Harbour Series

Harbour-3

Name: Harbour-3
Brand: Ropebraiders

Three-strand nylon. Still the correct answer for an anchor rode.

3-Strand TwistedNylon Splice 95%

Schematic — Three twisted strands

Still right for the job it was invented for. Harbour-3 stretches under surge, grips a windlass gypsy, splices in minutes, and is cheap.

When to specify this

Do not over-engineer an anchor rode. Elongation is a feature and gypsy compatibility is mandatory on most windlasses. Braid is worse at both.

Engineering notes

Runs on standard windlass gypsies. Braided line does not
Splices to a chain rode in minutes with no special tools
High elongation cushions the snatch loads that break ground tackle
Strand damage is visible without opening the rope

At a glance

Max break strength: 25,000 lb
Diameter range: 3/8" – 1"
Construction: 3-Strand Twisted
Fibre: Nylon
Elongation @ 30% MBS: 14%
Splice efficiency: 95%
Torque balanced: No

Standard colours

White · Black

Certification

ISO 9001 batch traceability

Request a quote Calculate working load

Full spec sheet and batch test certificate supplied with every order, and on request beforehand.

Typical applications

Marine & Yachting

Specifications

Minimum break strength is the value we publish and test to — not an average, and not a working load. Divide by your design factor before putting a number on a drawing.

Harbour-3 specifications by nominal diameter
Diameter	Min. break strength (lb)	Weight (lb/100 ft)	Working load @ 5:1
3/8"	3,700	3.6	740 lb
1/2"	6,400	6.2	1,280 lb
5/8"	10,400	10	2,080 lb
3/4"	14,200	14.5	2,840 lb
7/8"	20,000	20	4,000 lb
1"	25,000	26	5,000 lb

Working load shown at a 5:1 design factor for illustration only. Use the load calculator to apply the design factor, sling angle and termination efficiency your application actually requires.

Weights are nominal and vary ±5% with finish and coating. Elongation measured on new rope after bedding-in; expect higher values on the first cycle. Splice efficiency assumes a correctly made splice with the specified bury length.

Load against elongation

Measured to 30% of MBS. Beyond that the curve is extrapolated from the fibre, and drawn dashed to say so.

Load vs. elongation

Harbour-3 — stretch under load

Elongation as a percentage of original length, plotted against load as a percentage of minimum break strength. Drag, or focus the plot and use the arrow keys, to read any point off the curve.

Elongation: 14 %
Load: 30 % MBS
Stretch / 100 ft: 168 in
Source: Measured

Solid — measured at 10, 20 and 30% of minimum break strength, interpolated with a monotone cubic so the fit cannot overshoot.
Dashed — extrapolated to 20% using published Nylon elongation at break. Inferred, not measured. Do not design to it.
Shaded — working load at a 5:1 design factor, i.e. up to 20% of MBS.

Harbour-3 load against elongation. Load is a percentage of minimum break strength; elongation is a percentage of original length.
Load (% of MBS)	Elongation (%)	Source
0	0	Origin
10	5	Measured
20	9.5	Measured
30	14	Measured
100 (break)	20	Extrapolated from Nylon elongation at break

Strength to weight

Break strength per pound of rope, across the catalogue. This is the number that decides what a two-person crew can rig.

Strength-to-weight

12 ropes, ranked highest first

STRENGTH-TO-WEIGHT — LB PER LB/100 FT

Break strength divided by weight per 100 ft, best size in each range. Numerically this is breaking length in hundreds of feet — the length of rope whose own weight equals its break strength.

Strength-to-weight by product, highest first, in lb per lb/100 ft.
Rank	Product	Strength-to-weight
1	Apex-12	6,615
2	Apex-12 MAX	6,290
3	Vector-PC	3,793
4	Thermion-AR	3,136
5	Datum-LCP	3,125
6	Meridian Hybrid	2,663
7	Ascent NFPA-G	1,322
8	Meridian-DB	1,143
9	Canopy-24	1,063
10	Harbour-3 (this rope)	1,040
11	Surge-8	1,000
12	Drift-PP	809