Wheel Chocks Expiration Date

[CampingFamily1]

So, just for idle conversation, are there any physics majors out there? Who made the calculation to decide the of amount of chock material to stop a 13 inch wheel from moving? It seems that someone, somewhere in the industry decided a 4 inch tall chock with a 30-40 degree slope will stop most trailers from rolling away. If your chock expires, what's the minimum lump of crushed plastic you need to have to keep the tire from rolling?

When I talked to the tech service person at camco he said its just based on the age of plastic. Plastic ages in 4 years. That's all he said.
I imagine if you took the chocks and stored them in direct Arizona sun in the summer, and Arctic Circle cold in the winter, extreme conditions, plastic would deteriorate and crumble in 4 years. So you wouldn't want to crawl under a camper on your sloped driveway in those conditions. So the engineers probably took the most extreme conditions from some technical bulletin on plastic and set the date based on that study. A marketing person noticed the extreme end research also helps boost replacement sales and they can justify it with their technical bulletin or study done by some generally accepted research method held out as the standard for all plastic.

Apparently it takes about 1000 years for plastic to break down in landfill, so pushing people to fill landfills with chocks that could last longer is not responsible either.

I searched for a chart on when plastic breaks down, but couldn't find one. Instead I found a lot of charts that show how much plastic pollution we are adding to the environment.

I did my own scientific study on my chocks. I put them under my camper wheels on my sloped driveway, drove forward and rested the weight of my camper on them, and put my mininvan in neutral, adding the weight of my minivan to the equation. The minivan was on an even steeper slope of the driveway, adding much more force to the chocks. After 4 years, would the plastic hold both my 3200 lb camper and my 4000 lb minivan on the slope of my driveway? It held the 7000 lb load on my own driveway slope. Unhitched my minivan, knowing the chocks held 2x the weight needed.

 

[Milemaker13]

Illuminating point. In a land fill or ocean plastic take 1000+ years to breakdown. But behind your wheel or stored in a cubby it takes only 4 years.
Not making any comment here just an interesting observation.

When I talked to the tech service person at camco he said ... Plastic ages in 4 years.

.... it takes about 1000 years for plastic to break down in landfill...

 

[tombiasi]

The term "plastic" is not one universal thing. There are many different plastics. Like everything else on earth it has a finite life span. I think (hope) most of us can tell if we should no longer use the chocks.

 

[CampingFamily1]

I had a colleague at work once who died when not following proper safety practices with his boat. While loading the boat on the trailer he was in the water behind the boat (bad idea) and his teenage son was cranking the winch. The winch ratchet released and the boat came rolling backwards crushing the father which was fatal. So I try to understand safety around heavy boats and RV's. Setting up a camper on a low slope site is different than crawling under a camper on a steep slope. Sorry I should have explai ed this earlier, although I admit I found a lot of the posts funny and very enjoyable from the perspective of just setting a camper on a low sloping campsite. Made me laugh out loud!!

 

[HappyTraveler]

We have a dual axle so we made two chocks out of 4x4 (which is actually slightly less than 4x4) and put them between the wheels like this (used GreyFox' photo):

 

[CampingFamily1]

Yes I'm thinking about getting solid chocks for the driveway slope when dewinterizing on the driveway