What is Chainplates?
Chainplates are metal plates (usually stainless steel) that connect the standing rigging to the boat's hull structure. They transfer the enormous loads from the rigging to the boat's structural framework.
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What it is
Chainplates are metal plates (usually stainless steel) that connect the standing rigging to the boat's hull structure. They transfer the enormous loads from the rigging to the boat's structural framework. Chainplates can be external (mounted on the outside of the hull) or internal (passing through the deck). They're typically through-bolted to structural bulkheads or substantial backing plates and sealed where they penetrate the deck to prevent water intrusion.
What it does
Chainplates are the critical link between your boat's rigging and hull structure.They distribute the tremendous forces from the mast and sails across the hull's strongest structural points. Cap shroud and primary shroud chainplates can experience loads exceeding the weight of the boat in heavy weather. They must be sized, positioned, and fastened to handle these forces without failing, bending or pulling out. Proper deck sealing prevents water from following chainplates below deck, where it can cause hidden rot or damage.
Why it matters
Chainplate failure is a catastrophic event that can lead to rig loss. If a chainplate fails while sailing, the mast will likely come down, potentially causing injury, severe boat damage or even sinking. Hidden corrosion is common where chainplates pass through the deck, creating dangerous situations that aren't visible during normal inspections. Water intrusion around chainplates can cause extensive hidden damage to deck cores and structural bulkheads, costing thousands to repair. Regular inspection and proper sealing are essential safety measures that prevent these serious failures.
General Maintenance
Inspect chainplates thoroughly when rigging is removed. Look for cracks, corrosion, bent plates or rust staining. Check fasteners for tightness and corrosion. Re-bed chainplates with high-quality marine sealant anytime leaks or water intrusion are detected, but only after confirming the bulkhead and core are completely dry and free of rot. Sealing over trapped moisture will worsen hidden damage and compromise structural integrity. On older boats, consider pulling chainplates every 5-10 years for complete inspection, including areas hidden in deck structures. Inspect more frequently on boats that sail in harsh conditions or have shown previous corrosion issues. Seek professional guidance when re-bedding chainplates.
Common Issues
- Corrosion where chainplate passes through deck
- Hairline cracks developing at high-stress points
- Failed sealant allowing water intrusion and hidden damage
- Fasteners corroding or working loose
- Bent or distorted plates from overloading
- Delamination of deck core around chainplate
- Rot in wooden backing blocks or bulkheads
- Elongated holes in plates from cyclic loading
- Metal corrosion
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