seeing what happened at that school got my mind churning that there has to be an economical way to give kids in tornado alley a fighting chance. something that is functional in an everyday setting yet can offer protection from crushing debris and wind. a churning mind turned into churning sharpie. sorry, i don't do CAD, i'm old school.
drawings are not to scale. i hope this concept will be of use to those living in tornado alley.
Step 1: The Eco-shelter Concept
Eco-shelter = economical
Eco-shelter = environmentally friendly all recyclable steel construction
with the power of bulk purchasing, materials to build one in every classroom shouldn't be more than a few hundred dollars and the cost of hiring a welder. once measurements are made, there's no reason these cant be churned out production line style since most schools have standardized classroom sizes and layouts.
the materials used are cheap and easy to get.
u channel iron
flat bar iron
concrete expansion bolts
the Eco-shelter is a storm shelter that doubles as a bench. during regular school time kids can sit on it like any regular bench. easy to move items can be stored under it. during an emergency any items under the bench are pushed out and the kids hide under it. due to its design, it provides protection from at least 3 sides. since it is a u-shaped enclosure, it will act as a wind buffer. the seat cushions are removable so kids can use them to further protect themselves from flying debris.
the Eco-shelter is intended to occupy an entire length of wall as a long bench would.
see next slide for how it comes together.
Step 2: How the Eco-shelter Comes Together
in the picture below you see a blown up diagram of the assembly. the unit is comprised of ribs. each rib is made up of flat iron for the bottom where it is bolted to the foundation using expansion bolts, u-channel iron for the two uprights, and u-channel iron for the top bar. the flat stock and u-channel will all be welded together for strength and ease of construction resulting in a square frame. the u-channel is to go flat side out.
the u-channel iron for top rail and side rails was chosen because it's shape makes it easy for the human hand to grab onto it's edges. the average person can get a strong grip with just one hand and pull themselves in towards the shelter. the flat iron bar was chosen for the bottom rail to give the shelter compartment a flat unobstructed floor.
the overall size of the ribs hasn't been determined but you are looking for something tall enough to function as a useable bench and deep enough to be able to shelter a human that is hiding under it. 20" tall by 30" deep is a good starting number for inner compartment space that even a heavyset adult can squeeze into.
each rib shall be positioned on the floor up against a concrete wall. between the ribs and the wall shall be a steel plate. this plate will provide the strength to keep the ribs from falling over like dominos should there be heavy weight upon them like a collapsed roof. the ribs are to be aprox 2ft apart from each other in a row along the wall. the ribs will be attached to the foundation and the wall using heavy duty expansion bolts.
once the ribs are bolted down to the floor and the wall with the steel plate having been placed between the ribs and the wall, the ribs are to be spot welded to the steel plate for added torsional strength.
on the top of the ribs will be a second steel plate to function as the bench top. this plate will also be spot welded for further strength. the final piece is an angle iron rail that will run along the front edge of the bench facing the inside of the classroom. this will also be spot welded in place essentially making the entire assembly an extremely strong box capable of supporting thousands of pounds.
the top of the bench will have removable seat cushions that can be used to protect the exposed part of the body from flying debris.
none of these drawings are to scale and an experienced metal worker should be consulted when choosing materials. my goal was to share this concept for a cheap, easy to make, storm shelter that can serve double duty in a classroom setting.