Prerequisites: Academy level 10, Main Building Level 5

Siege engines like catapults and rams can be built in the workshop. The higher its level the faster units can be produced.

Also, at higher levels you can build other kinds of equipment once you have researched it in the academy.

Training costs for Roman troops
	Battering Ram	900	360	500	70	3
	Fire Catapult	950	1350	600	90	6

Training costs for Teutonic troops
	Ram	1000	300	350	70	3
	Catapult	900	1200	600	60	6

Training costs for Gallic troops
	Ram	950	555	330	75	3
	Trebuchet	960	1450	630	90	6

The level dependent attributes (such as construction costs and generated culture points) can be found here.
For the full table of construction times click this link for server with 1x speed, this link for server with 2x speed and this link for server with 3x speed.