Anchors

book summary

Once man had taken to the water by boat and raft the need to hold a craft in a fixed position in a currente would have become obvious. The first anchors wre simply large stones attached by rope to the craft, but these were inefficient and mariners soon realised that the crucial factor was the weight of the anchor but its ability to dig itself into the bottom of the sea, lake or river. It was also found that the anchor cable needed to be in length between three and a half and five times the depth of water for maximum security. This book tells the fascinating story of how anchors evolved from their primitive origins to the special designs required for huge modern bulk carriers of half a million tons deadweight. Progress has been made largely by trial and error and only since the middle of the 20th century has there been scientific investigation into the design of high holding power anchors
From ancient times to the middle ages
The 16th, 17th and 18th centuries
The 19th century
Modern developments