Anchoring
Anchors come in a huge variety of shapes and sizes. Some are centuries old and some are much more recent. They all share the same purpose, to keep a vessel in a fixed location, hopefully safely.
For all the variety of design all anchors have some common features.
Most seafarers will tell you that when it comes to anchors there is no substitute for kgs. Weight works.
Here we will look at some of the basic designs.
We will also look at the main points to consider when getting an anchor ready to deploy.
One of the things that helps an anchor hold better is if it has a large surface area. Think how much harder it is to get a welly out of mud compared with your foot.
For all the variety of design all anchors have some common features.
Most seafarers will tell you that when it comes to anchors there is no substitute for kgs. Weight works.
Here we will look at some of the basic designs.
We will also look at the main points to consider when getting an anchor ready to deploy.
One of the things that helps an anchor hold better is if it has a large surface area. Think how much harder it is to get a welly out of mud compared with your foot.
Fisherman (Admiralty)
Danforth Anchor
Learning by doing!
How about getting a few different types of anchor together and taking them to suitable beach. Attach different lengths of rode to them and try to defeat the anchor in a tug-o-war. Are some Anchors better than others? What happens when you put a longer or shorter rode on them? What if you add some chain at the anchor?
Preparing to deploy an anchor
The person in charge of the boat needs to consider where to anchor.
In picking an anchorage they need to bear in mind; Shelter from the wind, from tidal flows and waves now and for as long as you plan to be at anchor. Scope to swing around the anchor as wind and tide change without bashing into rocks or other craft. Depth. That there will be enough water to float safely even when the tide goes out. Seabed. Some seabeds are better than others. From best to worst is Mud, soft sand, hard sand, shingle, rock, seaweed but different anchors are more suited to different seabeds. The bowman also has an important role. First make sure that the anchor rode (the rope) is secured to the anchor chain with an anchor hitch properly seized. Also make sure that the anchor rode is secured to the boat. This may be a bowline, a round-turn-and-two-half-hitches or to a cleat. Make sure the anchor is set up. This applies only to collapsing anchors of whatever design. Make sure the anchor line is not tangled and is free to run. When the cox gives the command have the anchor hanging from the fair-lead/bow-roller and then on command let go the anchor and feed out the anchor rode. A good bowman will be able to tell when the anchor touches the seabed and know how much rode has been taken and so the depth. The cox will allow the boat to drift back with the wind or by rowing//motoring astern. This helps the anchor rode feed out and when the required amount is out, to help dig the anchor in. The absolute minimum should be 3 times the depth of water. 5 times the depth is the usual guide and if strong winds are expected 7-10 times the depth is advised. The bowman should check if the anchor is holding by hauling on the rode(does the boat move) and by watching to see if the shore is moving by! |