Observatory Removal

Secondary Mirror and Support Tube

The telescope disassembly starts with the secondary mirror.  This includes the glass of which the mirror itself is composed along with all the parts that hold the mirror in place--the mirror cell and the "spider" frame (which attach to the tube)--and the motor and gears which comprise focusing mechanism.  Because it is relatively light (only a couple hundred pounds), we removed this assembly several days before the major work of removing the rest of the telescope.

The illustration at right shows the secondary mirror assembly in place.  We removed the bolts that connect the spider frame to the tube, and the entire assembly is removed as a single unit.  We also removed the cables from the inside of the tube that provide electrical power to the focus motor.

The support tube is now essentially empty, and is the next item to be removed.  Because it weighs about 800 pounds, it will need to be lifted with a crane.  We rotate the tube to the vertical position, and secure the lifting straps.

Several bolts at the base of the support tube attach it to the primary mirror housing. We remove these and the tube is lifted off the primary housing, being very careful not to bump the light shield which extends outward from the primary mirror housing.

Now free of the primary mirror housing, and past the light sheild, the support tube is lifted out of the dome through the open slit.

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Next:  Primary Mirror Assembly