Means for measuring the shear strength at large strains in the wedge shear test over about the same range of normal stresses as at peak strength are described. By the same means it is now possible to prolong the test for larger shear displacements when loading is near-vertical; to perform a reshear test on cut planes; to obtain a strength envelope using a single test mould; and to perform a multi-stage shear test if desired. A double-cut, cylindrical test mould is described which enables clays or fine gravels to be sheared, in the same moulds in which they have been compacted, along planes relevant to the slope stability of embankments. A sufficiently accurate shear strength envelope can be obtained from two such cylindrical wedge shear tests (cylwests) which can be performed within 1 h. A larger version of this set-up, using a portable frame and a prismatic box cut to provide a shear plane area of 900 cm2 as in the in situ wedge shear test (iswest), is also described. This version (priswest) has been used successfully for testing gravels and clays with particles up to 38mm. The results of priswests on 5mm-10mm gravel agree closely with those drained triaxial tests on the same material.