Select Page

The rig of a sailing boat is put under huge stresses and strains so it is important for inspections of a yacht’s spars and rigging to be carried out at regular intervals.

All the elements of a sailing rig – the mast, spreaders, boom, kicker, stays and the fittings that hold everything together – are subjected to considerable forces when at sea.

Less obvious perhaps is that the process of cyclic loading, the cause of metal fatigue, continues unabated even when a boat is rocking gently on a sheltered mooring. The rig components continue to push and pull against each other, day in and day out. Added to the all stresses and strains imposed on the rig components are their susceptibility to different kinds of corrosion, caused in the case of aluminium masts both by exposure to the marine environment on the one hand and also by galvanic corrosion. This occurs when stainless steel or bronze fittings are fitted to aluminium masts and not adequately insulated from each other, which causes the aluminium to corrode. While wooden masts do not suffer from galvanic corrosion, they are susceptible to rot and de-lamination.

Rig care

As with many other kinds of boat care, regular checks, preventative maintenance and the correct set up of mast and rigging are key to ensuring longevity and preventing failure. With sailing boat rigs in particular, the integrity of all their parts is vital. The mast and rigging is a lightweight structure designed to be rigid and strong, a bit like a house of cards – if one of the components fails then the whole house comes tumbling down. Even if one part becomes loose this can increase loads on other parts, causing them to fail.

While doing regular checks of your rig throughout the sailing season is good practice, so too is a more detailed inspection when the boat comes ashore and if needs be the mast can be taken down. Even if the rig remains unstepped ashore it still needs to be checked by a trained eye.

Understanding your rig

There are many kinds of mast and rig configurations for sailing boats and it is important for boat owners to fully understand the rig set up of their particular boat. This understanding will help them know what to look out for when doing their regular checks. Here are a few questions that owners should be able to answer:

Standing rigging

  • What are the main causes of rig failure?
  • When was the mast last unstepped? Once every two or three years is generally recommended.
  • When was the standing rigging last inspected? Annual inspections are usually recommended.
  • When was the standing rigging last replaced? Once every ten years or so is usually recommended for wire rigging and about fifteen years for rod rigging.
  • Where are the main stress points on your rig?
  • How do you check the rig alignment?

Running rigging

  • When was the running rigging last inspected?
  • When should it be replaced?
  • What maintenance needs to be done?

Causes of rig failure

While many sailors live in fear of rogue waves and capsize, most dismastings happen either because of equipment failure or operator error. Leaving aside operator error, the main reasons include the failure of chainplates, spreaders, turnbuckles and tangs caused by either metal fatigue, corrosion or a combination of the two.

Chainplate failure is one of the most common causes of dismasting. Chainplates are not easy to inspect as they are hidden from view beneath the deck. Corrosion happens out of sight where the metal cannot be inspected without the plates first being removed.

Other causes are the failure of terminal fittings, clevis pins, cotter pins and all the parts that hold a rig together.

Surprisingly perhaps, the mast and stays are rarely the components that break first and cause a dismasting.           

Stresses and loads

The components of a rig are designed to withstand certain stress levels and loads caused by a boat under sail in varying conditions. The correct adjustment of the rig is important to maintain the rig’s strength and longevity for a number of reasons – not just the boat’s performance and ability to point to windward. These include:

  • If the rigging is slack problems can develop as it moves about, causing fatigue.
  • Rig components can become weakened by vibrations caused for example as sails flog in strong winds, or by shock loading caused for example by accidental gybes.
  • The misalignment of part of a rig can cause other parts to be overloaded resulting in metal fatigue and eventual failure.
  • Stress coupled with corrosion will accelerate the potential for rig failure.

Crevice corrosion

Some surface rust on stainless steel rigging is normal and usually polishes off very easily. While stainless steel does not rust in the way that regular steel does, it does suffer from crevice corrosion.

Crevice corrosion occurs because the stainless steel has been deprived of oxygen. As a result its protective oxide film breaks down, allowing chlorides to infiltrate and corrode the metal. This happens around joints and under fastener heads and where pieces of metal are in close contact. Chainplates often suffer from this type of corrosion where they pass through the deck and sea water has saturated the deck core.

Crevice corrosion also takes place where cyclic loading has caused stainless steel to develop hairline cracks on the metal’s surface. Sea water then gets into the cracks and the corrosion slowly takes hold.

 Galvanic corrosion

Aluminium masts with stainless steel fittings are at risk from galvanic corrosion. Galvanic corrosion is the transfer of electrons from one metal (the anode) to another (the cathode). In this case the anode is the aluminium and the cathode is the stainless steel. Positively charged electrons flow from the the anode to the negatively charged cathode. Galvanic corrosion also requires an electrolyte, a liquid that enables the electron flow to take place. In this case salt water is the electrolyte and a very efficient one.

Note: All stainless steel fittings should be insulated from aluminium masts by washers or sealant

Boat engine fuel system

If engines are installed and serviced correctly then most marine engines are very reliable, but one of the most important parts of the engine to check and service is the fuel system.

Safe Skipper – crew management tips

Effective crew briefings are a vital part of the good on-board communication that helps everything to run smoothly on a sailing vessel at sea, whether it is cruising or racing.

Boatyard Health and Safety

Boat storage facilities are potentially hazardous environments and it is the responsibility of both boat owners and boatyards to ensure that the...

Getting a tow for your sail or power boat at sea or on inland waterways

FREE tips from the Safe Skipper App for iPhone/iPad/Android: Getting a tow for your sail or power boat Plan how to secure a...

Navigating Through Rough Waters: Tips for Handling Adverse Weather Conditions in a Sailboat

Navigating through rough waters in a sailboat requires skill, preparation, and a good understanding of both your vessel and the environment. Here are some tips for handling adverse weather conditions including Preparation, Techniques, Safety and much more..

Jester Challenge 2022 – Sailing single handed from Plymouth UK to the Azores: Part 4 – Navigation

Jester Challenge – A modern experiment in old-fashioned self-reliance, self sufficiency, and personal responsibility. This is the fourth of a 10-part post where solo sailor, Bernie Branfield, shares his first hand account of his single-handed, 2022 Jester Challenge, from Plymouth, UK to the Azores, in his 26′ Invicta Mk2, Louisa.

Sailboat rig checks – Part 1

Sailing boat rigs need to be checked regularly to reduce the risk of rig failure at sea. In part one of Sail boat rig checks we run through a series of useful checks that owners and skippers can carry out.

Docking a Motorboat

Docking a motorboat can be a challenging task, especially for beginners, but with practice and attention to detail, it becomes much easier. Here’s a step-by-step guide to help you dock your motorboat safely and efficiently.

Steel and Aluminium Hulls

The two metals used for hull construction are steel and aluminium. These are both very strong materials and will last a long time as long as they are cared for, which primarily means protecting steel boats from rust and aluminium boats from electrolytic action.

VHF DSC radio – how best to communicate at sea

There are many ways to communicate with others at sea. What makes the VHF DSC radio the best form of short range...

Essential Knots: Clove hitch

Essential Knots: Clove hitch Use: Tying a rope to posts, bollards, rings or a guardrail. Step 1. Make a turn around the object and lay...

Jester Challenge 2022 – Sailing single handed from Plymouth UK to the Azores: Part 5 – Boat Management

Jester Challenge – A modern experiment in old-fashioned self-reliance, self sufficiency, and personal responsibility. This is the fifth of a 10-part post where solo sailor, Bernie Branfield, shares his first hand account of his single-handed, 2022 Jester Challenge, from Plymouth, UK to the Azores, in his 26′ Invicta Mk2, Louisa.

Leaking decks

Leaking decks are perceived as a nuisance by some boat owners, but if leaks are ignored a much more serious situation may well be developing, especially in the case of boats with balsa or plywood deck cores. So deck leaks do need to be investigated and dealt with.

Sailing into a storm

Weather forecasting has become increasingly accurate, but despite this, I was caught out recently by a forecast that considerably underestimated the wind strengths and consequently was sailing single handed in to a Force 8 gale, which proved to be challenging!

Diesel engine winterisation

An inactive boat engine needs to be protected from corrosion during the winter, caused by the rising humidity levels through the cold months and the salty coastal air. This applies whether the boat is left afloat or hauled out over the winter. Read here about the two important stages of winterisaton for a diesel boat engine.

Boat surveys

A full boat survey assesses the condition of the hull, mechanical gear and means of propulsion. The survey is carried out with the boat...

Five dangers a vessel may encounter at sea

What are the main dangers a vessel may face at sea and what should skippers do to reduce the risk of these happening?

Fire prevention on boats

  Fire prevention on boats - common causes of fire: • Smoking below decks • Galley cookers • Build-up of butane or...

Navigation safety: a quick-reference mobile app to learn the ColRegs NavLights and Shapes

 Safety at SeaSafety at sea will always remains a topical and important subject that will no doubt dominate the syllabuses of nautical...

Essential Yachting + Power Boat Safety Briefing

Yachting Safety Briefing   Down below Lifejackets and harnesses - fitting, when to wear, clipping on Gas - risks, precautions, gas bottles and...

Keel maintenance and repair – Part 1

Keels are designed to act as underwater foils that generate lift as the boat moves through the water, counteracting the leeward force of the wind and enabling the boat to sail closer to the wind. Keel maintenance and repair is essential for the performance of your boat.

Essential Boat Spares for Safety

  Boats Spares Tool kit What you carry in the boats tool kit will be useful for many boat repairs, but you might want...

Dripless shaft seals

Dripless shaft seals are designed to completely stop water from entering a boat’s hull via the stern tube. There are two main types of dripless seals known as face seals and lip seals which many boat manufacturers now fit to production boats.

How to ensure your boat is in proper working condition

In this article Eva Tucker from Volvo Penta presents a handy check list of all the things that you need to check regularly in order to make sure that your boat is in a seaworthy condition. Including maintenance, safety gear and electrical checks.

How to cope with an emergency at sea

A safe skipper will be mentally prepared for all kinds of potential emergencies happening at sea, including medical emergencies, engine failure, fire, a holed hull, capsize and dismasting.