Melt plug

Outline sketch of a melt plug on an old drawing

The fusible , as for the material lead mold plug called, is a safety element of steam locomotives to the steam locomotive boiler from overheating due to low water level and thus against boiler explosion protect. From the outset, the plugs were seen as an additional level of safety and monitoring of the boiler in the event of failure of the water level glasses and the sampling taps.

Installation position and mode of operation

The melting plugs are built into the ceiling of the fire box. If the water level in the boiler is too low - without the locomotive crew doing this e.g. B. noticed because of faulty water level glasses - the fire box cover would overheat. The lead furnace (letter b ), which melted under the influence of heat, created a hole through which the steam flowing in would extinguish the fire in the fire box.

The plugs could be easily screwed into the fire box ceiling through a multi-edged approach. The use of the fusible plugs required periodic maintenance and inspection in order to avoid false triggering, as the sprue was worn out from time to time and had to be replaced. Melt plugs must be marked with the date of use on the polygonal side as a result of irregularities in operation (e.g. the kettle crack in Bitterfeld ). The date of installation must be entered in the monitoring sheet of the locomotive and confirmed with a signature by the responsible foreman. The pouring of the melting plugs may only be carried out by authorized workshops.

literature

• F. Meineke "The Steam Locomotive", Springer-Verlag Göttingen, 1949
• Edmund Heusinger von Waldegg: Special Railway Technology, Third Volume, Der Lokomotivbau , Leipzig 1882

Web links

• Website of the Berlin Railroad Friends with photos of melting plugs in today's time
• View of a steam locomotive boiler with the depicted melting plug (number 82) on the society of the German Society for Railway History

Individual evidence

1. ^ Edmund Heusinger von Waldegg: Special Eisenbahn-Technik, Third Volume, Der Lokomotivbau , Leipzig 1882, p. 259.
2. ^ Edmund Heusinger von Waldegg: Special Railway Technology, Third Volume, Der Lokomotivbau , Leipzig 1882, p. 260.
3. ^ F. Meineke "Die Dampflokomotive", Springer-Verlag Göttingen, 1949, p. 282.
4. ↑ Regulations of the steam locomotive friends Salzwedel about melting plugs