It’s worth starting with the fact that at present, one set of turnouts is about 7.5 thousand parts. The total mass of all parts is approximately 30 tons. While the train is moving, some of these sections are subject to quite a strong dynamic impact. In addition, this effect can quickly change its character. For these reasons, there are certain malfunctions of the railroad switch, upon detection of which, it is forbidden to operate this railway.
Why it is important to check the correctness of the translation
Due to the large number of stations, it is sometimes necessary to arrange transfers closer to each other than permitted. This entails the fact that you have to use the minimum radius values for the translated curves. At a time when the train deviates from the direct path to the side wit, it sharply increases the lateral pressure from zero to maximum. The railway tracks have such a section, which is conditionally called harmful space. In this interval, the crosspiece of the wheel brace will be rolled onto the guardrail, and then on the core. At this time, those forces that act on the bearing parts of the switch mechanism will change their value almost instantly. And the resulting sharp dynamic pulses will upset the design. It is for this reason that it is necessary to ensure that the faults of the turnout switch are either eliminated as soon as possible, before the train arrives, or temporarily disable the entire railway until the problems are completely eliminated.
Path checks
The frequency of checking the turnouts that are located on the main and pick-up tracks, at least once a month. This inspection should be carried out directly by the head of management of this station. There should also be a road foreman and an electrician signaling.
There are certain norms that establish fundamental parameters for paths.
First malfunction
To date, there are 9 major malfunctions of the turnout, the detection of which, it is immediately forbidden to operate this branch.
The first of these failures is the lack of strong adhesion of switch points, as well as the moving parts of parts such as cores and crosses with rods. The reasons for the self-disengagement of the structure can be circumstances such as a kink, loss or breakage of the bolts that connected these elements with the wit. The rivets and bolts that connected the earring and the pin, etc. can also fall out or deform. If one of these breakdowns occurs, this will cause such a malfunction of the turnout as moving one of the pin while the second remains in the same place. A situation may also occur in which both wits can begin to spontaneously move right under the wheels of a moving train.
Other malfunctions
Sometimes a problem arises in which the sharp part begins to lag behind the track frame. The maximum allowable difference is not more than four millimeters. In order to understand whether everything is in order, it is necessary to measure the distance from the pointed part to the beginning of the moment of connecting rod in the opposite direction. At the core with a cross, having a sharp shape - in the direction of the direction of the sharp end. If such a malfunction of the turnout occurs, then when the train moves in a certain direction (against the direction of these elements) in the direction of the arrow of the pair of wheels with an undercut of the ridge, an incident such as a ridge between the sharp element and the railroad track frame is possible. This will lead to the fact that the running train will go off the rail, and the switch section of the track will be damaged.
Sometimes what happens is called chipping of the pointed part. In the event that the path is the main, then a value greater than 200 mm or more will be considered a breakdown. In the case of branches that are acceptance and dispatch, the breakage value is 300 mm or more. For all other branches that do not fall into the first two categories, the breakage parameter is 400 mm or more. This turnout malfunction is unsafe if the train moves “against the wool”, that is, in the opposite direction from the one in which the rails were laid.
Faults in violation of distance
To identify some translation malfunctions, you need to know exactly what distance should be between the elements and periodically measure these parameters. For example, an important indicator will be the distance between the working face of the core of the cross and the working face of the head of the counter rail less than 1472 mm. If this gap turns out to be shorter, then there will be a danger of a wheel pair of a new type coming off, for which the maximum permissible pair spacing is 33 mm, or an empty wagon with a distance between the wheel pair of 1440 mm.
Additional malfunctions
It was said earlier that there are 9 major translation problems. However, if you take into account additional ones, then in total you can find 10 faults of the turnout switch. In addition to those that have already been described, there may also be a problem with a break in the sharp part or frame of the railway tracks. There may also be problems associated with a violation of the distance between the working faces of the counter-rail head and guardrail. If the distance between these elements turns out to be more than 1435 mm, then a moving train with a wheel pair width of 1435 mm will leave one wheel either on the guardrail head or on the counter-rail head, which will lead to the train leaving the tracks. It is important to remember that for PTE, faulty switches can not be operated until they are completely repaired.
Sometimes a problem also arises, which is called lowering the wit against the frame rail, as well as the movable core against the guardrail by 2 mm or more. This malfunction is unacceptable, since when the train passes in a woolly direction, that is, from the cross to the sharp points, as well as the presence of a significant wheel rental, the train goes off the rails.
What is still important to note, in order to better understand or repair breakdowns, there are fault maps of the turnout switch.