Setting Records: The Largest and Heaviest Structure Ever Moved on Rubber Dollies By Peter L. C. Pan, New York, New York 1-212-465-5786, panp@pbworld.com and Medhat Okelly, 1-212-465-5519, okelly@pbworld.com Moving a vintage 1935 building, the world’s first passenger terminal, to a new location was one of several challenging projects facing PB at Newark International Airport. The authors tell how the building was prepared, jacked and monitored during this historic and successful move. The Port Authority of New York and New Jersey (Port Authority) has programmed numerous expansions and improvements at its New York metropolitan area airports, including JFK, LaGuardia, and Newark International. Prompted by the increase in air travel in recent years, the Port Authority’s aim is to meet the projected demand of the airport terminals and connector roadways. PB has been retained on an “as-needed” basis by the Port Authority since 1999 to perform multidisciplinary engineering services to implement several building and infrastructure projects at the airports. We have provided services in structural, electrical, mechanical, plumbing, and fire protection engineering, and have been involved in some especially interesting and challenging projects. We are serving as structural engineer on the owner’s team to prepare bid documents for Newark International Airport’s (EWR’s) first two design-build projects—a new cooling tower and the north cargo building. Perhaps the most remarkable project, however, is the relocation of EWR’s Building 51, the world’s first passenger terminal, to a new site about 1128 m (3,700 feet) away. Building 51’s Historical Importance Built in 1935 and dedicated by Amelia Earhart, Building 51 was the world’s first passenger terminal. It housed the world’s first airport restaurant, first airport hotel, first airport weather bureau and post office, the first open-air observation decks, and the world’s first air traffic
control tower. The steel track on its roof held the searchlights used for the world’s first night flight. Described by preservationists as a “revolutionary new building type,” when it was constructed Building 51 set the standards for comfort, safety and civility in the aviation world. Its layout created the physical pattern that was followed by newer airport terminals around the world. The building has since been designated as a National Historic Landmark. When the building relocation idea was first envisioned by the Port Authority, it became clear that, if moved, the beloved terminal would set yet another record—this time as the largest and heaviest structure ever moved on rubber-tire dollies. The project afforded the design team and stakeholders the opportunity to be part of this history making event. We also helped to reclaim the building’s masterful stature for aviation enthusiasts and to create a place where the glorious days of the birth of aviation and flying can be relived by generations to come. While Building 51 enjoyed a remarkable stature as the first modern airport terminal, it had sat idle in a state of disrepair for years. Its relocation allowed for runway extension, its renovation preserved the historic landmark building, and its expansion helped to create a new airport administration building. The building is now called “Building 1.” The Moving Process The building’s central portion is two stories high and 83 m (272 feet) long. Two wings flare 45 degrees from the central portion and extend an additional 30 m (100 feet). The building (Figure 1 on the following page) is a reinforced concrete frame structure with deep spandrel and parapet beams enclosing masonry wall and punched windows that fit within the concrete Civil and Architectural Design Services beams and concrete masonry walls. Due to the limited supply of heavy-duty dollies needed to move the building and the building’s massive footprint, the two 1,400-ton wings were separated vertically from the 5,000-ton central portion. The two wings were moved first and parked temporarily adjacent to the receiving site on timber towers. The center section was moved last (Figure 2) and laid on the new
permanent foundation first. Before jacking, a layer of cross steel beams hung to a layer of main steel girders was installed below the bottom of spandrel grade beams and under the first floor of the structure to provide the support required at the columns and grade beams. Due to low headroom under the first floor slab, the spandrel grade beams at some locations were cut to install the cross beams and to allow movement of workers and equipment. The hydraulic jacks were installed between each pair of main girders so force could be applied against the main girders to raise the building. The cross steel grid acted as a transfer structure of column loads to the hydraulic jacks. Based on the contractor’s experience and somewhat by trial and error, the final location of the jacks was set until the building could be raised with all points at the same plane with no relative deflection. Once the load was firmly transferred through the temporary steel grid to the hydraulic jacks and the building was maintained level, the process of jacking for placement of the dollies started. The building was jacked onto timber cribbing and towers up to 2.4 m (8 feet) high, and then two additional layers of steel grids were installed under the bottom of steel grid before the dollies were placed under it. The jacks were reset to the lowest position when the maximum height was reached in each cycle. The location of the dollies was placed in the same way as jacks to maintain the building in the same horizontal plane. At last, the building load was transferred to the dollies through hydraulic jacks attached to the top of the dollies. The self-propelled dollies provided the required power to move the building. The dolly system allowed the building to be turned a small angle along the move route. For sharp and 90 degree turns, however, the dolly system was temporarily parked and the dollies were reset one by one. The jacking system used to lift and lower the building utilized a unified jacking system, to which all jacks and pressure hoses were connected. The system, which had a central monitoring panel, maintained all points within 1 mm (0.05 inch) from the horizontal plane. The building’s rigid concrete frame required very close monitoring during the jacking and
relocation process. The building was continually monitored for deflections and deformation of the non-ductile concrete frame as well as plumbness and strain cracks in the concrete masonry walls by using a system of fixed lasers and strain gauges. It was also outfitted with seismographs to monitor lateral drift and minimize deformation and lateral swaying during the move. At its new location, a 6300 m2 (68,000 square foot) steel frame addition was constructed to house the airport’s police, fire, and emergency rescue facilities. The relocated Building 51 and the new two-story steel frame addition (Figure 3) are supported on pile foundations. The steel moment frames were built to resist horizontal wind and seismic forces. As a structural engineer for the project, we were responsible for engineering the move and ensuring that the building be relocated safely and reinstalled soundly. We also participated in the study of move options, and prepared: . Move performance specifications for the move contractor . Engineering drawings that showed the details of all the temporary bracings and stiffening of the building . A phased relocation plan . The design of the foundation for the relocated Building 51 and the new addition. A series of studies were conducted to determine the capacity of the beams and to establish the maximum allowable relative deflection between columns as the guide in the performance specification for the contractor. A 3-D computer model was used to study the behavior of the building and member capacity. Due to the massive footprint of the building, it was difficult to set the building within the strict criteria in the performance specification. The actual deviation of the columns from the center of pile caps was much larger than the criteria in the specification. In the design stage, based on the practical experience and a careful study of contractor’s previous performance, the pile caps were designed to cover all the possible deviations. At the end, only one pile cap showed the overloaded piles, and that problem was correctable by redistributing the first floor load without any underpinning of the pile group. Peter L.C. Pan is a senior structural engineer in buildings with more than 23 years’ experience. Prior to joining PB, Dr. Pan was involved in many ultra high-rise commercial buildings and long-span steel structures. Medhat Okelly is a professional engineer in buildings and project management with more than 19 years’ experience. He served as the project manager for the Newark International Airport projects.