Help! New Boat, New Boat Lift, Cable broke!

[WAVENBYE2]

Re: Help! New Boat, New Boat Lift, Cable broke!

So it is equipted with a grooved cable winder, Thanks REEL.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

"Grooved Cable Winder
?Protects the drive shaft and winds the cable without overlap"

That only works as long as there is tension on the cable, I bet.
But if you run it too far down until there is no tension, then the cable relaxes off the "cable winder" and becomes a rats nest when you lift again.
(Like a baitcaster reel will birdnest)
What size cables are used?
And where on the cable did it break?
I am guessing the cable broke where it is anchored on the "cable winder"
at the very last inches of cable? Or did it break at all? Maybe it was not properly anchored down to the "cable winder"? Just like a winch, you must always have at least 3 wraps of cable on the drum before pulling. The cable anchor on the drum is not to be used as the pulling force. The three wraps (min) allow the cable to constrict around the shaft and that is what is to be the pulling force. If the very end of the cable was not properly anchored and you could operate the lift a long time as long as the cable maintained a few wraps on the drum. But if you relaxed the cable too much and lost those minimum wraps and the end was not anchored, it would slip off.

Keep in mind there are thousands of wreaker winches with rats nests of cables on each one cause most don't have any fancy pantsy cable winder device on them. And they don't break cables.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

The Boat Lift U.S. website says they use Cables (4) 1/4″ SS ? 15′; 7 ? 19 SSAC cables, with grooved cable winders on the 8000lb lift.

The best 1/4"dia stainless steel wire rope is rated at 6400lbs breaking strength. The industry standard is to use 20% of breaking strength as the working load limit.
6400 x 20% is 1280lb working load limit. http://www.cooperhandtools.com/brands/CF_Files/model_detail.cfm?upc=020418193095

1280lb x four cables is 5120lbs working load capacity on an 8000lb rated boat lift?

This is serious stuff dude, are the engineers and/or bean counters at Boat Lift U.S. under engineering?

 

[Bondo]

Re: Help! New Boat, New Boat Lift, Cable broke!

You might be forgetting the Pulleys,.......
Adding a Pulley, Doubles the capacity........

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

You might be forgetting the Pulleys,.......
Adding a Pulley, Doubles the capacity........

True.
But looking at craig's pics, for the life of me it appears there are only single cables running down to and anchored to the cradle on three corners.
The far left corner being gone as that is the one that broke.

Looking at the Boat Lift U.S. website they picture the 10k lb cap. lift with a pully at the cradle, four places and using 5/16" cable with 3/4hp drives.
I can't find a factory pic of the 8k lb cap. lift but I see it has 1/4" cables and 1hp drives.

This link shows the sheave housing for use on the cradle. Which may or may not be on craig's lift. Hard to tell.

Craig,
does your lift have the pullys on the cradle and the cable going down to them then back up to the top frame?

 

[craig240DA]

Re: Help! New Boat, New Boat Lift, Cable broke!

Craig,
does your lift have the pulleys on the cradle and the cable going down to them then back up to the top frame?

No pulleys, 4 cables on each corner with 4 almost useful Grooved Cable Winders.

I do need to mention that the local Dock builder was extremely responsive in getting the boat off the twisted, broken, and collapsed lift, without any obvious damage to the boat. They have taken all the information that you fine people have provided and I am truly appreciative for your help.

Is it possible that they are using the wrong cables in every lift they make? I have checked many sources and they all agree with what you have stated, that the break strength is just a number that you use to determine the Safe Working Load Limit (SWL=20%XBreak Strength). The manufacturer was adamant about using the break strength and were very defensive. The local dock builder is much more open to resolving this and if I look down the canal, I can see why. 80% of the houses here have boat lifts and almost all of them have been built by this company. They would be really dumb to turn this into a big deal in a community where local news is someone that doesn't cut their grass on time.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

No pulleys, 4 cables on each corner with 4 almost useful Grooved Cable Winders.

Please clarify your above statement:
"4 cables on each corner"

Is way different than maybe "4 cables, one on each corner".

The Boat Lift U.S. website shows a lift like yours with the 10k capacity. That lift shows one cable at each corner coming down to the cradle (at each corner), thru a pully then back up to the cable winder.

Your pics appear to show one cable at each corner coming down from the cable winder and anchored to the cradle.

Cruise down your canal and scope out how many other 8k lifts of the same brand as yours has the same cable set-up as yours.

It is possible that the local installer used the pully brackets on the cradle to merely anchor the cable end instead of using the pully that is to be in the brackets. And then running the cable end back up to the cadble winder beams where they are to be anchored.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

The manufacturer was adamant about using the break strength and were very defensive.

Thats just crazy if they are basing the lift capacity on breaking strength of the cable. And mighty stupid business practice when the cost of another 16' of cable and four pullys is minimal compared to the potential liability incurred.

I hope they don't build elevators too.

I did miss these specs on the Boat Lift U.S. website:
8k lift has (4) 1/4″ SS ? 15′; 7 ? 19 SSAC cables
10k lift has (4) 5/16″ SS ? 31′; 7 ? 19 SSAC cables
http://www.boatliftus.com/specs.php

I think that confirms they are running one cable down to the cradle and not back up to the cable winder, thus 15' length of each cable for the 8k lift.
Notice the 10k lift comes with 31' length cables which would be required with the cradle pullys.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

Another point..................

Why on earth would they use four single 1/4" cables on the 8k lift with 5120lbs total working load capacity. Thus underrated by 36%.

And then use four 5/16" cables (and doubled via the pullys) on the 10k lift with 14,400lbs total working load capacity. Thus over-rated by 44%.

Their website also indicates the
16k models are underrated by 11%.
20k models are underrated by 39%.
24k models are underrated by 67%.
27k models are underrated by 41%.
35k models are underrated by 82%.
40k models are underrated by 208%.
If I had a 40k, 35k or a 24k, I would stop using them.

I hope their website info is a gross mistake.



?????????????

CRAZY

 

[craig240DA]

Re: Help! New Boat, New Boat Lift, Cable broke!

Please clarify your above statement:
"4 cables on each corner"

Is way different than maybe "4 cables, one on each corner".
.

Each corner of the lift has a winder with a cable that comes down and is anchored to the lift bed.

 

[craig240DA]

Re: Help! New Boat, New Boat Lift, Cable broke!

They replaced the 1/4 cable with 5/16″ SS 7 ? 19 SSAC cables which have a breaking strength of 9,000# so here is the math:

4 X 9,000 = 32,000 X 20% for SWL and that leaves me with a 6,400# Boat Lift. My boat has a Dry Weight : 5593 lbs. Add 75 gal of gas and 20 gal of water I am up to 6,300# so now I have the luxury of adding 100 lbs of gear!!!!!

The boat lift company said they have never experienced a new cable break like this. That surprises me if their specs are so far off.

 

[scoutabout]

Re: Help! New Boat, New Boat Lift, Cable broke!

...The manufacturer was adamant about using the break strength and were very defensive. The local dock builder is much more open to resolving this and if I look down the canal, I can see why. 80% of the houses here have boat lifts and almost all of them have been built by this company. They would be really dumb to turn this into a big deal in a community where local news is someone that doesn't cut their grass on time.

Ha ha -- yeah. How about hanging a nice big banner on the wreckage of your lift that says:

ASK ME HOW YOUR US BOAT LIFT CAN KILL YOU

It would almost be worth the lawsuit.

 

[Reel Poor]

Re: Help! New Boat, New Boat Lift, Cable broke!

My boat has a Dry Weight : 5593 lbs. Add 75 gal of gas and 20 gal of water I am up to 6,300# so now I have the luxury of adding 100 lbs of gear!!!!!

You will have to lower the boat into the water to load the gear. I'll bet you weigh over 100 lbs.

 

[jeeperman]

Re: Help! New Boat, New Boat Lift, Cable broke!

The boat lift company said they have never experienced a new cable break like this. That surprises me if their specs are so far off.

It would be a bigger surprise if they acknowleged cable failures to anyone or everyone that reported a failure!


I would do the neighborly thing and let everyone you see with a Boat Lift U.S. lift know about this potential problem.