Lever frame

A mechanical interlocking is a railway to throw points, signals ( see also signal box ) and other mobile devices in the rail track by mechanically transmitted muscular strength of the operator.

Construction

In mechanical interlocking muscular strength of the operator is of a tire mounted on a lever bank lever on the lever attached to the pulley and a Drahtzugleitung with several leadership and rolls for each external system, eg a switch transmitted. The Drahtzugleitung can be up to about one kilometer long. Sometimes used for very long signal lines instead of the lever signal winds, in some cases with double travel. Outside of Germany (eg in Switzerland and in France) and linkage lines were used for switches alternatively, (actually tubes ) move the rods on the course.

The lever wear a name tag and are marked in color. In Germany, turnout, bolts and track lock lever are blue, Gleissperrsignal lever blue, main and Vorsignalhebel marked in red with red ring. At the German "unity interlocking " are levers in the basic position, also called Plus position, upward; downward lever correspond to the folded position or minus position. In the old building types it can be reversed. The positive position (basic position ) is selected for the busiest location of the switch, it means thus not necessarily mean that the switch is set to travel on the straight course strand. In Austria, for rule type " 5007 ", but also for the widespread type » SBW500 " the lever to the normal position down.

The Drahtzugleitungen exist in the line of 4 (signals, barriers ) or 5 mm (points, bars, track locks ) strong crucible cast steel wire, by deflection and pressure rollers and levers and drives but from 5.5 mm thick wire. For the Austrian types chains are used instead of the wire ropes.

To ensure a positive connection between the lever and switch or signal at Drahtzugleitungen, wire break (failure case ) ( bring crossover in an end position or signal in stop position, fault display to the operator ) to reach a safe state of the Exterior amenities compensate and temperature- induced changes in length, the wires of tension works taut with large chip weights - are in some designs - such as the German unit switchboard. The chip works are either in the clamping space in the basement of the signal box or individually placed outdoors. Other types, such as in Austria, waive the chip works - in this case, the drives must be designed so that they cope with loose wire coatings.

In linkage lines temperature-induced changes in length must also be balanced. Serve balance lever in various designs.

At larger stations, the signal boxes had among themselves and, when present, interact with a command works. These dependencies can be either mechanical ( eg, see the museum signal box Kerzers ) or be electrical, the latter variant is more common by far. For these electrical command and consent dependencies that are collectively referred to as station block, are in the German language and used in Eastern European countries usually block works, which are connected via a secure transfer of information with the help of block fields.

The arrangement of the individual parts is different depending on the design.

• When the attachment from the unit interlocking lever Bank is with the adjoining block pedestal, which contains the block locks and mounted above the driveway levers on which the block box with the block fields. and is arranged behind the lock box.
• At the Austrian rule type 5007 is located on the bank of the lever valve body with the Fahrstraßenknaggen ( they correspond to the driveway levers ); sits on the valve body on the one hand, the block machine with the block fields. other hand, the track gauge.

All the parts work together as a complex mechanical system. They enable the backup of the route ( see also driveway ) for train under the requirements defined in the railway construction and operation order signal dependence.

Function and operation

Essentially, a driveway in mechanical interlocking is set as follows and saved:

The applied signal lever locks the block electrically defined driveway lever again mechanically, so that the signal dependence is realized in interlockings without station block; Step 3 is omitted in this case.

After the train has taken place and the train a well-defined place, the so-called Zugschlussstelle, has cleared with tail lamps, the electrical block down the driveway at driveways is usually manually resolved during trips by pulling action. Thereafter, the operator brings the system in the reverse order of operations back to the basic position.

All four steps for setting and securing the route for a train are realized in modern signal boxes. There, however, the steps are executed at least in part, automatically.

Decisive for the location and the number of mechanical interlocking was not only the control distance that depended on the maximum length of the Drahtzugleitungen, but primarily an overview of the setting range. Since the trains do not move in because of their long braking distance, the guards had to check the absence of the track immediately before authorizing train movements through inspection, especially at night or in fog (see also track test). It follows that one often even in smaller stations do not use a signal box the Auslangen found ( interlocking means ), but two signal boxes needed at each end of a train station ( Endstellwerke ). One of them, the command signal box, served the Dispatcher, the other, the interlocking guards, the switch guards. Large stations required several warders and possibly Dispatchers signal boxes in order to view the entire station area can.

Development

Initially, the course attendants had to bring each switch using their locking device on the ground in the correct position. Technical constraints or dependencies that helped set the track properly and to ensure it did not exist. The course attendants alone was responsible. The rapid expansion of the networks and the associated increase of the train and shunting required an improvement. Above all you needed before devices for securing the switch and during running.

The first step is used to switch locks that anbrachte the course attendants to the course; later they mounted it firmly. In front of a train set the switch guards the course in the right position, she graduated with a lock switch and hung the keys on a key board on which each key had its place. Only when the switch guard had all planned for the train ride keys attached to the key board, he was allowed to give the train permission to ride. This was done initially by a show of hands with the aid of a signal flag, and later by the on - ride sites of a stationary signal.

The key board has been preserved as a fallback for cases of disturbance to this day, even in modern signal boxes.

As the previous method no longer enough for the increased need for security, was developed mechanically acting key works. In simplified terms, it was in the key work for every course castle, which was installed outside, nor a counterpart in the fit, the same key. Should a train ride take place, of course guards put the key of the completed course in the corresponding locks the keys work. Were all located in a driveway belonging to key in the key work, the plug end in another castle main signal key was released. The removal of this key locked the other keys in their locks. With the main key signal of the switch guards then closed in place on the closed position stop in the main signal and put it on ride.

The key work is considered the forerunner of the mechanical interlockings, because it realized for the first time in a relatively simple manner, the signal dependence. Nevertheless, the method was still time-consuming because you still needed a lot of staff to operate the switches and signals in place can.

In Germany was the first mechanical interlocking, in a remote location from where points and signals and could be centrally backed up, taken in 1867 by the British company Saxby & Farmer in Szczecin in operation. In the following decades, developed and built many German companies mechanical interlocking in a number of different designs. Among them were signal boxes that used for power transmission instead of the wire pulls linkage or compressed air lines. However, the latter could not prevail. The numerous, completely different interlocking types already led to the beginning of the 20th century to problems in maintenance. A new interlocking design was therefore particular by the Prussian state railways on the basis of the type " Jüdel " developed. 1911 was built to the west of Berlin five prototype systems, after their testing the new " design unit " in 1915 reaching far made ​​binding for new plants. Until the twenties was interlockings of old forms were completed to consume a stocked material. Since then, this " unit construction " of the mechanical interlockings was only changed in details.

Designs

There are various types of mechanical interlocking. Some of the manufacturers have built only the interlocking systems of other producers under license. In Germany or were types of the following manufacturers in use:

• AEG
• Bruchsal
• Unit ( built by several manufacturers )
• Esslingen
• Fiebrandt
• Guest
• Harwig
• Hein Lehmann &
• Jüdel
• Krauss
• Müller & May
• Nöll
• Scheidt & Bachmann, for example: interlocking Tannenbergstraße, Bergisch Gladbach
• Siemens & Halske
• Späth
• Stahmer
• Thomass
• Vögele
• Weinitschke
• Willmann
• Zimmermann & Buchloh

The German railway estimates the lifetime of mechanical interlocking, in which the operation from a technical and economic point of worth, at 80 years old. The DB operational beginning 2006 1923 mechanical interlocking with 27,590 actuators. The main types are unit and Jüdel. According to the Deutsche Bahn, the operating and maintenance costs are of mechanical interlocking up to nine times higher than in modern technology. The oldest signal box in the DB was built in 1887 (as of 2006).

In Austria are or were, among others, the following manufacturers types in use:

• Siemens and Halske ( including the Austrian rule interlocking of the type " 5007 " )
• Southern Railway works
• Goetz and Sons

Building forms

The outsiders often used classification of interlocking after the shape of the building has to do with function and technology of the switchboard little, especially since this distinction is used only for existing plants with mechanical or electromechanical actuator technology, an overview of the regulated from the interlocking rail facilities for the purpose of free reporting test " by " require inspection. Here are particular

• Interlocking towers, which were built on the side of a railway system and have greater operating space on the chip works,
• Bridge Signal Box, the and its control room in a bridge across the railway facilities supervised
• Reiter interlockings, their operating space increased in the longitudinal direction over the railway systems is specifically designated.

Common to them is that they are available in railway stations, in which between the tracks a suitable space with an overview of the facilities for the purpose of free message otherwise could not be established, typically can be in these buildings chip works not accommodate in the building and, therefore, are on the verge of the track system.