by shipnerd1 » May 30, 2010, 9:21 pm
I did not see the photo you refer to but I work on a ship that regularly unloads stone at many of the undeveloped docks around the Great Lakes. The vessel is off the shore 30+ feet because, as you suggested, it is up against the shore under the visible water level. The ship maintains position because it is literally touching the shore below the water. To the casual obeserver, the ship is just floating in the middle of the river; however, this is not the case. The lines are usually left a little slack because as the vessel unloads it rises up out of the water. If the lines where left tight the vessel would heel over as it unloaded-creating a large amount of strain on the lines. Different ships have different winches -they all operate differently. On my ship we do not apply constant tension to the lines. Instead we set the lines how we want them and then apply the brake loosely. The ship is generally held in place but a big wind or a passing ship will cause the brake to slip. The lines are watched very closely and adjusted frequently. As also mentioned, ships may sometimes use their thruster to maintain position or assist with shifting the vessel along the dock. We use our lines to pull the vessel along the dock. The vessel can get stuck in the mud and the bow thruster can be used to help push the vessel off the shore to help it move. Depending on the situation, sometimes the engine must be used as well.
I did not see the photo you refer to but I work on a ship that regularly unloads stone at many of the undeveloped docks around the Great Lakes. The vessel is off the shore 30+ feet because, as you suggested, it is up against the shore under the visible water level. The ship maintains position because it is literally touching the shore below the water. To the casual obeserver, the ship is just floating in the middle of the river; however, this is not the case. The lines are usually left a little slack because as the vessel unloads it rises up out of the water. If the lines where left tight the vessel would heel over as it unloaded-creating a large amount of strain on the lines. Different ships have different winches -they all operate differently. On my ship we do not apply constant tension to the lines. Instead we set the lines how we want them and then apply the brake loosely. The ship is generally held in place but a big wind or a passing ship will cause the brake to slip. The lines are watched very closely and adjusted frequently. As also mentioned, ships may sometimes use their thruster to maintain position or assist with shifting the vessel along the dock. We use our lines to pull the vessel along the dock. The vessel can get stuck in the mud and the bow thruster can be used to help push the vessel off the shore to help it move. Depending on the situation, sometimes the engine must be used as well.