A coal forge is a piece of machinery that a blacksmith uses to build his fire in then to heat a piece of steel to forging temperature, usually about 1800 degrees or so and a light yellow color. The top tray is usually of cast iron then covered with clay to protect it from the fire. A blower is below to put a blast of air into the fire. Without the blast the fire will go out. This particular forge has a hand crank blower but the forge I use every day in my shop has an electric blower. I hope that helps explain what a coal forge is. I work over one most every day and forget that everyone doesn't know what the equipment is. Thanks for asking.
This is a quick sketch of an anvil bridge that one of the demonstrators was using. It allows you to work easier on smaller pieces. I'm going to build one of these as soon as I can get caught up in the studio. Also I found out when we got home that Saturday was International Drawing Day. So without knowing it, I participated.