Steam is a very dangerous product. Many people lost their lifes because of failures or bad operation of the installation, the boiler in particular. Since one liter of water becomes 1700 liters of steam, a sudden exposure of boiling and pressurised water to atmospheric conditions causes a gigantic explosion. Many many examples are known of.

Boiler explosions are caused by simple overheating and building up too much pressure, but more often the boiler exploded because of low waterlevel.

WatergaugeToo much pressure is guarded against by safety valves, opening when the pressure gets too high. But sometimes these valves were blocked, to get a higher pressure, to make the installation run more efficient.

Low water level is much more dangerous. The metal of the boilers is not resistant to the high temperatures in the fire. Therefore the metal needs constant cooling by the water inside the boiler. As soon as this cooling is lost, caused by low water, the metal will get too hot and loose it's strength. There are several indicators to prevent this situation, first of all the water gauges which indicate the waterlevel in a glass tube. Furthermore sometimes a whistle is mounted that will go off at low level. Mostly this whistle is of the type invented by mr. Black.

And last there is the fusible plug. This plug is mounted inside the boiler, directly above the fire, and will open when overheated. Water and steam escaping from this plug will extinguish the fire. These plugs are very dangerous for the stoker, the steam will force the fire out of the firebox and in the face of the poor stoker.


Another problem can be caused by a burst pipe. Of course a pipe can burst because of too high a pressure, or because of bad maintenance. But more tricky is a burst pipe because of waterhammer. Before a steamengine is started it should be heated very securely, to make sure no parts can cause condensation of steam.

In case of the piping there is always a possibility of water remaining in the tubes after the last stop of the engine. if too much steam is admitted to a tube still containing water, the steam can rapidly condensate, causing a vacuum. And such a vacuum can suck in water with a tremendous speed. When this water collides with the end of the tube it can cause serious bursts. Nothing can prevent accidents like this except for a well trained enginedriver.

Another very serious accident is a bursting flwheel. This can occur when overspeeding the engine. This can be caused by a sudden loss of load, for instance by a broken belt. A good governor will handle such an occurence properly and shut off steam, but many governors do not trace such an occurance. And many engines do not even possess a governor.

In that case the engine will overspeed seriously, causing the rotational speed of the flywheel to exceed the maximum and the flywheel will burst. Lots of little, rasorsharp pieces of iron will be released, causing havoc all around. Buildings can collapse and enginedrivers get killed.