Teamwork from a bird's eye view – two Liebherr crawler cranes and three mobile cranes operating together.
Miami's coastline and financial district is being transformed by Swire Properties' latest majestic creation, Brickell City Centre. The $1.05 billion mixed-use development includes a number of high-rise buildings skirting the Miami River just off the coast.
This 9.1-acre (3.7-hectare) city-within-a-city project includes 5.4 million ft2 (501,676 m2) of office, residential, hotel, retail and entertainment space, giving a new meaning to urban living. It is estimated that the project will have a $1 billion overall economic impact to the city, creating 3,700 direct jobs and 2,500 indirect jobs after construction is complete. Equally as important for the construction industry, the 3.5-year project – spanning from July 2012 to the end of 2015 – will add 1,700 construction jobs on average each year.
The Americaribe/Moriarty Joint Venture is tasked as the general contractor to bring Swire Properties' vision to reality. For planning the intricate lifting requirements and for constructing the shopping center, two office space towers, two condominium towers, hotels and apartments, the company trusted the experience and expertise offered by one of the nation's largest lift equipment companies, Bridgeville, Pa.-based Maxim Crane Works, L.P.
Construction of the structures within the confined City Centre's space is not easy, and the lifting equipment involved requires careful planning by Maxim Crane. "Jobsite conditions are such that several different types of tower cranes are necessary to accommodate the project's needs for coverage, while also fitting as many cranes into the project as possible," says Matt Hyden, V.P. of the Tower Division for Maxim Crane.
Maxim Crane's team works closely with Americaribe/Moriarty JV to provide a safe and economical solution for the project. "Our local sales team has the experience and expertise to partner with the customer to ensure that all of the coordination needed to move in, erect, climb and operate these cranes is perfectly orchestrated to meet the demands of such a critical path project," adds Frank Fioravanti, V.P. of the Florida Region for Maxim Crane.
Mixed-Use Cranes
Final lift plans require 11 tower cranes for the project, all of them Terex. The strategy employed a mix of Terex® hammerhead, flat top and luffing jib designs to safely handle all of the lifting needs at City Centre. "Maxim Crane and Terex Crane's history in the market and reputation for reliability and service are critical in the crane selection for the project," explains Hyden. "Due to the confined space and adjacent structures, we have specific needs where the different tower crane designs are required to meet the needs of the project, all of which are able to be met by Terex Cranes."
With a project like City Centre, tower cranes fill a crucial role in the construction of the high-rise structures, as they provide the majority of the hoisting. Everything from tools, concrete form work and rebar to structural steel, equipment and concrete are lifted by the cranes. Careful planning is required up front to make certain that every square inch of the project site is covered by a tower crane for construction crews. "We have up to 700ft (213.4 m) under hook height and up to 244ft (74.4 m) hook reach with the tower cranes," mentions Hyden.
Many of the cranes fit in the 300-400 meter-ton market range, and each tower crane design was selected to meet specific criteria. Since this is a downtown project, space is at a premium. "We need luffing jibs for work close to adjacent structures and to meet weathervaning restrictions," comments Fioravanti.
The Terex luffing jib line includes 8 different model configurations with lift capacity classes ranging from 11 to 72.5 US tons (10 to 66 tonnes) and maximum jib lengths from164 to 246.1ft (50 to 75 m). Offering a working range of 15° to 85°, Terex luffing jib cranes increase flexibility by giving the lifting crew a number of different working radii, while conserving space on the job.
With the City Centre project requiring so many crane configurations, it's inevitable that interference would be a concern. "There are as many as five interfering cranes working together in certain areas of the project," says Fioravanti, "so we used Terex flat top cranes for this part of the project."
Flat top tower cranes are constructed without the "tops" of conventional cranes and offer lift capacities reaching 44.1 tons (40 tonnes). "Terex flat top cranes are designed specifically for jobs like City Centre," says Terex Sales Manager Tower Cranes, Ruedi Van Coppenolle, "where space is confined or when working near airports." Maxim Crane is using the Terex CTT561/A-20 model on this particular project, which gave them a maximum jib length of 275.6 ft (84 m).
Where space is not a concern and the need for lifting speed and power were required, Maxim Crane selected the hammerhead crane design. Providing a jib length reaching up to 262.5 ft (80 m), Terex hammerhead cranes are designed specifically for heavy lifting and placement duties on challenging jobsites like City Centre. "Our SK series include cranes with maximum lift capacities ranging from 22 to 35.3 tons (20 to 32 tonnes)," mentions Van Coppenolle. Hyden adds, "We selected the hammerhead models for speed and capacity, and our customers and operators alike appreciate the speed and reliability of all the Terex tower cranes in use on the project."
With the project positioned near the Atlantic Ocean coastline and constructed over 3.5-year period, Americaribe/Moriarty JV and Maxim Crane leaders had to account for and establish safety procedures in case of hurricanes making landfall. "Terex provided application engineering assistance to help develop climb sequences, tie-off points and initial freestanding configurations suitable to this job to meet hurricane wind-load ratings," mentions Hyden.
Terex transfer masts help Maxim Crane meet the stringent wind-load ratings and gain more flexibility with regard to the initial freestanding crane configurations. The transfer mast also allowed crews to more efficiently use tower crane segments between the different tower designs. "The transfer masts allow any tower crane segment to be used with the hammerhead, flat top or luffing jib crane design, regardless of what model the segment was built for," explains Van Coppenolle. "Crews can mix standard upper segments with heavy duty lower segments to deliver a maximum freestanding crane height of 140 ft (42.7 m), while still meeting Florida's 146 mph (235 km/hr) wind-load standard."
More than two-thirds of the way through City Centre's construction cycle, Maxim Crane's crew and 11 tower cranes are efficiently helping to construct the site's structures. "The cranes will be on site for 16 to 24 months per crane," says Fioravanti. "They are working, and we are not hearing anything back from the job site. No news is good news once the cranes are put to work."
