mounting a trailer box on a single beam trailer tongue.

[inchadeboca]

i have a single trailer that i pull my sxr with and i want to mount a trailer box for my straps, oil, possibly securty chains, etc.
it has enough tongue space for a tool box and the trailer is rated for 1200#.
any ideas, or pics on how i should mount it to a single beam tongue?
i was just going to make a base for the tool box to sit on (3/4" plywood) cut into the same shape of the box bottom then U-bolt the plywood to the trailer tongue and either screw down the box to the wood
HomeDepot sells aluminum stock (L-shaped, boxed, etc.) maybe make a base with that and then plywood?

 

[whitca]

I'm doing the same and plan to use unistrut to build support bars under the box when I finally get around to it.

 

[KMN]

I just used 2 U bolts on the tongue and into the plastic box like you have shown above. I then used some tacky gasket sealant on the threads and all over the washers and nut to prevent leakage if I back up the trailer enough to submerge part of the box.
I put all kinds of oil, tools, boots, gloves, hoses, life jackets in there and it has enough strength to not move around too much. I also put a bolt on each side on the top end and attached it to my gas tank holder, which is also U bolted onto the tongue. Works great.