk of forming a slab avalanche.