LIGO Document E1300249-v2

ECR - Change Locating Dimensions of Oplev/Pcal Receiver Installations in all End VEAs

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E - Engineering documents
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Relocate the Oplev/Pcal Receiver Pylon to a position which is revised in the Beam Tube axial direction, and is according to document G1300437-v1. This constitutes a shift 2.60 farther from the A-1 Adapter viewport flange face than the current position designated by approved documents ECR E1200989-v1 & DCN E1200996-x0. Upon approval of this Change Request, all relevant documents will be revised accordingly through a new DCN.

NOTE: Both LLO End Station VEA floors will need to be re-filled & re-drilled for this change. LHO End Station VEA floors have not been drilled to date.

Due to inconsistencies between CAD models, available vendor (PSI) drawings, and actual installed V.E. hardware (all regarding A-1 Adapters), it was found necessary to measure the locations of vacuum/compression bellows and compression fittings on all End-Station installed A-1 Adapters on the side adjacent to planned Oplev/Pcal receiver pylon installations. These A-1 Adapter features will interfere with the receiver pylons at the currently documented receiver pylon positions. The measured locations of these A-1 Adapter features have been used to propose a viable new common location for all Oplev/Pcal receiver pylons. See G1300437-v1.

Also, this change provides added distance requested by the Oplev group to better accommodate the Oplev Receiver rubber bellows interfacing to the A-1 Adapter viewport protector.

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Notes and Changes:
IS- $450 estimated work crew (2 person) total job cost to refill and re-drill three slab holes in each of two LLO VEAs.

WAS- $2000

APPROVED on 7th May 2013.
Field install to fit as required. Encourage fit check of actual pylons (and all housing) prior to any further holes being drilled. Simple re-work to bellow or equivalent (default) instead of re-drilling holes. Op Lev and P-Cal to work together on this. Only re-drill holes if last option. Ensure work is captured in drawing or drawing note. CIT


Pursuant to our telecon on Monday, we asked Apollo to use our red-lined documentation (red-lined to include the 2.57" longitudinal translation for the OptLev Receiver pylon requested in ECR E1300249, now approved) to position the two pylons at the Xend station.
We have reviewed the temporary installation and find that it closely matches our designed locations, clearances, and accessibility. Thomas Vo, and Bubba, John Worden, Michael Rodruck, et al., also review the temporary installation. Thomas reported verbally that everything looks good to him.
We noted that the reference dimensions for the grout thickness were not quite right due to swapping the Xend and Yend measured heights of the A1 adapters above the LVEA floors. This does not impact the installation or the performance.
We will execute the work proposed in the ECR, basically updating all four end station drawings.
We feel that we can proceed with authorizing Apollo to proceed with drilling for placement of these two pylons at LHO Xend. However, as promised, we will await your approval.
Rick and Craig

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