Foreword

In order to fully achieve the service life potential of Python™ and standard wire rope for demanding crane jobs, these step by step instructions should be followed. They are intended to prevent rope damage caused by kinks, untwisting, and loose strands during handling and installation.

We realize that the ‘real world’ is not perfect. This applies also to wire rope installation. It is impossible to cover ALL imaginable installation situations, location difficulties, and crane set ups. You will also find that these instructions are not very different from the installation procedure of 6-strand or 19×7 ropes. Many experienced Riggers may find some of the following “old hat”. If you notice any omissions or have ideas that we can incorporate into this brochure we will be most appreciative.

Measuring the rope diameter

Before you start anything, make sure the diameter of the new rope you are about to install is the correct one for your crane. Remember that most wire ropes measure slightly over their nominal diameter.

Standard rope is allowed to measure up to 5% over their nominal diameter. Some PYTHON® wire rope is made with a maximum 4% tolerance only.

The rope you are going to replace may be worn and may measure less than the rope you are about to install.

Keep a record of the new rope diameter for future references. You will be asked to determine how much the rope diameter has decreased in service and you MUST know the ACTUAL diameter of the wire rope after the break in period (click here for more info).

When measuring the rope, don’t measure the layer on the reel. Pull a couple of feet off the reel and measure the rope when straight. It is advisable to take 4 measurements of the rope round its axis and average the results.

4% Diameter Tolerances
Nominal Dia. mm Maximum Dia. mm Nominal Dia. inch Maximum Dia. inch
10 10.40 3/8 0.39
11 11.45 7/16 0.45
12 12.50 1/2 0.52
14 14.55 9/16 0.59
15 15.60 5/8 0.65
16 16.65 3/4 0.78
18 18.70 7/8 0.91
20 20.80 1 1.04
22 22.90 1-1/8 1.17
24 25.00 1-1/4 1.30
26 27.05 1-3/8 1.43
28 29.10 1-1/2 1.56
30 31.20 1-5/8 1.69
32 33.30 1-3/4 1.82
34 35.35 1-7/8 1.95
36 37.45 2 2.08
 
5% Diameter Tolerances
Nominal Dia. mm Maximum Dia. mm Nominal Dia. inch Maximum Dia. inch
10 10.50 3/8 0.395
11 11.50 7/16 0.46
12 12.60 1/2 0.525
14 14.70 9/16 0.59
15 15.70 5/8 0.65
16 16.80 3/4 0.79
18 18.90 7/8 0.92
20 21.00 1 1.05
22 23.10 1-1/8 1.18
24 25.20 1-1/4 1.31
26 27.30 1-3/8 1.44
28 29.40 1-1/2 1.58
30 31.50 1-5/8 1.71
32 33.60 1-3/4 1.84
34 35.70 1-7/8 1.97
36 37.80 2 2.10