Archie,
In your description, you didn't mention an air supply. If you're going to get up to forging heat, you gonna need to put some air into the mix. To light my forge, I use a couple of sheets of loosely wadded newspaper, build the coal up around and above it, light the paper and apply a slow steady flow of air, which comes in from the bottom. With charcoal, once it's lit, it tends to keep burning till it's gone, unlike coal, which needs air to keep going. However, the application of air is what brings both up to heat, and air is what you need to maintain a good forging temperature.
Eric