Tom Kalbfus
Banned
Some Roman slaves were very skilled, many of them were used as tutors to teach Roman children. A Roman slave usually became that way because there were captured in battle, Greek slaves were often very skilled, this isn't the Antebellum American South where literacy among slaves was against the law.It's crazy, yes.
1. There is no way from the Hero's toy to the steam engine capable to move locomotives.
2. One need not only metal, but precision metal-working technology too, to build the steam engine. While the ancients could make very fine things from metals (but it was most commonly silver or gold, not iron), they couldn't make each of them precisely the same as previous one. The steam engine is built using many different but compatible parts, and for repair it needs exact copies of the parts used building it.
3. Metal was very expensive at the Roman age, and it means not only the high price for the engines and locomotives (and also rails - however, you propose to make them from wood), but also necessity to fight against thieves, who would steal high-quality iron blocks whenever machine team would leave their car.
4. Machinist's job requires high level of training and demands high wages (at least in OTL), so using the slaves would be very doubtful. At the same time free poor Romans weren't very willing to work for wages at all.