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Triple-Story Dance Floor and a Spiral Staircase

My House is hard at work building OPI, which stands for "Our Private Interhouse." Interhouse parties are open to all the undergrads on campus (and, unofficially, graduate student and non-Caltech guests as well as alumni), and each of the 8 student Houses hosts one for the campus each year. Back in the 70s, they allhappened on the same night–I can only imagine what a rave that must have been. The generic term is "interhouse," but each party tends to have a different nickname associated with it depending on the identity of the House, and this is mostly used in case one finds the entire phrase of "___ Interhouse" too much of a mouthful to use in casual conversation–so basically, evolving like any type of slang.

Some of the nicknames are of the pun variety, while others arose from traditions that most have long since forgotten. For example, Page Interhouse has been abbreviated to "Pinterhouse" by some members of the community. Avery Interhouse has been shortened to "Ravery" and Dabney always does "Drop Day" in honor of the academic Drop Day around the same time; Drop Day is the last day one is allowed to drop a class without a lasting mark on their transcript. As far as I’ve heard, Blacker and Lloyd interhouse are the only ones that have retained their full names. Ruddock’s own "OPI" stems from a few years back when the parties were actually closed to anyone who wasn’t a Caltech undergrad, hence the phrase "our private interhouse."

Having been here for over 3 years now, I can say that Ruddock always makes a pretty big effort in constructing their interhouses. And by constructing I mean, literally constructing. We have miter saws, impact drivers, belt sanders, levels, hammers, nails, and lots and lots of nails. And thousands of dollars in wood. We buy some extra lumber every year, but for the most part this stuff is passed down year to year.

The trickiest part of constructing the dance floor is to make it even so that people won’t stumble. It’s the main taskwhen building legs for all of the individual platform segments we’ve kept over the years. The use of a leveling tool, shown in the picture below, is quite paramount here. Note howthe level is designed such that the liquid in the cylinders is used tohelp the eye in determining if a surface is truly horizontal–pretty neat I thought when I first learned about them.

Lumber comes in differently-sized planks when we order it. There’s a funny naming system in that the nominal dimension is always a half-inch greater than the actual dimension. For example, a so-called 2-by-4 (written "2×4") is actually a rectangular prism whose cross-sectional area measures 1.5 inches by 3.5 inches (the height can go up to 16 feet, andI will talk aboutthis more later in this post). According to the internet, the naming system arose because the 2×4-cut wood would shrink as it dried to become 1.5×3.5. We use the 2×4’s of varying heights as vertical supports for the dance platform segments. On the ground floor, we shave pieces off old 2×4’s that range from 4 inches to maybe 8 inches tall. A "fully-elevated" platform means that it is raised 8 feet above the ground dance platform–meaning, lots of additional support and cross-bracing. I really wish I had taken a picture when the heads of the construction team sent a plea to the house asking for help carrying in all of the 2×4’s a few weeks ago. Two small girls shouldering three heavy, 2”x4”x8′ pieces of wood can be quite a formidable sight.

Another type of wood we use is called "OSB," which stands for "oriented strand board." Unlike the solid pieces of wood that are the 2×4’s, OSB is made of fragments of wood glued together into a type of fibrous board. The 2×4’s are used mostly for vertical and horizontal bracing, comprising the skeleton of the dance for structure; OSB forms the flat, solid, horizontal part of the dance floor that people can actually step on. We screw on the OSB over the skeletal structure of the platforms and even out the surface with spackling paste, then paint it a solid color for the aesthetic.

In the picture below, you can see how the 2×4’s really do make the backbone of the dance floor, but without the flat OSBs, one would simply fall through the holes!

The OSB is conveniently already cut in the same dimensions as the individual platform segments, but we use the miter saw to cut up the 2×4’s to the heights we want them:

The impact driver utilizes a quick spinning motion and magnetism to insert screws into wood, for the purposes of joining two pieces of dance platform legs, cementing OSB to the platform, etc:

A sander is used to smooth out finished surfaces, both to even out two segments that we’ve screwed together at slightly different heights and to obtain a splinter-free surface party-goers can rest their hands on. Disclaimer: it is highly possible that I am missing some things here, as I have mostly helped with art in the past. For anyone who is curious, Caltech provides construction training at the beginning of the year to teach those who want to help out with building interhouse how to use basic power tools.

Dance floors are a thing, but so are stairs and guardrails, and wallboard supports to hold up the murals that I will be talking about in my next post (on the artsier side of things, as opposed to construction). I won’t go into too much detail here, except to say that stairs in particular are a pain in the rear end because we have to make them all uniform heights.

As you might imagine, building a dance floor might get tedious. So, how do we vary it up between the years?

My freshman year, for the Ancient China-themed OPI, we built a big crack down the dance floor representing a river. We lit it up with neon lights and brought in a fog machine to create a misty, humid effect.

My junior year, for Star Wars OPI, we had 2 fully elevated platforms (8 feet above the ground) and 1 half-elevated (4 feet) connected with overpasses. Each elevated section represented a different planet world in the Star Wars universe.

This year, the construction team is really outdoing themselves. We’re building a doubly elevated, 16-feet tall platform that just barely reaches the roof, as well as a spiral staircase. Work in progress picture below, with Henry, one of the leaders of the construction team, descending the steps from the singly-elevated platform.

All of our construction is inspected multiple times by safety officers from the Caltech Housing Office before the actual date of the party. We’ve never had any structural failure. In the above picture, note the extensive cross-bracing, as well as the bracing of the wallboard supports on the second floor against the wall of the building when applicable. Henry briefly explained to me the other day that for the 20-foot DJ platform in that middle corner of the picture, we designed the structure so all the tension is forced toward the building. This way, when anyone in a frenzied partied state attempts to climb up to the DJ platform (not that they can, because the empty space will be blocked by a mural), there will be no danger of the supports snapping back in the person’s face. Henry is a math and computer science major, not a mechanical engineer, and I’m a chemist–but listening to him explain the physics considerations behind the dance platform design never fails to impress me with the degree of detail to which our designs have been so thoroughly thought out. And most people start out as complete construction novices, too, learning from upperclassmen and gaining experience to pass along.

Yeah…I’m still amazed at the construction we do. It blows my mind every time. Kudos to Henry, Jimmy, and Joe, our construction leaders this year, for all of the designing, supervising, teaching, coordinating, and actual building they’ve done. Since Week 1 of winter term!

Inmy next post, I will talk about the murals we are painting for OPI 2017, because of course, you cannot have a themed party without decorations.

Till next time.


Anita Chen

Anita is a senior majoring in chemistry and minoring in English. Born in the island nation of Taiwan, she braved the cold on the American East Coast for a year at the age of six before moving to San Diego, California. At Caltech, she is involved in the music program and the literary and visual arts magazines. She is also an upperclass counselor (UCC) in Ruddock House, one of the 8 dorms on campus, where she watches out for the mental health of her peers and every once in a while tries to stir up trouble and excitement for her hallmates. In her spare time, she tutors and TAs, writes poetry and prose, plays the violin, draws, paints, cooks, and climbs rocks. She is currently pursuing her senior thesis project under renowned professor of chemistry Harry B. Gray, and plans on attending graduate school next year.

Graduation year: 2017

Option: Chemistry

Minor: English

House Affiliation: Ruddock