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Review Of Movie Engineering: King Kong (1976)

You might ask why this Kong and not the more famous 1933 or 2005 versions? There are two answers: this was the Kong Kong of my childhood, and it has an issue related to the intent of these posts that really bugs me. As before, I am accepting the basis of the movie without question: Kong is a 40-foot tall gorilla who looks much like a normal-sized gorilla, even though the Square-Cube Law says that’s not possible.

In the original movie, Kong climbs the Empire State Building; in this remake, he climbs the still-new World Trade Center. I had been entranced by the poster for the movie, and was outraged – and am still somewhat outraged 45 years later – that at no point is Kong standing straddling the two towers. Rather he climbs one tower and, during his fight with the military, jumps across to the other. Given that the distance between the two buildings was on the order fo 140 feet, Kong would have had to be something like 280 feet tall to straddle, and indeed in the poster he looks like he might well be 30 stories tall. So the fault lies with the poster rather than the movie.

Another, less obvious issue is the load that he created on the buildings. An average male gorilla weighs about 400 pounds and is about 5 feet, 3 inches tall. If we scale up the height by a factor of 8, his weight will go up by a factor of 512, leading me to believe that Kong’s weight was a svelte 204,800 pounds, or, using the one significant figure this calculation deserves, 100 tons. (He could, of course, be made of materials less denser or denser than ordinary gorilla flesh, but there’s no indication of that in the movie.) He walks around the roof a bit, and any biped, in the middle of a step, has all their weight on one foot. So that roof was being repeatedly loaded with 100 tons in an area of what? four or five square feet? The long-span roof beams (the only columns at the WTC towers were at the core and the perimeter, with spans of 60 feet for the typical trussed beams) spaced at 6-feet, 8-inches would have supported 20 tons of live load for a place-of-assembly occupancy at the observation deck; Kong would weigh five times as much and it would be a concentrated rather than distributed load. In short, he would have ripped through the roof and the floors below, falling through the structure like a Warner Brothers cartoon character. Worse still, when he jumped from one tower to the other the effect of his weight on the structure would be increased by the impact of jumping.

The poor guy was doomed in more ways than one.