Know of any Pintle Accidents Needing Safety Chains?

[SteveKuhn]

I've spent quite a bit of time over the weekend looking up safety chain topics here and on Google. I found quite a few accident reports where the chains did or would have improved things. However, all were with ball hitches where the trailer wasn't properly seated, the locking mechanisms failed or weren't engaged, or a wrong sized ball was inadvertantly used. I didn't find one incident where a pintle/lunette was mentioned.

I'm wondering if anyone here knows of incidents where the pintle/lunette separated and the chains did or would have made a difference. I'd like to hear about it.

Thanks.

Steve

 

[quickfarms]

I can happen and is usually a result of fatigued bolts or forgetting to lock it closed.

On some commercial truck there is a cable running down the drawbar because the drawbars can fail.

 

[juanprado]

I noticed the m105a0 or 1 had a rounded type hook on the safety chains. I towed one that had one chain slip off when I assume I had hit a bump with my m923.

The m105a2 have a more elongated hook.

I also noticed a large batch of m105's sell at camp Shelby that all had been retrofitted with another set of chain hooks with the safety clasp on the hooks. The originals were still left on but the first free link had the "extra" hooks.

 

[Recovry4x4]

The long factory type hooks have a hole in the eye for a piece of safety wire. I often safety wire or tape my chain hooks just in case, especially with the tow bar.

 

[gimpyrobb]

I picked up an MKT for a member here. While hooking up the cotter pin holding the pintle shut missed the corresponding hole to keep it shut. The trailer didn't go flying into traffic because of the safety chains. Is that what your looking for?

 

[monkster]

I was told one incidence when the cotter pin did not get inserted in the pintle hook and it came open and 155 was lost off mountain in Germany. He told me then his Sergent covered him as to that the cotter was in and than came out during transient do to ware. Whew

 

[harleyhouse]

These two happened close to Pittsburgh.

http://www.post-gazette.com/stories...dent-on-rte-8-shatters-miracle-family-430136/

http://pine-richland.patch.com/arti...tops-in-front-of-hoover-olde-plank-restaurant

 

[SteveKuhn]

Thanks. These are the types of examples I was looking for in order to anticipate failure points. Interestingly, there are very few I've found where the hitch pin fails to the point of letting go. The question in my mind wasn't the value of chains but the kinds of failures. The unlocked latch and incomplete pinning are similar to the ball accidents and presumably could be avoided with careful inspection. I'd assume that fatigued bolts would be on older trucks and less often with fairly new hardware.

I have the hooks with safety wire holes and do use them. I was actually thinking about something similar to the dual hook setup above as well as a short chain around the riser reinforcement angle and back to the receiver frame to trap a snapped hitch pin.

I've taken some time looking up chain grades, working loads and max ratings. It's interesting to me that the chains on both military and civilian vehicles seem 'way over rated for a dropped tongue, but not really rated for the snapping loads that might take place if the hitch failed and the tongue missed the 'X' with a full trailer at 50+ mph. For my money, the commercial chains sold at the trailer counter are just a joke. When you do the math for F = ma, it takes 1/2"+ Grade 70 chain and hardware to really know it's going to hold on a 4500 lb M101.

I priced the stuff out and you end up with chain components that are upwards of $50, maybe more, and probably not coming from Harbor Freight. Then 'ya gotta wonder about the integrity of weld points on an old trailer.

It's good that for the number of times the chains come into play, they hold beyond what they appear to be rated at.

Thanks again.

Steve

 

[porkysplace]

I have seen several pinle open and trailer take off because welding rod or wire was used in place of the cotter pin . I have also seen the pivot bolts and holes wear to the point they wouldn't stay locked.

 

[Ferroequinologist]

Not a pintle accident, but one where the chains saved my bacon!
http://www.steelsoldiers.com/showthread.php?63828-Towbar-Incident-Report&highlight=


I had a civilian pintle on my pickup pop open crossing some train tracks, and my M101 came off. But she was chained up properly and nothing happened but skinning a little paint off the landing leg.

 

[harleyhouse]

I went to Tractor supply and bought safety pins to lock my pintle and ball couplers.
I drilled out the cotter pin hole one size larger and use a hitch pin with loop.
Locks them from opening.
The 2" bulldog coupler " black" has a locking pin, and the 2" croft coupler "Silver" is before the pin was inserted.

I also changed out the safety chains on my trailers with Safety cables.
Tey have locking hooks and stay fixed. I like them because they coil back and don't hang down low.

 

[Flyingvan911]

I remember one in Kansas City a few years ago. It was a trailer air compressor. I think the big four wheel size. It came off the truck towing it and went into the oncoming lane and killed a lady. I don't recall the circumstances behind it getting away.