Just finished a ballast box build. Wish I would of put a receiver hitch on it. Used 4x8x16 solid block to make weight adjustable up to 800 pounds
I have the ballast box ready for concrete. Here are a couple of pics that show the steel layout and the box form.
I used a cat II drawbar, drilled a hole in the plywood for each pin to stick thru on the two sides of the form. On the end of the form, I jigsawed a square cut for the receiver tube to fit thru.
I welded two pieces of angle at 90 degrees to the drawbar, drilled holes for the top link. After the concrete is poured, and the box is test fitted in the tractor, I plan on adding a bit more steel to tie the tops of the angles together.
The picture of the form shows the hitch pin location and also the receiver pin tube. I ran the tube wild..it will get cut off after I decide how I want to secure the pin.
Next step - coat the forms with some release agent and mix some concrete. 32 bags! Going for a weight of right at 2400 pounds.
What no wire mesh or rebar cage an inch in from the surface? Bridge inspector don't you know! Even though you pouring that one bag at a time I'd put a couple of rachet straps around the whalers to help the screws hold the pressure. Better safe then sorry.
We got the pour done. Rented a small electric mixer that really sped up the process. Built a platform next the form and was able to dump direct into the box.
I had some 2" PVC, that idea was stolen from others here on TBN. Sank 4 of those, and one 4" pipe as storage for shovels, etc
Going to let it cure for a week or so since my shop is unheated unless I feed the stove. It never gets below freezing.