With the completion of the final 7/10ths of a mile segment between Broadway and the Paramount Theater, officials Tuesday morning marked the end of some of the highest risk work in the construction of the nearly three-mile-long set of twin tunnels that will bring light rail service to Capitol Hill by 2016.
Officials now say the U-Link light rail project has reached its midway milestone — with plenty of work left to do. It’s too early to start thinking about a possible early start of service for the project.
“There’s still way too much work to be done before we can start realistically talking about opening earlier than planned,” a Sound Transit representative said. “Cross passages, stations (on CH, the station is currently a large hole in the ground full of conveyers and other tunneling machinery), rails, power, communications systems, testing all of the above,” he wites.
Still, the milestone is worth noting — and, to be fair, it’s not like the $1.9 billion project is behind schedule.
Officials say the end of boring brings to a close two of the five biggest risks for the construction process of the U-Link line. Those first two were the tunnels themselves and the risky double-pass below I-5. Remaining are the completion of cross-passages between the twin tunnels, the coordination of three sets of contractors at the Broadway site as construction of the station kicks in and, the final step, testing and coordination of the new line with the existing light rail system.
In terms of Capitol Hill’s community priorities, you might add a sixth top risk. The work to shape the transit oriented development that will accompany the construction of the Sound Transit station on Broadway between John and Denny is begging to heat up again. Last summer, the City Council was banging out an agreement with Sound Transit to provide a framework for the process to open up development around the station. With those contracts coming up for bids, expect the public process to kick back into gear. By the way, Sound Transit will also be opening up a development opportunity above the construction area where the U-Link tunnel connects to the downtown transit tunnel next to the Paramount.
Tuesday also marked the second successful run for the massive, 21-foot-tall tunnel boring machine as it completed the southbound tunnel. In early December, CHS caught the 679,000-pound “Brenda” at the surface after she completed her first run boring the future northbound tunnel from Broadway. The other set of tunnel boring machines completed their run from Montlake to Capitol Hill earlier this spring. We were there in spring 2011 when the boring began at UW.
If not perilous, Brenda’s journey from Capitol Hill to downtown was certainly challenging. Navigating a continuous curve that at one point brought her within 21 feet of I-5 at the surface, the machine operated by a team of contracting companies employed a team of on around 17 people to operate, five days a week, 24 hours per day for weeks at a time as it traveled from Broadway to the edge of downtown’s transit tunnel. At its fastest rate, the machine was able to churn through 105 feet of soil in a day.
Along the way, Sound Transit officials say some 19,900 trucks have plied the streets of Capitol Hill hauling muck churned up by the machine away from the Broadway station site.
The end of boring for all segments of the route brings to a close at least one chapter of concern at the surface as residents along certain areas of the route experienced vibrations and noise from the boring operations. Meanwhile, officials say that Franklin Tseng’s building near the Broadway station site experienced “some displacement” but that the small movement was within the “expected range.”
Whether issues at the surface arise during the cross-passage work is yet to be seen. As for the start of operations, residents concerned about permanent impacts from the route have a bit of a wait. Officials say they don’t plan to start testing actual light rail trains on the line and integration with the rest of the system until fall of 2016.