Marine Engineering and Naval Architecture

Single buoy or single point mooring :  Often larger ships which cannot approach ports and terminal are berthed outside the port limits or in sheltered anchorages and the cargo transfer carried out with the help of Single point or single buoy moorings. The basic principle of the buoy is to keep the position of the vessel with respect to the buoy steady and at the same time allowing vessels to swing to wind and sea.. Often a tug is provided at the aft to keep the ship at a fixed angle and distance from the buoy. The buoy is fixed by positioning it in the centre of four anchors connected to it. The ship is made fast to the buoy with the help of a single chain or two which is secured onboard to the bow stopper. In general while approaching Single point or single buoy moorings weather is a major criteria in determining whether to berth the vessel or not. Calm seas with low swell and wind force below 15kts are considered favorable to make an approach. Presence of strong tidal curren...

Mooring lines and docklines are being produced in various constructions (3-strand, double braided), materials (polyester, nylon, dyneema), diameters etc. First of all stretch in mooring lines is very important. The mooring line should be able to absorb shocks that are generated by waves or wind. The amount of stretch required is defined by the situation your yacht is moored. Marinas and harbours with good protection require minimal stretch, while mooring places in where you might experience big waves it is important to have great stretch. In this case even extra items may be required such as rubber stretchers. Stretch is being generated by the right construction and material used in the docklines. 3-strand construction generates very good stretch. The 3-strand construction is the oldest way of making ropes and still very effective for mooring lines! The disadvantage of 3-strand is that it might get a stiff after a while. The more modern double-braided ropes have 12-stra...