26 M falls off trailer

[kmclemore]

!	kmclemore:
	Merged topic with the "Fast Moving McGregor (no trlr) passes vehicles on Turnpike" topic as they are about the same incident. Filed under "Trailers & Towing" for obvious reasons.

[c130king]

Believe it may be jumping to a conclusion to blame the trailer...

Do we know the tow vehicle? How was it secured to the trailer? How much weight was in the back of the boat?

Jim

[Divecoz]

Hi King.. It was a Jeep SUV but nothing more than that was said.. Can we imagine that if left a foot from the winch this may have caused issues..
If the winch wasnt set that might have caused issues..??? IMHO.. and with Years and years and 1000's of miles hauling boats and such.. It Had NOTHING! to do with the trailer..

[Bleakco]

I would blame a loose nut at the steering wheel not the trailer........

[pokerrick1]

Uh, okay, guys. What's the lesson here? Are we not adequately securing our boats to their trailers? Conventional wisdom is that the weight of the boat alone keeps it nestled securely in the trailer. What say we?

I think that if you are going to travel at freeway speeds - - - you need to strap down the Mac with winch straps, as well as get the hull up to the bow roller (with the MacBump or however). Just more reasons why I hated trailering!!!!

Rick

edited for spelling

[SkiDeep2001]

Here is a link I posted to a while back about securing boats to trailer. http://www.macgregorsailors.com/forum/v ... =9&t=17437 Middle of page #2 - Hope this helps some. There are good posts RE: Strapping VS Not Strapping. Choose your POISON

[Catigale]

It is not only advisable to attach your boat at three points to your trailer, it is the law in most every state in the US to have your load secured.

[Crikey]

Up till now I was only going to add a safety chain next to the winch strap. We went through a pretty hairy crosswind trip to Kingston, Ont last year and learned very fast of the need to properly load the boat mostly ahead of the axle. It would have been even better if I saved filling the fuel tanks until I arrived.
This was all done with one of Rogers little delivery ropes used as backup tie on and no rear strapping - could've been me in that picture also!
Now I think I'll have an extra strap to a topside bow cleat as well as the saftey chain on the bow and a tiedown in the rear. I was also influenced by the previous blogs concerning the Mac's ability to stay put by itself, up till this point. Another piece of advice I was given on our last boat, though, was never to store the boat on a trailer with straps under tension as it will deform the hull which may crack under the expansion of hot weather.

Paranoia runs deep ...

[Catigale]

Another piece of advice I was given on our last boat, though, was never to store the boat on a trailer with straps under tension as it will deform the hull which may crack under the expansion of hot weather.

This sounds like an urban legend. Any engineering backup on this from a PE on board?

[Chinook]

When I pulled our boat out in Ft. With the winch strap cranked up tight, it became extremely stretched and taught after I pulled the boat out and she settled onto the trailer. Even after doing the "bump" the strap was extremely tight. During the drive home I hit some bumpy roads, and while doing a walk around inspection at a rest area I noticed that the bow was 3 inches behind the bumper on the trailer. I looked down at the strap and saw that it had broken. The boat had slipped back slightly while on the road, but the bow tiedown rope and the belly strap back in the cockpit area had done their jobs. I was amazed that the nylon webbing winch strap had failed. Apparently, exposure to weather over several years, combined with tightening stresses and a bouncy road, can cause failure there. I'll be replacing my strap very soon.

[Catigale]

During the drive home I hit some bumpy roads, and while doing a walk around inspection at a rest area

Cant post that practice enough, IMHO. Every hour on the road, check wheels, tires, bearings and boat for 'things out of place'

[Highlander]

During the drive home I hit some bumpy roads, and while doing a walk around inspection at a rest area

Cant post that practice enough, IMHO. Every hour on the road, check wheels, tires, bearings and boat for 'things out of place'

Steph thats a bit much , every 4-6hrs should be OK or when you stop for fuel,
If your having to check every hr then maybe your rig is'nt road worthy !!

J

[Catigale]

Ive gone up to 2 hours between checks. Wheel bearings will go to h*** and a handbasket in about this much time. If you catch it before massive failure, you can choose where you will be when you deal with it. This is much cheaper and much safer. I wont drive 6 hours straight without a break for my OWN body - and whenever I need a break, I take a walkabout...YMMV

PS - see my 'wing and a prayer thread' to see how quickly things go bad...

Here it is: http://www.macgregorsailors.com/forum/v ... er#p177743

[Québec 1]

My experience was as follows on my trip to Florida and back:
I have the original strap to winch attached to the bow bolt and a back up rope attached to the frame of the trailer and clipped to the bow bolt.
1. I keep the bow at least 3 to 6 inches from the trailer v;
2. I always let some loose on the strap ie. there is no tension on the strap when the boat is trailered as I had observed that when I did this the boat stayed in place in the period of a day of driving; If I cranked it up tight the boat would travel up on the trailer to the V and put to much weight on my ball.
3. When ever I stopped for gas I checked the tension on my strap and took it up or down a notch when I noticed tension on the winch strap .
4. When I started a trip I tensioned my strap to the point where it pulled the boat to the point where I was pleased with the weight on the ball and stopped and released a notch or 2 on the winch so that it would not be under tension when trailering.

My conclusion through empirical observation was that the winch strap when not under tension will be less prone to failure, and that a well balanced boat with no weight in the back except the motor will sit nicely on its tailor made trailer. I trailer with empty gas tanks.


Q1

[vizwhiz]

Not a PE, but a mechanical engineer by education and an experienced...person...

It doesn't matter how much the load weighs...everything on our planet accelerates downward at the same acceleration - gravity doing its job.**

That said, when you raise a load and trailer (going over the "up" side of a bump) and then drop it (going down the "down" side of a bump), both objects are going to "fall down" the bump at essentially the same rate. The load becomes "weightless" with respect to the trailer because they are both falling at the same acceleration and reaching essentially the same velocity at the bottom of the bump. Granted, this happens really fast, so we don't really think of it as "falling" and "gravity at work", but that's what it is. (It would be no different than driving the load off of a cliff...we're just talking teeny-tiny cliffs here.)

What happens when they reach the "bottom" of the bump is that...they stop. Pretty quickly. Your suspension compresses because there is momentum of the two objects (trailer and load) "stopping" as they come down. Hopefully, your suspension works properly, all the forces are balanced well enough, and the suspension dampens out the "bounce" effect that would be the next result.

BUT...what happens between the load and trailer, if not strapped down, is that there is room for movement. This is why it is essential to strap down the boat. You want the load and trailer to become ONE OBJECT, and the suspension to take all of the up-and-down load changes. If you leave them separate (no strap-down), you are ALWAYS at risk of the two objects moving relative to each other (boat and trailer)...and the speed, type of bump, suspension failure, tire failure, etc. etc. suddenly become the "catastrophe waiting to happen".

Thankfully, we don't experience many, but strapping the load to the trailer is very important.



**let's stick to loads on trailers so we don't have to argue about terminal velocity with wind resistance and objects in a vacuum and such, okay?