Yachting Monthly — November 2017

68 http://www.yachtingmonthly.com November 2017

How we tested

We visited Marlow Ropes in Hailsham where I met technical manager,

Paul Dyer. Four types of 10mm rope were chosen, in order of breaking

load: a three-strand pre-stretched polyester; Marlowbraid, a twisted

three-strand polyester core with a 16-plait polyester cover; Doublebraid,

a 12-strand braided polyester core with a 24-plait polyester cover and,

finally, D2 Racing which has a 7mm SK78 12-strand Dyneema core with

a 24-plait cover.

The ropes were fitted into lead-lined tapering jaws in one end of

Marlow’s Class 1 calibrated 30-tonne test machine. The machine has an

allowable 1% error on the load cell. For the loads and consistency we

used a shackle, with a 10mm body and a 5-tonne work load limit, at the

other end. We also tested the strongest loop against a Dyneema shackle

to see whether the small diameter of the shackle has an adverse affect

on the loop of a rope. Finally we tested to see whether there was any

difference in strength between a left handed and right handed bowline.

The knoTs

Round turn and two half hitches

A simple knot to tie, as the instructions are in its name. It's
important to remember to do the half hitches so the rope keeps
passing around the standing part in the same direction. In effect,
making a clove hitch, not a cow hitch. If pressure on the knot is
intermittent, it’s possible for this knot to work free.

Anchor Bend

Similar to the round turn and two half hitches, except the

first half-hitch passes through the turns next to the shackle.

Interestingly, this new position for the first half hitch increased

the retained strength in three strand and Doublebraid, but

reduced it in Marlowbraid. It is however more secure than the

round turn and two half hitches.

To a shackle or padeye

This group of knots were tested for use with a shackle on a halyard, or a quick-release shackle for a spinnaker sheet etc, or used to secure
a line to a padeye. If the rope you’re attaching is to be subjected to a high load, it’s highly possible these knots would have to be cut off.

*Slipped through
**Cover broke, enabling the core to slip through the knot

3 Strand 2640 1580 59.8

Marlowbraid 2850 2420 84.9

Doublebraid 3690 1330* 36.0

D2 Racing 5360 1830** 34.1

Round tuRn and two half-hitches

*Cover broke, enabling the Dyneema core to slip through the knot

3 Strand 2640 1680 63.6

Marlowbraid 2850 1860 65.3

Doublebraid 3690 1660 45.0

D2 Racing 5360 1730* 32.3

anchoR bend

Rope Break

Load (kg)

Knot Break

Load (kg)

% Strength

retained

Type of

Rope

Rope Break

Load (kg)

Knot Break

Load (kg)

% Strength

retained

Type of

Rope

A simple knot to tie, but it

can work free in use

More secure

than the round

turn and two

half hitches

Technical