World's Largest Telescope Mirror Moves to the LBT
Monday, 03 November 2003
The world’s most powerful optical telescope, which will allow astronomers to see planets
around nearby stars in our galaxy, took a giant step closer to completion late last week
when the first of its huge 27-foot diameter mirrors inched up a tortuous mountain road to
its new home at Arizona’s Mount Graham International Observatory.
The 18-ton borosilicate "honeycomb" mirror was escorted up the mountain by a team of scientists, engineers, police, and heavy-haul specialists to the Large Binocular Telescope (LBT) facility. The mirror and its all-steel transport box, which together weighed 55 tons, were transported over 122 miles of Interstate and state highway, then up the narrow hairpin turns of the 29-mile Swift Trail to the Mount Graham International Observatory (MGIO) high above Safford, Ariz.
The journey to 10,480-foot-high Emerald Peak was a two-stage, multi-day affair that required five months of intense planning and preparation. This included a full-scale trial run with a dummy mirror in September.
"Everyone is aware that there’s real glass in there this time," said J.T. Williams as the huge, yellow 48-wheeled transport rig rolled off pavement and onto the gravel road leading to the observatory. Williams, telescope assembly supervisor, walked every inch of the mountain road to inspect the surface and measure the turns during the transport operation.
Precision road grading by MGIO and Arizona Department of Transportation crews smoothed the worst of the washboard stretches of gravel, and haulers soon discovered that the near-vertical mirror load traveled best with a slight increase in speed over the washboard sections.
The mirror’s journey to Mount Graham began on Thursday, Oct. 23, when the Mirror Lab team and workers from Precision Heavy Haul, Inc. (PHH) loaded the mirror transport box and its precious cargo at UA’s Mirror Lab, which is located in the campus football stadium. The mirror-carrying convoy pulled out of the lab hours before dawn on Friday, accompanied by a 25-vehicle police escort that was organized by Mike Thomas of the UA Police Department. The police car-and-motorcycle escort formed a rolling blockade as the mirror rolled down I-10 and State Highway 191. They provided both traffic and mirror safety as the convoy averaged 45 mph to the MGIO base camp at the base of the Pinaleno Mountains.
Last Monday, Oct. 27, the team at base camp transferred the mirror to PHH’s Goldhofer trailer for the three-day, 29-mile journey to the telescope’s home on Emerald Peak. This 8,000-foot climb was made at about one mile per hour.