Have you installed a second set of lines/wires/ropes/ standing rigging as a safety measure backup or redundant system to prevent demasting? If so, please describe your system.
Safety measure to prevent demasting
- Thread starter Mich222
- Start date
- Status
some of the lighter rigs may not support the additional weight or strain on the rig and the chainplates. Can get in the way of the "real" stuff as well...
I would opt for technically stronger materials than were used on the vintage boats and check it as needed. The running rigging of today is often stronger than the standing rigging used in the earlier years...
Best of luck
I would opt for technically stronger materials than were used on the vintage boats and check it as needed. The running rigging of today is often stronger than the standing rigging used in the earlier years...
Best of luck
No, but I've managed to go 50 years without dismasting a boat, much more effective to make sure what you have is in good shape.
Many of the 'offshore' design boats have such redundant rigging already in place and already calculated in the 'mast loading' to take such strain .... a headstay/forestay combo or rigging wire in front of the mast & usually coupled with running backstays. Such boats are usually always braced with aft and forward lower side stays in addition to the usual 'cap shroud'.
Unless such a rig/boat is pre-engineered to support such loads/rigging, if one adds additional stays, etc. there exists the possibility that the headsails will not operate effectively on slack stays ( 1/2 +1/2 = 1) plus such additional loads acting along the axis of the mast may induce 'buckling failure' of the mast plus such increased axial loading of the mast puts a tremendous load on the butt end of the mast as it sits in the bilge and which is attempting to drive the butt end of the mast 'through' the bottom of the boat!
One has to acknowledge or remember that the function of rigging is not 'only' to hold the mast up but *also* to provide a consistent structure for the headsail(s) to operate ... and that requires that the stays are at a defined tension (usually ~15% of tension). Operating a headsail at one-half normal 'stay' tension (7.5% tension) will cause the boat to suffer the inability to 'point', will cause the boat to aggressively heel over and simply 'skid sideways off to leeward' when attempting to 'beat'.
If the rigging tension is nowhere near the 'expected' tension that the sailmaker 'expects', the boat will have the sailing characteristics of a PIG - a very slow and 'cranky' boat that 'heels over' a lot. So, if you increase the diameter of the wire, add 'secondary' wires, then you really should have the sails 'recut' to match the now increased SAG of the wire caused by the now 'heavier' shrouds acting at far below 'spec' tensions!!!!!!
Normal rigging usually has 'inbuilt' safety factors that increase the load bearing capacity of the 'wire' .... in a 'coastal design' that 'wire' is usually twice the strength it needs to be, an 'ocean design' may be 3+ times as strong as it needs to be ---- and that factor of safety is already 'built in'. This is all based on historical records or 'scantlings' that have over long time proven themselves to be 'more than adequate'.
Its by 'maintenance' and constant inspection that 'keeps the rig from failing' ... and that failure is usually by the mechanism of fatigue due to repetitive load cycles. Most rigging is made from 300 series stainless steel which has the characteristic of - when loaded beyond 30000 psi it can usually only withstand 1 million load cycles then quickly fails via fatigue. Fatigue is an 'additive' and continual process and begins from the very first load that is applied in excess of 30,000 psi.
What engineers and designers did not understand in the 1970s & 80s when stainless rigging was first applied on a general basis was 'crevice corrosion' a 'chemical failure' that occurs *inside* of the micro-cracks that are formed due to fatigue ... and still apparently ignore the lessening of strength due to crevice corrosion plus fatigue. Crevice corrosion is found by routine inspection and the component should be replaced immediately upon discovery. Visually it looks like 'rust' emanating from a 'line' or at a 'joint', swage fitting, etc. Any rigging component that is showing such 'rust' should be immediately replaced. (Note: this isnt the 'surface rust' that is cosmetic and is seen on 'roughened' surfaces .... but it 'could be').
In summary, you're better off in regular maintenance and inspection of the already 'overbuilt' present (quality) rigging, and replacing it *entirely* when you can estimate that it has received close to 1 million load cycles that exceed 30% *tension* .... or about ONE circumnavigation .... OR as 'riggers' recommend: at about every 10 years because of the 'duplicity' of fatigue failure PLUS the 'probability' of crevice corrosion.
Unless such a rig/boat is pre-engineered to support such loads/rigging, if one adds additional stays, etc. there exists the possibility that the headsails will not operate effectively on slack stays ( 1/2 +1/2 = 1) plus such additional loads acting along the axis of the mast may induce 'buckling failure' of the mast plus such increased axial loading of the mast puts a tremendous load on the butt end of the mast as it sits in the bilge and which is attempting to drive the butt end of the mast 'through' the bottom of the boat!
One has to acknowledge or remember that the function of rigging is not 'only' to hold the mast up but *also* to provide a consistent structure for the headsail(s) to operate ... and that requires that the stays are at a defined tension (usually ~15% of tension). Operating a headsail at one-half normal 'stay' tension (7.5% tension) will cause the boat to suffer the inability to 'point', will cause the boat to aggressively heel over and simply 'skid sideways off to leeward' when attempting to 'beat'.
If the rigging tension is nowhere near the 'expected' tension that the sailmaker 'expects', the boat will have the sailing characteristics of a PIG - a very slow and 'cranky' boat that 'heels over' a lot. So, if you increase the diameter of the wire, add 'secondary' wires, then you really should have the sails 'recut' to match the now increased SAG of the wire caused by the now 'heavier' shrouds acting at far below 'spec' tensions!!!!!!
Normal rigging usually has 'inbuilt' safety factors that increase the load bearing capacity of the 'wire' .... in a 'coastal design' that 'wire' is usually twice the strength it needs to be, an 'ocean design' may be 3+ times as strong as it needs to be ---- and that factor of safety is already 'built in'. This is all based on historical records or 'scantlings' that have over long time proven themselves to be 'more than adequate'.
Its by 'maintenance' and constant inspection that 'keeps the rig from failing' ... and that failure is usually by the mechanism of fatigue due to repetitive load cycles. Most rigging is made from 300 series stainless steel which has the characteristic of - when loaded beyond 30000 psi it can usually only withstand 1 million load cycles then quickly fails via fatigue. Fatigue is an 'additive' and continual process and begins from the very first load that is applied in excess of 30,000 psi.
What engineers and designers did not understand in the 1970s & 80s when stainless rigging was first applied on a general basis was 'crevice corrosion' a 'chemical failure' that occurs *inside* of the micro-cracks that are formed due to fatigue ... and still apparently ignore the lessening of strength due to crevice corrosion plus fatigue. Crevice corrosion is found by routine inspection and the component should be replaced immediately upon discovery. Visually it looks like 'rust' emanating from a 'line' or at a 'joint', swage fitting, etc. Any rigging component that is showing such 'rust' should be immediately replaced. (Note: this isnt the 'surface rust' that is cosmetic and is seen on 'roughened' surfaces .... but it 'could be').
In summary, you're better off in regular maintenance and inspection of the already 'overbuilt' present (quality) rigging, and replacing it *entirely* when you can estimate that it has received close to 1 million load cycles that exceed 30% *tension* .... or about ONE circumnavigation .... OR as 'riggers' recommend: at about every 10 years because of the 'duplicity' of fatigue failure PLUS the 'probability' of crevice corrosion.
Last edited:
I echo Calif Ted, dismasting remains a rare ocurrence to warrant such redundance. Just inspect your riggin thoroughly at regular intervals and if in doubt replace any doubtful comonents. There are no guarantees but the probabilities are way on your side. If you trailer your boat you need to place additional care as things get shaken around during travel and mistakes can be made while raisin or lowering. I would replace all cotter pins once a season and inspect all wires and fittings.
Trust your boat engineering team. In NASA redundancy is the key to success. In boating things are a little less uncertain. The max stress those members will see is known and there have been allowances for the various things that make cables break.
What can never be accounted for and is squarely in the captains responsibilities is to check for loose items, meat hooks in cables, corrosion, dents and cracks in the mast. If you inspect on a regular schedule or when something significant happens to the rig you should be fine.
What can never be accounted for and is squarely in the captains responsibilities is to check for loose items, meat hooks in cables, corrosion, dents and cracks in the mast. If you inspect on a regular schedule or when something significant happens to the rig you should be fine.
Unless you are crossing oceans there really isn't the need for that type of redundancy.
I have owned 6 boats from 13 to 38 feet and never come close to such problems. I bought a "Loos Tension Gauge" to measure all my rigging tensions and regularly inspect all my fittings and wire. It is an easy task, instructions are readily available and quite inexpensive. Less than $100 for books and tools.
You will feel better about your boat, she'll feel better and she'll point higher and sail faster.
Ray
I have owned 6 boats from 13 to 38 feet and never come close to such problems. I bought a "Loos Tension Gauge" to measure all my rigging tensions and regularly inspect all my fittings and wire. It is an easy task, instructions are readily available and quite inexpensive. Less than $100 for books and tools.
You will feel better about your boat, she'll feel better and she'll point higher and sail faster.
Ray
Not Always Better
i recall a dock neighbor who was setting sail to France from the west coast of the USA. Great guy who did a lot of modifications to his Catalina 30 for deep ocean sailing. He was totally paranoid about the rig and went so far as to make up huge chainplates and tie them to the hull. Well, he got caught in some pretty mild slop going south and lost her from rig failure coupled with hull damage. He had no clue but the seat of his pants, and it dropped around his ankles. meanwhile, stock Catalina 30's did that trip all the time in conditions way more challenging.
i recall a dock neighbor who was setting sail to France from the west coast of the USA. Great guy who did a lot of modifications to his Catalina 30 for deep ocean sailing. He was totally paranoid about the rig and went so far as to make up huge chainplates and tie them to the hull. Well, he got caught in some pretty mild slop going south and lost her from rig failure coupled with hull damage. He had no clue but the seat of his pants, and it dropped around his ankles. meanwhile, stock Catalina 30's did that trip all the time in conditions way more challenging.
Just a small tip. Check the cotter pins for corrosion and missing legs. Don't ask me how I know. And never, ever reuse one.
- Status