From the handbook (Page 12):
Built by The Smithy
Mobile unit - Combat - Weapon: Rotating Gun Turret.
Steam-powered tank with a simple, primitive gun. The Tortoise is topped by a tent-like conical turret sheathed with a heavy rivet iron. This houses a driver and artillery officer who operate this marvel of technology. A small but potent cannon provides an excellent field weapon which can swivel a full 360 degrees.
- One of many units in the manual described as being built by "The Smithy" instead of just "Smithy" as with other units.