Jason, Tyler and I measured the BSC9 chamber longitudinal position from the face of the gate valve (GV19) nearest to the termination slab and compared it to the drawing position call outs. We found the chamber to be 6.01mm further north than the drawing perfect position. 

We set a new monument on our offset line perpendicular to BTVE-8 and measured longitudinal positions for EX-B1 ,EX-T3, IAM-17.
So far first error found is BX-B1 has a positive error 19.5mm +X which caries over to EX-T2 which we are using to shoot the ETMx from 
When we finish up with the BSC9 chamber centerline we will know more.