The slewing sector is a 250-pound aluminum structure that has to be placed on the telescope with the crane. It is transported in a special crate designed to protect the drive structure from dents.

1. Orient the mirror cell vertically in the fork, and secure it with the special stay-bar attachment. (This may be difficult, since the tube will be unbalanced at this point; use the crane to rotate the tube.)
2. Attach the two guide pins into holes at the top and bottom of the cell. Be sure the 5/16-inch locating pins are in place.
3. Lift the drive sector with the crane, using one 6-foot sling through one of the holes in the plate. Orient the sector with the four feet at their respective (marked) attachment points, using the guide pins and sliding onto the locating pins, and attach with the 3/8-in socket-head cap screws provided. Torque screws to 35 lb-ft.
4. Attach lateral support struts to cell and drive sector with screws provided and torque to 30 lb-ft.
5. Attach stay-bar fixture to foot of sector. Attach shock absorbers to the drive sector and cell, if not already attached. Attach strikers to structure on fork.

1. Orient the mirror cell horizontally in the fork, facing down, and secure it with the special stay-bar attachment. (This is the orientation you will have immediately after putting it into the fork.)
2. Remove guards protecting the four attachment points on the telescope tube, if they are still on. Attach two guide pins into holes in the two outer attachment points. Be sure the 5/16-inch locating pins are in place.
3. Lift the drive sector with the crane, using two 6-foot sling threaded through two of the holes in the center of the plate to give a double basket configuration. Orient the sector with the four feet at their respective (marked) attachment points, using the guide pins to lower it onto the locating pins, and attach with the 3/8-in socket-head cap screws provided. There are four shorter screws for the holes nearest the center of the tube. Torque the screws to 35 lb-ft.
4. Attach lateral support struts to cell and drive sector with screws provided and torque to 30 lb-ft.
5. Attach stay-bar fixture to foot of sector. Attach shock absorbers to the drive sector and cell, if not already attached. Attach strikers to structure on fork.