Photography

ELLEN M. BANNER / THE SEATTLE TIMES

Geoffrey Loo, a union laborer with Traylor Frontier-Kemper JV, tightens two pieces of concrete tunnel segments together in the light rail tunnel connecting Capitol Hill and the University of Washington campus on Friday, March 30, 2012.

As construction continues on the light rail tunnel that will connect Capitol Hill and the University of Washington campus, crews keep the tunnel boring machine (TBM) advancing forward and install tunnel segments along the walls. The TBM uses hydraulic jacks, pictured at the top, to push off the last ring and mine forward. The TBM at work in this photo, nicknamed "Balto," could reach Capitol Hill early next week. When complete, the University Link tunnels will connect with the Downtown Seattle Transit Tunnel offering a six-minute ride between UW and downtown with a stop on Capitol Hill.