Görlitz weight brake
The Görlitzer weight brake is a continuous and automatic train brake developed by AG Vulcan around 1893, which makes use of gravity and was mainly used on small and branch lines in Germany.
construction
A weight is freely movable on the vehicle and acts on the brake linkage and the brake pads via levers and rods. If the weight is lowered, the brake is applied; if the weight is lifted, the brake is released. There is a hook on the weight into which a pulley is attached for operation. A rope runs through this, which is passed over rollers attached to the roof of the car and at the end of the car with the brake weight is guided downwards over a pulley. It runs in the middle of the car roof so that it is shortened or lengthened as little as possible when cornering, as this would have an effect on the brakes. On the vehicles there is an easy-to-operate tensioning device with a turnbuckle, with which the braking force can be regulated. This regulation is necessary so that the braking effect of all cars is as equal as possible. Usually the weight is attached to a lever across the front of the car. The disadvantage of this type of construction is that there is no space between the interchanges. That is why there is also the guide for the weight on the side of a rod; but additional pulleys were required for this.
function
The ropes of the individual wagons are linked to one another with frogs , the rope is attached to the wagon on the last wagon to be braked. There is a reel in the baggage car, or more rarely on the locomotive , with which the rope can be tensioned or loosened again. There is a lock on the reel that can be released with a light operation of the crank against the direction of rotation, so that the rope can run off quickly to achieve a quick braking effect. The braking force can then be regulated by turning in the direction of rotation.
The reel is actuated at the signal of the engine driver.
The braked wagons were coupled together and stopped at the end of the train. (At the beginning of the reel on the locomotive). As a rule, it was not possible to guide the rope over unbraked wagons. The weight brake is automatic, since the brake cable breaks when the train is disconnected and the brake comes into force.
The braked wagons are left standing for shunting mixed trains in stations.
commitment
The installation of the brake is relatively simple and cheaper than the comparable lever brake . In contrast to it, the brake test can also be carried out on the stationary train, as the brake pads apply when the rope slackens, while the brake pads can only take effect on the moving train with the lever brake. That is why the Görlitz weight brake was used by many small railways, especially the Lenz group .
The disadvantage of the brake is the limited range, according to the manufacturer over three to six cars, depending on the size of the car. For low-speed railways, however, the required braking percentages can also be achieved with a few cars. A lot of experience and also the strength of the operating personnel were required for braking, as the entire rope had to be tensioned again after each braking process. Since the continuous rope is loaded by the weights of all braked cars, the mechanical load on the load-bearing parts of the car to which the pulleys are attached is very strong, which led to damage to the vehicles.
Today this brake can still be seen in Germany on some vehicles of the Bruchhausen-Vilsen museum railway , it is still approved as a railway brake .
Difference to the lever brake
The continuous rope is a characteristic of both brakes and leads to confusion. With the lever arm brake , however, the rope only serves to move relatively small weights that the brake rollers press on the axles and thus initiate or cancel the braking process. This means that the jack brake can also be used on longer trains. The disadvantage of the lever brake was the relatively complex mechanics and the wear and tear caused by the friction rollers and friction wheels.
literature
- Wolfram Bäumer: The Görlitz weight brake . In: The Museum Railway . No. 1 , 1989, pp. 16–22 ( museumseisenbahn.de [PDF]).
See also: brake (railroad)