Disasters Tend To Happen In Threes

[barry2952]

DISASTERS TEND TO HAPPEN IN THREES

8-10-2006 I carelessly damaged my Mark II as I pulled it out of the garage to go to a Press Preview of the Willistead Classic. It's parked on a four post lift, in the down position during the summer as I park the Porsche on top for winter storage.

I pulled too far over and took off the Mark II emblem and left a very nasty set of gouges in the paint with the lift's support cable. I went to the Press Preview anyway.

I loaded up the Porsche and had a friend, who moves cars professionally, tie it down for me for transport. I had positioned the car so that it lent some noticeable tongue weight.

Friday 8-11-2006

My employees and I spruced up the work truck for travel. I had just had every system service and checked on the truck. I wanted an uneventful ride. I drove home and packed and loaded the truck for a fun weekend at a Concours that we helped develop.

We shortly encountered some construction that required some lane changes and the trailer handled pretty well. We made it about 30 miles when disater struck. I had been traveling in the left lane of a freeway and exited on a continuation of M-14. This is one of those left-entrance ramps and I wanted to end up in the right lane. I had a clear shot at a lange change and moved over at about 45 miles an hour. The road was crowned and slightly curved.

I felt the truck start to pull and I knew I had a problem. The trailer started to fishtail quite forcefully. I had read, and I had pacticed, using the brake hand controller in the event of a bad sway to drag the tow vehicle down in speed and straighten out the sway. I used the hand controller and it had no effect the first time. Apparently I didn't leave it on long enough as it has to build up pressure in 24 pistons. The second time I tried I got almost immediate results and the truck straightened out as I was headed for the concrete median wall.

By this time the trailer had done about 4 wags. I pulled away from the median as the 4th wag smacked the driver's side tail of the trailer against the median. That seemed to interrupt the pending catastrophy and shoot us off across the sholder and two lanes of the e-way. I was now headed for what I perceive to be a ravine. My wife remembers it as a large ditch. I was now somewhat in control. At least I was headed in the same direction as the rest of the traffic.

The ravine was fitted with a guardrail that probably saved our lives. Unfortunately, that impact tore the Porsche loose from its mountings and slammed it into the passenge side wall and rear door of the trailer.

The only thing that kept the Porsche from crashing ino the lounge was the spare tire for the trailer. It wedged the front tire of the Porsche up against the winch.

The Porsches's pretty messed up, but repairable.

The trailer suffered some structural damage, but also can be repaired. I'll have to find a donor trailer.

I believe what happen had to do with the newly installed load distributing and sway control hitch. One of the torsion bars dropped out of its socket and hit the pavement as did the chain cinch it was attached to.

One of the torsion bars, the one that hit the pavement, shows signs that it worked its way out of its socket as its wear pattern shows.

I believe what happened is that the torsion bar fell out of its socket as we crested the crown of the road. This is when there would be no tension on the bar. The hitch is fitted with a pull pin that must have worked its way out or rolled over to reveal its tapered side. The conditions must have been just right and allow the torsion bar to drop out.

The torque that the trailer went through with one of two torsion bars exerting torque on the frame was amazing. The 2" solid steel hitch insert bent to about a 20° angle. It looked like tubing that had bent. Very scary.

While this may have been an unfortunate couple of days I believe I am fortunate to be amongst the living.

BTW, I believe we have chosen the name for our trailer. It will be forever known as "The Phoenix". Appropriate on so many levels.

 

[billcu]

This is just horrible Barry.

I'm so sorry to hear this. 3 beautiful vehicles damaged.

I am very glad to hear that you're OK though. The vehicles can be fixed.

 

[Conti94]

Thankfully you are ok, that is what matters. I am really sorry to hear about the vehicles though, but they can be repaired.

 

[barry2952]

Thanks guys,

8-12-2006

Now I'm angry. Let's see if you come to the same conclusion.

First, let me describe the way the system works. A round tube torsion bar system does work well under normal circumstances.

The 2 x 2 solid steel bar that fits into the receiver on the tow vehicle is held in place with a hardened steel shaft with a spring pin passing through a hole in the end of it, holding it in place. That shaft becomes an extension of the vehicle as it is tied directly to the vehicle frame. I believe it was bent when the trailer nearly jackknifed.

The 2 5/16" ball is mounted to the new equalizing hitch, not the hardened steel shaft, as is normal for a non-equalized hitch.

The equalizing hitch is attached to the hardened shaft through the vertical shaft drilled with additional holes for height adjustment. A proper height is selected and proper shims are installed to make the ball tip slightly toward the trailer. This angle is important because it will change slightly when the torsion bars are put in tension.

The bars are put in tension by a cam device that snugs up the chains, transferring the load equally to the trailer and the tow vehicle. You are suppose to level out the trailer and tow vehicle and then apply tension to the bars by equally counting the number of links and setting the tension devices on both sides. 8 links produced no tension. 6 links was nearly impossible for me set. 7 was just right.

Each chain tensioner is fitted with a safety device that keeps the tensioner closed. These parts did not fail. The tensioner is fitted to the frame with a set screw. They supply different length screws for various frame widths. These clamps are snugged in place, but are mainly held by the spring tension pulling them straight down on the frame.

The objective is to make the trailer and tow vehicle a unified structure so that "porpoising" is minimized. The sway control comes from the round tube connection. The torsion bar has a diameter that is smaller than the tube it fits into. It is designed to move freely when not cocked in the opening by the tension provided by the chains. The rubbing of the round bar in it's receiving tube is what gives you sway control as that resistance is what makes the tube intentionally bind when needed.

There are many times that the tension drops and the round bar is free to move in its socket. It is held in place at this time, on this model, by a tapered, spring-loaded pin that allows you to push the round bar into place without pulling back on the pin.

That pin fits into a groove in the round bar that is designed to stay engaged with the groove, keeping it from falling out of the socket.

After a sleepless night I went back to the shop and made a closer inspection of the mechanism.

My first observation was that the pins were nowhere near as long as they could have been, based on the depth of the groove. Even so, they should have stayed in.

I then observed that the beveled face of the pin didn't line up with the locating grooves that are supposed to firmly position the pin.

If the beveled pin were allowed to rotate 180° the round bar would never stay in as it would simply push the pin back by sliding down its ramp. These pins didn't rotate 180°, they only rotated about 20-25°, enough for the pin to work its way out and disengage the safety device.

To check my hyphypothesis I used two metal plates with straight edges inserted all the way into the locating grooves. You can clearly see that they are not within any tolerances that I (or anyone else) would find acceptable.

This manufacturing flaw wasn't the total cause of the failure though. The springs installed to keep the pins in place are made of either very cheap or very thin spring steel. They offer little resistance to the pin being pushed out of place.

This is the last link in the failure. The top round bar is the one that fell out. The one that stayed in has a nice crisp edge while the one that fell out has a ramp-like edge that would definitely shorten the effective length of the pin.

In my opinion it was the cumulative manufacturing flaws that led to the torsion bar dropping out of its socket.

When the passenger side torsion was lost the torque of the remaining torsion bar put the trailer into a severe pull to the side that remained. It's indescribable how I felt at that moment as I've never encountered that effect before. Instead of diminishing sway the remaining bar was inducing it. Had I not applied the trailer brakes the trailer would have continued on its circular path clearly leading to a flip of either or both of the vehicles.

Does this qualify as negligence on the part of the manufacturer? I'm sure my insurance company will go after them to recover their costs. Is a retailer responsible for a product they sell? Keep in mind that this product is marketed and sold as a safety device. Is this an issue for NHSTA? Is that who would regulate this product or would this be a Product Safety issue?

I've heard from four people that they have observed round bar hitch failures, too.

 

[chicken]

damn that sucks i would pursue the manufacturing company of the hitch, the seller would just say that "they just sell it and they dont make it" my boat trailer broke in the south side of chicago coming back from indiana at 2:30 am now that sucked, so i feel for ya man

 

[kissedvfd]

Glad you're ok, could have been so much worse! The pictures nearly brought a tear to my eye. It's heart breaking to see wonderful pieces of art and history damaged. Here's hoping all goes well.

 

[barry2952]

Thanks, I'm sure it will. Things tend to work out in my life.

 

[driller]

Wow. I just stumbled upon this thread.

Sorry to hear of your misfortune.

I was very impressed with your workmanship seeing the setup at the meet in Michigan, and that makes it more disheartening now.

 

[mespock]

Glad you and your wife are ok.... Sorry to hear of the misfortune.

Take care and post your the progress on the repairs

 

[JC1994]

man that sucks.... sorry to hear about all the bad luck.