LDX Project Status

July 20, 1999

Vacuum Vessel Construction Continues

The crew began by playing a game of musical chairs with the vacuum vessel pieces. Starting with the mid-section close to the deck and the bottom section close to the spiral staircase, they used straps and the crane to tilt and lift the midsection into an upright position, move and flip the bottom into place, and put the mid-section on top of it. Shown here are the bottom section (at left) and the mid-section in action (below, left and right).
Once the two pieces were put in place, the welding began. Shown here (at right) is some of the early welding between the bottom and mid-section of the vacuum vessel. Note that the protective sheets are still attached to the interior surface of the vessel.
Once those two sections were firmly joined, the workmen put sheets of plywood down so that they could safely move around in the interior of the vessel. Below, at left, is the lower vacuum vessel with temporary plywood floor. At right, some of the early flanges are attached.
For better bottom access, for strength, and for convenience, the vessel is placed on three piles of wooden beams (at left); meanwhile, the top section of the vessel appears at the far end of the cell, and is welded together.
July 10th was a big moving day. After lifting the vessel up to put it on the wooden beams, we lifted the top segment and very carefully positioned it on top of the bottom part of the vessel. We took the opportunity to use a transducer, shown at right, to determine the weight of the two pieces -- 13650 lbs for the bottom, and 730 lbs for the top piece.
The first look at what the main portion of the vacuum vessel will look like. Here it is with the top piece finally touching the bottom, properly aligned. Note that the top has not yet been fully released -- the straps holding it from above are still tight. Before the top fully touched down, the work crew put small pieces of wire in the crack at periodic intervals, to allow an even gap for the welding to fill in. Then they welded a bunch of small pieces on to the vessel on both sides of the gap, which they used to clamp the top down in place. Below, at left, one of the clamps used. At right, the welding begins.