One of the most common mistakes that manufacturers and service technicians find onboard are, crew greased the remote control wires of the davit winch. As you know the remote control wire goes through a series of pulleys before being led into the lifeboat so in times of emergency evacuation, no one is required to stand on the deck to lower the lifeboat. Grease, is tacky. Hence causes the pulley to not function well and will require extra force to pull. And when grease is left on the wire to dry, it comes in contact with dust, dirt and other nasty stuff that jams up the pulley.
Second common mistake, not using non-rotating and stainless steel wire rope. If wrong type of wire is installed, it will not last for the intended usage period. Mostly remote control wires will last for a good 2 years and more if well taken care of.
Remote control wire installed in the wrong direction. What I mean by this is, the wire rope should be installed in such a way when the drum is paying out, it is also rotating in the pay out direction. Some times, we find that the wire is installed in the opposite direction and if the lifeboar is lowered, it will cause something to break. Wire rope snap, pulley pulled out, lifeboat fibreglass top crack, etc...
Weight on the top pulley (the pulley that is just above the lifeboat top hatch) is too high when installed. There has to be some slack between the counter weight and the pulley so when the davit is activated to lower the lifeboat, there is enough leeway for the wire rope to move and the weight does not come in contact with the pulley, causing tension on the wire rope. The same must be observed when recovering the lifeboat, if the weight moves too close to the top pulley, stop operation and slack 1 rotation from the remote control wire drum.
If you have any topics you wish to explore, please write to me at francis.wong@npmarine.sg
N&P Maritime is Singapore based company specialising in Lifeboat & Davit inspection, repair, troubleshoot, sales & oommissioning of new equipment. Visit our page for more lifeboat & davit related information as well as our contact means.
