Why do you suppose they made them....

[Chuck]

I've been perusing some diagrams of how the tanks and drain systems worked in the early 70's trailers, and noticed something interesting. The fresh water tank is held in place by angle iron bolted to the frame, that supports a 1" piece of plywood, upon which sits the tank. seems to work ok...

The grey and black tanks, however, sit inside a gavlaized metal pan, which is in turn, supported by similar looking angle iron bolted to the frame. Why a galvanized pan in the back, and only plywood in the front?

anyone? Beuller?

[uwe]

Chuck,
My tradewind has a galvanized pan under the plywood that holds the fresh tank, and the black tank sits on top of the plywood that also makes the bathroom floor. My grey tank is held in with 3 metal straps, but that's a retrofit, of course.
I think it varies widely by floor plan, and size, as well as year. i have looked at 1973 Tradewinds that were completely different from mine.

[Chuck]

yes, well I was referring to frame-mounted tanks only. My black tank sits on top of the floor, too...but looking at the service manual for 1973 shows that there were some models that had frame-mounted black tanks. the fresh tanks were all the same, according to the manual, and there is no indication of a galvanized pan for that particular tank...only one drawing that applied to all models. so what's the purpose of the galvanized pan?

[uwe]

I suppose since it is low and in the splashzone of the tires, that it would protect the wooden sheet from water, and perhaps from critters attacking the wood.

[Chuck]

I just thought of something else, too (hey, its a "process" )

in the back end of most of these trailers, there are frame extensions...3 inch plates that are welded on to the frame rails, making the enclosed space 7" deep, instead of 4. If the angle-iron supports attach at the bottom of those plates, they could support a single sheet of plywood, like the freshwater tank up front...but then there'd be a 3 inch gap in the middle, where the tanks would be open to the elements along the forward and aft sides. (because the cross members that form the cavities are still only 3 or 4" tall, like the main frame rails). The walls of the galvanized pan close up that "gap".

the fresh tank doesn't need this, because the bottom of it is at the same level as the bottom edge of the frame/bellypan. the angle iron hangs down 1"...but the 1" thick plywood "floor" fills in that space. with the angle iron around all 4 edges, everything is closed up.

[uwe]

Good thinking!

[53flyingcloud]

Originally Posted by chuck

The grey and black tanks, however, sit inside a gavlaized metal pan, which is in turn, supported by similar looking angle iron bolted to the frame. Why a galvanized pan in the back, and only plywood in the front?
anyone? Beuller?

(galvanized)

Maybe it was designed as a safeguard;To contain and/or, prevent damages to those tanks that we all don't want leaking? Yuck~

ciao
53FC