In the previous posting to this blog, In the Light of Dark, I introduced the concept of non-signaled operations used in the Americas that is most frequently referred to as Dark Territory (DT). In fact, there are two basic types of DT, i.e., Dark/Dark and Dark/Lighted (my terminology and not Googable). In Dark/Dark operations, neither the dispatcher is presented with any indication of where the train is (as in signaled CTC operations), nor is the train crew provided with any in-cab or wayside signals to present the crews with the indication of the time & speed parameters of the current movement authority (a.k.a. aspects). Instead, the crew obtains the movement authority via voice radio or as data via data radio (a.k.a. digital authorities) from the dispatcher. That is, both the dispatcher and the train crew are in the dark, so to speak, as to the train position and authority, respectively. Contrarily, in Dark/Lighted operation, the dispatcher is still unable to see the position of the train, but signals are used within the corridor to keep trains separated by block. This use of Absolute Block System (ABS) increases the possible capacity of the DT operation by adding a second level of vitality (i.e., the generation of movement authorities) to the primary authority so as to place multiple trains into a sequential set of blocks instead of having one train hold all blocks exclusively until it releases the whole set of blocks. Although a signal engineer will declare ABS to be signaled operations, it is actually DT in that the primary authority to get the train into the corridor was so generated. Regardless of the type of DT, two critical points remain true: 1. the dispatcher doesn’t know where the train(s) is in the DT corridor, and 2. the dispatcher doesn’t know the speed of the train(s). But, that’s OK, seemingly, because DT is used for low to medium density operations … or is it really OK? Actually, it is no longer OK.
Traditional railroaders have accepted that DT has limited capacity due to the manual efforts of transmitting authorities and subsequently releasing them. But, what if a railroad was to obtain the actual position and speed of trains, and then use mathematical movement planners to adjust the generation of movement authorities in a more dynamic fashion? That is, what if a dispatcher had a Planning Platform, either integrated or independent of CAD, that could more efficiently plan the generation of authorities, and then have the dispatcher use CAD as the execution platform that it truly only is? That is, what if the dispatcher had what I have introduced 5 years ago as Proactive Traffic Management (PTM) instead of the reactive, crisis-based management of train movements (more on this in a future posting)?
Now, the question is: How much capacity can be obtained with DT operations that use the dynamic duo of digital authorities and PTM, whether dark/dark or dark/lighted? Of course, the answer varies for each individual corridor. But no railroad, to my knowledge, has attempted to answer that question. They don’t know what they don’t know. Instead, they take the traditional signaling approach that requires heavy investment in infrastructure as well as extensive maintenance costs to ensure the reliability of the equipment. Additionally, such signaling operations in developing countries are subject to theft and deterioration due to poor maintenance given a lack of adequately train maintenance personnel.
The great news is that such capacity evaluations can be performed through the use of mathematical models not unlike those that are used to calculate the theoretical throughput of signaled operations. But again, to my knowledge, no one is using such models. Clearly, neither suppliers nor traditional consultants that advise railroads are doing such analyses in that they will not sell anything since 1. there is no infrastructure investment for DT other than wireless data, and 2. they don’t have operational experience with such operations, respectively. That’s where my associates and I can be brought into play.
As my team of professional railroaders and planners are pursuing with small and emerging operations in selected areas of the globe, there is the opportunity to bring those types of alternatives to railway management. The icing on the cake is that we also can advise on the use of enforcement systems, such as PTC, so as to provide for as safe of a railroad operation that is possible with both reliable traffic control and efficient traffic management, as well as assure that a train crew will not violate their authorities. It doesn’t get any better than that.
If what I have discussed above applies to your railway, then we need to talk. By the way, my team doesn’t represent any suppliers, nor do we accept commissions from suppliers. We work for your railway’s best financial and operational interests.