On behalf of a friend of mine, that is not a Trains member, but a fan of antique cars and trains, I have to ask this question, that he posed to me recently.
If you go back in time, before the beginning of the early 1900’s, when steam locomotives were still the king of the rails, when a steam loco was sent to a roundhouse for routine work, how were the turntables rotated? What form of power, BEFORE electricity, did the railroads use to turn the turntables? Horses? Mules? Man-power? How was it done?
I don’t have a huge reference library, but I think the answer to your question is all of the above. Most old photos show man-power. I remember reading that man-power was already on the payroll and they fed and cared for theirselves, so why keep animals for that job? And men didn’t need to be harnessed either.
Armstrong (manual) turntables lasted in outlying points almost until the end of steam. Locomotives had to be positioned carefully to balance the load on the turntable’s center pin or the turntable would be almost impossible to move.
The turntables would have a large handle on each end and laborers would push on it in a fashion similar to sailors manning a capstan to weigh anchor.
Note the large diameter bar at the end of the table. This is what is pushed to turn it. There’s a plate in the end that slides out between the rails to hold it in place while moving the loco on and off the table.
I have heard of turntables (outside of major terminals) that had compressed air motors for turning the table. This was supplied with air from the locomotive brake hose. I don’t know when these were developed but it could have been any time after introduction of the air brake (1870’s).
FWIW - “Armstrong” turntables were in use after the steam era. We have seen slides of Peter Maclaughlan turning a NHRR FL-9 on the Pittsfield Mass hand operated turntable in 1968. No laborers involved, Peter was the engineer and he and his conductor would turn the diesel for the return trip down the Berkshire to Danbury every day. As mentioned previously the trick was the balance over the center pivot. J.R.