One of the first things I usually want to know, is there a replacement interval recommended by the manufacture?
Edson Marine recommends the steering chain and wire assembly be replaced every 5 to 7 years; and replaced more frequently if in tropical/equatorial zones. This recommendation is very similar to the standing rigging replacement recommendations in tropical environments, so it is not unreasonable and unfounded. Edson Marine offers complete chain and wire assembly kits that if used, replace not only the chain and wire, but all the interconnecting hardware - this is prudent as all the items in this assembly are subjected to the same stresses and environmental conditions.
The loss of steering blog site article does not reveal if the steering chain and wire assembly was replaced as recommended by the manufacture. However, it did referenced another loss of steering failure four years earlier that was caused by an eye bolt that sheered in half and they indicated they replaced "only" the sheered eye bolt. It was also not disclosed if the eye bolt sheered in half due to corrosion, but it is a reasonable possibility. Per articles on their blog site, their boat has principally been cruising the tropical zones which should have resulted in the consideration of a more frequent replacement and inspection interval. Regretfully with the scant information provided, this leads to the assumption that it is most likely that the steering chain and wire assembly was installed as part of the original boat construction in 1982, 36 years past. This assumption is not without merit, as many cost-conscious cruisers foster the common attitude, "if it is not broke, don't fix it", in lieu of sound preventive maintenance practices. Ironically, sound preventive maintenance practices tend to be cheaper in the long run and result in less dramatic and catastrophic failures.
Knowledge of this replacement interval should result in additional considerations:
- You should know the date of installation of the existing system/parts and forecast a scheduled date of replacement. Document this in writing on a tracking list that makes sense to you.
- You should have a copy of all available manufacture's documentation, manuals, drawings, etc., pertaining to this system and associated parts.
- You should determine and document the part number(s), cost, and a supplier of the replacement assembly/parts.
- You should decide if this item should be included in your spares kit. On a multi-year round the world voyage such as this boat was on, this item probably should have been included in the spares kit.
One of the next things I usually want to know, what is the recommended inspection interval and criteria?
Per excerpts from Edson Marine documentation the inspection interval should be:
".... it is important that all boats fitted with Edson Steering Systems get an annual inspection of the critical system parts and that routine maintenance guidelines are followed."
"Make note of your inspection date and schedule your next inspection. Once to twice a season is a bare minimum - racing boats and heavily sailed cruising boats should consider more frequent inspections. An aggressive maintenance schedule needs to be followed if sailing in the Caribbean or other equatorial level locations."
"CAUTION: When the equipment is in the tropics or in charter service, the maintenance schedule must be speeded up."
"CAUTION: On extended voyages your steering system should be inspected each day and lubricated weekly. Carefully inspect your steering system at least once a week before a vacation cruise to avoid last minute maintenance."
Per excerpts from Edson Marine documentation the inspection criteria for the chain should be:
"Inspect the chain from one end to the other. There should be no sign of rust on it, especially where the pins are peened over as they come thru the link plates. Rust is a sign of crevice corrosion and your chain should be replaced immediately. Steering chain should literally drip over your finger. When crevice corrosion sets in it freezes the links in place. So, when the chain passes over the sprocket, it doesn’t want to bend. This causes failure of the link plate, and ultimately the chain."
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The loss of steering blog site article stated they had inspected the chain about a year earlier, under magnification, and it appeared serviceable. While this appears in line with the manufacture's annual inspection recommendation, it does not comply with the cautionary inspection criteria for the tropics or the extended voyage they were undertaking. As they stated they performed an inspection a year earlier, than it is reasonable to conclude it was "due" inspection around the time of failure. Also the picture above showing the broken chain reveals a significant accumulation of black grime on the chain; it is hard to imagine that it accumulated to this extent in less than a year in the closed protected confines of the binnacle enclosure if proper maintenance was performed. It would be extremely challenging to properly visually inspect a chain with this black grime present, without first cleaning the chain thoroughly and removing all this residue.
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It is worthwhile to note that after the steering failure occurred and was temporarily fixed with a length of Dyneema rope, they instituted a daily inspection regime to monitor the Dyneema rope for chaff issues and security; they had to occasionally adjust the tension to accommodate for rope creep . It would have been beneficial if the same level of attentiveness existed before the failure occurred. A few experienced sailing reader's comments to their blog article proclaimed they had permanently replaced all their steering wire/cable with Dyneema rope when they experienced similar steering failures. So there is the possibility that this temporary fix with Dyneema rope could become the permanent fix, disregarding the other steering components that are probably also degraded due to "indifferent maintenance". One can only hope these experienced cruisers realize that there is a difference between the groove in a synthetic-rope sheave versus a steel wire-rope sheave, and the implications it presents.
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Knowledge of the recommended inspection interval should result in additional considerations:
- You should document, track, and forecast the inspection interval on a list that makes sense to you.
One of the other things I usually want to know, what is the maintenance requirements?
Edson Marine provides a very comprehensive Steering Inspection Checklist that details what to look for and what specific maintenance action to perform for the entire system. As for chain maintenance requirements, it is actually very simple: clean it, inspect it, lubricate it, and verify proper tension.
The importance of cleaning the chain should not be under estimated. A complete and thorough cleaning removes the build up of old gummy oil and dirt that provides a surface for corrosive particles to accumulate, accelerating corrosion. A clean chain allows the oil lubricant to penetrate easier into the chain rollers and bushings, retarding corrosion. Based on my prior experience with dirt-bike motorcycles, to properly clean a chain it would require it's removal so it could be immersed it in a cleaning solvent bath to loosen up the grunge. Scrubbing with a stiff bristle brush would aide the removal of stubborn grime. Bathe, scrub, rinse, and repeat until spotless. After allowing the cleaning solvent to dry off/disperse, then soak (completely immerse) the chain in a container with 30 weight oil - this is the only sure way to get oil into all the crevices between the pins, rollers, and bushings. Suspend the chain above the oil container and allow the excess oil to drip off. Next, it is ready to be reinstalled. This entire process should take less than 10-15 minutes to complete; oh, my error - it is a boat - multiple time estimate by 3 or 4.
The picture above showing the broken chain reveals a significant accumulation of black grime indicating the chain had not been properly cleaned. With the picture zoomed in close, was unable to detect the glisten/shine of the presence of oil - the black grime areas also appear to be almost dry. Its is reasonable to conclude this chain needs to be cleaned and lubricated.
Knowledge of the recommended maintenance requirements should result in additional considerations:
- You should compile a list of "all" items necessary to perform the required recommended maintenance and maintain an adequate stock level aboard.
- You should determine what additional miscellaneous pieces of hardware should be carried aboard. Stripped screw head, dropped bolt/nut, lost chain spring clip, etc. are a few potential candidates.
So what was the most likely root cause of failure and the lesson to be learned?
Based on the limited information provided and pictorial evidence, it appears the failure can be reasonably attributed to non-compliance with manufacture's maintenance recommendations. Both the broken chain and sheered eye bolt most likely occurred due to the effects of corrosion. Replacement of the steering chain and wire assembly in a time frame of less than five years due to operation in a tropical environment as stipulated by the manufacture would have significantly reduced the possibility of this type of failure occurring. Additionally, adherence to the manufacture's inspection and maintenance requirements for tropical environments and extended voyages, should have resulted in early detection of any degradation and enabled the appropriate repair action, eliminating almost to zero any chance of these failures occurring. The probability that the rest of their steering system maintenance requirements has been neglected is most likely - time will tell.
Lesson: Read and follow all manufacture's recommendations. Convert the recommendations to actionable lists: replacement date, inspection dates, parts list, consumable lists, pre-departure inspection checklist, etc. Do this for each and every item aboard, and your more likely to have less drama and more enjoyment aboard.
Note: As we were genuinely concerned we posted a comment to their article. Was not surprised that our comment to their article was not well received and we were deemed “ignorant”. What surprised us was the disdain stated about “preventative maintenance”; but that professed attitude was the likely cause of the lack of steering system “preventative maintenance” that resulted in the failure jeopardizing his boat – but each is the captain of their own ship. Our further response resulted in no further discussions as shown below: