Take a look at some of the commercial shelters, what they’re made of, how they’re made and start there.

Friend of mine wanted a tornado shelter for his farm but like the rest of us, couldn’t afford a prefab shelter.
His answer, take a community college welding course.

After taking the course, not only could he fix his own machinery, but he picked up some work with a local welding shop when they’re busy, in exchange for his labor, he gets welding supplies, the use of the welders and metal at cost.

Fast forward a few months, he’s now taken all the ideas from websites, advertising and evennmovies and put it on paper.

Since he figures he can’t afford many of the ways and means the pros use, he figures his own ways.

No crane, no problem, a couple hunks of very heavy pipe cut to attach to the side of a flatbed trailer.
He digs the shelter hole the hard way with a front end loader, from the side moving a whole lot of exrra dirt but creating a ramp down to the bottom.
He purchased an old underground gas tank, in great condition, and when it was delivered, cut off all the vents and anything that would prevent it from rolling.
figuring the size of the tank, the distance from the bottom of the hole he jockeyed the trailer around until the part he wanted upright would end up that way.
He put a couple of heavy beams in the bottom of the pit (railroad ties) and had previously put down a mess of gravel for drainage.

The tank was in place, he pushed it off the trailer with the end loader down the pipe ramps, into the hole.
He messed up his figures a bit, but for the better, he forgot to figure in the extra on the far side of the hole so it over rotated.
The delivery driver was sent on his way and the grinders were pulled out, the rust and scale was quickly removed from the bottom portion of the tank which was almost a quarter turn up. When it was clean, the tank bottom had the “stops” added to the upper side and the entire bottom sprayed with epoxy sealant.

The bottom was allowed to dry while the inside was being prepped.
Chained in place for safety, he went in and cleaned it out again, the company he bought it from had done so previously but he did it again.
Once the bottom was hardened properly, he removed the safety chains and used a small tractor to roll it back upright. While a few feet off from his original plans, it was close enough.
The stops did their part and the tank was upright. An extra safety stop was added on the side that had been down so it couldn’t move and was again chained in place.

He masked off the areas where the vents, stairwell and escape hatch would go, then sealed the inside and outside with the epoxy paint.
He had welded some attachment points to the inside before painting,

Yes he painted before putting the rest on, it was the rainy season and he didn’t want to have a mess inside.

Out of the barn came the stairwell, using the front end loader again to position and lift it, it was quickly welded in place, as were the vents, power couplings and escape hatch.

These were quickly cleaned and painted.
The exterior essentially done he started filling in the hole.
When it was good and level, he put the sod back. He had cut huge chunks of sod with the loader, rolled them and laid them in a field, his kids watered it daily.
He just rerolled it and put it back.

Over the next 6 months he added the interior, plumbing, electricity, floors, including a flush toilet.

He said the paint was the most expensive part of the shelter.
The wood came from construction site drops, the end loader wasn’t in use so the rental company let him keep it at his place and just change the oil before he brought it back, saved them having to move and clean it after its last job.
The diesel fuel was a farm write off, the metal either scrap or bought at cost.

He said he put three weeks of full time work into it, prep to buried, and another six months puttering around with the rest.
He plumbed it into the farm well and the septic system.
Into the power box as well.