Definition of the word sheet anchor

The term "sheet anchor" originated from the nautical world in the early 1800s. In sailing terminology, an anchor's weight is measured in pounds, and the larger ones were often referred to as "cable" anchors due to the rope (called cable) needed to secure them. These cable anchors were typically used as main anchors and primary sources of support for large ships in rough waters. However, there were smaller anchors, known as "cutter" or "kedge" anchors, which were used to help steady smaller boats in shallow water or for keeping them from drifting. In contrast, a "sheet anchor" was a smaller cable anchor, usually mounted on the opposite side of the ship from the main anchor, intended to provide additional, emergency support. The concept of the sheet anchor as a secondary or backup anchor became particularly crucial during naval engagements. Ships engaged in combat could suffer damage that made it difficult or unsafe to use the main anchor, in which case the sheet anchor - essentially a backup plan - could be a crucial line of defense. Ultimately, the term's association with naval matters and its history as an essential insurance policy against danger led to its figurative use in other areas, namely to refer to something that can provide a critical, backup source of support in situations where primary resources fail or become jeopardized.