Almost lost my boat! (Winch problems)

[beene]

I talked about this before..... long ago.....


Reading the side of the winch on the trailer it is rated at 1100lbs

I wonder it that meant the trailer winch was not meant to hold the Mac on it when coming out of the water.
Let alone doing a ballast tank check.
You know the one we are told to do by the manufacture to ensure no leaks...
Leaving the ballast in and hauling out.....
Lets see, grade 4 math..... boat, plus water.... or just boat alone.... subtract max winch rating...... equals.......





G
[mod="kmclemore']"Winch problems" added to topic title for easier searching in future.[/mod]

[Catigale]

Yikes....its that Canadian heavy water....

[Ormonddude]

I will bet it was a steep ramp the ramp is a incline plane and usually greatly reduces the load by extending the distance traveled by the distance raised. However on a steep ramp there may not be the mechanical advantage needed in other words if the ramp drops a foot for every five foot of distance traveled the weight on the winch is reduced five to one and would not be a problem however if the ramp is one foot of drop for three foot of travel and the mechanical advantage is only three to one you could easily break the winch (SO) do not test ballast tanks on a steep ramp EVER. If the boat load and gear weighs five thousand pounds on the five to one ramp your winch would only exert one thousand pounds of force on haul out - on the three to one ramp it would exert seventeen hundred pounds of force and over load the winch.

[NiceAft]

I will bet it was a steep ramp the ramp is a incline plane and usually greatly reduces the load by extending the distance traveled by the distance raised. However on a steep ramp there may not be the mechanical advantage needed in other words if the ramp drops a foot for every five foot of distance traveled the weight on the winch is reduced five to one and would not be a problem however if the ramp is one foot of drop for three foot of travel and the mechanical advantage is only three to one you could easily break the winch (SO) do not test ballast tanks on a steep ramp EVER. If the boat load and gear weighs five thousand pounds on the five to one ramp your winch would only exert one thousand pounds of force on haul out - on the three to one ramp it would exert seventeen hundred pounds of force and over load the winch.

A verbose way of saying "get a winch that will hold the boat on most any ramp"

I replaced my winch a few years ago with one that was rated at 2000 lbs. It was, and is, inadequate for all ramps. I now tie an extra line onto the eye hook on the bow.

Ray

[Champguy]

Wow! I'm glad the damage was minimal. I always thought the strap would break before the metal would deform.

I almost lost my boat this weekend too. When I went to hook the trailer to the vehicle, I wasn't exactly lined up with the ball hitch, so I gave the trailer a little push over to settle on the ball. When I did this, the ball moved! Upon further inspection, the nut on the bottom was completely loose and about to fall off. I was using my vehicle to haul aggregate for the past week for a patio project, and all of those heavier loads with lots of turning must have loosened the nut. I tightened the nut and everything was fine, but this could have been a really bad start to the day.

Lesson learned: Preflight ALL of the equipment.

Take care,

Aaron

[kmclemore]

...Upon further inspection, the nut on the bottom was completely loose and about to fall off. I was using my vehicle to haul aggregate for the past week for a patio project, and all of those heavier loads with lots of turning must have loosened the nut. I tightened the nut and everything was fine, but this could have been a really bad start to the day.

Arron, I've posted several times in the past regarding securing trailer hitch balls, but I suppose it bears repeating...

As for the ball coming off, I had that almost happen once too and I learned my lesson. Henceforth whenever I install a ball I tighten it down to the proper torque and then drill a 3/16" hole in the threaded bit that extends past the nut, as close to the nut's face as I can. I then install a split pin (cotter pin) and peen it over. This will absolutely prevent any backing off of that nut.

Also, always ensure you have *only* a lock-washer under the nut before tightening... no other washers.

Cheers,
Kevin

[Mac26Mpaul]

The winch thing just came up in another thread. Very common I guess as the winch is so underated. Mine failed a few times. I took it off and bashed it back into shape in my vice and then used a huge stainless steel washer in it for a bit, until I got off my cheap ass and bought a proper winch Amazed that Roger hasn't fixed this issue, as it would cost very little more to put a decent winch on these trailers..

[Tomfoolery]

...Upon further inspection, the nut on the bottom was completely loose and about to fall off. I was using my vehicle to haul aggregate for the past week for a patio project, and all of those heavier loads with lots of turning must have loosened the nut. I tightened the nut and everything was fine, but this could have been a really bad start to the day.

Arron, I've posted several times in the past regarding securing trailer hitch balls, but I suppose it bears repeating...

As for the ball coming off, I had that almost happen once too and I learned my lesson. Henceforth whenever I install a ball I tighten it down to the proper torque and then drill a 3/16" hole in the threaded bit that extends past the nut, as close to the nut's face as I can. I then install a split pin (cotter pin) and peen it over. This will absolutely prevent any backing off of that nut.

Also, always ensure you have *only* a lock-washer under the nut before tightening... no other washers.

That's what I do, also. I got that idea from a ball I got from UHaul (I think) long ago. It had the hole for a cotter pin, so I used it. I now drill every hitch ball stud and put a big cotter pin through it, under the nut. The cotter pin always ends up with a tiny bit of play that I can feel with my finger, and if the nut ever loosened and ended up against the cotter pin, I'd feel it in the cotter pin. Hasn't happened yet, but I retorque them every once in a while just to be sure.

[kmclemore]

...if the nut ever loosened and ended up against the cotter pin, I'd feel it in the cotter pin.

If you bang the one end of the cotter pin (split pin) back against the nut (bending it over one of the flats), this will almost certainly prevent the nut from loosening in the first place.

[MAXIMUMBOB]

Speaking of winches, can someone recommend a winch because I purchased a 1500 or 2000 lb winch from West Marine a while back only to find when I installed it that the lever was too long and banged against the "v" for the bow. So I took it back. I would certainly like to upgrade. The other problem I have is -because I have a fairly rough coat of bottom paint (PO) I cannot do the quick stop to move the boat all the way forward when leaving a ramp. So my boat always ends up several inches (and very unbalanced) away from the stop. It must have something to do with the angle of the boat while in the water vs. trailer because I have it cinched up tight-no matter as it comes out of the water it ends up further back on the trailer.

[Ormonddude]

Well unless its a real bad ramp you should not have a problem IF the Ballast is Empty - I am sure the new Mac owners don't want to replace a brand new winch However its important that they understand the stress involved (Hence the physics lesson) sorry if I was wordy

[TFlight]

I just posted my winch replacement a few week back. "check your winch"

[Tomfoolery]

The other problem I have is -because I have a fairly rough coat of bottom paint (PO) I cannot do the quick stop to move the boat all the way forward when leaving a ramp. So my boat always ends up several inches (and very unbalanced) away from the stop. It must have something to do with the angle of the boat while in the water vs. trailer because I have it cinched up tight-no matter as it comes out of the water it ends up further back on the trailer.

That's exactly why the bow pulls away when you pull the trailer up the ramp - the angle between the boat partially floating and the trailer is not the same as when the trailer fully supports it. But I would NOT put a giant winch on there to crank the boat forward when it's out of the water. You may end up pulling the bow ring right out of the bow. Instead, try treating the bunks with liquid rollers before hauling the boat next time, and give the Mac bump a try - not too hard at first, though, as that stuff makes the boat slide like it's on goose poop.

The tongue weight is low enough without the boat sitting several inches back, and the trailer is flexy enough that it's probably bobbing and weaving as you drive down the road.

[kmclemore]

I just posted my winch replacement a few week back. "check your winch"

In the spirit of making life easier:

http://www.macgregorsailors.com/forum/v ... 11&t=20813

[vizwhiz]

However its important that they understand the stress involved (Hence the physics lesson) sorry if I was wordy

OD...I ran the basic calcs on the two ramps you suggested and three boat weights, just to put a little set of numbers together for everyone.

For a 5:1 ramp, the angle is ~11.3 degrees. The multiplier for force should be .196 (SIN 11.3)
For a 3:1 ramp, the angle is ~18.26 degrees. The multiplier for force should be .313 (SIN 18.26)

Just from that, it is obvious that the increased boat ramp steepness results in more than 50% increase in the force on your winch.
So, using those multipliers - the static force down each ramp is:

5:1 ramp
For 3000# boat load, (3000 * .196) = 588#
For 4000# boat load, (4000 * .196) = 784#
For 5000# boat load, (5000 * .196) = 980#
3:1 ramp
For 3000# boat load, (3000 * .313) = 939#
For 4000# boat load, (4000 * .313) = 1252#
For 5000# boat load, (5000 * .313) = 1565#

This is how much force would be exerted down the ramp against the winch just from having your boat attached. However, it would be modified by the friction of your boat against the bunks***! This is important...and a very good reason to consider using a bunk slickening agent as some on this board have suggested!

For example, when you pull your boat up onto the trailer on the ramp, and haven't yet attached the winch strap - if your boat doesn't move (slide back down), then there is enough friction between your boat and the bunks to resist the forces shown above. This means that when you try to winch the boat UP onto the trailer, you have to overcome both the weight of the boat AND that amount of friction (or a significant portion of it) just to get the boat up onto the trailer. This is probably why roller bunks are so popular, as they add almost no additional friction force to the weight of the boat that the winch has to handle.

***Friction works against motion, resists motion, so whatever direction your boat is trying to move, the friction will resist that. This kinda works in your favor when launching, meaning when you back your boat down to launch, if you release the winch strap and the boat doesn't slide off, the friction is resisting the weight that is trying to make your boat slide down, and holds the boat on the trailer. But that's less of a problem than getting the boat onto the trailer, where the friction will resist the movement of your boat UP the bunks onto the trailer, meaning your winch has to pull against both the weight force shown above AND the friction resisting the boat's movement up the bunks.