LBT PROJECT 2x8.4m TELESCOPE
	TECHNICAL SPECIFICATION ELEVATION STRUCTURE WINDBRACING STRUCTURE
	Doc. 401E030/C 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 WINDBRACING STRUCTURE and the relative ELEVATION PLATFORM 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 (Fig. 1) (ref. dwg. No. 407e001).

The WINDBRACING STRUCTURE and the ELEVATION PLATFORM represent the central and external part for the connection of the ROLLING SECTOR of the telescope's elevation structure.

On the ELEVATION PLATFORM are fixed the M1 CELLS and the support structures of the DEROTATORS and pertinent instruments.

They are mainly composed by steel tubes, pre-welded in portable elements, machined and assembled by means of bolts.

The supply of the WINDBRACING STRUCTURES and the ELEVATION PLATFORMS 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
Windbracing Structure/General Assembly/Unifilar View Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi01 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi02 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi03 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi04 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi05 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi06 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi26 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi27 Elevation Structure Assembly/Horiz. Windbracing External Nodes/Node Pe09 Elevation Structure Assembly/Horiz. Windbracing External Nodes/Node Pe10 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pe11 Elevation Structure Assembly/Horiz. Windbracing External Nodes/Node Pe04 Elevation Structure Assembly/Horiz. Windbracing External Nodes/Node Pe06 Elevation Structure Assembly/Horiz. Windbracing External Nodes/Node Pe05 Elevation Structure Assembly/Horiz. Windbracing Internal Nodes/Node Pi19 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Node Pi18 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi15 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi17 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi13 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi16 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi07-Pi43 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi09 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi10 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi14 Elevation Structure Assembly/Horiz. Central Windb. Internal Nodes/Node Pi11-Pi44 Elevation Structure Assembly/Vert. Central Windb. Internal Nodes/Unifilar View Elevation Structure/Horizontal Bracing/Unifilar View/Horizontal Platf. Elevation Structure/Horizontal Bracing/Internal Nodes/Unifilar View Elevation Structure/Horizontal Bracing/External Nodes/Unifilar View Elevation Structure/Horizontal Bracing/Internal Nodes/Unifilar View Elevation Structure/Vertical Central Bracing/Top Assembly Elevation Structure/Vertical Central Bracing/Diagonal Assembly Side L Elevation Structure/Vertical Central Bracing/Central Assembly Elevation Structure/Horizontal Bracing/Front Beam Elevation Structure/Horizontal Bracing/Front Beam Sh. 1/3 Elevation Structure/Horizontal Bracing/Front Beam/Details And Sections Sh. 2/3 Elevation Structure/Horizontal Bracing/Front Beam/Adjustment Flange 1 To 8 Sh. 3/3 Elevation Structure/Horizontal Bracing/Back Beam Elevation Structure/Horizontal Bracing/Back Beam Sh. 1/2 Elevation Structure/Horizontal Windbracing/Back Beam/Drilling Flange And Adjst. Sh. 2/2 Elevation Structure/Horizontal Bracing/Ext. Nodes/Back Assembly Side L Elevation Structure/Horizontal Bracing/Lateral Back Beam Side L Sh. 1/2 Elevation Structure/Horizontal Bracing/Lateral Back Beam Side L/Adjustment Flange 1-2-3-4 Sh. 2/2 Elevation Structure/Horizontal Bracing/Ext. Nodes/Central Assembly Side L Elevation Structure/Horizontal Bracing/Ext. Nodes/Front Assembly Side L Elevation Structure/Horizontal Bracing/Lateral Front Beam Side L Sh. 1/2 Elevation Structure/Horizontal Bracing/Lateral Front Beam Side L/Flange 5 And Adjustments Sh. 2/2 Elevation Structure/Horizontal Bracing/Diag. Assembly Side L Elevation Structure/Horizontal Bracing/Central Assembly Elevation Structure/Horizontal Bracing/Assembly Pi13-Pi90 Elevation Structure/Horizontal Bracing/Rotators Structure Sh. 1/5 Elevation Structure/Horizontal Bracing/Rotators Structure/Sections Sh. 2/5 Elevation Structure/Horizontal Bracing/Rotators Structure/Sections-Views And Flanges Sh. 3/5 Elevation Structure/Horizontal Bracing/Rotators Structure/Adjustments Sh. 4/5 Elevation Structure/Horizontal Bracing/Rotators Structure/Details Sh. 5/5 Elevation Structure/Horizontal Bracing/Rotators Structure/Floor Plate Elevation Structure/Horizontal Bracing/Construction Assembly Sh. 1/4 Elevation Structure/Horizontal Bracing/Details Sh. 2/4 Elevation Structure/Horizontal Bracing/Details Sh. 3/4 Elevation Structure/Horizontal Bracing/Details Sh. 4/4	510E000 510E001 510E002 510E003 510E004 510E005 510E006 510E009 510E010 510E011 510E012 510E013 510E014 510E016 510E017 510E019 510E020 510E022 510E023 510E024 510E025 510E026 510E027 510E028 510E029 510E030 511E000 512E000 512E001 512E004 512E026 511E002 511E009 511E014 512E002 512E039 512E049 512E052 512E003 512E042 512E048 512E005 512E011 512E046 512E006 512E007 512E015 512E047 512E016 512E018 512E023 512E045 512E051 512E063 512E064 512E065 512E066 512E078 512E079 512E080 512E081

• Interface Drawings:

TITLE	DOCUMENT
Elevation Structure/Rolling Sectors/General Mount Of C Rings L And R Elevation Structure/Rolling Sectors/General Assembly Of C Rings L Elevation Structure/Rolling Sector/C-Ring R Carpentry/Rolling Sector Structure Sh. 1/3 M1 Cell Structure/Interfaces To Elevation Structure And Mirror Cover M1 Cell/M1 Cell Structure/M1 Cell Interface Sh. ½ Elevation Structure/Central Structure/Rotators Structure/General View Elevation Structure/Central Structure/Rotators Structure/Orthogonal View Elevation Structure/Central Structure/Rotators Structure/Plan View Elevation Structure/Central Structure/Rotators Structure/Rotator Supp. Lower Back-Beam General Telescope/Central Structure/Hydraulic Utilities-Dynamic/Balancing System-General Assembly General Telescope/Telescope Special Utilities/Access To The Telescope/General Layout Ortogonal View Specification: Balancing System Ballast	514E003 514E004 514E024 721A011 721E003 513E000 513E002 513E003 513E005 406E002 407E002

3.0 ITEM DESCRIPTION

The WINDBRACING STRUCTURE and relative ELEVATION PLATFORM (see dwg. No. 510e000) are made up of the following elements:

• NO.1 TOP ASSEMBLY OF VERTICAL WINDBRACING (dwg. No. 511e002)

• NO.1 CENTRAL ASSEMBLY OF VERTICAL WINDBRACING (dwg. No. 511e014)

• NO.2 DIAGONAL ASSEMBLY OF VERTICAL WINDBRACING (L & R) (dwg. No. 511e009)

• NO.1 HORIZONTAL WINDBRACING-FRONT BEAM (dwg. No. 512e002)

• NO.1 HORIZONTAL WINDBRACING-BACK BEAM (dwg. No. 512e003)

• NO.1 DEROTATORS PLATFORM HORIZONTAL WINDBRACING (dwg. No. 512e045)

• NO.2 DIAGONAL ASSEMBLIES HORIZONTAL WINDBRACING (dwg. No. 512e016)

• NO.1 CENTRAL ASSEMBLY HORIZONTAL WINDBRACING (dwg. No. 512e018)

• NO.1 ASSEMBLY PI13-PI90 HORIZONTAL WINDBRACING (dwg. No. 512e023)

• NO.2 EXTERNAL NODES BACK ASSEMBLY HORIZONTAL WINDBRACING (dwg. No. 512e005)

• NO.2 EXTERNAL NODES CENTRAL ASSEMBLY HORIZONTAL WINDBRACING (dwg. No. 512e006)

• NO.2 EXTERNAL NODES FRONT ASSEMBLY HORIZONTAL WINDBRACING (dwg. No. 512e007)

• NO.30 PIPES

• NO.2 NODES (dwgs. No. 510e009/010)

• VARIOUS BOLTS, SHIMS AND ACCESSORIES

The WINDBRACING STRUCTURE and relative ELEVATION PLATFORM are a steel structural work made up of pipes and plates with different thickness, cut, finished and assembled by means of welding.

Each element shall be machined according to the tolerances indicated in the drawings and in chapter 8.0.

The WINDBRACING STRUCTURE and relative ELEVATION PLATFORM have a structural function to connect the two ROLLING SECTORS for the support of the M1 CELLS and DEROTATORS' structures and instruments. Those instruments are internal spiders, electrical switchboards, balancing system, M1 cover mirror.

4.0 INTERFACE DEFINITIONS

The WINDBRACING STRUCTURE and relative ELEVATION PLATFORM are interfaced with the following elements:

• SPIDERS M2-F25 (*)

• ROLLING SECTORS (dwg. No.514e003)

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

• DEROTATOR STRUCTURES (dwg. No. 513e003)

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

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

• PLANTS INSTALLATIONS (*)

• M1 COVER MIRROR (dwg. No. 721a011)

All above mentioned interfaces are indicated in the drawings listed in dwg. No. 510e000. 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 WINDBRACING and relative ELEVATION PLATFORM are the following:

• rigidly connect the two C-rings;

• provide a stiff support for the M1-cells;

• provide a walkway for inspection, access, maintenance at the Elevation axis level and of the whole Elevation structure up to the top of the spiders.

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

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 propose alternative solutions, in order to obtain the requested performances.

The contractor shall fabricate all parts, equipment, components and materials of the WINDBRACING STRUCTURE and relative ELEVATION PLATFORM in accordance with the requirements indicated in the present Technical Specification, pertinent drawings and Proposal documents.

In chapter 2.0 are listed the assembly drawings of all nodes. Moreover, the details of each element composing the node have been developped as an example to underline the construction type of each one of them (dwg. No. 512e078).

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.

8.1 General Dimensions and Mass

For the dimensions of the assembly and pipes which compose the WINDBRACING STRUCTURE, please refer to the pertinent drawings.

The total weight is 84569 kg.

8.2 Materials

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

STEEL PIPES AND PLATES: Fe 510C UNI EN 10025

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 operation 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 WINDBRACING STRUCTURE and pertinent ELEVATION PLATFORM after its assembling on the C-RING.

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 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 epoxy polyamide corrosion resistant primer (80 microns)

• 1 coat 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.

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 WINDBRACINGS' STRUCTURE and relative ELEVATION PLATFORM shall be coupled each other in order to obtain the indicated tolerances.

Each element of the WINDBRACING STRUCTURE, after fabrication, pre-assembling, welding and machining, shall be checked by means of a measurement system or positioning fixtures, in order to guarantee the positioning of the various coupling flanges and the pertinent fabrication tolerances. Subsequently, the different elements of the WINDBRACING STRUCTURE shall be assembled one another to verify the general geometries and tolerances. The same procedure shall be adopted for the ELEVATION STRUCTURE.

The Contractor shall predispose an adequate assembly and control procedure, to be submitted to the P.O. approval.

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

As indicated on # 8.8 the Contractor shall pre-assemble by his premises both the WINDBRACING STRUCTURE and the ELEVATION STRUCTURE, 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 particular, 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

Not applicable.

ANNEX A

Doc_info_start
Title: ELEVATION STRUCTURE WINDBRACING STRUCTURE
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/401e030c.doc
Category: TELESCOPE AZIMUTH PLATFORM
Sub-Category: GENERAL TELESCOPE
Assembly: TELESCOPE TECHNICAL DOCUMENTS
Sub-Assembly: ELEVATION STRUCTURE/WINDBRACING STRUCTURE
Part Name:
CAN designation: 401e030
Revision: c
Doc_info_end