This weekly engineering report summarizes mateline studies from week 3 of construction at the B2 site. Data was collected for electrical, plumbing, carpentry, and sprinkler matelines. Electrical made good progress completing connections from the 11th to 7th floors. Plumbing installation of temporary storm pipes and steam risers progressed from the 8th to 12th floors. Issues noted include a 4-inch vertical drop of a sprinkler riser that needs repair, provided wall frames not being utilized, and grooved 1-inch pipes. The next week's objectives are to compile collected data into charts and graphs for a midterm report.