DO I NEED AN ENGINEER TO HANG A TIRE SWING?
Let’s start with the basics…
DEFINITION: Professional art of applying science to the optimum conversion of the resources of nature to the uses of humankind. Engineering is based principally on physics, chemistry, and mathematics and their extensions into materials science, solid and fluid mechanics, thermodynamics, transfer and rate processes, and systems analysis. A great body of special knowledge is associated with engineering; preparation for professional practice involves extensive training in the application of that knowledge. Engineers employ two types of natural resources, materials and energy. Materials acquire uses that reflect their properties: their strength, ease of fabrication, lightness, or durability; their ability to insulate or conduct; and their chemical, electrical, or acoustical properties. Important sources of energy include fossil fuels (coal, petroleum, gas), wind, sunlight, falling water, and nuclear fission.
OK, so that was a mouthful. The long and the short of it is that engineering is the use of physics to design…well, everything: building structures, machines and/or their internal and connective systems.
Every human being in the industrialized world is surrounded by products of engineering; from the car you drive (or bike you pedal), the stove you cook with (or the stoves at restaurants you frequent), to the hinges used on your front door. If you use it or live in it, it’s a good bet that it was dreamed up by an engineer.
DOES EVERYTHING THAT IS DESIGNED NEED TO BE DESIGNED BY AN ENGINEER?
Well, no. But…
Let’s say you want to put up a simple tire swing for the kids. Not a project you would look to hire an engineer for, right?
You haul out an old used tire from the garage and dig out a healthy length of brand new, never used rope. You select just the right oak tree branch for strength and finally hang the tire; securing it to the specially selected tree branch using a complex threaded figure 8 knot which you thoroughly researched on the internet and used because it was certified to hold up to 610lbs (and if it says it on the internet…).
Ten minutes later your 10 year old twin boys come charging outside to play on their new swing. You survey your good work with a proud smile and eventually go back to the garage to tackle your next project.
A short time later you hear a thud and simultaneous shouts. What happened?
- The rope you used, though new, was not appropriately rated for the combined load of TWINS + TIRE
- You tied the tire swing too close to the tree truck; not taking into account the trajectory of TWINS + TIRE when the inappropriately sized rope stretched due to the load stress
- You tied the tire swing too far out on the branch; not taking into account the combined weight of TWINS + TIRE; the overall load stress on the smaller diameter portion of the branch causing it to snap
- ANY of the above
Though one is not required, had an engineer been consulted on the tire swing project, they would have calculated the distance and load, factoring in wind speed variables to design a safe and functional tire swing. And though you still may not be convinced that an engineer is need for a tire swing project, the fact of the matter is most people don’t realize that there are any number of household projects that do require an engineer.
If you are working on remodeling your home or business, you will probably need a permit. If you need a permit, in many cases you will need a stamped architectural and/or engineers drawing.
So before embarking on a building addition or improvement, check with your local building department for the do’s and don’ts of your upcoming project.