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Process Column falls off of Transporter
2

Process Column falls off of Transporter

Process Column falls off of Transporter

(OP)
I don't have more detail yet other than the pictures in the article:

350,000 LB Process Column falls off of Transporter

I was really surprised to see this, especially on a straight road as this heavy haul transport is a pretty mature business. The last time I saw anything related to a transporter losing a load, it was trying to make a turn.

There are some comments I've seen from supposed witnesses that the car that got crushed raced around the escort vehicles trying to pass the transporter and ended up colliding with.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.

RE: Process Column falls off of Transporter

I guess a couple of ratchet straps from Lowes was not good enough?

RE: Process Column falls off of Transporter

The fourth photo in that gallery - the one with all the rescuers working underneath the column, with it (maybe) stabilised by a row of jacks, earth anchors and chains - just makes my hair stand on end.

A.

RE: Process Column falls off of Transporter

See https://scontent-ord5-1.xx.fbcdn.net/v/t39.30808-6...

it looks like a palletized cradle that the column is attached to with a large amount of chain (4 chains in place, one has come loose), but the pallet wasn't attached to anything - no sign of breakage or bending. It has some kind of king-pin mount underneath, I suppose to allow the trailer to turn without bending the column, though unless there are only two of them there will be too much constraint anyway.

That this much column could come loose without toppling the trailer is concerning.

The suspension looks like Scheuerle units, so this was the aft end. It looks like there was a push vehicle by the presence of the tow bar (in other photos)

RE: Process Column falls off of Transporter

It wouldn't let me connect tot he first link but this one https://ordonews.com/two-people-killed-in-texas-af...

has the other end.

Very difficult to see why this should have happened. Everything looks straight unless one of the tow trucks swerved and set off a rocking motion.

The supports look like separate temporary ones and most of the locking force is gravity and friction by the look of it. There really isn't much holding it down.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Process Column falls off of Transporter

To get to that image: https://www.facebook.com/TempleFireRescue/posts/87... then click the close X on the "sign up or sign in" request. Click on the image you want to see, then right click and "Open image in new tab" That produces the above link to the Facebook image address. You can then zoom in.

RE: Process Column falls off of Transporter

Look at the blocking. This structure is very long but is only sitting on blocks in 2 or 3 locations. The trailer appears to be built up of 2 axle segments. That means all of the weigh may have been on as few as 8 axles. In this case it may have exceeded the road's weight limits.

RE: Process Column falls off of Transporter

(OP)
Yes, it looks like every version of the story including my OP is using the same four images from the Temple Fire & Rescue posting. Those four images are all we have to go at this point.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.

RE: Process Column falls off of Transporter

The suspensions are hydraulic load distribution suspensions. All wheels of any trailer segment will have nearly identical loads. This load distribution capacity allows it to cross bridges without overloading them. This is the system used on the M1000 HETS trailer for the M1 tank and the Tunner 60k transporter, both of which I worked on. **


In the case of the M1000 HETS trailer, there is another cylinder that shares the load via the gooseneck to move weight to the tractor.

Notice that the trailer segments cannot pivot relative to one another. I believe there is a bridge structure that carries the bending load across that joint.

Also note that each suspension is steerable, allowing even long trailers to go around corners with the trailer group remaining straight.

** Typically the load is centered right-to-left, which is good. To keep the trailer from rolling over all the right hand suspension cylinders are joined on any segment and all the left hand ones are joined. It looks like the combined multiple sub-units into larger segment.

RE: Process Column falls off of Transporter

The trailer would have to be very rigid in order to distribute two block loads across its entire length. I guess that a properly strapped column would add to the rigidity of the system.

RE: Process Column falls off of Transporter

It doesn't need to be very rigid. That's what the linked hydraulic cylinders do. They are all plumbed together to form a raft of hydraulic suspensions. As long as the sag where the load is applied doesn't bottom out the cylinders, it could have a noticeable bend; they don't normally do that, but rigidity of the structure isn't key to distributing the load.

RE: Process Column falls off of Transporter

Were they overtaking the other vehicle or visa versa?
A little gust of wind, some sway and the two vehicles come together.
But how then entire rig didn't roll is beyond me.
I wonder who made the column?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Process Column falls off of Transporter

Ah - I didn't recognize it before - this image shows the pickup truck under the column, the one with the end of the column base opening. Look to the right of the orange vested fireman.

https://scontent-ord5-2.xx.fbcdn.net/v/t39.30808-6...

There is a large jog in the platform, as if the rear unit(s) steered out from underneath the column. All the wheels should line up, especially when the platform is heading basically straight - see the video link I posted just above.

RE: Process Column falls off of Transporter

(OP)
Yes, the other thing I'm noticing is that right in the middle of that picture, pretty much right in front of the guy in the vest, is the support cradle that the near end of the column was sitting on. We're looking at the bottom of it in this picture.

It's hard to conceive of the combination of motions that lead to the saddle sliding off the edge of the carrier. Once it did, it looks like it embedded itself in the road and then flipped away from us as the column rolled out of it.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.

RE: Process Column falls off of Transporter

Update: SH-36 reopen after oversized load fell off semi-trailer killing 2, injuring 1; Author: Mike Rogers; Published: 6:23 PM CDT April 29, 2024;Updated: 8:03 PM CDT April 29, 2024
The City has now stated the stretch of road, near Highway 317, has been cleared of debris and is reopened for normal traffic flow.

Nothing more to see here??

About the transport
OEM PR Videos here https://www.youtube.com/@tii-scheuerle/videos

RE: Process Column falls off of Transporter

These are faymonville trailers. Says so right on the trailer. Similar to Scheuerle.

RE: Process Column falls off of Transporter

I got this from the Faymonville website.



How is any of the weight transferred all of the way out to the wheels on the right? Surely the modular dollies are not rigid enough.

RE: Process Column falls off of Transporter

They are all plumbed together, distributing the load. This allows traditional AASHTO calculations to be skipped when supplied with the appropriate analysis. Because they are all joined, at least from front to back, not side to side, when they hit a bump, that one tire group goes up but it also distributes fluid to all the others, causing the shock of the abrupt change to be evened out over the entire trailer.

In our trailers hitting a 4X4 at speed was similar to a conventional trailer hitting a one inch high obstacle. Very advantageous in the warzones it operated as people were around to neaten up bombed out roads and collapsed buildings.

Ours also plumbed the gooseneck to the front set of axles, so the load would also be varied to the tractor, which made trouble for hired tractor drivers as there was also a hydraulic pump to even out the trailer. With the landing gear down and attached to the 5th wheel, the system was capable of lifting the drive wheels off the ground. Failing to get them completely clear of the ground still left the tractor with insufficient traction.

It would not be a problem to handle - simply measure the height of the frame rails before putting the trailer on, then restore that height with the gooseneck to get out from underneath - but drivers for some reason did not do that.

RE: Process Column falls off of Transporter

If I take a rope and put many hydraulic jacks long it's length and a load in the center, will the ends of the rope transfer any load to the jacks as they hold the rope straight? I don't see enough rigidity in this system to transfer load.

RE: Process Column falls off of Transporter

I am rather sure they didn't make the deck out of rope and they didn't make a design that doesn't work.

RE: Process Column falls off of Transporter

If the design is good why is the column on the ground next to the trailer?

RE: Process Column falls off of Transporter

The trailers appear undamaged. What it looks like is there are two groups, fore and aft, and each group has a pivot pin arrangement in the center of the group to allow the groups to turn independently of the load. However the load is so long it might not survive being supported solely on those cradles, at least on the highway, so additional cradles are added farther fore and aft with slide plates to slip back and forth on the deck.

The accident occurred where they were moving from a 4-lane to a 2-lane section of highway, so they would be shifting the groups from the right most lane to the continuation of the left lane.

If the driver of the rear group used only a crabbing motion rather than turning, that could have put the rear slide cradle off the edge of the trailer, pulling the rear side cradle with it, as seen in the photos.

I presume someone thought that making 2 groups would allow more maneuverability getting out of and into the original build site and the final installation site respectively, places where the lack of large loads or harmonic vibrations could allow removal of the slide blocks.

Other places said it took 1.5 lanes and it may be the driver coming the other direction saw the truck come far over the centerline and tried to make it to the open, right, oncoming lane. It's possible the rear driver saw the car and panicked and crabbed to avoid scuffing the tires on the trailer, dumping the tower on the car.

Good job to the police and escorts in closing all access to the road.

RE: Process Column falls off of Transporter

Quote (TugboatEng)

If I take a rope and put many hydraulic jacks long it's length and a load in the center, will the ends of the rope transfer any load to the jacks as they hold the rope straight? I don't see enough rigidity in this system to transfer load.

I tend to agree. How is there enough stiffness in that slender trailer for that to be effective?

RE: Process Column falls off of Transporter

Possibly the four wheeler clipped the trailer and damaged some hydraulic lines.
That could affect the steering and/or the side to side balance.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Process Column falls off of Transporter

Quote (The trailer would have to be very rigid in order to distribute two block loads across its entire length.)


The hydraulics should be able to accommodate that.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

RE: Process Column falls off of Transporter

It's a uniformly loaded beam with a wide support in the middle.

Maybe the thought is they are made as flimsily as OTR trailers usually are?

RE: Process Column falls off of Transporter

Quote (waross)

Possibly the four wheeler clipped the trailer and damaged some hydraulic lines.
That could affect the steering and/or the side to side balance.

To be honest, if the overtaking vehicle got itself wrapped up in the transporter's wheels, it would wreak havoc even without damaging the hydraulics. That's pretty much what happened in this other accident.

A.

RE: Process Column falls off of Transporter

Quote:

Chains had been secured to a metal plate which protected brake and electrical hoses.
Mr Hunt described this as "extremely dangerous".
"The reason I say this is that there is nothing to stop the chain moving forward and taking out the hoses".

From the BBC 2008 accident article it seems like the poorly secured vehicle on the trailer was chained to the pneumatic brake lines and damaged the lines when it rolled forward as well as from placing 3 battle tanks onto a trailer that had capacity for 2.

RE: Process Column falls off of Transporter

Context: These were CVRTs (weighing 7 or 8 Tonne each, on a trailer plated for something like 56T), rather than Main Battle Tanks.

The (allegedly) dodgy lashing - to a plate close to the brake lines, rather than to the brake lines themselves - was actually on vehicles that weren't involved in the accident. A surprising number of people were a bit taken aback to discover that lashing schemes are spec'd to restrain loads during manoeuvring and emergency braking - not to hold everything together throughout a catastrophic series of high speed collisions.

(Allegedly), the taxi driver joined the motorway as the truck was passing, pulled out and began to overtake it, then started searching in his door pocket for a road atlas, discovering too late that he wasn't going where he thought he was. With a taxi caught up in its wheels, the trailer started to go places it wasn't meant to, hit things it shouldn't have and then shed it's load.

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