Now that the biaxial apparatus is ready to run (we're just hammering out some bugs with our National Instrument gear), our attention has turned to the triaxial rig. It applies a confining pressure using either gas or a solid medium. The pressure inside the vessel can really build and if it blows, it could be deadly, so this behemoth sits in its own room in the back of the lab. Our first task was to rotate the steel cylindrical vessel 90 degrees so that it can connect to new gas tubing and then check the integrity and alignment of the vessel. The vessel and attached top plate together weigh almost 1000 lbs, so taking things apart is no small feat. Ted rigged up a pulley system to a beam in the ceiling and we carefully lowered the two parts, which immediately began to swing out on us.
Eventually we got the parts under control, rotated, and back up in place. Next week while I am away, Ted and Heather will make sure the vessel is perfectly centered. They will use a tool that precisely measures the location of the inside wall of the vessel with a needle. Using the machine hydraulics they will raise the needle up the inner length of the vessel. If there is any tilt to the vessel wall, the tool will indicate that and they can shove little wedges of wood or thin steel around the top plate to center it.