Looking for opinions.

[mrlupr]

Just finished installing two 55 gallon drums for fresh water. I used mobile home hurricane tie-down straps bolted to the floor with 5/8 in bolts and on the outside bolted to the rail also with 5/8 inch bolts. I installed two bulkhead adapters on top of each drum. One for short connections, the other for an overflow line.
Each barrel is laying on top of a 3/8 inch thick rubber mat.
I'm looking for critiques. Do you see anything dangerous or untrustworthy?

 

[musigenesis]

I wonder if, as the barrels are drained of water, they would change shape slightly and reduce the tension on those straps, allowing the pads to wiggle free? Maybe these are more rigid than the kind I'm thinking of.

 

[mrlupr]

Interestingly, I filled them up before I installed the straps. And sure enough they did change shape and became about an inch shorter and about an inch and a half wider.
What I didn't do was empty them again afterwards to see how much strain is applied to the plastic when it grows back to its original shape.
I'm going to be trying that experiment out tomorrow. Hopefully it's not so much pressure that the straps cut into the rubber.

 

[Rucker]

If I did the math right a full drum would be about 450 lbs. A little research indicates the load should be secured to withstand a force of .8 gees in the forward direction, .5 in all other directions. This means a max of about 3.6K lbs of force.

You load is secured with two straps, each having a 5/8" bolt, which has a tensile strength of 10,000 lbs, easily. For the sake of easy calculations let's assume just one bolt needs to fail for the barrel to become unstable.

Looks like your securement is good by a factor of almost 3x.

I wonder what the tensile strength of the straps are where you've drilled into them. And how about those boards screwed into the floor? Are the boards able to withstand the crushing or shearing force without splitting or letting go?
Would the barrels crack or be cut by the straps in a forceful crash?

 

[Rucker]

I should've also said the installation work of those barrels look damn good.

 

[musigenesis]

As a loading comparison, an International bus seat with three 150-pound children (it happens) belted in would be attached with four 5/16" bolts all the way through the floor (with the big angle brackets on the underside) and three (or four?) 5/16" bolts to the chair rail. Four 5/8" bolts should be stronger overall (assuming the floor bolts are all the way through and not just screwed into plywood), especially since the water barrels' CGs are closer to their attachment points and thus would have less leverage.

 

[mrlupr]

Floor bolts do indeed go all the way through the floor.

 

[BeNimble]

I'd be concerned about sloshing.

 

[mrlupr]

All I could do to prevent sloshing would be to make sure they are either completely full or completely empty during travel.

 

[BeNimble]

All I could do to prevent sloshing would be to make sure they are either completely full or completely empty during travel.

google stop tank sloshing to get some ideas. I think the challenge is you have potable water, so can't stick just anything inside it.
I might think maybe half fill it with a bunch of short thin 1in pvc pipe segments might do it, i dunno, but need to do something.

 

[Danjo-SKO]

I have 50 gallons under the bed. It’s secured with 2” angle iron corners that thru-bolt through the floor with four 1/2” all thread bolts, as well as a pry wood 2x4 frame incorporated into the bolt hold downs.

In your design, I think I’d put bigger straps. The attachment point looks a little weak. Wider straps like water heater straps, or make some out of 1/8”x2” flat bar steel.

I have not noticed sloshing from the tank. It doesn’t seem to be a problem.

 

[mrlupr]

Thanks for everyone's feedback. You folks convinced me. I decided to go back to the drawing board and rethink a much sturdier method of tying them down.

 

[Sehnsucht-SKO]

RE the sloshing: if it's any consolation the length of these tanks will help to mitigate the effects of liquid momentum. I would prefer this setup over longer shallow tanks because the length of potential travel inside the tank is what allows the liquid to gain momentum or more accurately to maintain forward momentum as the environment (the vehicle) slows. In tanker trucks that aren't food grade this is accomplished with baffles which either segment the entire tank into smaller compartments or at least restrict the amount of liquid transfer in order that it fails to gain that momentum. Food grade tankers are THE WORST because they cannot have baffles for sanitizing reasons therefore when you stop it takes about 12 seconds and suddenly you're rear-ended by 45,000 pounds of liquid against the front bulkhead, enough to shove you an entire car length forward! So as long as you solve the securement issues I think you're in no real danger from an unsafe or unexpected handling situation with this setup.

 

[UFO pilot]

IMHO looking great mrlupr! That seems like a lot of freshwater capacity.

Are you planning on lots of boondocking? Sorry if I missed your plans in another thread this is the first I am seeing your build

 

[Elliot Naess]

Terminology, if I may:
Is that a 5/8 bolt?
Or does the head of the bolt take a 5/8 wrench, which would probably make it a 7/16 bolt?

 

[mrlupr]

Elliot, they are 5/8 in bolts. Their heads are 9/16 in.

UFO, I don't know how much boondocking we will be doing. The idea was to use her for camping and trips across the country. To be honest I've never been camping a single day in my life, but I dreamed of this since I was a kid. I still remember watching The Partridge family and saying I'm going to have one of those buses one day.

 

[mrlupr]

Elliot, I think you're on to something. 5/8 in bolt wouldn't use a 9/16 wrench. I'm going to verify exactly what it is again.

 

[musigenesis]

Elliot, I think you're on to something. 5/8 in bolt wouldn't use a 9/16 wrench. I'm going to verify exactly what it is again.

https://www.boltdepot.com/fastener-information/Bolts/US-Bolt-Head-Size.aspx

3/8" bolts take a 9/16" wrench. I thought those heads looked a little small to be 5/8".

What grade are these bolts, by the way? You'd probably want to be using Grade 5 or Grade 8.

 

[mrlupr]

I decided that instead of taking it all apart, I am going to build a cage around each of them. I'm thinking about purchasing two 24 ft galvanized steel 1 and 1/2 in 14 gauge square tubes. One 24 ft tube for each side should be enough to weld two decent cages.
Bolting the cages down on the inside with actual 5/8 in bolts, maybe three of them on the insides and three more bolts against the rail.
My main concerns are having two 500 lb torpedoes flying towards the front in a head-on collision or having two 500 lb bowling balls flinging around the inside of the RV during a rollover.

I think a well structured cage will at least keep us safe from that damage.

 

[rhbcub]

I'm a bit of a novice in the Skoolie world, but I have hauled thousands of pounds of explosives thousands of miles.

There is no way in **** I would do what you're proposing -- even with your re-design. I want that **** below, or way, way behind me.

As you said, a couple of 500# missiles behind your head is just bad business. You have a front end collision and death is the only possible outcome. And it won't be pretty for your loved ones.

I've seen exactly what happens when pipe and other equipment moves forward in a front end collision and it's not something you want any part of.

Just my take.

Best of luck and best wishes!