Yano, Simon, K. Tanaka, Akutsu + Darkhan (observer from CAL) on Nov 9 2018; see here for the details.

Pulled up the whole NAB suspension with PD holders + inner tower with the chain block (Fig 1 and 2). We attached sligns at the both sides of the bottom beams of the inner tower for handling (Fig 3), as was done already during the installation at the  IXA.

Then inserted into the IYA chamber (Fig 4 and 5), and aligned the tower.

• 10cm shift from the center of the chamber in the Yarm direction. (CAL's request.)
• Aligned the center of the NAB (still fixed to the EQ stop) to the laser beam line, which was indicated by a red line drawn on a white tape attached on the breadboard in the chamber. We used a laser level for this bussiness (Fig 6 and 7).
• Using some shims, the pitch and the roll of the tower were aligned by referring bubble levels put on the top parts of the NAB suspension structure. A jack was used to make space for inserting the shims (Fig 8).
• Yaw alginment was slightly difficult; the edges of the feet of the tower was somewhat aligned to the line of screw holes on the breadboard in the chamber.

The originally used clamps were not suitable and not sufficient to fix the tower completely (FIg 9, 10, 11, and 12), so never enter into the IYA chamber now without informing to us.

Anyway the NAB with PD holders has been installed in the IYA chamber (Fig 13).