spool up

The large rotational inertia of the heavy compressor and turbine rotors makes the engine slow to spool up from idle.

I guess it shows a couple of things, doesn't it; one is, when we're talking about 1941, although the industrial potential of the United States is there, the actual industrial production that we're so used to thinking of when it comes to World War II hasn't quite spooled up yet, because we're talking - we're talking there, about, as you say, they're quibbling about the Navy requisitioning a number of guns that's the equivalent to, later in the war, y'know, barrel-wise, the same number as you'd find as the heavy antiaircraft armament of a single battleship, and they're smaller guns[…]