This paper reports progress towards characterizing the laser induced damage threshold (LIDT) for zinc selenide and copper components in CW/C02 laser optical systems. The work has been undertaken by industrial partners and research centres supported by the CRAFT initiative of the European Commission.Specimen surfaces have been characterized by a wide range of experimental methods, including absorption calorimetry. Thermal modelling on the basis of these observations indicates that the temperature rise in irradiated components is dominated by surface absorption, and that the maximum temperature rise is proportional to the ratio of the total power P to focal spot size d rather than to the areal power density.A CW/C02 laser damage facility has been constructed by one of the industrial partners. Preliminary. experiments have determined P/d values at the LIDT an order of magnitude less than those predicted by the measured level of surface absorption. SPIE Vol. 2714 / 281 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/15/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

Propellers of ships generate high velocities adjacent to quay walls, jetties and locks. Generally, a bottom protection is installed in order to prevent instability due to scour. Although design guidance exist, propeller-induced loads are far from fully understood and have predominantly been derived on the basis of model tests. The validation of the existing design methods is lacking, especially for specific types of bow thrusters. In this research, field measurements of flow velocities induced by a 4-channel bow thruster system against a vertical quay wall have been performed. Test results showed a flow characterized by low mean velocities and large fluctuations, with the extent of reflected flow limited to few meters from the quay wall and inflow beneath the suction points playing a role.