LBT PROJECT 2X8.4m TELESCOPE Doc.No: 401e047 Issue: D Date: November 24th, 1999 Title: ENCLOSURE CABLE CHAIN

1.0 SCOPE OF WORK *

2.0 APPLICABLE DOCUMENTS *

3.0 ITEM DESCRIPTION *

4.0 INTERFACE DEFINITIONS *

5.0 PERFORMANCE CHARACTERISTICS *

6.0 RELIABILITY, MAINTAINABILITY REQUIREMENTS *

7.0 ENVIRONMENTAL CONDITIONS *

8.0 DESIGN AND CONSTRUCTION REQUIREMENTS *

9.0 PRE-ASSEMBLY *

10.0 PACKING AND TRANSPORT *

11.0 ACCEPTANCE TESTS *

12.0 SPARE PARTS *

The ENCLOSURE CABLE CHAIN is a component of the LBT Project.

The aim of the LBT (Large Binocular Telescope) Project is to realise a telescope having two mirrors of 8.4 m diameter, to be installed at Mount Graham in Arizona (ref. dwg. No. 407e001).

The ENCLOSURE CABLE CHAIN represents a system of distribution and guide of cables and pipes between the fixed and the mobile part of the enclosure.

The ENCLOSURE CABLE CHAIN is installed on the Upper Ring Structure of the Telescope Pier.

The supply of the ENCLOSURE CABLE CHAIN includes:

• execution of all workshop drawings and Part Lists, based upon the design drawings included in the Request for Proposal;
• preparation of the Manufacturing Plan;
• selection and purchase of all materials, components, etc.
• preparation of all procedures and methods to execute the critical operations of the manufacturing;
• fabrication of all components;
• fabrication and/or purchase of all tools, necessary for the manufacturing and pre-assembly;
• painting or surface treatment;
• performance of checks and tests;
• drawing up of the inspection and check documentation.

The ENCLOSURE CABLE CHAIN (see dwg. No. 310e001), is made up of the following elements:

• No.2 cable chain with accessories
• No. 1 inner distance structure
• No. 1 external chain guide structure and relative interfaces with upper pier ring (welding plates, shims etc.)
• No. 1 towing arm complete of couplings to the chain and to the building
• No. 1 various bolts and accessories for the assembly

The ENCLOSURE CABLE CHAIN is realised in a load bearing steel structure; its function is to support and guide the chain.

The chain is made of steel or other material and is mounted on support and guide wheels. The inner distance structure is realised in various steel sectors, bolted among them, and assembled on wheels.

The ENCLOSURE CABLE CHAIN has a function to support and guide the cables and pipes during rotation of the telescope and enclosure.

The ENCLOSURE CABLE CHAIN(see dwg. No.310e001) is interfaced with the following elements:

The main performance characteristics of the ENCLOSURE CABLE CHAIN are the following:

• to contain cables and pipes;
• to guide cables and pipes during telescope and enclosure’s rotation.

The useful lifetime of the telescope is expected to exceed 25 years.

This chapter defines the natural and induced environmental conditions the telescope and subassemblies will encounter during its lifetime.

Storage temperature:	-30 to +50°C
Operating temperature:	-20 to +25°C
Storage pressure:	500 to 750 Torr
Operating pressure:	500 to 600 Torr
Storage humidity:	5 to 80%
Operating humidity:	5 to 95%

The maximum velocity of rotation is 1.5 degrees/second.

The maximum acceleration is 0.2 degrees/second/second.

The scope of the present chapter is to introduce the main characteristics of the supply from a manufacturing point of view.

The contractor shall take care of confirming the adopted criteria or may propose alternative solutions, in order to obtain the requested performance.

The contractor shall fabricate all parts, equipment, components and materials of the ENCLOSURE CABLE CHAIN in accordance with the requirements indicated in the present Technical Specification and the applicable drawings.

Subsequent to fabrication, but prior to packaging the materials, the contractor shall store, at its sole expenses, all components, materials and equipment in manner that will reasonably protect such components, materials and equipment against loss or damage.

Suitable allowances for contraction and expansion during welding shall be made in the lengths of the steel parts prior to welding, so that final machined lengths are correct within the acceptance tolerances specified in this Technical Specification and relative drawings. Welding procedures shall be such that distortion and lock-up stresses are minimised. Tack welds, temporary stiffeners, tie bars, controlled peening, pre-heating and stress relieving during welding may be used for this purpose, as approved by P.O..

Surface to be welded shall be dry, clean and free for loose scale, grease, or unsuitable protective paints or coatings. All welded parts and assemblies, unless specified or approved otherwise by P.O., shall be fully stress relieved prior to final machining operations. Stress relieving shall be accomplished by the heat treatment method in a chamber with sufficient volume and temperature capacity to fully stress-relieve the welded parts and subassemblies.

The general dimensions of the ENCLOSURE CABLE CHAIN are shown in dwg. No.310e001.

The materials are indicated in the drawings and relative Part Lists.

All welding operations shall conform to the standards set forth in American Welding Society Specification AWS D1.1 or equivalent approved by P.O..

Welding operations shall be performed in such a way as to guarantee the following mechanical machining in terms of tolerances, as indicated on drawings. For this purposes, welding procedures shall consider possible shrinkages or expansions during welding operation and minimise the distortion and lock-up stresses.

The contractor shall perform and provide trial welds to demonstrate the soundness of any proposed welding method, and the competence of any person performing welding work, as required by P.O. at any time.

For welded parts: CNR-UNI 10011 and UNI 11001.

Tolerances for linear and angular dimensions are specified on relevant drawings. These tolerances are mandatory, for structure acceptance. Where not specified, ISO 2768 part 1/m and 2/k shall be applied.

• Metric bolts class 8.8 or 10.9, CNR UNI 10011 paragraph 4.1.3

All metallic surfaces, other than rating machining surfaces shall be painted, coated or otherwise permanently protected against atmospheric corrosion.

At a minimum all paints and coatings shall provide for the following functional requirements:

• 25 years service life (with maintenance)
• (two months continuous salt exposure during shipping)

The contractors shall utilise the following surface treatments in performance of the work.

• sand blasting SA2.5 ISO 8501-1:1988/SS055900:1988
• Galvanizing cycle (t.b.d. with the contractor).

The supplier can propose an alternative painting cycle; in any case this shall be able to guarantee the above mentioned requirements.

The surfaces which are machined and not painted shall be protected with protection material of "peeling" type.

The ENCLOSURE CABLE CHAIN will be pre-assembled to verify the total dimension, the pertinent tolerances indicated in the drawings and the functionality.

The special tooling required to perform the assembly and the alignment is part of this contract supply. Before disassembling for shipment, all couplings shall be opportunely locked by a pin.

All the supply includes a "sea-packing" type no-reusable structure and accessories shall be packed in such a way as to guarantee:

• the degree of the physical-chemical protections against weather conditions during holding and transportations of goods;
• the degree of mechanical protection for the preservation of the goods during handling and transportation to destination;
• the determination of volume and weight in relation to the transportation means.

The delivery of the material and relevant conditions are described in the SOW.

The contractor shall prepare and submit to the P.O. the Acceptance Test Plan.

The following tests and inspections shall be performed prior to Plant Acceptance, and shall be included in the Acceptance Test Plan:

• certificate of raw material and fasteners;
• certification of welding procedure and welding control;
• stress relieve certification;
• dimensional control, machining tolerances;
• mass check;
• certificate of surface treatment;
• certificate of assembly tolerances.
• functional test including towing effort tests.

Contractor shall prepare a list of recommended spares for P.O. review.

The P.O. shall purchase all desired spares at its sole expenses.