Best way to reinforce long base or skid with a steel weldment?

[pep930]

I am shipping a part that is about 40 ft. in length X 12ft. wide X 10ft.high.The pc. is not heavy but the customer is very concerned that the crate will flex when lifted and is requesting a steel weldment to make it more rigid.The pc. is extremely fragile and the crate can not bow.Any suggestions on a steel weldment and even crate design would be helpful.Thanks in advance and have a great day.

[Marcel]

Firstly I am not aware of what this product looks like, weighs or if the entire piece is spread across the whole skid base or is it also supported with legs. Most importantlyyour base should be very well built as this is the first place the Crate would flex. Bolt together Using 4x6x12 on edge installed every 24" as your joist and 7 rows of 4x4 spliced in different places over the skid as your skid runners. Then nail doubled 2x6 Rub Strips every 36" & Nail on a 2x6 Top BASE.
When building your walls rather then the usual style of wall panel make your walls like a house wall
2x4's will be fine. Then after building walls plumb & square them up. Notch cross bracing on the outside portion of all four walls. Also cross bracing in the mid area of your side walls similar to a "W" is needed as again this is where it will flex. If you wish you can use metal cross bracing but it would most likely have to be made up and you do say the product is not heavy. There is a product that house builders use that you just make a saw cut in th wall and then fit in the cut a "T" shaped cross brace and then nail it. Lag your walls to the base every 24" or less.
Then when your nailing the plywood you can also nail into the bracing.
Also your plywood should come down to the bottom of the 4x6 to ensure plywood has good nailing.
This design will most certainly not flex however I am not responsible for how it is handled especially in the loading area.
Designing the lid to fit inside the frame or at inside the plywood edge will also strengthen the flex. Make your lid with 2x4's on edge for strength
You might want to consider a software to design these type of crates. If you do email me and I will get you information.

[pep930]

Thanks.I have built many crates using that design.My main concern is the request for steel weldment on the base.Something I have not done much of.

[Marcel]

You could buy some 3" Angle Iron and Lag or bolt it down both sides of the skid to strengthen...

[Admin]

Separate from the container you may want to consider asking the customer how they envision the weldment and why they feel it's needed. Typically, something this size that can't flex has a frame structure to keep it from flexing. If that's not the case, it would be helpful to know what the tolerances are. My guess is that you'll either find out that the need for steel is a raw assumption or, if not, you may want to enlist the help of a structural engineer. Request for a weldment is a bit vague.

Good luck!