been a long time since I’ve attempted a true arch. always hesitant to work with anything but corbelled construction, as I don’t have the experience with building proper form-work or the patience (bizarrely) to make sure that the curve of the arch is smooth. I especially don’t want to put the time in to make a nice arch, only to have to fall down on me when I remove the form-work.
what’d I use? duh, we’re in Maine – discarded lobster trap. a nice short length of 6×6 post served as a cheat so I didn’t have to fully build up from the bottom, which saved me a TON of time. I should note that the lobster trap’s interior was partly filled with stones to keep it from being crushed by the weight of the arch.
I was entirely prepared for the project to fail when I made the slightest movement to the forms, so it was a satisfying surprise to have it all work out.
you can see that the shape of the trap and the beam influenced the overall shape of the arch itself, not lending itself to a semicircular form, but the important aspect is that this is a compression structure, an actual arch. some of the central objects don’t quite make sense to my instincts, and yet here it stands. why?
the key to stability is a lack of freedom. ironic, considering the very reason I build is the freedom of it – no one can tell me what must happen; I build how, when, what, and where I want; both success and failure are… well, not pointless, but… neutrally accepted. ANYWAY. lack of freedom is the key to remaining stable. one must restrain involved objects from sliding, rotating, tilting, or being squeezed out. stability is simply having nowhere better to be.
how does one ensure this?
- there shall be a minimum of three points of contact between an element and its supports.
- the center of mass for the gestalt shall fall within its footprint.
- exterior elements shall not be placed at more than their angle of static friction.
- interior pressures shall be directed towards the center.
the basic way to uphold these commandments?
- overlap and interlace elements.
- build level.
- cram every nook and cranny.
that’s really it. shall we say this also describes a stable life? interlink everything you do, leave the endings of things even for the next steps, and fill up the empty space? is this depressing or calming? I don’t know. certainly not talking any sense about stacking at this point.
thanks for reading. I will have some questions for you next time.