KVM 32 separate placing boom is mounted on octagonal mast. Two mast locations were necessary for concrete placement.

In one of the mast locations on the project, floor frames are set into the decks and the bolted together mast is stabilized with pins and wedges.

By adding sections to the octagonal mast, boom height is optimized to achieve maximum reach.

Brackets are provided on every octagonal section to mount a platform, ladder and pipeline without welding.

The octagonal mast gave the contractor the option of free-standing in an elevator shaft and reducing the number of openings in the post-tensioned deck.

Placing Boom is Good Investment On Royal Bank Project

The centerpiece at the 2007 Schwing World of Concrete Booth was an innovative octagonal mast for separate placing booms. “I saw the modular design of the mast and thought it had potential for the right project, “recalls George King, owner of Modern Concrete Pumping, Newington, Connecticut. Little did he know that the right project was just around the corner. In a matter of months, Modern had a 32-meter separate placing boom mounted on the new style mast for an expansion of the Royal Bank of Scotland in Stamford, Connecticut.

The office and parking garage complex, designed by Thornton-Tomasetti of New York City, features a combination of post-tensioned concrete parking garages as well as conventional concrete construction. According to concstruction managersTurner Construction, concrete was selected because of its availability and speed of construction. The project will consume an estimated 30,000 yards of concrete.

The work consists of three five-story buildings with parking on the lower levels. More than one half million square feet of post-tensioned decks are due to be finished by November 2008. The placing booms are speeding the construction after several unusual delays. “One of the large cranes on the site bent a boom section causing the job to be stopped while they figured out what to do with it,” King explains.

Because of the sensitive nature of the post-tensioned decks and the need to profile the cables, separate placing booms with their precision placement were the natural choice to fast-track the concrete placement after the delays. “Because of the post-tension design we wanted to minimize the number of holes in the decks, but we needed two mast locations to reach the entire deck, “according to Rich Kalriess, project manager for concrete contractors, Tri-Star Building Corporation, Stamford. A 10-foot square opening for a service elevator proved to be too inviting to pass up for one of the mast locations.

The octagonal mast is available in four or six-meter sections allowing it to be lengthened as the building gains height. A cross frame on the lower level supported the initial set-up of two 6-meter octagonal sections in the elevator shaft on the north end of the building. As the building rose, the boom was removed from the head section and one additional 6-meter section was added. “This enabled us to get the maximum reach of the 32-meter boom on the lower floors, without getting the elevation too high. The modular sections bolt together in less than an hour, “King stated. Because each section is tabbed with brackets for pipeline and ladders, no welding is required.

In the other opening on the south end, another octagonal mast made up of two six-meter sections is inserted in floor frames located in 41-inch square openings.
The floor frames are located on separate floors that must be a minimum of 11’6” apart and utilize wedges and a pins to brace the mast. A self-climbing option is available that attaches to the floor frame and eliminates the need for crane time to raise the boom and mast.

Tri-Star is renting the octagonal masts and KVM 32-meter boom for the project from Modern but using their own Schwing KVM 39 truck-mounted boom pump to feed the separate placing boom. Depending on accessibility, the Roll and Fold 39-meter boom’s 127-feet of reach is used to pump lower levels.

Each deck is consuming 450 yards of concrete pumped through the KVM 39’s 2023-5 pumpkit. With 60-feet of hardpipe to the mast locations, the total distance pumped is more than 250-feet. “The pump is keeping up with the production requirements and it handles the 6,000 psi mix with no problems, “according to Kalriess.

The Royal Bank of Scotland complex will have the world’s largest trading floor when completed. In order to keep up with the data transfer and communications requirements for this volume of trading, enough electrical wire to wrap around the world eight times will be needed.


Project: Royal Bank of Scotland Campus, Stamford, CT
Owner: Royal Bank of Scotland
Architects: Roger Ferris & Partners, Westport, CT, Adamson Associates, Toronto
General Contractor: Turner Construction, Milford, CT
Concrete Contractor: TriStar Building Corp., Pleasantville, CT
Pumping Contractor: Modern Concrete Pumping, Newington, CT
Equipment: Schwing KVM 32XL separate placing boom, Schwing KVM 39X truck-mounted pump with placing boom.