Built in 1964, the design was based on another pool:

The photo below was taken in 1961:

Dimensions:

Filtration:

(From David Morrison) The T-Pool water was kept clear by a diatomaceous earth filter housed underground, below the T-Pool Locker Room. The filter had to be backwashed, generally twice daily, and a new application of diatomaceous earth applied each time. During my tenure at the camp, it was mostly me or Dominic who performed this function.

Unfortunately, no one at the time fully understood the dangers of inhalation associated with crystalline diatomaceous earth (which, while not asbestos, is an asbestos-like substance), so we didn’t wear masks to prevent it. In today’s environment, doing that kind of work without a mask would be unheard of. I shudder to think of how much of that stuff we inhaled. Fortunately, the summer was only 60-some-odd days long, so I doubt that any permanent harm was done to either of us, although the damaging effects are cumulative, since the fibres never really leave one’s system. In any event, whaddaya gonna do?

TRIVIA: The first people to swim in the T-Pool were  Ellen (Eli) Sobel, Jeff Levy, Jackie Sugarman, Janice Langer and Myrna Mosoff.

See also:

T-Pool Construction / Locker Room Addition