Reinforcing the under bus storage area

[gobygoby]

I have a 40' 98 Thomas MVP with under bus storage compartments. I am about to install the water tanks and a battery bank but I'm worried about all the weight. I've been reading on the forums about the storage compartment weight capacities and I've read conflicting reports. Some people say the factory compartments are crap, while others say it depends on the brand.

So I had a few questions I was hoping someone here could answer;

#1) Are the Thomas storage compartments any good?

#2) How much weight do you think they could safely hold?

#3) What is the typical failure mode? Does the compartment floor fall out, or the supporting braces break, or does the entire compartment drop off after hitting a big bump?


Thanks!

[gobygoby]

This photo shows the bottom of the storage compartment. There are 4 C-channels running the length of the compartment.

[gobygoby]

This photo shows the center truck chassis and a view of the metal beams supporting the interior bus floor.

[gobygoby]

The storage compartment floor is attached to the chassis at the ends, and supported in the middle by two of these clamps.

[gobygoby]

Here are the items I would need to place in the storage compartment:

(2) 33 gallon tanks
(1) 44 gallon tank
(4) Marine deep cycle batteries

I would also like to add more batteries in the future as well as an extra freshwater tank.

[gobygoby]

If I do need to reinforce the storage compartment, here are the supplies I can work with:

(15) 53" long 1.5" x 2.5" steel beams
And the threaded rod shown below
I can buy bolts and small stuff, but I don't have any budget for a total overhaul or anything fancy.

Also, I no longer have access to my welding setup So if possible, I would like to stick to bolts and rivets.

[gobygoby]

Because I don't know yet how the storage compartment would fail (if over stressed), I don't know how to reinforce it. But here is what I was thinking:

I take the long 1.5 x 2" steel tubing and attach it to the bottom of the storage compartment. (I don't know if I need to go lengthwise or crosswise or both) Then I drill vertical holes (just a little bigger than the threaded rod diameter) through the newly added tubing and the compartment floor. I would cut sections of threaded rod and insert them into these holes up to either the truck chassis or up to the metal subfloor. (I would drill corresponding holes in the truck chassis or metal subfloor beforehand)

I could then anchor the upper part of the threaded rod with nuts and lock-washers. I would repeat at the bottom end of the threaded rod beneath the storage compartment.

Do you think that would work? Also, these supports would mainly help with vertical loads, not inertia from starting or braking. Do you think I would need to add something else to help with that?

[mrblah]

Originally Posted by gobygoby

This photo shows the bottom of the storage compartment. There are 4 C-channels running the length of the compartment.

How many c channels per compartment?

How are they attached to the frame?

[milkmania]

Originally Posted by gobygoby

Here are the items I would need to place in the storage compartment:

(2) 33 gallon tanks
(1) 44 gallon tank
(4) Marine deep cycle batteries

I would also like to add more batteries in the future as well as an extra freshwater tank.

Dang, you're already talking about potentially carrying an extra 1000 pounds under there! I say potentially, because your tanks won't be filled to capacity at all times.

Sounds like you need solid plate steel suspended (at least 8 places) from the beams with hardened all-thread. And the steel plate is going to be a couple hundred pounds also.

There's no room for error and underbuilding this thing for sure!

[milkmania]

Originally Posted by gobygoby

This photo shows the bottom of the storage compartment. There are 4 C-channels running the length of the compartment.

That C channel looks awful thin for the weight you're trying to add

[Iceni John]

I would say don't use your bellybins at all! I suggest hanging your house batteries, propane, water and waste tanks, and anything else like a generator, directly from the frame rails and bodyside. Yes, it's a lot more work to do this, but the advantages are two-fold: A) Obviously you keep all your underfloor storage bays for storage (and yes, you'll be very thankful to have that space), and B) if/when anything leaks it will drip harmlessly down onto the road, not create a festering swamp (or worse) inside your enclose bellybin. Imagine your propane cylinders leaking slightly - where would you rather have that propane go, into an enclosed space or harmlessly dissipated away into the air flowing under the bus? What happens if a battery case splits - do you really want sulphuric acid swilling around inside a storage bay?

To give you some idea of what's possible, my bus has an 8-feet long full-width 'pass-through" underfloor storage bay, but I've managed to also fit under the floor all the following:
1) Spare tire/wheel (with its own winch and wheeled dolly) under the stairs;
2) Generator between the door and front wheel, and a quick-connect outlet for regulated propane (I converted the generator to run on propane);
3) A vented storage compartment for anything that could leak or smell (I keep spare oil and fluids there), ahead of the left front wheel;
4) A 120 VAC air compressor above the front axle between the frame rails, tied into the bus's accessories air system and with three air outlets around the bus for running tools or inflating tires;
5) Two 110-gallon water tanks either side of my fuel tank, hanging from the frame rails and the floor's longitudinal structural supports;
6) A quick-connect outlet for unregulated propane (for a BBQ grill), and some access to the fuel tank's filler neck and pipe (just in case it ever leaks and needs attention) and to the two water tanks' outlet valves and drain valve;
7) A water compartment that has two pumps on a slide-out tray, an 8-branch distribution manifold, whole-house filter, 2-gallon pressure accumulator tank, water pressure gauges and valves, all in a space less that a foot wide next to the left water tank;
Two pull-out trays for eight golfcart batteries, open to the ground and with all the house batteries primary switchgear, with the propane distribution manifold above them, and with a 1.5" dump valve for curb-side grey water emptying, just ahead of the right rear wheels;
9) A 115-gallon grey water tank under the frame rails, just ahead of the differential;
10) A 65-gallon poo tank and the three main dump valves on the left side just ahead of the rear wheels;
11) A vented compartment for two 20 lb propane cylinders on a pull-out tray and their regulator and master shut-off valve, fully compliant with NFPA 1192;
12) A pull-out tray for the two Group 31 start batteries, just behind the right rear wheels;
13) A hydraulic fluid cooler for the radiator fan motor and a remote transmission fluid cooler with fan, between the left rear wheels and radiator.
All this is in otherwise empty spaces under the floor, and nothing is using up any of my precious bellybin space that I can keep for Other Stuff. There's still some space left under the driver's seat where I maybe could put a mini-split A/C condenser, but that would require some serious finaigling to make it fit there. My intention is to not have any unused space at all under the floor - I think I'm getting there!

John

What's up with that stupid yellow blob thing that shows when I type Eight) ? Is my computer possessed, or is it a forum glitch?

[chad.nuesmeyer]

Originally Posted by Iceni John

I would say don't use your bellybins at all! I suggest hanging your house batteries, propane, water and waste tanks, and anything else like a generator, directly from the frame rails and bodyside.

What do you use to anchor these? Are you customer building the shelves and systems holding them or have you found mounting systems?

Originally, I was planning on mounting my gray water using unistrut. However, as I have thought about will road debris perforate the tank?

The 4 things I would like to get under the bus are: Gray Water, Batteries, Propane, and Generator. However, I have not found a good source of shelves or boxes that can support those heavier items... Any direction or thoughts?

[Brad_SwiftFur]

Two words: Truck Junkyard. For wastewater, why not cannibalize a road tractor style aluminum tank (formerly used for fuel)? Get the frame rail mounting brackets while you're at it. Do the same for the battery box/tray. Both are designed to bolt right to the frame, and hold the weight you intend to use them for. The engineering has already been done for you.

While you have the former fuel tank off, that would be an excellent time to have any necessary welding done for the new plumbing fittings. Most are aluminum, some are steel, but occasionally a stainless tank can be found.

The generator probably isn't as heavy, so you can find or fabricate the necessary brackets to hang it under the floor. I'm not sure what you plan to use for a propane tank, unless you find a vehicle that had a propane conversion done and cannibalize the hardware from it.

[chad.nuesmeyer]

Originally Posted by Brad_SwiftFur

Two words: Truck Junkyard.

Great point... Thanks

[Iceni John]

Originally Posted by chad.nuesmeyer

What do you use to anchor these? Are you customer building the shelves and systems holding them or have you found mounting systems?

Originally, I was planning on mounting my gray water using unistrut. However, as I have thought about will road debris perforate the tank?

The 4 things I would like to get under the bus are: Gray Water, Batteries, Propane, and Generator. However, I have not found a good source of shelves or boxes that can support those heavier items... Any direction or thoughts?

Each water tank is sheathed in 1/2" plywood, and sits on a support frame made of heavy angle steel. This frame is suspended from the frame rail and floor support with ten lengths of double-nutted 1/2" threaded rod, and the tank is laterally located by further angle steel at the top under the floor, i.e. the tank's hangers only need to hold the tank tight under the floor and do not need to control any lateral movement at all. This way the tank is positively located in all six possible directions of movement. The battery trays and generator and propane are made similarly, open to the ground in case of leaks.

Everything is custom-made - I did not use any ready-made shelving or support systems. This way I could be sure that absolutely no space whatsoever is wasted - I have only small fractions of an inch gaps between things! The four tanks were made by Ronco Plastics in Tustin CA from 3/8" polyethylene with lots of fittings spin-welded in where needed.

Remember, nature abhors a vacuum! That's pretty much my overall philosophy when it comes to fitting everything in place - no wasted space!

John

[gobygoby]

I would love to make custom hanging storage, but I'm running out of time and budget, so I need to use the storage compartments for the water tanks. Eventually, I do plan on adding extra storage under the bus wherever possible. Also, I am stuck with the 3 tanks that came with the bus, sadly I can't buy new ones or have anything fabricated.

Here is a quick update:

I built a wooden frame to hold the two black tanks. I will post a photo soon. I am going to plumb them in parallel. This means I won't have a 'grey water only' tank, but it simplifies things a lot for me. I have access to a sewer connection, but it is 200ft away and I can't bury a line or leave a hose out all the time. It is downhill though, which helps. I am going to reinforce the storage compartment frame as best I can. Once it snows I'm kinda stuck here until spring, so I'm not really worried about traveling with full tanks. Because of this, I have decided to put some jack stands under the bus to help support the tank weight for the next 6-7 months. I should be able to weld something more permanent later.

My garbage disposal arrived from amazon. It is 1/3 hp and only cost $42! I think I've found a good way to mount it under the RV toilet. Today I bought a 3.5 in bi-metal hole saw and I should start drilling tomorrow. The toilet will be mounted in the back of the bus behind the wheel well. After flushing, waste will fall into the garbage disposal. I will have a manual switch that will grind everything up and pump it over to the black tanks.

This configuration uses a little more water when flushing than I would prefer, but it allows me to put the bathroom in the back of the bus beneath the bedroom.

The combined black tank capacity is 67 gallons. We have been trying to use bathroom facilities outside the bus as much as possible (at work, at school, plus we have a lot of family nearby).