W.M. Schlosser Co., Inc.

Scope Of Work

This project involved the construction of new structures and complete renovation of the underground utility distribution system throughout the National Institutes of Health (NIH) campus in Bethesda, Maryland.

The NIH campus is comprised of forty-nine hospital buildings, laboratories, office buildings and clinics. Our project stretched throughout the entire campus and we were required to deal with pedestrian traffic, automobile and bus traffic, utility outages, deliveries of pipe and concrete, etc. There was very little staging area available and we scheduled deliveries so as not to disrupt traffic. We performed a great deal of the work after hours and on weekends when the campus was less crowded. Much of the piping was fabricated at our shop in Hyattsville, Maryland and then transported to NIH. We utilized our own trucks and trailers to ensure prompt deliveries to NIH, thus allowing precise scheduling of the material handling at the job level.

We built temporary sidewalks, widened roads, installed traffic signs and generally maintained and directed traffic throughout the campus. This was necessary to accommodate the huge amount of both vehicle and pedestrian traffic throughout NIH. The project was heavily phased and we relocated our own trailer compound several times as conditions changed on site due to NIH’s ever-changing program requirements. We maintained full-time clean-up crews to prevent debris from piling up at our multiple work sites. We built pedestrian pathways between buildings and across lawn areas, so that pedestrians would have a safe way to access their offices and laboratories.

Communication between NIH personnel (including NIH police and fire departments and the NIH Maintenance Department) and construction personnel was very important. We informed NIH every time there was a utility tie-in or shut down, usually at least fourteen days in advance.

The general focus of the project was to extend, parallel, or replace existing utility services including chilled water, high pressure steam, pumped condensate, domestic water, high voltage electric service, compressed air, and natural gas to various existing new and future facilities located on the campus. As the tunnel wound it way through the campus, many of the existing sanitary, storm drain, and water lines were relocated. The scope of work included 3,900 feet of tunnel and trenches, 7700 feet of chilled water pipe, 3850 feet of ductbank, and 9 large cast-in-place vaults.

Major items of work included:

• Asphalt paving restoration, including rebuilding walks and retaining walls, road relocation and temporary traffic patterns 
• Traffic maintenance, including temporary fencing, barriers, flagmen, etc. 
• Sheeting and shoring (the entire length of cast-in-place tunnel had to be completely tight-sheeted) 
• Demolition, saw cutting and removal of portions of existing underground tunnel 
• Cast-in-place concrete (approximately 8,000 CY) 
• Structural steel, gratings, stairs, engineered pipe supports, manhole covers 
• Waterproofing of entire underground tunnel system (approximately 250,000 sf) 
• Mechanical insulation 
• Underground electrical distribution system 
• Relocation of existing utilities 
• Natural gas lines performed by a specialty subcontractor 
• New piping, which had to be x-rayed.