The '60s was a time of change on the 3rd and 4th subs, things were quite different by the end of the decade from the start of it. You can post your question on the BR&P Yahoo group and Brian can give you all the details you want.
In about 64, there were 3 rounds crews working between Rochester & E. Sal. How fast they turned was a function of what was moving. In the summer with dock coal running things were busy, but the docks usually closed from late November/early December till early April. Starting about n Feb '64 there were unit coal trains to Kodak in Rochester. They started out as every other week, alternating with NYC, but later that varied more.
3rd sub, to Buffalo, I'd have to dig out info but off the top of my head I believe they had two road crews plus a local. Of course on both sides an occasional extra crew was needed.
In the same time period Rochester had many yard crews - 3 (?) days crews, 2 or 3 afternoons, and I'm not sure about 3rd trick. The docks were sometimes switched by one of the regular yard crews, often by an extra.