Discussion on Papers 5–7

Paper 5

MR J. W. VAN DER MEER

The Hudson formula can be rewritten to give an expression where the stone diameter is directly related to the wave height. In the Hudson formula only one damage level is considered, but the Shore Protection Manual gives a table with higher damage levels. Using the data for rough quarry stone the Hudson formula can be extended with an expression for the damage level

15 H /AD =1.125 cot1/3a S°' qn s TLDKJ

(KD= 4; S = 2 is equivalent to 2.5% damage). More than 250 tests can be used to check the reliability of this Hudson formula, together with the results of Thompson and Shuttler of Wallingford. Fig. 1 presents all the test results. At the