| Document No.: | 270e500 |
| Issue: | a |
| Date: | May 9th., 1997 |
| Prepared by: | Gianpietro Marchiori |
| Approved by: | Gianpietro Marchiori |
INDEX
The CIRCULAR RAIL and the relative EMBEDDED BEAM are the elements composing the enclosure 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 in a rotating building at Mount Graham in Arizona (ref. dwg. No. 270e002).
The circular rail and embedded beam represent a part of the fixed structure of the telescope enclosure.
The EMBEDDED BEAM is the part cast into the concrete of the enclosure ring wall. The beam provides the structure to support the CIRCULAR RAIL.
The CIRCULAR RAIL, fixed to the embedded beam, forms the support and guide for the rotation carriages of the enclosure mobile part.
They are made up of steel structure machined elements, assembled each other by means of bolts.
The supply of the CIRCULAR RAIL and relative EMBEDDED BEAM includes:
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| Circular Runway for Enclosure/Enclosure Track/General Assembly | |
| Circular Runway for Enclosure/Enclosure Track/Rail Pieces Distribution and Details-Sector Type A | |
| Circular Runway for Enclosure/Enclosure Track/Rail Pieces Distribution and Details-Sector Type B & C | |
| Circular Runway for Enclosure/Enclosure Track/Rail Support Beam Pieces Distribution and Details-Sector Type A | |
| Circular Runway for Enclosure/Enclosure Track/Rail Support Beam Pieces Distribution and Details-Sector Type B | |
| Circular Runway for Enclosure/Enclosure Track/Base Plates on the Concrete Distribution and Details | |
| Circular Runway for Enclosure/Enclosure Track/Rail Stop-Blocks Distribution and Details |
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| Circular Runway for Enclosure/Enclosure Track/Embedded Beam Solution/General Concrete Interface (sheet 1/2) | |
| Circular Runway for Enclosure/Enclosure Track/Embedded Beam Solution/General Concrete Interface (sheet 2/2) | |
| Circular Runway for Enclosure/Enclosure Track/Embedded Beam Solution/Wall Bracket Fastener | |
| Circular Runway for Enclosure/Enclosure Track/Embedded Beam Solution/General Concrete Interface | |
| Enclosure Drive Mechanisms/Bogies | |
| Enclosure Drive Mechanisms/Plant | |
| Enclosure Drive Mechanisms/Section |
The CIRCULAR RAIL (see dwg. No. 270e002) is made up of the following elements:
The CIRCULAR RAIL is a steel structural work made up of a base plate on which is welded a rectangular rail in special steel pre-levelled.
Each element composing the CIRCULAR RAIL is individually machined and subsequently assembled to the other sectors by means of bolts, for the verification of the general tolerances indicated in the drawings and in chapter 8.0.
The CIRCULAR RAIL supports the axial and radial loads transmitted, through No.4 carriages (see Dwg. No. 341a000), by the enclosure mobile part in the different conditions of operation and/or storage.
The EMBEDDED BEAM (see Dwg. No. 270e002) is composed by the following elements:
The EMBEDDED BEAM is a steel structural work made up of plates with different thickness, cut, finished and assembled by means of welding.
After pre-machining the sectors shall be assembled each other by means of bolts, for the verification of the general tolerances indicated in the drawings and in chapter 8.0.
The EMBEDDED BEAM's main function is to support and distribute on the ring wall the load transmitted by the rail, as well as to facilitate laying a level plane centered on the telescope pier.
The CIRCULAR RAIL (see dwg. No. 270e002) is interfaced with the following elements:
The EMBEDDED BEAM (see Dwg. No. 270e002) is interfaced with the following elements:
All above mentioned interfaces are indicated in the drawings listed in dwg. No. 270e002.
The main performance characteristics of the CIRCULAR RAIL and relative EMBEDDED BEAM are the following:
The useful lifetime of the enclosure 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.
This chapter defines the natural and induced environmental conditions the telescope and subassemblies will encounter during its lifetime.
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 CIRCULAR RAIL and EMBEDDED BEAM in accordance with the requirements indicated in the present Technical Specification, pertinent drawings and Tender documents.
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 from 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 and masses are shown in Dwgs. No. 270e002008.
Sector type A (for every one):
in total there are No.7 sectors.
Sector type B (for every one):
in total there are No.2 sectors.
Sector type C (for every one):
in total there is No.1 sector.
Sector type A (for every one):
in total there are No.8 sectors.
Sector type B (for every one):
in total there is No.1 sector.
Base plates (for every one):
in total there are No. 18 base plates.
The materials are indicated in the drawings and relative Part Lists.
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.
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 |
Rail shall be welded according to the WPS reported in Annex A.
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/f and 2/H shall be applied.
Complete stress relieving.
Parameters: t.b.d. with the contractor.
According to the following table:
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Note: it is important to grease the screws before tightening them.
Clamping shall be performed with hydraulic bolt tensioner
Grease advised: type OKS 200
Denomination: MoS2 grease or equivalent.
Warning: the tightening torque does not consider the bolt's greasy effects.
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:
The contractors shall utilise the following paint system in performance of the work.
The supplier can propose an alternative painting cycle; in any case this shall be able to guarantee the above mentioned requirements.
The contractor will present, in a detailed way, the following documents:
To understand the meaning of some pre-arrangement in doc. No. 270e501 issue a is described the positioning procedure for site.
Note: the overmetal is not indicated on the drawings. It is up to the contractor to establish it, in order to ensure the successive mechanical machining and relative tolerances. The P.O. shall be informed for approval.
The CIRCULAR RAIL SECTORS and the EMBEDDED BEAM SECTORS shall be pre-assembled to verify the total dimension and pertinent tolerances indicated in the drawings.
After disassembling for shipment, all couplings shall be opportunely locked by a pin. All special tooling required to perform the pre-assembly of the circular rail and the assembly of the rail on the mountain is considered part of this contract supply. This special tooling should be included in the shipment of the rails.
According to doc. No. 401e037 (Packing and Transport).
In particular, all steel structure shall be packed in such a way as to guarantee:
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:
Title: EMBEDDED BEAM & CIRCULAR RAIL
Document Type: TECHNICAL SPECIFICATION
Source: EIE
Issued by: G.MARCHIORI
Date_of_Issue: 09/05/97
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:
Category: FIXED ENCLOSURE
Sub-Category: CIRCULAR RUNWAY FOR ENCLOSURE
Assembly: ENCLOSURE TRACK
Sub-Assembly: EMBEDDED BEAM & CIRCULAR RAIL
Part Name:
CAN designation: 270e500
Revision: a
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