Wire Rope & Line Reference
Three-Strand Nylon Rope
Best for anchor rode and dock lines - excellent stretch and shock absorption
| Diameter | Breaking Strength | Working Load (10:1) | Weight/100ft |
|---|---|---|---|
| 3/8" | 4,200 lbs | 420 lbs | 4.5 lbs |
| 1/2" | 7,200 lbs | 720 lbs | 8.0 lbs |
| 5/8" | 12,300 lbs | 1,230 lbs | 12.5 lbs |
| 3/4" | 16,700 lbs | 1,670 lbs | 18.0 lbs |
| 1" | 29,800 lbs | 2,980 lbs | 32.0 lbs |
Double Braid Polyester
Best for halyards and sheets - low stretch, excellent abrasion resistance
| Diameter | Breaking Strength | Working Load (5:1) | Weight/100ft |
|---|---|---|---|
| 5/16" | 4,000 lbs | 800 lbs | 3.5 lbs |
| 3/8" | 5,600 lbs | 1,120 lbs | 5.0 lbs |
| 7/16" | 7,500 lbs | 1,500 lbs | 6.5 lbs |
| 1/2" | 9,800 lbs | 1,960 lbs | 8.5 lbs |
| 5/8" | 14,800 lbs | 2,960 lbs | 13.0 lbs |
Dyneema/Spectra (HMPE)
High-tech fiber - minimal stretch, floats, excellent strength-to-weight
| Diameter | Breaking Strength | Equivalent Wire | Weight/100ft |
|---|---|---|---|
| 3/16" | 5,500 lbs | 1/8" wire | 0.9 lbs |
| 1/4" | 8,600 lbs | 5/32" wire | 1.5 lbs |
| 5/16" | 14,000 lbs | 3/16" wire | 2.3 lbs |
| 3/8" | 19,600 lbs | 1/4" wire | 3.3 lbs |
| 1/2" | 34,000 lbs | 5/16" wire | 5.8 lbs |
Line Selection Guide
Dock Lines
• Nylon - stretches to absorb shock
• Size: 3/8" per 10' of boat
• Length: 2/3 boat length minimum
Anchor Rode
• Nylon for shock absorption
• Chain leader for chafe protection
• 8× boat length minimum
Stainless Steel Wire Rope (7×19)
Most common for running rigging - flexible and strong
| Diameter | Breaking Strength | Working Load (5:1) | Weight/ft |
|---|---|---|---|
| 1/8" | 2,000 lbs | 400 lbs | 0.035 lbs |
| 5/32" | 3,000 lbs | 600 lbs | 0.050 lbs |
| 3/16" | 4,200 lbs | 840 lbs | 0.065 lbs |
| 1/4" | 7,000 lbs | 1,400 lbs | 0.116 lbs |
| 5/16" | 10,500 lbs | 2,100 lbs | 0.175 lbs |
| 3/8" | 14,400 lbs | 2,880 lbs | 0.260 lbs |
Stainless Steel Wire Rope (1×19)
Standing rigging - stiff, high strength, minimal stretch
| Diameter | Breaking Strength | Working Load (3:1) | Weight/ft |
|---|---|---|---|
| 1/8" | 2,100 lbs | 700 lbs | 0.032 lbs |
| 5/32" | 3,300 lbs | 1,100 lbs | 0.050 lbs |
| 3/16" | 4,700 lbs | 1,567 lbs | 0.072 lbs |
| 1/4" | 8,200 lbs | 2,733 lbs | 0.128 lbs |
| 9/32" | 10,300 lbs | 3,433 lbs | 0.163 lbs |
| 5/16" | 12,500 lbs | 4,167 lbs | 0.200 lbs |
Wire Rope Construction
1×19
Single strand, 19 wires. Stiff, high strength, used for standing rigging (shrouds, stays).
7×7
7 strands of 7 wires each. Semi-flexible, used for lifelines and light rigging.
7×19
7 strands of 19 wires each. Very flexible, ideal for running rigging.
Rod Rigging
Solid rod construction. Highest strength, minimal windage, used on performance boats.
Stainless Steel Shackles
| Pin Size | Working Load | Breaking Strength | Use With |
|---|---|---|---|
| 3/16" | 660 lbs | 3,300 lbs | Light blocks, small boats |
| 1/4" | 1,000 lbs | 5,000 lbs | 1/4" line/wire |
| 5/16" | 1,500 lbs | 7,500 lbs | 5/16" line/wire |
| 3/8" | 2,000 lbs | 10,000 lbs | 3/8" line/wire |
| 7/16" | 2,800 lbs | 14,000 lbs | 7/16" line/wire |
| 1/2" | 4,000 lbs | 20,000 lbs | 1/2" line/wire |
Thimbles
Always use thimbles when terminating line or wire in a loop around hardware
| Rope/Wire Size | Thimble Size | Notes |
|---|---|---|
| 3/16" - 1/4" | 1/4" | Light duty |
| 5/16" - 3/8" | 3/8" | Standard |
| 7/16" - 1/2" | 1/2" | Heavy duty |
| 9/16" - 5/8" | 5/8" | Anchor rode |
| 3/4" - 1" | 3/4" | Commercial |
Safety Factors
| Application | Safety Factor | Working Load |
|---|---|---|
| Standing Rigging | 3:1 | Breaking ÷ 3 |
| Running Rigging | 5:1 | Breaking ÷ 5 |
| Anchor Rode | 8:1 to 10:1 | Breaking ÷ 10 |
| Dock Lines | 10:1 | Breaking ÷ 10 |
| Life Safety | 15:1 | Breaking ÷ 15 |