The construction of a $6.5-million building and installation of its sophisticated treatment equipment at Boston's Brigham & Women's Hospital required some creative rigging and crane operation due to challenging site conditions.
Boston-based Suffolk Construction is building the 2,600-square-foot cast-in-place structure and bringing in its valuable biomedical equipment — a 22-ton cyclotron — at a site sandwiched by existing hospital buildings and a large air-handling unit.
The first challenge was an existing underground high-voltage electric power line in the way of the new building, according to Brian Scribner, Suffolk job superintendent.
"We had to have the electrical contractor J.M. Brown relocate a 13,800-volt underground power line serving the main campus,' said Scribner. "And excavation for the line was difficult. Because of the tight site, the largest machine we could use was a Bobcat mini-excavator."
Foundation work for the new, one-story 64-foot by 40-foot building was even more of a task, he explained.
"The piers for the building were 14-feet deep, and we had to dig them by hand." He said the crew of subcontractor, G.A. Climo & Son Inc. of Stoughton, Mass., worked inside trench boxes, using hand shovels and buckets to excavate the soil.
With the building excavation completed, the concrete for the structure, including its piers and 2-1/2-foot- to 3-1/2-foot base slab, was formed and placed. Since no pressure from concrete forms could be transmitted to the existing buildings that crowded the new building on three sides, the contractor was forced to use blindside, stay-in-place forms with wire mesh to contain the poured concrete. Moreover, all concrete had to be pumped to the building site.
"We couldn't get a truck inside the area, so Independent Concrete Pumping pumped the 600 cubic yards of ready mix from the street about 150 feet away," said Scribner.
As part of the construction, crews had to assemble a galvanized steel exhaust riser, running from a prefabricated mechanical/electric structure sitting on top of the new cyclotron building to the top of an adjacent building — a distance of about 160 feet.
Job conditions, such as lack of room at the construction site and the hospital's location right next to a residential neighborhood, dictated that medical equipment would be flown in by crane during off-hours. Additionally, the contractor had to compromise on the size of the crane allowed for the work.
"The biggest crane allowed was a 240-ton Liebherr hydraulic crane," said Gerry Finerty, job superintendent for Shaughnessy & Ahern, a Boston rigging company. The crane, provided by Shaughnessy/AmQuip, an equipment rental firm, was set up in a parking lot between the hospital campus and the residential neighborhood.
Finerty said the crane was able to deliver ancillary cyclotron equipment directly to the work area, reaching up over a hospital building and into a small courtyard next to the new building site. But the principal piece of equipment, the cyclotron itself, was too heavy for such a long reach.
"The cyclotron was only about 5-foot by 5-foot by 5-foot tall, but it weighed 44,000 pounds, and the crane couldn't reach out with a load that heavy all the way to the new building site," he said. "So the operator picked the cyclotron over the hospital building and put it down in a narrow alley between the building and the air-handling unit."
Since project specifications restricted crane operations during off-hours, and prohibited the use of any machinery on Sundays, the pick of the cyclotron had to take place on a Saturday.
"We could use the crane only between 7 a.m. and 7 p.m., so it was set up in the parking lot on Friday night, ready to go Saturday morning," said Finerty. Once the pick was completed, crews broke down the crane and moved it off-site by the 7 p.m. deadline.
To move the heavy equipment to the building that was to serve as its home, riggers placed the cyclotron up on 100-ton skates — basically heavy-duty miniature dollies — and rolled the machine over temporary steel plates to the new building. It was a tight squeeze under the air-handling unit.
"We had between four and five inches of clearance under the air-handler," he explained.
Their final destination was next to an opening on the side of the new building about two feet off the ground.
On Sunday, they finished the job — quietly. Using 25-ton jacks, they raised the machine to the required elevation and employed a comealong to pull the 22-ton cyclotron to its permanent location inside the building where medical technicians would set it up for operation.
Once the cyclotron is in operation, it can be used to treat cancer victims. Basically a type of particle accelerator, the machine's strong magnetic field and alternating high-frequency voltage produce a continuous stream of particles. These charged particles can pinpoint and kill cancerous tumors while minimizing damage to healthy tissue along their path.