Dome Intro &

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  • Dome Status

    J. DeVries


  • Introduction

    Dome Contractor Selection and Background

    Present interactions and status


    Azimuth Mechanism (Rail, Bogies, Drives)

    Cladding, Louvered Light Baffle Vents (LLBVs)

    Light-Wind Screen

    Thermal (AC Ducts, Seals, Heat Loads)

    Electrical (Interfaces, Power Budget, Slip Ring, Cabinets)

    Mass Budget

    Action Items

    Future Work and Milestones


  • Dome Events To Date Dome FDR May 2014

    RFP release August 2014

    Bid evaluations completed January 2015

    Dome Contract signed May 2015 with European Industrial Engineering (EIE), Mestre IT

    Kick Off Meeting in Mestre, May 2015

    Bi-weekly telecoms ongoing since May 2015

    EIE visit to LSST Offices in Tucson August 3-7 2015 for workshop


  • EIE Background Dome feasibility studies (E-ELT)

    Dome design, manufacture, pre-assembly, packing & transport, erection on-site, acceptance testing (NTT, VLT, LBT, VST, VISTA)







  • Structure


    Dome FEM (ANSYS) has been developed by EIE Team Models of both closed and open shutters Fundamental frequencies > 2 Hz requirement Additional structure proposed to more equalize

    bogie loads. Max bogie load in Baseline is 860 kN.Added structure reduces the maximum bogie loads to < 600 kN. Upper Vent maintenance access with added

    structure needs to be worked out Must conform to LTS-105, LTS-126

  • Bogies


    With the lower bogie loads, essentially a standard bogie design that was used on VLT can be used, with a few modifications: Added lubrication holes for ease of

    maintenance The wheel steel needs to be of higher yield

    strength and hardness than what was used in the past to survive LSST fatigue conditions

    Roller bearing selection (more investigation) Repair in place

    600 mm dia wheels X 125 mm wide Wheels overlap the edge of the Azimuth track to

    prevent groove from developing in track The total number of bogies can also be increased

    to further reduce the load per bogie

  • Azimuth Drives / Rail


    Drive stations shorter than baseline design due to smaller bogie wheels (reduces moments)

    Drive interface plates embedded in concrete pier (early deliverable to Facility Contractor)

    Selection of drives has been evaluated as suitable for LSST

    SEW EURODRIVE; Reduction gear: K127/R R87 Servo motor:

    CM112H/BR/HR/TH/RH3L/KK50 Azimuth rail material and hardness

    deemed appropriate for LSST Rail interface to Pier needs to be

    analyzed for tensile stress in the epoxy and concrete

  • Cladding


    Contractor would like to use panels with Polyurethane foam insulation (used successfully by them on past Dome projects)

    1 m X 12 m X 0.08 m thick panels, fully enclosed by metal and plastic exterior Good thermal resistance, but the proposed insulation is not truly fireproof Current requirement is for fireproof insulation Sample of insulated panel will be sent to LSST by Contractor LSST needs to evaluate this selection for fire safety

  • LLBVs


    Hinged Light Baffles Allows simpler Vent seal maintenance access from

    inside Dome Currently, there are interferences in the open

    position with AC Ducts and Calibration Screen Resolve with alternate hinging schemes, Duct

    relocations (future work)

  • Light-Wind Screen


    Dynamic modeling has been started by Contractor Initial drive selection: SEW EURODRIVE

    Reduction gear = R 107 Servo motor = CM112H

    Baseline panel mass estimate seems adequate to Contractor Contractor would like to simplify the panel design for manufacture and look at the possibility of using

    other materials (LSST Baseline is Aluminum) Interference between lower panels and light path detected in the Contractors layout

    This interference does not exist in the LSST Baseline, clarification on clear aperture size is needed High duty brake / clutch for holding panels in position are being sought (used when drives are off to

    reduce overall heat dissipation)

  • Seals, Ducts and Heat Loads


    Both labyrinth and inflatable seal for Azimuth Inflatable seal is interlocked, deflated

    before Dome rotation Zero drag when deflated Good sealing when inflated (Dome parked)

    AC Duct routing may need to be altered to resolve hinged light baffle interferences (future work)

    Contractor has proposed an unaligned AC duct solution to resolve the interferences Contractor to provide more thermal

    analysis regarding this LSST not optimistic that this will work

    LSST to evaluate moving / re-routing ductwork up the arch girders. Affects LTS-101

    Contractors calculation for Dome heat loads differs from LSST and Arcadis values Needs to be reconciled by LSST

  • Electrical (the mechanical part)


    Initial Power Budget has been provided. Needs to be reviewed by Project.

    Electrical cabinets have been presented as located near the arch girders, at the Service Floor level for good maintenance access Cabinets near Rear Doors impede real estate

    and visual confirmation in that area Heat dissipation a concern for (rotating) LWS

    cabinet. Would like to locate this cabinet on the Main Dome Platform

    Azimuth Drive cabinet locations need to be agreed upon

    Electrical schematic needs to be developed by LSST showing the expected deliverables and interface configuration between EIE and Besalco

    Slip Ring configuration also needs resolution between EIE and LSST

  • Mass Budget


    Agrees with Baseline estimate

  • Current Action Items List


    Origin Action required Closure CommentsAI

    N Originator Meeting



    Ref. AI

    N Date Actione by Due Date Description


    Status Date Document

    1 EIE KOM 08815-MIN010 1 27/5/2015 LSSTLSST to review and approve the Documentation list

    proposed by EIEOpened

    2 LSST-PO KOM 08815-MIN010 2 27/5/2015 EIE EIE to send the Documentation List Opened

    3 EIE KOM 08815-MIN010 3 27/5/2015 LSSTLSST will deliver to EIE its Site Safety Plan to

    integrate it into EIEsOpened

    4 LSST-PO KOM 08815-MIN010 4 27/5/2015 EIE

    Safety Management Plan: The term High altitude

    needs to be changed to a more proper term indicating

    height-above-ground rather than geographical altitude.


    5 LSST-PO KOM 08815-MIN010 5 27/5/2015 EIESafety Management Plan: EIE to update the

    documentation regarding safety with LSST/AURAOpened

    6 LSST-PO KOM 08815-MIN010 6 27/5/2015 EIERisk Management Plan: scaling the risk (cost, impact

    on the schedule) a project levelOpened

    7 LSST-PO KOM 08815-MIN010 7 28/5/2015 EIE PDR

    EIE to perform a preliminary evaluation of MTBF value

    for the PDR based on the EIE experience and

    proposal. The acceptability of this value will be

    discussed during PDR.


    8 LSST-PO KOM 08815-MIN010 8 28/5/2015 EIEAdd in the compliance matrix the requirements of the

    Applicable DocumentsOpened

    9 EIE KOM 08815-MIN010 9 28/5/2015 LSSTProvide New document LTS-158 Interface Control


    10 LSST-PO KOM 08815-MIN010 10 28/5/2015 EIE

    EIE will provide a list of variable that the DCS will

    publish for the TCS with the sample period. This list

    will be agreed with LSST


    11 LSST-PO KOM 08815-MIN010 11 28/5/2015 EIEEIE will provide a proposal for the local control station

    (laptop, tablet).Opened

    12 LSST-PO KOM 08815-MIN010 12 28/5/2015 EIEEIE to look at booster fan inside ducts (2 fans per


    Proposed for

    Closure22/6/2015 E-mail form S. De Lorenzi

    13 EIE KOM 08815-MIN010 13 28/5/2015 LSSTLSST will provide the information on the booster fans

    that were already selected by LSST

    Proposed for


    e-mail form J.DeVries;

    Fantech Duct Fans 09 June

    2015 07:00

    14 EIE KOM 08815-MIN010 14 28/5/2015 LSST

    Discussion about relative motion between Dome and

    platform lift. See presentations. LSST-PO will send the



    15 LSST-PO KOM 08815-MIN010 15 28/5/2015 EIE

    EIE should propose the extended the Embedded

    Beam (with bolts) to hold the inflatable seal (if

    implemented) and LPS slip ring, includes the

    information concerning the concrete pass throughs for

    inflatable seal air supply.


    16 EIE KOM 08815-MIN010 16 28/5/2015 LSST

    Solution: Exterior surface finishing with corrugate mill

    aluminum. LSST will evaluate the proposed solution for



    17 LSST-PO KOM 08815-MIN010 17 28/5/2015 EIEEIE provide the table describing the definition of the

    different fireproof classes for the insulationOpened

    18 EIE KOM 08815-MIN010 18 28/5/2015 LSSTEIE proposes class B fireproof panel in polyurethane,

    LSST will verify with their safety if it is acceptableOpened

    19 LSST-PO KOM 08815-MIN010 19 28/5/2015 EIEPrepare the electrical power budget for the rotating

    part and fixed part.Opened

    20 LSST-PO KOM 08815-MIN010 20 28/5/2015 EIE

    EIE to provide impact in terms of

    costs/efficiency/safety, etc., to LSST of not having

    distributed neutral.


    21 LSST-PO KOM 08815-MIN010 28/5/2015 EIE

    EIE will try to change during the next design activities

    the layout of the windbracing (i.e. K bracing instead

    of X-bracing) in the fi