How to stay put with a snub­ber

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At its most ba­sic, a “snub­ber” is a short length of non-stretchy cordage at­tached to the an­chor chain and to a strong point on a yacht, with the aim of tak­ing the load off the wind­lass or to stop the chain rat­tling on the bow roller. A wind­lass is not de­signed to take snatch loads, nor, typ­i­cally, is the deck to which it is at­tached.

More com­monly, the term de­scribes a long piece of cordage that cush­ions the boat from snatch load­ing. Typ­i­cally, ny­lon rope is used for a snub­ber. Ny­lon stretches about 40 per­cent at break­ing point, but about 10 per­cent is con­sid­ered the safe work­ing load limit (WLL). The more cy­cles above 10 per­cent of WLL, the shorter the life. Ny­lon’s elas­tic­ity is a func­tion of weight—the thin­ner (less weight) it is, the eas­ier it will stretch—and by mea­sur­ing weight per me­ter it is pos­si­ble to cal­cu­late ex­ten­sion.

Ny­lon is not the only cordage you can use as a snub­ber. Polyester is also suit­able, although it lacks the de­gree of elas­tic­ity of ny­lon, so you will need longer lengths to achieve the same per­for­mance. In the un­likely event you can­not source ny­lon, then polyester is an al­ter­na­tive, but ny­lon is the most suit­able.

AB­SORB­ING EN­ERGY

Snatch loads are all about en­ergy—the en­ergy of a mov­ing yacht. If a yacht sails at an­chor, it de­vel­ops mo­men­tum, or ki­netic en­ergy. En­ergy is mea­sured in joules and is de­fined as:

En­ergy, joules = 0.5(mass, weight, kgs) x (ve­loc­ity m/sec)2

The vast ma­jor­ity of cruis­ers will never ex­pe­ri­ence a blow such as this in an an­chor­age, but that’s no rea­son not to pre­pare for the worst. Inset: an an­chor snub­ber at work

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