Anker met thermometer handgemaakt van hout

In ancient times it was an anchor often only a large stone, a bag or basket with stones, a bag of sand or, at the Egyptians, a weighted tree stump. They held in place on the ship's weight. A major change was coming to the triangular anchor. Because of the shape it could get caught on a rock blocks, making it had a better holding force, in spite of the lower weight. The next major change was the use of a stick. In the first instance, used in wooden anchors, took care of a stone, and in that the armature later lead stick was forced to concentrate, so that one of the two sides could dig into. The latter type is considered to be metallic anchor, although it consisted in part out of wood. The Greeks were the first of which it is known that they used metal anchors; the Romans used iron anchors that are surprisingly similar to modern pole anchors, although still equipped with straight arms. In 1813 anchors with bent arms were introduced and from 1852 was used by the Royal Navy Admiralty Anchor. In 1821 the stick-free anchor was invented. Due to the flow, or arms, to make a small angle under hinged, it could burrow itself without a stick was needed. This made the use of the anchor is much easier. By making use of chain instead of rope - as a rule of thumb, with a length of at least three times the depth of the water - can be ensured that the tensile force at the location of the anchor is directed horizontally. When an upwardly directed force, most anchors will be pulled out of the soil and largely lose their holding power. From this property shall be used when the lights of the anchor.

 
Woodcarving