TMC driver parks his Truck in the back of another

Wrong, you could legally secure 50,000lbs with 6 chains...

they have a WLL of 6600lb but you only need to secure 1/2 the actual weight of the load, that is the Aggregate WLL.

therefore for 38k you could legally secure that load with 4 chains...

if it were me, I would've put 4 chains over the top and one bunk/header chain in the front...

Remember the old rule of steel on steel, straps are not meant for ingots in my eyes.

 

if it was only tarped......

 

when I ran flats out of Chicago in the 90's, we tied steel and aluminum down all the time with straps. Including belly wrapping pipe.

Yeah, you only have to provided for 50% side to side and 80% to the front for braking.

But you also only get 50% for your tie downs on each side. So your load for "side to side" is 19,000, your chains at 4 per is only 13,200. You're still short 5800 lbs WLL in tie-downs.

They changed that crap on me from when I was doing it before for lengths, but the general rule for weights aren't much different.
http://www.fmcsa.dot.gov/safety-security/safety-initiatives/cargo/cs-manual-chap2.htm

Yeah, I go and look this crap up all the time. I get fidgety about some of the stuff they put in my van and I think, "Dang, this should REALLY go on a flat."

 

All bets are off on impact anyway, that stuff is only rated for stopping, once you have impact, anything goes.


Joe

 

Where was the van stopped? on the shoulder or stopped for traffic?

 

Sorry, but that's wrong, as per the FMCSAs regs on load securement. See here. Most relevant part of all that:

That means 80% of the weight of the load must be secured from moving forward, 50% to the sides and read. Remember, 1g of acceleration equals the full weight of the load, since that's what gravity causes normally in the downward direction and we measure as "weight." There's also a requirement for 20% of the load being secured downward, but that's normally covered already so not something you normally have to worry about. Additionally, only tiedowns going from the trailer TO the load are rated at 50% of their WLL. Tiedowns that go from a point on the trailer, over/around the load, then back to another point on the trailer count as 100% as per here:

I'm assuming the 50% is because of the force being applied to the tiedown is only being transferred to one tiedown spot on the trailer, instead of 2 on a tiedown that goes through/around the load.

Basically, you must secure the load to meet the 3 standards of acceleration FIRST, then add additional securement if those aren't enough to meet the minimum 50% of the weight of the load rule that you cited. And last, you have to have make sure you have the required amount of tiedowns based on the length of the load. Usually, this just means moving some around since if you've met the first 2 rules you should have enough securement to have this one covered as long as you space it out some. For long, light loads though it may require adding further securement.

Straps over the top of a load like that are not legal according to the regs. The real confusion comes in when trying to figure out how much forward movement is prevented when downward force pulls the load into the deck/dunnage on the deck. While it certainly accounts for some, it can in no way meet the 80% requirement of the regs. Even a bulkhead attached to the front of a trailer might not be enough for heavy loads, though I haven't seen anything that applies specific values to the amount of weight those bulkheads are rated for.

 

I'd have x chained the front and back of that bad boy as well as chains all over top. Dang, that's a mess.


Joe

 

I never claimed to know the physics of a wreck. it just stands to reason that you have 40,000 pounds moving at say 55mph and you abruptly stop it's forward motion. you wont hold that 40,000 pounds with anything less than mabe welding it to the truck. I used to drive a tow truck. I have seen a bottel of shampoo go thru a windshield in a wreck. not just smash it go clear threw it.

thankfully for the driver TMC outfits their trucks with nice cabnet style headache racks. for those that are better at surfing the web there is a formula that a person can use to find out what kind of energy we are talking about.

 

I drove for TMC for 2 years and one thing that was stressed heavily and reported when it wasn't done, is x-chaining the front of x-chainable (or x-strappable) loads. If you had a load of ingots or such and it didn't get x-chained with 2 chains (or otherwise bulkheaded), you'd probably be getting called into safety the next day because some other driver would drop a dime and you're only allowed one of those reprimands.

The point is, I suspect the load was x-chained and the further point is, as was mentioned earlier, at some point all the chains and straps and technique in the world isn't enough in a ≥ 10 MPH impact stop or rollover.