“The towers will be like two trees,” explained Bertrand Goldberg in March 1961. “The central columns will house the elevators, stairways, and utility lines. They will be the trunks in the tree design.”

16 reinforced concrete beams would radiate 37 feet six inches from the trunk as branches. At the perimeter, columns would support the weight of the floor above. Beyond the floors would be the ten-foot-wide balconies, like leaves in Goldberg’s tree analogy.

Elevator lobby (left) and hallway on residential floor of Marina City.

“A person upon entering a Marina City apartment will be moving toward an expanding area and vista,” said Goldberg. “Leaving the elevator, the person finds the apartment door only a few steps away. From there, he will enter a small, triangularly-shaped room. The apartment spreads out, and beyond the glass wall is the balcony and the horizon of downtown Chicago. It will be like living in the wide open spaces.”

Goldberg also described this as “kinetic space.” He maintained the circular design of the building helped the psychological well-being of its tenants. “In a box-like dwelling, an apartment dweller often gets a feeling of being merely an anonymous member of a large group.” The Marina City design, he said, tries to “capture the feeling of individuality that comes from living in a single-family residence.”

Because the central column provides the major point of orientation, Goldberg pointed out “there are no long and winding corridors.”

16,000 tons of concrete would be used to build the residential towers. Approximately 200,000 square feet of glass would be installed on the exterior of the 40 apartment floors of each tower, plus another 100,000 square feet of glass for the office building.

The marina, located below the two-story structure forming the base of the project, was already being downsized from an original estimate of mooring 1,000 boats. In March 1961, the estimate was for 700 boats stored using motor-driven racks capable of launching 250 boats per hour.

The two-story theater building, intended for live theater and motion pictures, would seat 1,250 people.

James McHugh Construction Company was predicting completion of the residential towers by April 1962, with some apartments available a month or two before that. Charles Swibel, president of the property management company, was preparing to rent the apartments for $115 a month and up for an efficiency, $155 to $195 for a one-bedroom apartment, and $295 for a two-bedroom apartment.

(Above) Floor plans for studio and one-bedroom apartments at Marina City.

By June 1961, the 32-foot-diameter central core for the east residential tower was taking shape. It rose about four stories from the foundation.

Constructed over the inner of three concentric rings of caissons, concrete for the central core was being cast as a rate of eight feet six inches per day. The thickness of the core wall would decrease from 30 inches at the base to 12 inches at the top, 588 feet up.

One of the challenges BGA had to deal with was the effect Chicago winters had on the building. Exterior columns were partially exposed to the elements and connected to the building’s warmer core. As the building shrunk in the winter and expanded in the summer, this would cause the columns to grind against the floors.

In fact, when work was completed on about the 54th floor, they started noticing small amounts of plaster residue from this grinding. The solution was to use a separation between the joints that was less dense and would allow for small movement. But they also had to trim many doors on the upper floors.

Another CTA photograph, circa 1961, is looking north on State Street, possibly from the L station at State & Lake. The sign on the building at lower left reads SHANGRI-LA. Shangri-La was a Cantonese restaurant at 222 North State Street that operated from 1944 to 1968. It was then converted into a movie theater that showed adult films. The entire block was demolished in 1981. The site is now occupied by Renaissance Chicago Hotel. (Below) This photograph by the Chicago Sun-Times of Shangri-La Theater (with Marina City in background) was for a story about pornography.

Undated photo (circa 1962) shows work in progress on the 47th floor (east tower at right) and 43rd floor (west tower at left). Sign toward top of east tower parking ramp is for radio station WCFL (“The voice of labor”). The sign below it mentions Mayor Daley. The large sign at the bottom includes the words “The city within the city.” WCFL was a 50,000-watt radio station owned by Chicago Federation of Labor. It moved into an entire floor of the office building at Marina City in 1964. It is now an ESPN sports radio station, WMVP, and located in the Chicago suburb of Downers Grove.

At a cost of at least $50,000 ($344,000 in 2007 dollars), full-size mock-ups of a one-bedroom and efficiency apartment were constructed. Complete with balcony railing, they were furnished by Marshall Field’s department store. Murals were displayed behind the mock-ups, constructed from photographs taken from a helicopter at about where the 40th floor would be later.

The mock-ups were shown to investors and prospective residents.

The two model apartments were open to the public – seven days a week – starting on January 9, 1962. They were located at 316 West Randolph Street, south of the river in the northwest corner of the Loop. This was the office of the rental agent, Marina Management Corporation.

By September 1963, Marina City had furnished model apartments inside the building to show off. The three apartments on the 48th floor of the west tower were designed by members of the Illinois chapter of the American Institute of Interior Designers. The cost to furnish each model apartment ranged from $2,500 to $15,000.

A full size mock-up of an office at Marina City, circa 1963. The “tower” at right is a drawing. This photograph was taken by Bertrand Goldberg perhaps to simulate the view from the fifth floor of the office building, which had not been built yet. The “buildings” in the background are large photographs. Note the Unitrin building, completed in 1962, is shown (immediately left of the tower illustration) still under construction.