Tongue box

[KCStudly]

Working on it, I don't have much concern for what you have done since your box is way out in front of your front cabin wall. Your concern is more about the load on the tongue and whether the tongue is adequate for the loads.

My concern was more for what I had proposed early in my build, and what I have seen others do; building the tongue box into, or through the front cabin wall.

I had hoped to build a gun locker thru my front wall that would be deeper than my front wall is thick. In order to hide this I had originally planned to build the gun locker into the back of my tongue box with a false wall at the back of the tongue box. Basically stealing some room from the tongue box and hiding the difference by having the tongue box be unitized with the front of the cabin.

However, once I had my frame built (2x2x1/8 sq tube main frame, 2x2x3/16 sq tube front xmbr and A-frame tubes) I was still able to see some flex between the main frame and tongue. Once the main frame is stiffened up significantly by the installation of the cabin, I expect this flex between the cabin and tongue to be the same or even greater.

My first reaction was to plan on putting rubber isolation mounts between the floor of the tongue box and the tongue, but I am still concerned that the forces might transmit from the tongue through the box and try to break the joint between the box and front cabin wall.

I have great confidence in the tongue and chassis, allowing that to flex is a natural thing, but fixing the tongue box to the front wall of the cabin is not. Remember, TPCE is a hybrid foamie deal, so my front wall is not that rigid.

My concern may be highly specific to my own construction, but I felt that it was worth sharing to a broader audience, and had hoped to get some feedback from others that have built their boxes into the front wall.

[working on it]

KC- You're right, your tongue box construction is completely different from mine, and even from citylights. Your foamie hybrid presents unique problems, especially when opening up a structural piece (hole in front wall). citylights' tongue box is a more closely related situation to yours, though it is a solid wall joined to another solid wall (box to front). And both his and my trailers have heavier steel drawbars. My isolated box doesn't weaken my structure in any way; citylights and I are just concerned with my use of lightweight, non-structural "outriggers" as perhaps insufficient to resist movement and/or unintentional distortion of the supports. However, whomever is right about the strength needed, then any who read this thread will have more info to base their build choices on. KC-Might I suggest that in your case, that you might physically detach the box from the wall, surround the box itself with a wooden frame, then do the same with a frame attached to the foam wall. Join the box to the tongue, then use a flexible membrane between wall frame and box frame (shower floor liner, pond liner, butyl rubber, or even canvas). The box will be thus prevented from transmitting major vibrations to the superstructure, the cut-out in the wall will be re-inforced by the wood frame, and the membrane will keep the elements out. Just a suggestion.

[KCStudly]

It's even easier than that. I'll just make the sides of the tongue box shroud the cabin side cabinet without actually contacting the front wall; just leave a small gap that will form a shadow line but allow for relative movement. Similar to the way that Dan did the tongue box on the AT.

[working on it]

Spent all day re-wiring the trailer: 4 gauge cables to the tool/tongue/battery box, added a main cut-off (positive) switch prior to cabin entry (also shielding the external electrical connections from inadvertent contact) , and re-attaching the box in a more solid way. The perforated outrigger angle bars now have 1" steel (solid) angle pieces crossing the tongue, firmly bolted to the outriggers, front and rear (crossing the tongue beam supports the weight better). The front crossbar is also bolted to the box (5 attachment points, now). The front u-bolt is now snugged tight, since I firmly believe that "give" is no longer needed, as I also removed one set of Tek screws from the frame mount rear, and replaced them with bolts/washers/nylocks. I tested by standing on them...no "give". The previous round of posts here with Kc and citylights made me re-think, and I decided to ensure that my re-conditioned and re-located Optima would remain on the tongue. I also made my own chain-hanger for the single-beam weight-distributing spring bar. I'll post some pics tomorrow in my gallery; too pooped tonight to take them.

[working on it]

Here are some pics of the work: However, the trailer is still not finished...the A/C problem has reared its ugly head once more : http://www.tnttt.com/viewtopic.php?f=50&t=56667