The prior post shows the concentric exhaust with a bottom weep, this prevents fire extinguishing.
This photo is of another Märklin TE. The first draft didn’t have a bottom weep hole and the steam exhaust intake was higher up. When I tested that, the fire promptly went out!
The upright exhaust was assembled with JBWeld for the high heat resistance (600F) and also to experiment with different construction techniques. The horizontal exhaust with lead-free solder for 400F heat resistance.