General Contractor: J.E. Dunn Construction
Location: SLAC Campus Menlo Park, Ca
Project Scope: Overlap Core Drilling, Electric Flat Sawing, Demolition & Removal
Description: In the hills of Menlo Park sits a campus where scientists around the world come to, to conduct research and testing. Originally named Stanford Linear Accelerator Center, SLAC is one of 17 Department of Energy national laboratories and one of 3 National Accelerator Laboratories. One special aspect of SLAC is their 2-mile-long particle accelerator where essentially, they shoot an x-ray laser beam up to one million x-ray pulses per second. The LCLS-II is and upgrade from their previous LCLS laser. With up to a million X-ray flashes per second, 8,000 times more than its predecessor, it transforms the ability of scientists to explore atomic-scale, ultrafast phenomena that are key to a broad range of applications, from quantum materials to clean energy technologies and medicine. With lasers moving in that speed, they need to stay cool. Lombardo was brought on by J.E. Dunn to open up a shaft to the tunnel to bring Helium in to cool the laser. The tunnel is 24’ below the earth and then there is 24” thick concrete ceiling to get through. We first started with scanning the slab on grade, locating any conduits and rebar pattern in the areas that needed to be cut and removed. Next, we electric sawed and removed approximately 6’x6’ area where the earth drillers needed to drill 24’ down to the lid of the tunnel. After the dirt was removed and sleeve was grouted in place, we tackled the concrete lid. The only option for us to remove the 48” diameter opening in the ceiling was from below in the tunnel, overlap core drilling upside down. We utilized hydraulic core drilling with a 480v hydraulic power pack. Our skilled operator carefully drilled out the mass of the opening with 12” diameter cores, then drilled the perimeter with 4” cores. Once the opening was completed, it allowed access for the mechanical contractor to run the cooling line. All in all this was a very challenging project. Access being so far down in the tunnel and working in close proximity to priceless hardware made for stressful work days. On top of that, core drilling upside down creates quite a bit of a mess. However, our skilled and professional crew was able to tackle this challenge and we are proud to say that there were ZERO time lost accidents and ZERO damage to any items that belonged to SLAC or any trade partners.

SLAC fires up the world’s most powerful X-ray laser: LCLS-II ushers in a new era of science