New bridge restores full McChord airfield capabilities Published Dec. 22, 2020 By John Norgren Joint Base Lewis-McChord Public Affairs JOINT BASE LEWIS-MCCHORD, Wash. -- A McChord C-17 Globemaster III took off Dec. 22 over the new underground bridge to commemorate the reopening of the McChord Field runway to its full, 10,100-foot operational length. This follows the 11-month closure of almost half of the runway due to two failing culverts under the runway, taxiway and infield. “After the culverts failed, we were forced to limit aircraft operations at McChord Field hampering our ability to project global airlift,” said Col. Brian Collins, 62nd Airlift Wing vice commander. “However, thanks to our mission partners, we are excited to announce our runway is once again fully operational. The new concrete airfield bridge will provide a long-lasting solution toward ensuring McChord Field continues to fill its key role in our national defense.” Construction of the new concrete, arch bridge under the runway — a nearly $80 million construction project started in July by Brice Civil Contractors, Inc. — was finished ahead of schedule. The new 1,800 foot-long airfield bridge, consists of 300, 50-foot-wide concrete archways, each about 6-feet wide, placed side-by-side. The new airfield bridge is significantly larger than the old culverts, and it’s built to handle water flows generated by a 100-plus year storm, compared to the previous culverts’ design to handle a 50-year stormflow. “This project is important for so many reasons, and we are extremely pleased that it could be such a great win-win for all involved,” said Col. Skye Duncan, JBLM Garrison commander. “We re-enabled the daily worldwide strategic airlift from McChord Field, and we improved the environment for decades to come. The communities east and west of the base will see improved water quality and fish passage with this new 100-year bridge, and once again we are able to support all the types of aircraft that depend on JBLM to project around the globe to protect our nation.” During the construction, pumps and pipes were used to divert Clover Creek around the construction site, and dewatering wells were used to drain and dry the construction site. When construction is finished, Clover Creek will flow under the new, wider airfield bridge that runs under the McChord Field runway, taxiway and infield and, once again, this key environmental waterway will flow completely with no obstructions. “JBLM was able to take advantage of the emergency and provide a better habitat for the fish that inhabit Clover Creek,” said Steven Kelley, JBLM Area engineer, Seattle District, U.S. Army Corps of Engineers. “We replaced two steel culverts that channeled Clover Creek under the runway with a fish friendly passage constructed in accordance with state and federal guidelines that features an LED lighted meandering stream designed to replicate a natural streambed.” In January 2020, ground depressions formed on either side of the McChord Field runway. Investigation showed two 1950s-era, 12-foot diameter, 1,800 foot-long steel culverts allowing Clover Creek to flow under McChord Field were failing. The 70-year old corrugated steel culverts, which were installed during a $4 million runway extension project in 1951-52, had significant structural problems to include ruptures, warping, and debris blockages. The damage made the runway over the culverts unsafe for aircraft to land, takeoff or taxi over them, and the airlift wings at McChord Field ceased using the south end of the runway beyond the culverts. Although McChord Field runway operations continued throughout 2020, the tempo of flight operations were limited. The 62nd and 446th Airlift Wings will now resume normal day-to-day operations at McChord Field and the community should expect an increase in C-17 flights around JBLM. McChord Field airfield bridge construction timeline 1951-1952 – McChord Field runway extended to 8,100 feet. Clover Creek diverted under it through two, 1,500-foot long, 12-foot-wide culverts; part of a $4 million runway extension project. McChord Field runway was upgraded to handle the largest transport aircraft of the day (C-124 Globemaster IIs). The 62nd Troop Carrier Wing, equipped with C-124s, reactivated at McChord Field in September 1951. 1954 – Original culverts extended to 1,800 feet when additional ramps and a taxiway were built. January 2020 – Ground depressions formed along the culvert’s route under the runway on both sides of the runway. Depressions rapidly worsened after significant rainfall in early January. Late-January 2020 – Conditions deemed unacceptable for safe aircraft operations over the existing culverts. The runway was reduced by about 3,500 feet and impacted ramp and taxiway were also closed. This limited the types of aircraft and the cargo loads that could use the runway. Early-February 2020 – The depressions were excavated, and a remote controlled submersible was used to examine the culverts’ interiors. The search confirmed the culverts were blocked by rocks and debris in several places, and the culverts were deformed: in one place compressed from a 12-foot to 4-foot diameter. Both culverts had ruptures, and water was flowing into and out of the culverts in multiple locations. It was determined the culverts could not be repaired. Late-February 2020 – Department of the Army approved expedited project approval and acquisition process. March 25, 2020 – 62nd Operations Group commander, on behalf of the 62nd Airlift Wing commander, signed Memorandum for Record declaring the culverts’ failure an operational emergency. May 5, 2020 – State Historic Preservation officer concurred with the work proceeding. The Puyallup and Nisqually Tribes also concurred with this action. May 12, 2020 – JBLM requested expedited consultation with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service pursuant to 50 CFR § 402.05. May 27, 2020 – USACE Seattle District Regulatory Branch issued an Emergency Notice to Proceed on allowing the project to proceed under the Nationwide Permit 14 terms and conditions. May 28, 2020 – EPA Region 10 provided a letter confirming they’d authorized a Clean Water Act Section 401 Certification for the project. May 28, 2020 – Army Corps of Engineers awarded design build contract for the project. July 16, 2020 – Construction starts with excavation work and installation of dewatering wells. Late-July 2020 – Clover Creek diversion around construction site begins via pumps, pipes and hoses. Clover Creek diversion will remain in place until the bridge structure is complete in the summer of 2021. Mid-September 2020 – First of the 50-foot-wide reinforced concrete arch sections installed for the bridge structure. Installation of 300, 50-foot by 6-foot arch sections, totaling 1,800 feet, continued for 10 weeks. Nov. 20, 2020 – Runway paving completed, ahead of schedule. Nov. 23, 2020 – The last of the reinforced concrete arch sections put in place, ahead of schedule. Dec. 22, 2020 – McChord Field runway reopened to its full operational length. During the 7-month construction period, the contractor used: 6,846 cubic yards of concrete, or just over a half mile of Interstate 5; 1,500 tons of steel rebar weighing more than seven 747s; excavated enough dirt to fill nearly half of the new State Route-99 tunnel in Seattle; pumped more than 660 million gallons of ground water, or enough to fill nearly 1,000 Olympic swimming pools.