Check Your Lift Cables

[scuppers]

A big reminder to everyone who has a boat lift with cables. One of mine broke last night. It was less than a year and a half old, 1/4 inch stainless holding up a stock 2007 MC 197. About a 4 foot drop. Fair amount of damage including my Mapple ski that got flung out somewhere on the way down. The lucky part is no one else was there with their hands or feet in the way. Beat the dock up too. I'm sick about it but happy to be in one piece to ski tomorrow.

[BraceMaker]

Yikes, been there. Ours is on a physical lift, so when it broke the boat got hung up on its skeg and prop and banged around.

 

Sounds like yours is an overhead style?

[Wish]

WOW... Glad no one was hurt as well. I was in my boat as it was being hoisted up when the cable started making pinging sounds. Looked over and could see tiny individual strands snapping. Screamed at my family to get off the dock as I leaped out onto the dock and flipped the switch to down. Ran off the dock myself muttering the words "please make it down..please make it down." It did and with so few strands left I was shocked it did not fully snap.

 

A long time ago, I heard someone say the SS cables break down (rust/corrode) from the inside out so there is no indication that they are going bad. Any truth to that?

 

[scuppers]

This Broke on the way down! It doesn't look corroded at the break and was on a bushing roller wheel. Probably never know what caused it.

[gregy]

Happen to a boat where I ski also. My guess is they fail due to fatigue. What part of the cable are failing typically?

[SkiJay]

Thanks for this heads-up @scuppers‌! Yikes!!

[Wish]

@scuppers call the manufacturer. Ace in Leesburge FL I believe. They may have some insite.

 

Also, I've been looking around some on the web for replacement cables for myself. Most places sell both galvanized and SS. I wonder what the difference is. I have actually run only galvanized. Less cost but wondering after hearing about a SS snap like that, if there is true advantage to SS in freshwater. Kinda back to the corrode from the inside on SS question. When my galvanized starts looking corroded on the outside, I change them....well accept for that one time I obviously waited to long.

[oldjeep]

Make sure to look at the pulleys as well. When the cable on my father in-laws lift snapped it seemed to have something to do with some seized/worn out pulley wheels wearing on the cable. (Cantilever style lift)

[Skoot1123]

First, Glad your OK!! Good quick thinking in telling the famiy to get out! Regarding the corrosion aspect of this - high grade stainless does NOT rust. There are different series of stainless steels available (300 series (non-magnetic), 400 (magnetic) series etc). Stainless that is 300 series has VERY LITTLE carbon (which rusts) in the chemistry of the metal. Stainless that is 400 series has a little bit of carbon in the chemistry so you will get some surface rust. 400 series stainless steel is very tough (think hard, doesn't scratch easily), so it is used in high wear applications. The 300 series stainless is used extensively in the marine application because of its resistance to corrosion and heat (think maintain physical properties when it experiences higher temperatures (>350C). What you have to think about with these strands though is fatigue - that would be a big factor in it's failure. Might want to try and get a wire that has more strands in the braid for a given rope diameter vs fewer stranded big diameter cable. Thanks for sharing so we all are aware of this in the future!

[scuppers]

@oldjeep I did check, and the pulley is good. @Wish - now that you mention it I think I've heard that the galvanized is stronger -I'm gonna check it out! @skijay - YIKES is right. I was standing in the back of boat, had just that second flipped the lever to lower it and bang, the thing went down so fast in the front that it kinda catapulted me up and to the right. Just lucky I didn't get myself caught between boat and dock.

[DW]

@Scuppers: The typical failure point for galvanized cables which do rust is at the waterline. The air and water mix promotes corrosion which ends up leading to cable failure. Over tensioning is also an issue if not enough safety factor when pulleys become frozen or sticky. Galvanized cable is more flexible and recommended for tight bends, stainless cable is more corrosion resistant (see the additional detail above) and should last longer when exposed to the elemants. I also just had a galvanized cable failure (right at the water line) much earlier than expected due to corrosion so I will have to dig on why it happened with that particular cable choice (from a different supplier than previous cables).

 

Several websites offer quite a bit of detail on cable, cable construction, strength of the various options (# strands, winding style, material), simply google wire rope or cable.

 

One last item, always expect your cable to fail when it is cold, rainy, dark or at least the most inconvenient time for it to happen...

[LeonL]

1/4 cable is insufficient no matter what the capacity says. I recommend galvanized over SS. I broke a 1/4 after 1&1/2 years use. Went to 5/16 and have had no problems for ten years.

[6balls]

Mine broke with me in the boat maybe 1 foot off the water...landing was super soft after a moment of fear. The way mine is set up I don't think a drop from higher would cause much if any damage, either.

[behindpropellers]

Stainless is not good for going around corners due to it stress cracking easier.

 

Galvanized is typically best for lifting where it goes around a pulley...etc.

 

Tim

[Wish]

I will admit my latest cable is galvanized and 5/16. The 1/4 galvanized is the one that broke on me. Reading what happened to scuppers has me thinkn time for a change..been 7+ years but now reading @LeonL‌ I don't know anymore. The other advice I received before I installed the 5/16 was to soak the galv cable in motor oil for days. 5 gal bucket with enough oil to submerge cable did the trick. So far so good. But still thinkn change.

[ToddL]

Hmmm... Sounds like the best of both worlds is stainless steel cables from bunk frames up to above the water line. Then, a joint of some sort to a Galvanized cable which can bend and turn around the pulleys, etc.

 

The lif the @Gregy spoke of uses a fixed pivot point at the nose and then cable lifts in the back. The cables go up to and wrap around a 3 inch bar that is rotated using a geared motor. Thus, the top portion of the cables are tightly wrapped around that 3 inch bar. I guess physical fatigue could become an issue for that portion of the cables over time, eh?

[thompjs]

Use heavy galv chain to above waterline then cable. 5/16 not a bad idea either.

[mwetskier]

Cable wrapped around a 2 1/2 to 3 inch pipe sometimes wears out simply due to the friction of rubbing against the side of the previous coils as it winds onto the pipe. every additional wrap increases angle that the cable is wound on at and too many wraps can create a lot of side pressure which = wear. greasing the cable is also recommended.

[eleeski]

Scuppers, sorry to hear of your problems. Glad you're OK. I will check my cables.

 

Almost all of my cable failures (lots on the equipment) have shown evidence of fraying first. Then a bit of an overload. An inspection of the cables would tell me when to have a spare handy. Quite reliable.

 

Stainless is not always stainless. I have had "stainless" cable corrode completely in a well. My water is a bit corrosive so true stainless is a necessity. Galvanized is a joke around my water. Not an option in my boathouse. I'm using 5/16 stainless (306 I think but I make sure the riggers know I need the best stainless and they set me up). I'm worried thinking I need a proper spool to wind my cable on the lift pipe. I certainly don't want to drop my boat.

 

Eric

[thager]

With a cantilever lift it is also a good idea to bring the boat all the way up so the weight is directly on the lift frame legs and not entirely on the cable. Amazes me how many people with hefty boats bring the lift up only far enough to clear the water leaving all the weight on the cable. Even more puzzling to me is how many leave part of the boat in the water!!

[Texas6]

Glad you are ok! Man, that could have been bad. I've had this happen to me twice now and it isn't fun. I added cable winders after it happened the first time (5/16th galvanized), and switched to 5/16 stainless and it popped with no warning two years later. I don't know which is better, but the second I see a rough spot, I replace my cables now

[gsm_peter]

Thanks for the warning.

I will fore sure try to check ours at the club.

 

Galvanized is stronger than stainless as long as they do not corrode.

Has anybody tried kevlar rope instead?

Would assue it could be an alternative

[Spuddy]

We have a manual vertical lift that is removed each winter. The winch itself broke earlier this summer, the boat was about a foot out of the water and was basically stuck as the winch was broken on one side and would not move. Lucky for me I have a good friend in the air force who has 5000lb capacity straps we attached those to hold the boat in place. Then we released the pressure off the winch by using another winch to just move the lift a bit. Took off the broken winch replaced it with the new one. Took some time but it was a little uneasy feeling having the winch itself snap with the boat hanging out of the water; of course the day we spent doing all that the weather and water was perfect to ski and here we were with a boat stuck on a lift!!

[Marco]

@gsm_peter - I had kevlar rope (at least I think it was kevlar, it was given to me by a sail manufacturer who uses it for rigging), and he told me it would last forever. Not! I got about 4 years out of it before it broke. My neighbor was using the same material that he installed at the same time, and his broke within 2 weeks of when mine did. I'm back on stainless now.

[oldjeep]

Kevlar rope degrades in sunlight

[scuppers]

Hi Ballers! and thanks for the input. Here is the sad update. In the split second that the front of the boat went down it bent the prop and shaft on the way (got hung up as it slid forward on the cradle). So my otherwise pristine MC 197 is hurting. Any my ski is questionable. I'm gonna drop it off at Andy's shop and see what they think.

No skiing for a week or two at least. I think @leonl is correct -1/4 just isn't enough. It broke right where it makes a 2" radius turn.

[6balls]

We have original cables on a porta dock vertical lift at "the swamp" will be season 13 next year. One break in 13 years on my home lift same style.

@scuppers sorry to hear about your boat.

[LeonL]

On further thought my cables are 14 years old. I look at them pretty often. During ski season they're only in the water for about an hour to an hour and a half every other day. I'm not sure the water has much detrimental effect anyway.

[lathompson]

Sorry to hear about your cable break. Agree that 1/4" cable is not strong enough. I had galvanized 5/8 7x7 strand cable that frayed due to an incorrect snatch block pulley size (3" for 5/16 cable). Before it broke I installed 5/8" 7x19 strand stainless steel and a 6" diameter snatch block. Probably a bit over-engineered, but that should keep my SN200CB safe for a few years.

[Waternut]

Not all wire is created equal. The numbers of strands and wires make a big difference in strength, fatigue, and the cables ability to bend. Wire rope (cables) are designated in terms of strands and wires and a 1/4" 1x7 means the rope is made from 7 solid wires wrapped together. Very good for abrasion and straight pulling but it really sucks in bending and wants to tear itself apart. A 1/4" 7x7 means there are 49 total wires with 7 strands in each wire and 7 wires in each rope but the strands are much smaller and therefore bend easier.

 

What size pulleys are you guys using that are having failures? My guess is less than 3" diameter pulleys. Bigger pulleys will really help a lot.

[JayG80]

I use 7X19 Galvanized with hot dipped galvanized hardware (thimbles & wire clips). 7X19 is better for rolling over pulleys. I buy it all from http://www.e-rigging.com/cable . Split up a spool of cable with my neighbors. Also known as aircraft cable.

 

Breaking Strengths:

1/4" - Galvanized 7,000 lbs. & Stainless 6,400#

5/16" - Galvanized 9,800 lbs. & Stainless 9,000#

 

Never a failure, I replace every 3 years.

 

 

[jhughes]

We use Shore Station lifts and in the 3 or so lifts I have direct experience with have never had a cable snap and the cables seem to have a very long life span. The lift at the club is used multiple times daily all summer. The main lift cable has been very visibly frayed, too, and no snapping (it is preventatively replaced when it gets that bad). My personal lift is 10yrs old this year and all the cables look great. I don't know what type/diameter they use.

[jimski]

has any one use the shore master 8 foot aluminum vinyl covered lift bunks with there tournament boat just wondering how slippery they would be on the bottom of the boat

[DW]

@jimski: the rubber covered ones are fine, I would think the vinyl would be slippery.

[scuppers]

@Waternut & @JayG80‌ - Thanks, That's the info I've been looking for. My cable was making a pretty tight turn on the idler pulleys.

[RAWSki]

@jimski I have the vinyl covered bunks and they are work fine. my first ShoreMaster had pressure treated 2x6 encased in vinyl but they got wet and heavy over time. The aluminum is the way to go.

 

[jimski]

@rawski Thanks, I have put two sets of pressure treated bunks on the lift over the past 5 years and sounds like aluminum is for me. Are the shore master ones long enough for the sn 200?

Also in are lake we have a huge problem with electrolysis due to all the electric water pumps ( people drawing water from the lake ) the galvanized cables don't last a good grade stainless cable is the only way to go

 

[JayG80]

I upgraded to a slightly larger 4" sheave for overhead 4 point lift but I'm not sure if it makes much difference since the cable is still spooling onto a 2.5" dia. pipe.

 

@mwetskier made an important comment about not putting excess cable on the pipe. More cable increases the "fleet angle" of the cable spooling off the pipe and causes increased abrasion. Higher you raise the boat the more friction and wear on the side of the spooling cable.

[mopowpow]

@jhughes‌, I agree Shore Stations are the best lifts. We had one on a public lake for over 15 years and never had a frayed cable. We purchased a used one for our ski lake that is now over 10 years old and it's still in great shape. Although I have see cables snap on them when overloaded with a huge Cobalt.