The locomotives were very simple, usually made in brass, with a simple oscillating cylinder driving the main wheels. They were basically a boiler mounted on wheels, although simple decoration (usually bands of lacquer) was sometimes applied. Track was not used - the boiler was filled with water, the burner lit, and when steam was being produced, the locomotive was placed on the floor and allowed to run until either the water ran out or it crashed into the furniture. Very quickly, after a number had exploded, simple safety valves were fitted.
They quickly gained the nickname of Birmingham Dribblers, as they had the unfortunate habit of leaving a trail of water behind them as they ran across the floor. Very often this trail would be mixed with the fuel used for the burner, and there were numerous incidents of fires caused by the locomotive crashing into furniture and over-turning so that the burning fuel was spilled over the floor.
As time passed, embellishments were added, such as wooden buffer beams, buffers and steam whistles.
Birmingham Dribblers are now very collectible, and a model in good condition will easily reach £400 at auction in the United Kingdom.