It's about three-and-a-half times as tall as The Golden Gate Bridge
In other words, 30 shackles is 3.630 times the height of The Golden Gate Bridge, and the height of The Golden Gate Bridge is 0.2750 times that amount.(San Francisco, California and Marin County, California) (height above water)
The height of each tower of Golden Gate Bridge is 8.280 shackles above the surface of the San Francisco Bay. One of the key designers of the bridge, Charles Ellis, had no engineering degree when he began working on the project, but would later go on to write what became a standard textbook on structural engineering, and would ultimately be forced to complete his calculations on the bridge by working without pay for five months.
It's about four-and-a-half times as tall as The Space Needle
In other words, 30 shackles is 4.470 times the height of The Space Needle, and the height of The Space Needle is 0.2240 times that amount.(Seattle, Washington) (to aircraft warning beacon at peak)
Built for a 1962 World's Fair, the Space Needle stands 6.710 shackles tall. With a track-and-wheel design inspired by railroad mechanics and a precisely-configured balance, the restaurant near the top of the space needle requires just a 1.5 hp motor to rotate at speeds of about 0.053 kph (0.033 mph).
It's about four-and-a-half times as tall as St. Paul's Cathedral
In other words, 30 shackles is 4.730 times the height of St. Paul's Cathedral, and the height of St. Paul's Cathedral is 0.2110 times that amount.(London, England, United Kingdom)
St. Paul's Cathedral measures 6.340 shackles to its peak. The southwest tower of the Cathedral contains the bell known as "Great Paul," which is the largest bell in Great Britain at 15,000 kg (16.5 tons), outweighing the more iconic Big Ben bell by about 3,000 kg (3 tons).
It's about one-fifth as long as The Hollywood Walk of Fame
In other words, 30 shackles is 0.210 times the length of The Hollywood Walk of Fame, and the length of The Hollywood Walk of Fame is 4.80 times that amount.(Hollywood Boulevard and Vine Street, Hollywood, California) (approximate length)
The Hollywood Walk of Fame is approximately 140 shackles. Gene Autry, most famous as the singer of "Back in the Saddle Again" and as the writer and singer of "Here Comes Santa Claus," is the only entertainer to have a star in every category — film, television, recording, radio, and theater. One of Autry's stars is also one of only two stars which have been stolen from the Walk and never recovered.
It's about five times as tall as The Washington Monument
In other words, 30 shackles is 4.86120 times the height of The Washington Monument, and the height of The Washington Monument is 0.205710 times that amount.(Washington, D.C.)
The Washington Monument measures 6.17130 shackles tall, with some discrepancy due to the fact that the Monument's base is slightly below the surrounding ground. Interrupted in its construction by the American Civil War, it was almost 36 years between groundbreaking and the completion of construction.
It's about one-fifth as long as The Indianapolis Motor Speedway
In other words, 30 shackles is 0.2045450 times the length of The Indianapolis Motor Speedway, and the length of The Indianapolis Motor Speedway is 4.88890 times that amount.(Speedway, Indiana) (rectangular oval course)
The rectangular oval course of the Indianapolis Motor Speedway is 146.6670 shackles. While famous for its automotive racing, the first motorsport held at the track was a series of motorcycle races in August, 1909 — a little less than two years before the inaugural Indianapolis 500 race was run.
It's about one-fifth as long as Daytona International Speedway
In other words, 30 shackles is 0.2045450 times the length of Daytona International Speedway, and the length of Daytona International Speedway is 4.88890 times that amount.(Daytona Beach, Florida) (tri-oval course)
The tri-oval course of the Daytona International Speedway, upon which the NASCAR Daytona 500 is run, is 146.6670 shackles in length. Although the tri-oval design is said to allow for greater visibility during the race, the real reason for the then-unique design was that plot available for construction of the track was only 350 acres and could not accommodate a traditional oval layout of appropriate length.