To find out how big the anchor chain is, use calipers to measure the wire diameter (the thickness of the metal link) for the primary size. You should also measure the pitch (the length of the inside) and the overall width to make sure it will work with the windlass. Make sure to measure a few links away from welds and buildup. The best way to do this is to measure the wire diameter and pitch to match the gypsy/wildcat on your windlass. This is important for the chain to work properly.
Table des matières
Tools and Prep for Accurate Measurement
Use calipers (vernier or digital) for the most accurate results. A ruler or tape measure can work, but they’re less precise, especially on worn or coated chain.
Before measuring, clean off salt crust and heavy paint. Then, select 5 random links to measure. Avoid links that are visibly worn, stretched, or deformed.
Step-by-Step: How to Measure Chain Link Dimensions
Measure 5 non-adjacent links, avoid the weld zone, and average the results. This reduces errors from individual bad links and gives a more accurate representation of your chain.
- Measure wire diameter (chain “size”): Measure the side of the link where the steel is round and consistent, away from the weld. Take multiple readings and calculate the average.
- Measure inside link length (pitch): Measure the inner length of the link from one inside edge to the other. This dimension is critical for gypsy compatibility.
- Measure inside link width: Measure the inner width from one inside edge to the other. While less sensitive than pitch, it still affects smooth gypsy engagement.
Quick checklist:
- Clean the link (remove crust and paint).
- Select 5 random links.
- Measure wire diameter away from the weld.
- Measure inside length and width.
- Average each dimension.
- Record units (mm or inches).
Recommended measurement record template:
| Objet | What to record | Example |
|---|---|---|
| Wire diameter | Avg of 5 readings | 8.0 mm |
| Inside length | Avg of 5 readings | 24.0 mm |
| Inside width | Avg of 5 readings | 10.0 mm |
| Notes | Wear/coating/stretch | “Light wear, cleaned” |
Common Anchor Chain Standards and Where They’re Used
Standards matter because two chains can share the same diameter but differ in pitch and width. This is often the root cause of windlass issues.
DIN 766 – Metric short-link chain
DIN 766 is a common metric short-link format defined by wire diameter and link geometry. It’s widely used where a calibrated fit is required.
If you’re matching a gypsy, confirm the inside length and width, not just the diameter.
ISO 4565 – Metric calibrated chain
ISO 4565 is a metric standard designed for windlass compatibility. It ensures consistent link dimensions for smooth gypsy operation.
If your windlass manual specifies ISO, use ISO, not “close enough” DIN, unless the manufacturer confirms compatibility.
BBB – Short-link chain in North America
BBB refers to a short-link chain pattern often paired with windlasses. Its links are more compact than general-purpose chains.
Don’t assume BBB matches a specific metric size. Measure and confirm against your gypsy’s specifications.
G4 (Hi-Test) – Stronger chain for U.S. anchoring
G4, or Hi-Test, is a high-strength chain commonly used in U.S. anchoring setups. However, strength doesn’t compensate for mismatched pitch. Even a strong chain can jam a gypsy.
DIN 766 reference dimensions (example guide; always verify with your supplier or windlass manual):
| Chain Size (mm) | Wire Diameter (mm) | Inside Length (mm) | Inside Width (mm) |
|---|---|---|---|
| 6 | 6 | 18.5 | 8 |
| 7 | 7 | 22 | 9 |
| 8 | 8 | 24 | 10 |
| 10 | 10 | 28 | 14 |
| 11 | 11 | 31 | 14 |
| 13 | 13 | 36 | 18 |
Chain-to-Windlass (Gypsy) Matching: The Practical Check
To match a windlass gypsy, you must match the chain’s diameter, inside length (pitch), and inside width to the gypsy’s specifications. Matching only the diameter is a gamble.
Start by checking your windlass manual or the gypsy markings. Look for the specified standard (DIN, ISO, BBB, or G4) and chain size. If the manual is unavailable, measure and compare your chain to the manufacturer’s chain table.
Once you’ve chosen a chain, test it. Feed a short length through the gypsy under light load and check for climbing, skipping, or binding.
Quick Selection Notes After Measuring
Once you’ve measured and identified the chain’s dimensions and standard, select a chain that matches your windlass calibration. This prevents costly wear and tear.
For strength, choose a chain grade designed for anchoring. Check the manufacturer’s working load limit (WLL) and breaking strength for your size. Avoid mixing different chain geometries in one rode if you’re using a windlass.
Keep the scope practical. In calm conditions, a 5:1 ratio works. For general use, aim for 7:1. In heavy weather, plan for 10:1 if you have enough room to swing.
Common Measurement Mistakes and Troubleshooting
Most “wrong size” issues come from measurement errors, not math mistakes. Fix the process, and the correct chain size becomes clear.
| Problem you see | Likely cause | What to do |
|---|---|---|
| Diameter seems inconsistent | Measured near weld or on a worn flat | Measure away from weld; use 5-link average. |
| Chain “almost fits” gypsy but skips | Pitch mismatch | Confirm inside length vs gypsy spec. |
| Measurements read too large | Salt crust or coating buildup | Clean down to steel before measuring. |
| Chain jams under load | Wrong standard or deformed links | Verify standard; inspect for stretch/deformation. |
| You’re between two sizes | Wear or mixed chain | Measure more links; treat as suspect chain. |
Résumé
Henger Shipping Supplies is dedicated to providing the best solutions d'équipements marins. We know that choosing the correct anchor chain is very important for safe and effective maritime operations. When picking anchor chains, you need to think about things like the vessel’s specs, the expected anchoring conditions, and any special safety needs.
FAQ
How many links should I measure for anchor chain size?
Measure 5 links and average the results. Avoid adjacent links and the weld area to reduce errors.
What if my measured size falls between two standard sizes?
Treat it as a warning. Worn or stretched chain, as well as coatings, can skew readings. Clean the chain, measure more links, and compare to the gypsy spec.
Can I measure anchor chain size with only a ruler?
Yes, but accuracy suffers. If you must use a ruler, measure carefully, repeat multiple times, and average the results. Calipers are more reliable.
How do I identify the standard of my existing chain?
Start with your windlass manual, then verify by measuring the chain’s geometry. Markings on the chain aren’t always clear. The combination of diameter, inside length, and inside width confirms the standard.
Can I mix different chain types or grades on the same ride?
Avoid mixing if you use a windlass. Different link geometries can bind or skip, even if the diameters look similar. If you must change chains, match the same standard and dimensions.
