Steel plates for job site with the mini

[skyking1]

I have to leave trenches open for inspection, and face logistical challenges getting the bedding in to place as I go.
The 35G with cab has a 1508 pound capacity over the side @10' radius. I am contemplating purchasing a couple of 6' x 6' sheets of my own, and welding in ADB fast-Lok plates.
https://www.westechrigging.com/fast...TWlixdfLvgPPycoXEzjvNkk28Wy4PpqQaAhsLEALw_wcB
I may go with the threaded crosby instead, as my rental company uses them and I could skip renting one of the adapters if I own one.
For non-road use, I am thinking a 3/4" thick plate is plenty for crossing 2' trenches with the 8800 pound machine plus an ~800 pound bucket of pea gravel. The plate weight is 1100 pounds.
I can heel plant the bucket on crossing to reduce the plate center load until the track frame spans the trench, and swing around and repeat as I back off.
Do you think I could go 5/8" and keep the plates in good shape?

 

[Tags]

How much of a gap will the plates be spanning? If it's just a 18"-3' wide trench I would think 3/4 would be more than enough.

 

[skyking1]

yes typically exactly that. I was probably dreaming I could use a thinner plate, but I fear time would start to show some bending issues, unless I get it heat treated.
I figure as long as I keep the 120 off of them I'll be OK at 3/4".

6' x 6' seems to be the most useful shape for a 67" wide mini and those trenches. It would suffice for a 79" wide 50 in a pinch.

 

[Bls repair]

I like to carry road plates with little machines by pinching plate between blade and bucket . No swinging load ,walk up to side of trench at 90 degrees center it over trench ,set it down.

 

[skyking1]

I've done that. At the end of the day I will want the picker to load/unload. I don't mind the swinging loads.

 

[code54]

If you are only crossing 2' of trench very little weight will be on the plate as ½ your track will be on one side or the other.

For roads you need a 12" overlap with a 1" thick plate on a 35mph road and under. That means it can carry something like a tractor trailer. ¾ for 9500lbs of weight is more than enough.

 

[Tugger2]

You might consider going with QT 100 plate (100000 yield material) ,costs abit more but should be a lot more durable for that application.

 

[Welder Dave]

A higher tensile plate could likely be 5/8" thick and do the job just fine.

 

[skyking1]

Checking on that, thanks Tugger.

 

[skyking1]

I went with the 5/8" A514 T1 plate, with a yield of 110,000 PSI and tensile of 118,000 PSI. That is significantly stronger than the typical A36. The 6x6 weighs about 919 pounds.
The seller was nice to let me use his torch and cut a 3/4" picking hole in the center and a 1.5" hole in the center of one side.
I put a 3/4" picking eye and nut through it, and then I rigged it, picked it with his forklift and spun it to an on-point position in the back of the bed to get it farther forward.

 

[skyking1]

I used it already on the job, and it was easy to pick and set. I think I will go with a weld in coil rod nut for the center picking.
https://www.ematerialhandling.com/materialhandling/lifters/hoist_rings/nut/nut.htm