Cranes, trains and massive equipment complicate Riverside project
With project specifications that included 522 tons of structural steel, $5 million of prefabricated equipment, installation of a 30-ton overhead crane and a construction site surrounded by active rail on three sides, the Riverside Heavy Maintenance Building project left no room for error.
Safe operations on such a demanding industrial project hinged on several things, including close coordination with CSX and MARC. In conjunction with the two rail companies, Clark Construction developed a logistics plan to completely separate construction operations from rail operations onsite, said Chuck Martin, Project Executive at Clark Construction. The team created barriers, gates and access points, educated all subcontractors on the site’s restrictions and required all workers who would conduct any work outside the project compound, to complete training and earn their CSX Right of Way Training Badge.
To ensure that all crane picks were completed safely, “we installed swing limit flags and barriers so that crane operators knew they couldn’t swing past certain areas so if there was any type of crane failure, the boom wouldn’t land on active tracks,” Martin said.
The team also had to compensate for a unique site problem.
“A lot of that site was built on top of brick and rubble from the Great Fire of Baltimore so we had a lot of undocumented fill,” Martin said. “There was no guarantee that 10 feet down, there wasn’t a big void where they backfilled with other material. That could create a catastrophe. If you have a crane doing a heavy pick, you want to understand the pressure points and the bearing capacity. So, we lowered the ground-bearing pressure to less than 2,000 pounds per square foot, a low value, to increase our margin of safety. We went over normal requirements by running crawler cranes on top of the existing asphalt, with12-inch crane mats everywhere the crane traveled and made heavy picks of structural steel.”
The project, which also won three individual Craftsmanship Awards, required craftsmen to handle heavy industrial requirements and machinery with precision.
The Kinsley Steel team spent 10,000 hours prefabricating materials and another 7,000 hours erecting the steel, 36 precast concrete wall panels and 14 double-pitched trusses in order to meet the design’s extremely tight tolerances.
Clark Concrete and Sissco Material Handling conducted extraordinary and highly technical collaboration to ensure the concrete work would perfectly support the installation of several massive pieces of prefabricated equipment. Sissco oversaw the acquisition and installation of equipment including the 30-ton/10-ton double gantry overhead crane, a 10-ton overhead crane, a 100-ton capacity drop table and a 44,000-pound wheel truing machine.
Members of the Clark team visited the manufacturers’ sites to learn more about the equipment, check measurements firsthand and witness the manufacturer acceptance testing of the completed pieces.
To accommodate that equipment and the rail cars coming into the facility, Riverside’s shop floor had to be constructed precisely. The floor would include an embedded rail line for MARC trains,recesses of nearly 2,000 linear feet in the 24-inch structural slab, and 1,500 cast-in-place anchor bolts. Accuracy of rail pockets and anchor bolts was critical for fit and alignment with the pit equipment, including the drop table and wheel truing machine. To ensure highly accurate concrete dimensions and to suggest changes to improve constructability, Clark personnel made a 3D model of the concrete design.
“We completed the concrete early and our inhouse tech team did a point cloud scan of the structure to create a model of the actual concrete with dimensions,” Martin said. “We provided that construction model to the manufacturers so they could do clash detection by comparing it with the 3D model of their equipment… Luckily, the concrete work was so good that there were very few areas that were even close to being an issue.”
The process identified a single problem – an area of concrete that was 3/8 of an inch beyond tolerance. Clark Concrete did a saw cut to fix the issue, well ahead of the equipment’s arrival. Since equipment installation had to happen late in the project after the building was weather-tight and fully powered, that proactive fix averted what would have been a two- to three-week delay at a critical point in a tight schedule.