Single Span Stand for a 700 Litre tank !

[mitcheg]

Hi All - I need some advice on a tank stand I have build and am about to put a 1 metric tonne tank on it .... So I have some trepidation here.

Basically I have taken a 196cm (6 foot three inches) wide wardrobe out of an alcove. On each end is a thick brick wall. On each wall I have bolted a reinforced steel plate, 5mm thick, which touches the concrete floor. Nine 8mm bolts are implanted through the plate into the wall with brass fittings ebbedded into the bricks. The plate has a top and bottom welded "lip" of 2x2cm solid steel. So the total top surface of each plate is 2.5 CM wide. The "lips" are supported by three hollow verticals of 2CM square steel tube. That's the plates described.

I plan to place three 7cm H bars, also called I Beam, from one side to the other WITHOUT A Centre support, spanning the 196cm gap on which I'll place plywood and a support for the glass box.


Now, 7cm I Beam is very VERY strong. My question is how many beams should span in order to support the weight without flexing at all ?
-

 

[fishfreek]

NOTE: I am in no way a structual engeneer so take my advice with a grain of salt.


First I would avocate having a local building inspector come and check things out and inform them of what you want to do and confirm the weight will be supported properly. I take it this is on the ground floor with no basement under it? If there is a basement then your supports should go beyond just the ground floor.

I would have two I beams one running the span in the front and one running teh span in the back.

But again I would have someone who is knowedlage in building and your local building codes to come and confirm your plans.

 

[mitcheg]

Concrete floor

Hi - Thanks for the advice. The floor is solid concrete. The walls are supporting walls that are brick. It's a new Swiss building build like only the Swiss build..... I agree that two is a minimum. One would be, er, unstable Anyone know what the bending strain on a 7cm steel I-beam is across a 6' gap ? I might just put 5 I beams in to be sure ..

 

[BillyZ]

well, You'll need a minimum of two to support the plywood base and keep the tank secure anyway (otherwise you're balancing the tank on a single beem... not a good idea). And that is if I'm understanding your description correctly.

What will the 7cm beams be constructed of? Steel, Aluminium? That will obviously make a difference in how many you'll need. I think if you've got two steel 7cm beams, I would think you'd be ok with them not flexing, but I am NOT an engineer. I would suggest finding out the stats on the beams and making sure with some good math. Also, how do you plan on attaching the beams on the ends? The beams may not flex, but you need to be sure your welds will hold the weight. Remember that water is over 8 pounds per gallon plus anything you put in the tank, equipment, decorations etc.

And... Welcome to AquariumAdvice.com

 

[BillyZ]

:? I type too slow sometime!

 

[mitcheg]

Hi There Thanks for the post and the welcome. ! The I-beam will be made of steel. They will rest on TOP of the vertical plates and the welded 'lips'. They will not be fixed in any way - they must move. They will overlap on the far side of the plates by 1cm. Fixing them introduces a lateral pull on the plates -pulling them off the wall. non-fixed will allow them to move - like the slack areas on a bridge top ..... The final effect will be a 'floating in the air' tank with no base at all - Just nice parket floor.. My worry is that strong though it be - I-Beam does flex. and if it flexes to much it will let the glass flex .... dot dot dot

 

[BillyZ]

even just floating on the steel lips, you'll need to verify the strength of the welds on the steel lips. Be sure they'll be able to support their portion of the weight. (not just the tank, but the I-Beams and Plywood etc)

How much cost is associated with these beams? if it's feasible, go with 4 or 5 beams, just to be sure. then put a rubbermaid tub that will hold almost as much water on top. Use a level or line stretched across the opening and mark a reference on your beam. start filling the container and see if the reference mark changes. The rubber maid will stand up to the flexing without any risk of breakage, and you'll be able to use it as a sump for your system later

 

[jsoong]

I am no engineer either, but I see a problem with the "add more beams" approach.

As I understand it, all the tank weight is supported at the edges of the tank, & the bottom pane is raised so will not transmit any weight to ground. In that case, the weight of the tank MUST all be supported by the outter 2 beams directly under the tank edge, right???

Adding more beams under the middle of the tank won't help at all, as the weight will not be transmitted to them. In order for the middle beams to help, you'll need to tie them to the outter beams somehow ... eg welding 2 beams together (kinda like "sistering" beams together in a deck ... sorry, I am generalizing from my deck building here)

 

[mitcheg]

Here it is the final product

I managed to make the thing in the end - seems very very strong