winch mount size of metal

The eagle trailer I ordered, 10K 16 foot double axle 5200 lb axles should be here in a few weeks. I ordered it with a box for tools . The box will interfere with placement of a tripod for winch support so will mount the winch with a receiver hitch at front of trailer bed
Trailer is constructed with 5 inch channels running full length of the tilt bed. 3 inch channels lie flat on top of the 5 inch channels with 2 x 6 planking on top of the 3 inch channels.
It is my intention to attach a piece of 5/16 inch plate, or 6 inch wide 5/16 inch flat steel to the front 3 inch channel. Will drill through the 2 x 6 planking and through the 3 inch channel to attach the plate. Will weld a 12 inch piece of 5/16 plate or 5/16 inch flat bar at 90 degrees to the plate attached to the deck. Will weld gussets to help support the vertical piece.
Have two winches: one is a simple 3000 lb type which quickly attaches to a trailer ball. The other winch is a 3500lb model, Harbor Freight, on a mount which I use on the front of my pickup and my JD 850 tractor. Winch slips into a receiver hitch.
Would like to see a picture of anything similar any of You have used. Secondly want to know if 5/16 inch plate or flat steel is heavy enough. I will need to counter balance trailer at back as it is a gravity type model and additional weight at front of the tilt will interfere with the gravity system of the tilt bed. { I think }

It sounds good to me except for the wood plank spacer between your front frame part and the plate that is providing the attaching surface. I don't think that long term the wood will stand up to a good pull. Some suggestions would be to drill the holes in the planks oversized and put some thick bushings in to carry the load, or, cut the front few inches of two planks and weld a plate under the back edge of your horizontal support and attach your 1 or 2 planks to that plate.

5/16" is more than adequate. I would just run the plate from the front crossmember up to the pipe across the front. You can either weld or bolt it to both pieces.

Jonfmn,

Thank you for reviewing what I want to do regarding attaching a winch to my tilt trailer. Your idea is good about attaching a support plate to front edge of tilt bed and bar across the top. Do you think it would be necessary to built a gusset from the top bar to trailer deck
Chris. Seattle. Wa

Showcrop,
Thank you for taking a he time to read my lengthy >explanation
Your ideas , obvious experience, is appreciated
Chris. Seattle. Wa
Trailer will end up on Orcas Island in the San Juan
Islands. Materials to build things such as winch
supports not available there

Wouldn't hurt, but I don't think it's necessary. If you bolt the winch directly to the plate maybe a 1 1/2 x 1/4 flat welded on edge virtically between the bolts as a stiffener.