We held a brief meeting this morning to make sure everyone was "on the same page" since this chamber is slightly different than the BSCs that we have already cleaned: there are four tubes attached to BSC4. There was some discussion about the number, type, and location of barriers. As agreed at the meeting, work started with the barriers in all but the north nozzle which is attached by a short spool to HAM9. Working without a barrier at the HAM9 spool preserves access to the chamber cleanroom and precludes any confined space related safety issues. The trade-off is that one extra person is required to be a runner. 

Once brushing started, work went quite smoothly. The guys worked with one drill all day (#21) which was possible because John has given us permission to run a drill until it dies. The collar and upper sections were completed by lunch time. The mid-section and two nozzles were finished by the end of the day.