Hydraulically operated equipment, such as the cranes of the rescue boats, are also exposed to these
cranes of rescue boats are also exposed to these conditions and are therefore at increased risk of failure if required.
Due to high humidity and long downtimes of the hydraulic system, the risk of condensation in the tank is particularly high. Diffusion in the air will cause moisture to continuously enter the hydraulic tank, remain there, and condense the next evening when the temperature drops below the dew point. Contamination of the hydraulic oil is thus pre-programmed and ensures failure when rescue systems are needed. In addition, biodegradable hydraulic oil is increasingly being used so as not to pollute the environment in the event of a leak. However, these synthetic esters are highly hygroscopic and attract atmospheric moisture to subsequently decompose and cause premature aging due to hydrolysis.
During the voyage, the temperature on the ship’s deck fluctuates greatly. For example, ambient air during the day at 20°C and 90%RH already has a dew point of 18.2°C. Thus, the water bound in the air of 15.5g/m³ will liquefy when the temperature falls below this level. The result is water in the oil, the promotion of corrosion, hydrolysis and, in the worst case, total failure.