[Still Thinking]

I can’t believe they did pours in inches at a time. Sheesh, they’d still be pouring the thing today. I’m thinking more like 10 or 20 ft of height at a time. Reasonable balance of required form strength and progress rate.

[digger48]

You can see the men inside the forms.

Looks to be at least 6-8' high.

[tenger]

According to wikipedia regarding Hoover Dam: “Concrete cores were removed from the dam for testing in 1995; they showed that ‘Hoover Dam’s concrete has continued to slowly gain strength’.” So, it seems to still be curing. I’ve read that somewhere else.

[digger48]

“...concrete blocks in columns were poured, some as large as 50 feet (15 m) square and 5 feet (1.5 m) high. Each five-foot form contained a series of 1 inch (25 mm) steel pipes through which first cool river water, then ice-cold water from a refrigeration plant was run. Once an individual block had cured and had stopped contracting, the pipes were filled with grout.”

http://en.wikipedia.org/wiki/Hoover_Dam

[mountn man]

The buckets they used to transport the concrete was 4 or 8 yd dump buckets. The concrete was a very dry mix and had a very short set up time. If the crane operators were too slow, the concrete could set up in the bucket. For this reason, the operators were the highest paid workers, ensuring they had the best. 7 "puddlers" with shovels, would then scoop and push the concrete around and men with vibrators would vibrate out the voids.
By the time another bucket would arrive, the previous concrete pour would already be setting.