The equipment and techniques used at H. R. Wallingford Limited (HR) for testing the properties of estuarine muds are described. Erosion under unidirectional currents is measured in an annular flume; a relationship between shear strength, tau(e), and density, rho(d), is determined in the form: tau(e) = a rho(d)b. Self-weight consolidation tests are run in settling columns, with density profiles and excess pore pressures measured during the consolidation period. An empirical relationship between effective stress, sigma', and density is determined in the form: sigma' = a0 + a1-rho + a2-rho-2. Permeability, k, against density is determined in the form: log(k) = c0 + c1-rho.