Large Binocular Telescope Project

Questions & Answers

concerning the RFP for the

Azimuth Frame Structure

October 8, 1997

Question 1. (received 30 Sep 97)
Please provide us with the technical data for bearings as shown in drawing 460a009. What are the loads and specifications? We have not been successful in finding the information anywhere in the RFP.

Followup to Question 1.
Is LBT planning to provide the gears also?

Answer 1. The specification of the Azimuth Bearing for LBT is not included with this RFP. Our plan is to have another RFP later to purchase this bearing and the others for the instrument rotators. Only the mounting of the Azimuth Bearing is included in the present RFP.

The specifcations for the Azimuth Radial Bearing are as follows:

Type: (to be confirmed by the Manufacturer)	Radial Cylindrical Roller
Inner Diameter (460a009)			3000 mm
Maximum Radial Load in Operation		25000 N
Maximum Exceptional Load			135000 N
Required Radial Stiffness			> 0.2e+11 N/m
Required Radial Runout				< 0.055 mm
Grease Sealing					low friction type

LBT is NOT providing the gears that serve as the main telescope drives.

(See also question 2 under Mirror Cells, Bell Jar and Dummy Cell regarding bearings and gears for the instrument rotators.)

Question 2. (received 3 Oct 97)
What kind of packing should be used for the Azimuth Platform?

Answer 2. It is quite possible that the Azimuth Platform will require ocean shipping to reach the Factory Pre-Erection site. The assumed default packing should be that suitable for transport on a ship. It is also possible that the Azimuth Platform will be manufactured in close promity to the Factory Pre-Erection site. In that case, open containers suitable for truck transport would probably be sufficient. The details can be worked out once the Factory Pre-Erection site is determined.