So, it looks like I have a major wrinkle in my sub-floor mounted winch idea. One of the things I liked about this trailer when I looked at it was the fact that the crossmembers were on 16" centers. Perfect for a heavier vehicle as some I looked at were at or even over 20" centerlines. After getting it home and when I looked under it at first glance a couple of weeks ago, I measured nearly 14" from the front of the tilt deck tube back to the front of the first crossmember. My initial idea was that it would be tight to build a box less than 14" due to the arc in which it would need to swing to drop down flush, but I thought worse case, when I cut through the decking if I needed to trim a little of that front crossmember I could just weld it back to the box and make everything one solid mounting and it may actually work out better having the entire front of the trailer braced using the sub-floor winch box at the intersection point between the front and the first crossmember.
While I was looking under it a couple of weeks ago, I measured for a HPU (Hydraulic Power Unit) and decided I had plenty of room to mount both the HPU and the battery box under the deck about 5' back from the front. This would work to keep the weight low and centered under the trailer and more importantly, out of the way and not in the tongue box taking up valuable space. I would do it similar to my last trailer and have remote battery lugs/connection point to connect jumper cables to in the event of a low battery issue, but with the deck up the battery would be quite easy to access and be out of the way. I also figured it would be easier to route battery cables up to the winch if the battery was already under the deck and nestled in the frame rails so it would be a win/win.
I still think the HPU and battery will go right where I have planned, but I am going to have to rethink my approach to the winch. I've ordered the HPU and battery box, but before I purchased the winch I figured I had better take some more measurements, and that is where I saw what I originally missed. With the tilt deck of the trailer up and looking underneath it all looks like a great plan. However, with the deck lowered and sitting on the frame rails there simply isn't enough room for a sub-floor mounted winch, unless I want to cut into structural crossmembers and the latching system for the deck which I do NOT. I had not taken the front tongue crossmember and latching system into account during my initial planning.
It may be hard to see what I am talking about in the pictures, so I'll try to explain why this plan is dead before it started.
Here you can see I only have 5" between the underside of the deck and the frame rails with the deck in the lowered position.
Then, what I thought was 14" front to rear space originally, has now shrunken down to less than 8" with the deck lowered. This is the front crossmember tying across the tongue, providing the mounting location for the latching system as well as the longitudinal support for where the tilt cylinder mounts. There is no way a standard winch will fit in this space, and I surely don't want to cut the entire tongue apart including the latching system just to move it a few inches. I guess maybe that explains why I see so many tilt deck trailers come equipped with a winch mounting plate right here at the front of the deck, it is even an option from Texoma on this particular trailer.
Then as I was measuring for a tongue box, I thought I would just do a surface mounted winch similar to my last trailer's second iteration. On my previous 18' Big Tex car trailer, originally I came up with a temporary mounting solution for a winch, however, I got tired of having the winch sitting on the floor under the cabinet in my home's attached garage and having to install it when needed. It never failed, if I needed the trailer at my parent's farm where my paint shop was located, the winch was at home, if I needed the winch for the trailer at home, I had left it at the paint shop. So when I redid the trailer the second and final time, I permanently mounted the winch to the front and used one of those soft sided Warn covers to keep it covered and "somewhat" protected. It worked well having it permanently mounted on the trailer, but I went through multiple covers over the course of about 10 years.
I am leaning towards surface mounting the winch and installing a 1/4" winch mounting plate under the deck which I can tie into both the front 2" x 5" main tube and the first crossmember back, which will really be a solid mount and tie the front of the trailer together much like the sub-floor box idea that I was originally going to run with. Then, rather than a soft cover, I think I will fabricate a box enclosure that will bolt down to the deck to fully enclose the winch and protect it both from the elements and theft. I seriously doubt I will ever need that space at the very front of the trailer anyways as the winch box will be about even with the rear of the flush mounted 6k pound swivel D-rings.
This is relatively close to where the winch and winch box will reside side to side on the front of the deck and where I have seen winch mounting plates installed from several manufacturers on these tilt deck trailers.
This is about where the winch and winch box would lie front to rear.
Measuring for my tongue box. I think by the time I install a tongue box, it may be very close in height to the winch box once completed and actually tie in quite nicely. I was also thinking of putting a small solar charger on the tongue box to keep the battery maintained.
In the winch box, I think I will install a 4-pin trailer style of connector that can act as a quick connect for the winch controller and make it less cumbersome to connect the controller than inside the box. Then just open the front of the box where the fairlead and hook are at, plug the controller into the side of the box and be set, easy peazy.
This will free up nearly the entire tongue box for tie downs, controllers and still have room remaining rather than trying to stuff all of the trailer's mechanics into the tongue box.
Also planned are adding 4 more flush mounted 6k pound D-rings, a permanently mounted spare tire mount on the right side and I still want to make the fenders removable. I also don't particularly care for the tread plate style of fenders so I may convert them over to smooth dual cutout fenders once I get the originals removed.
Thanks for looking and sorry to disappoint, no drop-down winch being installed on this trailer.
Seems like whenever you need them to work, the damn battery is dead. I haven't been sold yet and even if I do decide to use one, I still want a hard-wired controller for when the wireless doesn't work. 
