Page 56 - Bob Holtzman "The Field Guide to Knots How to Identify.."

Buying Rope

There are dozens of factors to consider when buying rope for a specific
purpose. One has to consider how it’s going to be used—the environment it

will be used in and the stresses it will incur—and weigh that against the
performance characteristics of different kinds of rope. These factors are
summarized in the table below.

Usage Considerations

Static versus dynamic uses Will the rope pretty much stay put when it’s in use (as when securing a
bundle) or will it be in motion (controlling a sail, for example)? Will it
rub against rough surfaces, making abrasion resistance important? Is
stretch desirable (for example, to absorb shock loads) or undesirable?

Strength and safety margin What continuous and shock loads will it be subject to? How large a
margin of safety is required?

Knotting requirements What kind of knots are required? Will the rope be tied tightly or loosely,
and will it be tied to itself, to other ropes, or to other objects? Will the
required knots force the rope into small-radius curves, and will they
diminish the strength of the rope significantly?
Friction Is it desirable or undesirable that the rope slides easily against itself or
against other objects? Will it be handled frequently? If so, will it offer
sufficient grip without excessive roughness?
Environmental exposure Will the rope be exposed to sunlight for a long time? Will it be wet when
it’s in use? Will it remain wet for long periods? Will it be exposed to high
heat, oil, or other chemicals?
Weight and size Is a large diameter desirable for easy gripping, or a small diameter for
easier knotting? What length of rope is needed? How much space and
weight-carrying capacity is available for storage and transportation?

Buoyancy Some ropes float and others sink in water. Is either characteristic relevant
to your application?

Appearance Are bright, easily recognized colors desirable, or is it preferable that the
rope blends in with its surroundings?

52