Small Size, Big Advantages
Small Size, Big AdvantagesCompact size of Putzmeister 20Z-Meter boom pump delivers big benefits in efficiently placing concrete at Port of Providence petroleum terminal
STURTEVANT, WI (February 1, 2008) – This year, the concrete industry was taken by storm when Putzmeister announced the development of the world’s largest boom pump – the 70Z-Meter, with its 227' 3" vertical reach. On the other end of the product spectrum is the manufacturer’s smallest truck-mounted boom pump – the 20Z-Meter, whose compact size elicits its own type of “wow” reaction, especially from contractors facing extremely tight jobsite conditions.
One contractor realizing the size advantage of the compact boom pump is RDA Construction Corporation (RDACC) of Quincy, Massachusetts, a 27-year-old company specializing in marine and civil construction projects. They witnessed the unit’s unique features in action when they required special concrete placement techniques to construct new barge mooring dolphins, resting piers and a hose tower pad for a petroleum terminal at the Port of Providence in Rhode Island. The terminal’s dock, owned by Motiva Enterprises LLC, was damaged by a fire and only temporarily repaired to remain operational for unloading petroleum barges.
The new construction project faced tight space constraints and a far distance from land; however, the small boom pump made a big difference in efficiency with the concrete placement of four challenging pours this past fall. The pours were handled by the L. Guerini Group of Boston, Massachusetts, a third-generation, family-owned construction business since 1917.
RDACC, having utilized Guerini’s services in the past, again relied on the pumping company’s experience, latest equipment technology and willingness to tackle the project’s unique demands. The end result would be the highly efficient placement of a total 300 cubic yards of concrete.
A Potential Pier Problem
With no direct path for concrete to easily reach the farthest point of placement over 1,200 feet from land, concrete placing equipment was a necessity. The closest location for equipment setup was a pier parallel to the construction site. To access pours from this spot, a truck-mounted boom pump would be ideal to reach over the water; however, the pier had strict weight restrictions. Ready mix trucks, even with reduced loads of concrete, would create an overweight condition when discharging into a boom pump’s hopper. Further compounding the situation was the exceptionally narrow width of the pier, which would prevent most boom pumps from fully deploying their outriggers.
With its advanced technology and maneuverable size, the Putzmeister 20Z-Meter met the pier’s demanding criteria. First, the 63' 10" reach of the unit’s boom easily extended over the water to access the pours. In addition, its weight of only 35,740 pounds was considerably less than the pier’s maximum 50,000-pound limit, and its compact outrigger spread of only 11' 2" in the front and 8' 6" in the rear could easily accommodate the snug 12-foot wide pier.
“There’s no other boom pump on the market today with a smaller outrigger spread than the 20Z,” says Bob Magliozzi, a partner of the L. Guerini Group. “Its lighter weight, compact dimensions and versatile boom reach made it the perfect machine for setup on the narrow, weight-restrictive pier.”
Routing the Concrete
However, routing concrete to and from the 20Z-Meter to access four difficult pour locations required a special strategy from Guerini partners Andy Guerini Jr., Lou Guerini, Joe Guerini and Bob Magliozzi. Combining their 90 plus years of concrete-related experience, the group worked with RDACC personnel to mastermind a concrete placing solution that would yield the greatest efficiency in handling all pours.
The team determined that the ultimate setup to reach the farthest point of concrete placement should include a Putzmeister 28Z-Meter boom pump situated on land where ready mix trucks could conveniently discharge concrete into the unit’s hopper. The concrete was pumped by the unit’s high pressure .16H pump cell into four-inch delivery line that stretched 650 feet down the pier and into the hopper of the BSF 20Z.09 boom pump.
The concrete traveled through the 20Z-Meter boom, which was extended to its maximum reach. When the concrete reached the boom’s end hose, it continued through an additional 500 feet of five-inch delivery line that was connected to the end hose. The concrete’s long journey finally ended in a mooring dolphin over 1,200 feet away.
Three ACPA-certified Guerini operators were on-site during this particularly demanding pour. “With delivery line strung out a quarter mile over water, we didn’t take any chances. We sent two experienced operators to operate the pumps and a third “trouble-shooter” to ensure all went as planned,” says Andy Guerini Jr. “We didn’t question the reliability of the equipment. We were more concerned about the concrete in the pipe because one minor mishap could have been an environmental nightmare.”
Timing and Logistics
A speedy completion was critical, and although other concrete placing alternatives were considered, all were deemed more time-consuming, more labor-intensive and more costly. Therefore, all concrete pours were handled in a similar method, simply changing the length of delivery line based on distance.
“To achieve faster set times and further expedite the process, a higher strength 7,000-psi concrete was used instead of the specified 5,000 psi,” says Dick Gundersen, RDACC’s Vice President and Project Manager. The concrete was supplied by Cardi Corporation of Warwick, Rhode Island, who dispatched a highly pumpable mix that allowed the use of four-inch delivery line for the longest run.
Gundersen, experienced in marine construction and instrumental in the project’s timely completion, also notes that, “the project logistics were very unique and timing was crucial, as construction had to be scheduled around the petroleum barges’ arrival and departure. No ‘hot’ work could be performed at this active facility while a barge was unloading combustible fuel.
“Therefore, we worked closely with Mike Sullivan, facility manager at Motiva’s Providence, Rhode Island location, to continuously update a schedule that would accommodate barge deliveries yet help achieve our construction deadline,” adds Gundersen. “Sometimes, this meant a halt in construction for a critical barge to unload, or a barge might be held at sea while an urgent concrete pour was performed.” For the latter situation, equipment reliability for an on-time completion was paramount.
Tight Space, No Problem
“For jobs with tight space and time constraints like this one, we specifically rely on our 20Z,” says Magliozzi. “Since joining our fleet in May, the boom pump has been consistently busy, averaging about an 85 percent utilization rate.”
“Besides commercial work, the unit also handles countless residential jobs in congested urban areas, using its low 12' 10" unfolding height and four-section, Z-Fold boom to snake under trees and over obstacles,” says Magliozzi. “Plus, being so quick and easy to setup, the machine would allow us to pump concrete at the dock in the morning and head over to a residential site in the afternoon.”
“Guerini are pros at what they do,” says Gundersen. “The entire setup was well planned, and the concrete was placed without a problem. The $4.5 million project was completed in the fall of 2007, and the terminal is fully operational.”
“Pours using the smallest sized boom pump in our fleet receive the same dedicated effort as the ones using our largest 42X-Meter model,” says Andy Guerini Jr. “It’s all about solving the contractors’ concrete placing needs, no matter the size.”