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[Ext-GDE-66] BDS Change Config Request - Sep.21, 2006

Dear Colleagues,

I am announcing that CCB has received a change request for the Beam
Delivery System (BDS) section of ILC Baseline Config Doc from A.Seryi,
who is co-representing the BDS AG with D.Angal-Kalinin and H.Yamamoto.

This change request relates to an attempt at clarifying the assembly 
procedure for ILC detectors. The present BDS BCD does not explicitly 
specify the method of underground assembly; however it has been implicitly 
assumed in the BCD that detectors are assembled underground. 
This change request is to specify in BCD that assembly of detector will 
be done on-surface, in a manner similar as was done for CMS detector at 
CERN. According to the requesters, this is expected  to reduce the construction 
time of the IR-related portion of ILC since the detector subassembly work 
does not have to wait for completion of the underground hall, and is 
also expected to reduce the construction cost. 

The requesters suggest Class 1 as classification for this change
request. The CCB chair tentatively agrees to treat this as Class 1,
pending analysis of the associated cost-delta and impacts.

I am assigning T.Markiewicz and G.Blair (to be confirmed), plus 
myself, to act as CCB co-reviewers.

Although some statements have been already offered by groups outside
BDS (e.g. MDI) I will be requesting remarks, comments and assessments,
if any, from

- Cost engineers
- CF/S GG leaders
- Installation GG leaders

in separate emails.

Now this request is brought to review by CCB, and is also open to
general discussion. Any members of GDE or GDE-related task groups with
comments or questions on this request, please, direct them to
ml-ccb@xxxxxxxxxxxx and/or ml-ext-gde@xxxxxxxxxxxx by the end of
Wednesday Sep. 27, PDT.

Details of this change request is available as
BCD is available at
BCD change history is available at
RDR-related information repository for BDS is found at

--- Begin Message ---
 Dear Nobu and Colleagues in CCB, 

We are submitting a change request which 
is described in the attached file "CCR_surface_assembly.doc". 

The supporting files are linked from "CCR_surface_assembly.doc"
and are placed here

 Best regards, 
  BDS Area leaders
  Deepa Angal-Kalinin, Andrei Seryi, Hitoshi Yamamoto

Attachment: CCR_surface_assembly.doc
Description: CCR_surface_assembly.doc

--- End Message ---