Water crane (railway)
A water crane is used to supply steam locomotives with large amounts of water for steam generation. This steam is continuously expelled into the atmosphere after it has passed through the engine cylinders , so the water supply must be topped up regularly during operation. The normal water crane consists of a vertical tube with a boom tube that can be swiveled sideways over the tank filler opening of the locomotive or tender .
historical development
In the early days of the railway, the water cranes were often attached to the water station houses or to the coal shed directly on the house wall. In later station renovations, the wall-mounted water cranes were replaced by free-standing water cranes.
Every 19th century railway company had its own design, so there were quite different types. Water cranes with a rigid boom (which can only be rotated around one suspension point) require that the steam locomotive stops very precisely under the outlet of the water crane, which requires a slow braking process (the ability of train drivers to be able to stop very precisely to pick up water, especially with heavy trains an extremely high quality criterion for their driving skills). Water crane booms with an additional joint (Prussian) or with a movable water pan (Bavarian) made it possible to move the outlet of the water crane within certain limits via the inlet opening of the water tank of steam locomotives or tenders that were not stopped exactly, which saved shunting time. Height-adjustable water crane booms made it easier to fill water tanks of very different heights, especially for small tank locomotives, and were therefore sometimes found on narrow-gauge railways. The German Reichsbahn introduced the Prussian structures of a normal and a joint water crane as a unit types from the 1924th
The flow rate of a water crane was 1–2 m³ / min at less important water stations, but was increased to 5 m³ / min by decree from around 1900. In the case of water cranes for locomotives with tender in front of express trains , which had to be quickly filled with water on the platform, the water flow rate was set to 10 m³ / min. so that the tender could be filled in just three minutes.
The water supply for steam locomotives
With the help of water tanks on a slope or a water tower , the required amount of water and the required water pressure were ensured. In some cases two or three water towers of several generations stood in one place. Occasionally, wind pumps were also used. In Germany, water supply systems were located approximately every 25 to 30 km, and in the low mountain range, on particularly steep stretches, at shorter intervals. The water cranes were usually located in the stations at the end of the platform between the tracks at the points where the passenger trains with their locomotives had to stop.
In the locomotive stations or railway depots (Bw), the water cranes were usually at the purification system, sometimes also on the Bw exit track. At the beginning of the railway era, small water cranes were placed on the locomotive shed entry and exit track in old round sheds, also known as the rotunda or boiler house dome. The slagging point was also located here. Later the water cranes in the locomotive sheds were often replaced by hose systems.
In the harsh winter, the water cranes had to be protected from frost, they were wrapped with hemp or heated columns or brackets using open steel baskets that were fired with coal or coke.
The addition of soda or lime milk to the boiler feed water prevented the formation of scale .
Today there are only a few water cranes left. They are primarily used for museum purposes. The water supply of steam locomotives on special trips is therefore often supplemented with fire hoses, which means that the filling times are significantly longer than with a water crane.
Examples
Water crane in Stützerbach
The water crane in Iselle di Trasquera station ; in use until 1929. Recording from 2017.
Water crane in Altenberg
Water crane in Lauscha ( Thuringia )
Water intake in the Bochum-Dahlhausen Railway Museum
