LBT PROJECT 2x8.4m TELESCOPE
	TECHNICAL SPECIFICATION ELEVATION STRUCTURE ROLLING SECTORS & SUPPORTING ARMS
	Doc. 401e029/D August 4th, 1997 Prepared and Approved by: Gianpietro Marchiori/EIE

INDEX

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
8.1 General Dimensions and Mass
8.2 Materials
8.3 Class of Welding
8.4 General Tolerances
8.5 Thermal Treatments
8.6 Tightening Torque of Bolts and Screws
8.7 Surface Treatments
8.8 Special Manufacturing Instructions
9.0 PRE-ASSEMBLY
10.0 PACKING AND TRANSPORT
11.0 ACCEPTANCE TESTS
12.0 SPARE PARTS
ANNEX A

1.0 SCOPE OF WORK

The ROLLING SECTORS and the relative SUPPORTING ARMS are the elements composing 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 ROLLING SECTORS and SUPPORTING ARMS represent a part of the elevation structure of the telescope.

The ROLLING SECTORS (L & R) form the sliding track of the hydrostatic bearing system of the telescope's elevation axis, the support for the ELEVATION RIM GEAR and for the encoder system.

Each one of the two SUPPORTING ARMS (L & R) is made by a frontal element called SUPPORTING ARM OF M1 CELL and a vertical element called SUPPORTING ARM OF SPIDERS.

They are made up of steel structure machined elements, assembled each other by means of bolts.

The supply of the ROLLING SECTORS with ELEVATION RIM GEAR and relative SUPPORTING ARMS 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/or assembly;

• painting or surface treatment;

• performance of checks and tests;

• drawing up of the inspection and check documentation.

2.0 APPLICABLE DOCUMENTS

• DRAWINGS:

TITLE	DOCUMENT
Elevation Structure/Rolling Sector/General Mount Of C-Rings ;"L" And "R" Elevation Structure/Rolling Sectors/General Assembly Of C-Ring "L" Elevation Structure/Rolling Sectors/Supporting Arm "L" Of M1 Cell Elevation Structure/Rolling Sectors/Supporting Arm "L" Of Spiders Elevation Structure/Rolling Sectors/C-Ring "L" Machining (Sh. 1/3) Elevation Structure/Rolling Sectors/C-Ring "L" Machining (Sh. 2/3) Elevation Structure/Rolling Sectors/C-Ring "L" Machining (Sh. 2/3) Elevation Structure/Rolling Sectors/Adaptor For Plates Of Spiders M2-F15 And M3 Elevation Structure/Rolling Sectors/Adaptor For Plates Of Spiders M2-F4 Elevation Structure/Rolling Sectors/Internal Support Elevation Structure/Rolling Sector/Supporting Arm "L" Of M1 Cell/Hole Coordinates Elevation Structure/Rolling Sector/Supporting Arm "L" Of Spiders/Sections Elevation Structure/Rolling Sector/Supporting Arm "L" Of Spiders/Internal Hole Coordinates Elevation Structure/Rolling Sector/Supporting Arm "L" Of Spiders/External Hole Coordinates Elevation Structure/Rolling Sector/Support For Hanger Of Spider M1-F25 Elevation Structure/Rolling Sector/C Ring "L"/Internal Hole Coordinates Elevation Structure/Rolling Sector/C Ring "L"/External Hole Coordinates Elevation Structure/Rolling Sector/C-Ring "L"Carpentry/Rolling Sector Structure Sh. 1/3 Elevation Structure/Rolling Sector/C-Ring "L"Carpentry/Rolling Sector Structure Sh. 2/3 Elevation Structure/Rolling Sector/C-Ring "L"Carpentry/Rolling Sector Structure Sh. 3/3 Elevation Structure/Rolling Sectors/General Assembly Of C Ring "R" Elevation Structure/Rolling Sector/C-Ring "R" Carpentry/Rolling Sector Structure Sh. 1/3 Elevation Structure/Rolling Sector/C-Ring "R" Carpentry/Rolling Sector Structure Sh. 2/3 Elevation Structure/Rolling Sector/C-Ring "R" Carpentry/Rolling Sector Structure Sh. 3/3 Elevation Structure/Rolling Sector/C-Ring "R" Machining/Rolling Sector Structure Sh. 1/3 Elevation Structure/Rolling Sector/C-Ring "R" Machining/Rolling Sector Structure Sh. 2/3 Elevation Structure/Rolling Sector/C-Ring "R" Machining/Rolling Sector Structure Sh. 3/3 Elevation Structure/Rolling Sector/C Ring "R"/Internal Hole Coordinates Elevation Structure/Rolling Sector/C Ring "R" External Hole Coordinates Elevation Structure/Rolling Sectors/Supporting Arm "R" Of M1 Cell Elevation Structure/Rolling Sector/Supporting Arm "R" Of M1 Cell/Hole's Coordinate Elevation Structure/Rolling Sectors/Supporting Arm "R" Of Spiders Elevation Structure/Rolling Sector/Supporting Arm "R" Of Spiders/Sections Elevation Structure/Rolling Sector/Supporting Arm "R" Of Spiders/Internal Hole Coordinates Elevation Structure/Rolling Sector/Supporting Arm "R" Of Spiders/External Hole Coordinates Elevation Structure/Rolling Sector/C-Ring "L" Machining External Side Holes For Elevation Track Protection Elevation Structure/Rolling Sector/C-Ring "L" Machining Internal Side Holes For Elevation Track Protection Elevation Structure/Rolling Sector/C-Ring "R" Machining External Side Holes For Elevation Track Protection Elevation Structure/Rolling Sector/C-Ring "R" Machining Internal Side Holes For Elevation Track Protection Elevation Rim Gear	514E003 514E004 514E005 514E006 514E007 514E008 514E009 514E010 514E011 514E012 514E013 514E014 514E015 514E016 514E017 514E018 514E019 514E020 514E021 514E022 514E025 514E026 514E027 514E028 514E029 514E030 514E031 514E032 514E033 514E034 514E035 514E036 514E037 514E038 514E039 514E040 514E041 520A014

• INTERFACE DRAWINGS:

TITLE	DOCUMENT
Elevation Drive System/C-Ring Section Elevation Roll Shield (T.B.D.) Stow Pin And Auxiliary Drive Stow Pin Elevation Measuring System Elevation Measuring System Elevation Structure/Rolling Sectors/Position Of Attachment Of Spider Support M1 Cell Structure/Interface To Elevation Structure M1 Cell Structure/M1 Cell Interface Sh. ½ Hydrostatic Supports/General Drawings/Elevation Lateral Floating Support Hydrostatic Supports/General Drawings/Elevation Lateral Fix Support Hydrostatic Supports/General Drawings/Elevation Support Hydrostatic Supports/General Drawings/Elevation Support View Elevation Structure Assembly/Windbracing Structure/General Assembly Unifilar View General Telescope/Central Structure/Hydraulic Utilities-Dynamic/Balancing System-General Assembly General Elevation Mount/General Elevation Assembly/Elevation Mount Assembling/Phase 07/42 General Telescope/Telescope Special Utilities/Access To The Telescope/General Layout: 3d View	520A012 522A010 523A010 524A010 530A010 530A011 514A003 721A011 721E003 440A010 440A011 440A012 440A015 510E000 406E002 500E020 407E000

3.0 ITEM DESCRIPTION

The ROLLING SECTORS (see dwg. No. 514e004), side L and R, are made up of the following elements:

• NO.1+1 C RINGS (L & R)

• NO.22+22 ELEVATION RIM GEAR ELEMENTS

• NO.1+1 SUPPORTING ARMS OF M1 CELL (L & R)

• NO.1+1 SUPPORTING ARMS OF SPIDERS (L & R)

• NO.4+4 ADAPTORS FOR PLATES (H & I) OF SPIDERS M2-F15 AND M3 (L & R)

• NO.2+2 ADAPTORS FOR PLATES (H & I) OF SPIDERS M2-F4 (L & R)

• NO.2+2 ADAPTORS FOR PLATES (H & I) OF SPIDERS M2-F25

• NO.1+1 INTERNAL SUPPORTS (L & R) FOR CELL

• NO.2+2 SUPPORTS FOR HANGER OF SPIDER M1-F25

• VARIOUS BOLTS AND ACCESSORIES

The C-RINGS are a steel structural work made up of plates with different thickness, cut, finished and assembled by means of welding.

After pre-machining the two C-RINGS shall be assembled together to form a complete circle, and then shall be turned on a lathe according to the tolerances indicated in the drawings and in chapter 8.0.

The C-RINGS have a structural function and compose the axial and radial tracks of the hydrostatic bearing system for the elevation axis.

On the internal side of each C-RING the ELEVATION RIM GEAR, for the elevation axis drives (see dwg. No. 520a014), is installed with bolts.

The directions given on drawings and technical documents with regard to the ELEVATION RIM GEAR represent a construction hypothesis for the obtainment of the requested requirements. The contractor shall submit any other alternative production system that gives guarantee of obtaining the demanded final accuracy with more economical procedures.

On the external side is welded a machined rolling plate for the interface with the strip encoder system (dwg. No.530a010).

The SUPPORTING ARMS are made in steel structure, using plates of different thickness, which are cut and assembled by means of weldings.

They have a double function, one structural, one of supporting the SPIDERS (dwg. No. 514a002) and the M1 CELL (dwg. No. 721a011).

The INTERNAL SUPPORTS are a supplementary support for the M1 cell (dwg. No. 721a011).

The ADAPTORS FOR PLATES, made up of steel structural work, represent the extension for the SPIDERS' couplings.

4.0 INTERFACE DEFINITIONS

The ROLLING SECTORS (see dwg. No. 514e003) are interfaced with the following elements:

• WIND BRACINGS & ELEVATION PLATFORM (dwg. No. 510e000)

• M1 CELLS (dwgs. No. 721a011/721e003)

• ELEVATION RIM GEAR (dwg. No. 520a014)

• HYDROSTATIC PADS SYSTEM (dwgs. No. 440a012/ 011/ 010/ 015)

• ENCODER SYSTEM (dwg. No. 530a010)

• SPIDERS (dwg. No. 514a003)

• STOW PINS AND END STOP (dwgs. No. 524a010/523a010)

• ELEVATION TRACKS' PROTECTIONS (*)

• ACCESS AND MAINTENANCE EQUIPMENTS (dwg. No. 407e000)

• PLANTS' INSTALLATIONS (*)

• DYNAMIC BALANCING SYSTEM (dwg. No. 406e002)

• STATIC BALANCING SYSTEM (dwg. No. 406e009)

• MOUNTING DEVICE (dwg. No. 500e020)

• DEROTATORS (*)

The main above mentioned interfaces are indicated in the drawings listed in dwgs. No. 514e003/004. All drillings and machining requested in the pertinent interface drawings shall be arranged for.

* The interfaces with those subsystems are not included in the present Technical Specification and will be prepared in the occasion of the pre-erection.

5.0 PERFORMANCE CHARACTERISTICS

The main performance characteristics of the ROLLING SECTORS and relative SUPPORTING ARMS are the following:

• rigidly support and provide monitors, interface to, and access to, primary mirror cell, secondary and tertiary mirrors and other items listed in chapter 4.0;

• allow -4° +94° rotation about the elevation axis.

The main performance characteristics of the ELEVATION RIM GEAR are:

Mechanical characteristics of Elevation axis:

• Torque with wind at 24 km/h 7770 Nm

• Torque with wind at 80 km/h: 86520 Nm

• Torque with umbalanced axis: 32470 Nm

Driving system characteristics:

• No.4 motors QT-13701 for each axis

• Peak motor torque: 795 Nm

6.0 RELIABILITY, MAINTAINABILITY REQUIREMENTS

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

The contractor shall take into account of all aspects which could limit the lifetime of the supply.

He shall also contain the number of maintenance interventions, supply adequate access for maintenance operations and minimise risks of damage, loss and injury to personnel and the telescope from telescope maintenance operations.

7.0 ENVIRONMENTAL CONDITIONS

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%

• Maximum operating windspeed: 80 km/h

• Maximum observing windspeed: 120 km/h

• Survival windspeed: 150 km/h

8.0 DESIGN AND CONSTRUCTION REQUIREMENTS

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 ROLLING SECTORS with ELEVATION RIM GEAR and SUPPORTING ARMS 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 contractor 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.

As indicated on # 4.0, drillings shall be foreseen for the fixing of a device named ELEVATION TRACK PROTECTION for the tracks covering, according to dwg. No. 514e003; more detailed information will be given to the P.O..

8.1 General Dimensions and Mass

The general dimensions of the C-RINGS are shown in dwg. No. 514e007.

Maximum dimensions: length 14000 mm

1. width 7000 mm

2. thickness 890 mm

Total weight: 50136 kg

Lifting points: t.b.d. with the contractor

The general dimensions of the SUPPORTING ARMS are shown in dwg. No. 514e005.

Maximum dimensions: (5440 mm x 4440 mm x 890 mm

Total weight: 7183 kg

Lifting points: t.b.d. with the contractor

and in dwg. No. b514e006:

Maximum dimensions: (3725 mm x 10582 mm x 890 mm

Total weight: 11026 kg

Lifting points: t.b.d. with the contractor

ADAPTORS FOR SPIDERS (dwgs. No. 514e010/514e011/514e017) and INTERNAL SUPPORT (dwg. No. 514e012):

Total weight: 1625 kg

The specific technical data of the RIM GEAR WHEEL are the following:

Elevation axis:

Outside diameter: 14112 mm

Primitive diameter: 14100 mm

Module: 6 mm

Teeth number of every element: 47

Reference profile: DIN 867

Quality: 6 f 22

Max. error on a tooth: 0.02 mm

Max. error on the joint: 0.03 mm

Max. cumulative error: 0.5 mm

Steel: C 40 UNI 7845

Primitive circumference concentricity: 0.2 mm

8.2 Materials

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

STEEL PLATES: Fe 510C UNI EN 10025

GEAR: C40

Steel plates relevant to surfaces to be further machined shall be supplied with complete Ultrasonic Examination Certificates, according to UNI EN 160/87 or ASME SA-578, acceptance standard level I.

8.3 Class of Welding

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.

(Butt Joints Complete Penetration:

Class I according to UNI 10011, UNI 11001 and UNI 1307/2.

NDT: X-ray or Ultrasonic examination; acceptance criteria as required for above mentioned class of welding, according to UNI 7278, or welding procedures tests according to EN 288-3.

Welding material	electrode:	according to UNI 5132: Class IVB or according to AWS A5.1: E 7018-1
	wire:	according to AWS A5.20: E 80T5/G

(Corner or T Joints Complete Penetration:

Class II according to UNI 10011, UNI 11001 and UNI 1307/2.

NDT: X-ray or Ultrasonic examination; acceptance criteria as required for above mentioned class of welding, according to UNI 7278, or welding procedures tests according to EN 288-3.

Welding material	electrode:	according to UNI 5132: Class IVB or according to AWS A5.1: E 7018-1
	wire:	according to AWS A5.20: E 80T5/G

(Corner or T Joints Partial Penetration:

Construction: according to UNI 10011, UNI 11001 and UNI 1307/2.

NDT: Magnaflux 60% examination, acceptance criteria category II as per UNI 7278 par.A.4.3.

Welding material	electrode:	according to UNI 5132: Class IVB or according to AWS A5.1: E 7018-1
	wire:	according to AWS A5.20: E 80T5/G

8.4 General Tolerances

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.

Particular attention should be paid to obtain the tolerances requested by the ELEVATION RIM GEAR after its assembling on the C-RING:

Max. height difference between two teeth: < 0.02 mm

Max. height difference between the junction: < 0.03 mm

Max. cumulative error of height: < 0.5 mm

and tolerances requested by the TRACK according to RUNNING ELEVATION PADS.

Note: the overmetal indicated on the fabrication of the steel works requires an accurate fabrication (carpentry dimensional tolerances 5÷8 mm). It is up to the contractor to maintain them or to modify them, in order to ensure the successive mechanical machining and relative tolerances. Any modification must be approved by the P.O..

8.5 Thermal Treatments

Complete stress relieving.

Parameters: t.b.d. with the contractor.

8.6 Tightening Torque of Bolts and Screws

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

8.7 Surface Treatments

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 paint system in performance of the work.

• sand blasting SA2.5 ISO 8501-1:1988/SS055900:1988

• 1 coat (oil resistant) epoxy polyamide corrosion resistant primer (80 microns)

• 1 coat (oil resistant) vinyl high-build mastic (80 microns)

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

The rim gear wheels must be protected with grease SKF LGMT 2/5 or other equivalent product.

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

8.8 Special Manufacturing Instructions

The contractor will present, in a detailed way, the following documents:

• Weldings specifications and procedures: these have to be approved by the Project Office (P.O.) prior starting the work.

• Fabrication plan and control: these have to be approved by the P.O. prior starting the work.

As indicated in chapter 3.0, after machining on every elements the two c-rings L & R shall be coupled each other for lathe. Subsequently, the elements of the ELEVATION RIM GEAR WHEELS shall be installed as reported in the Technical Specification No. 401a004 and adjusted, in order to obtain the indicated tolerances.

The directions given on drawings and technical documents with regard to the ELEVATION RIM GEAR represent a construction hypothesis for the obtainment of the requested requirements. The contractor shall submit any other alternative production system that gives guarantee of obtaining the demanded final accuracy with more economical procedures.

Note: the overmetal indicated on the fabrication of the steel works requires an accurate fabrication (carpentry dimensional tolerances 5÷8 mm). It is up to the contractor to maintain them or to modify them, in order to ensure the successive mechanical machining and relative tolerances. Any modification must be approved by the P.O..

9.0 PRE-ASSEMBLY

The ROLLING SECTORS with ELEVATION RIM GEAR and the SUPPORTING ARMS shall be pre-assembled to verify the total dimension and pertinent tolerances indicated in the drawings.

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

10.0 PACKING AND TRANSPORT

All steel structure 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.

11.0 ACCEPTANCE TESTS

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, roughness test;

• mass check;

• certificate of surface treatment;

• certificate of assembly tolerances.

12.0 SPARE PARTS

If it is adopted a solution of RIM GEAR with elements, the contractor shall supply No. 2 elements completed with bolts.

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ANNEX A

Doc_info_start
Title: ROLLING SECTORS & SUPPORTING ARMS
Document Type: TECHNICAL SPECIFICATION
Source: EIE
Issued by: G.MARCHIORI
Date_of_Issue: 04/08/97
Revised by:
Date_of_Revision:
Checked by:
Date_of_Check:
Accepted by:
Date_of_Acceptance:
Released by:
Date_of_Release:
File Type:MS-WORD 6
Local Name: C0301/DOC/401e029d.doc
Category: TELESCOPE AZIMUTH PLATFORM
Sub-Category: GENERAL TELESCOPE
Assembly: TELESCOPE TECHNICAL DOCUMENTS
Sub-Assembly:ROLLING SECTORS & SUPPORTING ARMS
Part Name:
CAN designation: 401e029
Revision: d
Doc_info_end