Beiträge

Definition of tram

The tram is a transport system that cannot easily be squeezed into a concrete scheme. It takes on the most diverse forms and modes of operation in the cities across the world. In this chapter, we will discuss all relevant forms of operation, both in front of and behind the scenes. In addition to the classic one-way tram, there’s also bi-directional operation. Or the tram independent of road traffic. More inconspicuous to the passenger are other forms of development, such as operation with signaling systems, depot control systems, or speed monitoring systems.

Thought one stage ahead, the tram system can occasionally be conceptualized as a train configuration coupled to each other.And last but not least, there are trams that do not even touch road traffic in any way. Especially with the last-mentioned developments, they are already initial stages or already converted systems of a light rail or subway, for which separate definitions apply in each case.

Operating points

The infrastructure of railroad systems can be clearly divided into different facilities, categorically and spatially. For this purpose, there are the so-called operating points and their respective designations. These would be, for example, junctions, transfer points, stations, stops, connection points and many more. Each of these types of operating points fulfil their own function in the overall rail operation process, which is explained in detail in our video chapter. By clearly classifying and assigning an operating point to the categories, the related operating rules and responsibilities are then defined. They standardize the behavior of driving personnel, control center personnel, but also, for example, the behavior of planning engineers.

Another part of this short video is the superordinate division of rail lines into station areas and areas of free track. It also serves to standardize procedures by establishing rules. Further, it represents a further level of categorization in rail operations. It may happen that the above-mentioned types of operating stations can be operating stations of the free track. Otherwise, it can be an operating stations of the station area.

Train configuration

Trains have a certain train configuration. This refers to how individual train sections can be combined to form an entire train set. Locomotive-hauled trains are a classic example of this, but not only in freight traffic. They also used in passenger traffic. However, they are increasingly being replaced by multiple units. These are closed vehicle units that can only be separated for workshop purposes, but no longer for operational reasons.

How the car bodies and their axles are arranged, or where the traction motor is installed, these are all criteria for the classification of trains. But there are more than the before mentioned. Each train configuration has its advantages and disadvantages. Usually, they are system decisions adapted to the environment that we deal with in this chapter.

Intermittent automatic train control

The “intermittent automatic train running control” is the default automatic train control in rail traffic.  This saves us from collisions even when the engineer disregards a halt signal. It’s initiated by on board brake supervision. This, also referred as braking graphs, ensures that the traveling velocity is always less than the allowed velocity.

In this chapter you will learn all about the most important coherences. In the case of the widespread construction type „PZB 90“, a train passes a trackside radio beacon. If this radio beacon is activated, the train-born supervision for deceleration is enabled. This means the engineer must maintain a traveling velocity below the allowed supervised velocity. If this is not the case, the onboard computer starts a forced brake procedure. The radio beacon is only active, when the following track part is not assigned.