Palomar History Photo of the Week - August 9, 2010

The 200-inch telescope was fabricated at the Westinghouse Electric and Manufacturing Company's plant in South Philadelphia. I believe that the largest single piece was the yoke for the south bearing of the telescope.

Here it is back at the Westinghouse plant:

As you can see it is pretty huge. As you can imagine the task of bringing it into the dome was not easy. Ronald Florence described it nicely in his book about Palomar, The Perfect Machine:

The Caltech engineers had calculated the size of the hatch in the dome the way a mover can calculate whether a sofa or piano will fit through a doorway. The opening was mathematically large enough for the largest components--the sections of the horseshoe and the lower section of the yoke mounting, which held the two tubes that connected to the horseshoe. A draftsman with a slide rule could demonstrate that with the right twists and turns the hatch would accommodate everything that had been shipped.

......

For one piece, the bottom section of the yoke, the engineers at Caltech had designed a special lifting harness to bring the assembly off the truck and up through the hatch. The harness didn't arrive in time for the unloading, so [superintendent Byron] Hill and his crew did it with lifting hooks and slings they put together on the spot. The unit had been trucked lying on its back and had to be tipped onto its side to fit through the hatch. Tipping a structure while it is hanging from rigging is a tricky operation, because the center of gravity of the item shifts as it turns. The fit was tight. The next day, when the yoke had been squeezed through the hatch and the exhausted crew had gone to bed, Hill said he finally understood what women went through at childbirth.

Here is the view of the yoke as it was brought in through the hatch and into the dome:


I think that it is no exaggeration at all to say that it was a tight fit.