I'm not an ironworker, although I've hung iron before.
When I was younger, I could participate with projects involving the erection of steel. Most were for pre-engineered metal buildings, but some were standard structural members.
Most people don't pay attention to the erection of steel, but it's an involved process, with many pitfalls. From conception, to finish, many are involved and the final result is the frame for a building, or support for an object, or machinery.
Engineers determine the correct size of members after given the task. Whether it's an architectural firm, or a customer that needs a structure built, the process of designing the members requires calculations, plans of the structure and fabrication details for manufacturing.
Usually, after the design is determined, a draftsman details the structural members for fabrication. The details are given to the engineer for review and any corrections made with red pencil remarks. A good contractor will review the final plans, also. Mistakes can be made and a good review can take a long time, since it requires verifying measurements and structural shapes.
What are structural shapes? Most steel for fabrication is of standard sizes. The shapes include W-shapes, which are wide flange beams; S-shapes, which are commonly known as I-beams and a multitude of others, like angles, tees and square tubing. All have known characteristics, such as weight and how they behave under certain stresses.
No matter what the shape, all deals are off if the steel is heated to the point it starts becoming plastic. That's why many structures are fireproofed after erection. Whether it's an insulation, or gunnite, the coating helps prevent failures during a fire. Even then, exceptional events, such as the World Trade disaster happen, which exposed lightweight trusses to tremendous heat and caused them to fail. After the first failure, the static force of the above floors falling literally ripped the building apart as the combined loads struck the floors below.
Fabrication involves cutting, welding and hole drilling. Standard connection details are used and holes are drilled to accommodate the bolts. If the steel is to be galvanized, the members are tagged before the process of "pickling" - the acid bath before dipping - and then dipped in a vat of molten zinc. If painting is required, the steel is sand blasted before painting.
Steel arrives at the project site on flatbed trilers. What can be bundled is wrapped with wire, or placed on pallets. The larger items are just placed on the bed and bound with straps. This is where things can get interesting.
There's no guarantee the fabricator sent exactly what is needed. An error might have left some key members off, or the galvanizer may have lost some pieces. That's why the erection drawings, which usually come with the first load, are consulted. Every member has a number, and the location where it will be placed. Since assembly is an ordered process, someone is required to inventory the steel and verify it's what's needed. This "shaking out" can be as simple as going through the contents of a pallet, or as complicated as using a crane to move heavy members from a bundle and laying them out on dunnage. Losing a finger, or being crushed is always a possibility during this process. Steel is heavy, slides easily and a wrong move can end in disaster.
Before any of this happened, a foundation was placed. It may have been a simple concrete slab or an elaborate conglomeration of concrete foundations with multiple anchor bolts. This is where it all begins and the foundation must be correct.
Even with smaller structures, the first members are usually heavier than what a person can handle. This is where cranes, or forklifts are required. The columns are placed on the anchor bolts and the connecting girders are bolted. All bolts are just run up to snug, since steel can change dimensions due to heat and movement is required to assemble the steel.
As members are placed, ironworkers use spud wrenches to "stab" the bolt holes and temporarily hold the steel, until they can place a bolt. After that, the spud wrench is used to align the holes for more bolts. After all the bolts are placed, they move to another member.
Eventually, enough members are placed, the columns can be checked for plumb and the bolts can be "rattled up". Usually this means using an impact wrench, which can be a cumbersome tool, while working in an aerial lift, or standing on a beam, with only a harness to keep you from falling.
In the winter, steel is cold, can be slippery and if working up high, can lead to a miserable day in cold, unblocked wind.
In the summer, the steel can be too hot to touch with bare hands. Sitting on the steel can scorch the family jewels and being in close proximity adds heat to days that are already blistering hot.
Back in my younger days, I could hang with anyone all day and never look back. Now? I don't think I could do it for any length of time. Ironworking is a tough trade and best left for the young. When I did "hang iron", examining the finished project always left a sense of pride. Unless you've done it, it's hard to understand the satisfaction of seeing the hard work turn into something important.
In Case You've Wondered
My blog is where my wandering thoughts are interspersed with stuff I made up. So, if while reading you find yourself confused about the context, don't feel alone. I get confused, too.
If you're here for the stories, I started another blog: scratchingforchange.blogspot.com
One other thing: sometimes I write words you refuse to use in front of children, or polite company, unless you have a flat tire, or hit your thumb with a hammer.
I don't use them to offend; I use them to embellish.