The cone penetration test (CPT) represents the leading tool to assess the in situ state PSI, strength, and liquefaction susceptibility of sandy soils and mine tailings. Much of the interpretation of CPT results in such geomaterials is based on the results of calibration chamber test programs on sand and, increasingly, mine tailings. While these efforts have led to the current procedures to interpret CPT data, two factors relevant to CPT application and interpretation require consideration: (i) the available calibration chamber experimental data set is dominated by tests with consolidated effective stresses < 600 kPa, and (ii) tailings storage facilities (TSFs) are being constructed to significant and increasing heights, such that in situ stresses are far higher than those of the available calibration chamber test database. While much of CPT interpretation is carried out in a dimensionless framework, there is clear evidence that – even across the range of stresses for which calibration chamber tests have been carried out – relationships between some forms of stress-normalised cone resistance and PSI are dependent on effective stress. This stress-dependence is usually attributed to a variation in shear rigidity with effective stress. However, at the increasingly high stresses relevant to TSFs, other factors such as the curvature of the critical state line (CSL) are likely to play a role. To provide further information on the cone resistance of sands at high stresses, a new calibration chamber and miniature CPT capable of testing soils consolidated to up to 2000 kPa are outlined. Initial results from the system for tests carried out across a wide range of stresses are presented.