Throwback Thursday: Rebar in old-time ballparks
As baseball fans in New York, Tampa Bay and other American League East towns are painfully aware, the Boston Red Sox have clinched the division title. Naturally, being builders, we got to thinking about the team’s ancient home, Fenway Park (above). Built in 1912, it belongs to the first generation of sports stadiums constructed of steel-reinforced concrete, a material gaining widespread acceptance in the wake of San Francisco’s devastating earthquake of 1906. Other examples include Stanford Stadium (1921) and Los Angeles Memorial Coliseum (1923) in California, and of course the original Yankee Stadium (1923) in New York (pictured below).
Believe it or not, when crews erected Fenway’s “spacious grandstand” (as the Globe called it then and nobody does now), the process was so cutting-edge that the local Society of Civil Engineers visited to observe (below). Nevertheless, much of the project’s construction practices seem outdated today.
For example, carpenters built the formwork for the columns and deck slab out of oak timber, according to Glenn Stout, a former concrete foreman and the author of a history of the park’s construction. “They had to do everything with wood,” Stout said in an interview. “They didn’t use plywood back then; they used wooden planks—usually oak, which was readily available.” In fact, you can still see the marks of wood grain on the concrete in some places.
Today, said Fred Collins of Liberty Construction, formwork is typically a composite of plywood and steel—a modular steel frame, with plywood facing. “For efficiency, for speed,” said Collins, who is Liberty’s northeast regional general superintendent of concrete field operations. “It enables you to pour larger quantities of concrete.”
The pouring process in 1912 was different, too. As Stout wrote in his book:
Unlike today, concrete was not mixed and then hauled to the site by truck. Instead a concrete plant was built on-site [where] cement, sand and an aggregate of crushed stone and water were mixed together [then dumped] into a concrete dump bucket. The wet concrete was hoisted to the appropriate place and the concrete emptied into wheeled sidecars . . . essentially wheelbarrows, but with much larger wheels and a much greater capacity.
Workers then “manhandled” these wheelbarrows into place and, “where possible, simply dumped the concrete onto the deck [then] raked it into place and agitated the concrete to remove any air bubbles,” Stout wrote. Where the deck sloped, the mix was “dumped into chutes, and workers then had to force the concrete down manually, using shovels not unlike canoe paddles.”
It was dirty, dangerous work, Stout added. A scratch from the rebar carried the threat of tetanus. “Shoulders and arms ached from the burden of shoveling the heavy mixture, which typically weighed 150 pounds per cubic foot. . . . For this, the workers earned perhaps fifty cents an hour.”
Though some of that process is familiar, workers today have the benefit of ready-mix concrete being delivered to the site by concrete mixer trucks, and they can place the product using concrete pump trucks, some with booms able to reach nearly 200 feet. See, for example, how concrete was poured at the new stadium for the NFL’s Minnesota Vikings. In work on skyscrapers, a standpipe can enable pumping over even greater distances, up to 700 feet in extreme cases.
To cure the concrete during a brutal winter, said Stout by phone, the workers of 1912 covered it with straw and probably also kept it warm with “salamander”-style space heaters. These methods helped protect the concrete from freezing during its curing process and allowed the concrete to reach its intended design strength.
Sean Nelligan, former COO for Liberty’s concrete division, said he used hay to cure a small section of concrete once, ten years ago, and even then it was rare. Today, workers typically use insulating blankets and modern methods such as ground thaw heating equipment.
Remarkably, the early reinforced-concrete stadiums could often be completed within months. Fenway Park (initial capacity: 24,000) was built between October 1911 and April 1912, including a month-and-a-half stoppage due to freezing temperatures—though workers were still installing the “opera seats,” as they were called, during an exhibition game. Stanford Stadium (capacity 50,000) was built over the summer of 1921. The Red Sox spent $650,000 on construction; the University of Stanford, $200,000.
For comparison, the new Yankee Stadium (2009) and Marlins Park (2012) each took two years and eight months to complete. (The former seats about 50,000; the latter, 37,000.) The Yankees spent $2.3 billion to build their new home; the Marlins, $634 million. (Also, thanks to leaps in the technology of documentation, the curious can view a rapid replay of the entire day-by-day construction of Marlins Park.)
Though in many ways Fenway Park has not aged well (the size of those seats!), Stout maintains that it was solidly built. Among other signs, he notes the lack of spalling: “Unlike at the parking garage across Lansdowne Street, which was built around the same time, Fenway’s concrete hasn’t deteriorated or flaked or dusted away in over 100 years.”
That said, a truly ancient stadium, such as Rome’s Colosseum, might not be impressed with a mere century of solidity. Concrete has a long history in construction—albeit with an enormous gap from the fall of the Roman Empire until the Victorian era—and we’ll be revisiting the topic again. Stay tuned.
This post was written by Suffolk Construction’s Content Writer Patrick L. Kennedy. If you have questions, Patrick can be reached at PKennedy@suffolk.com. You can connect with him on LinkedIn here or follow him on Twitter at @PK_Build_Smart.