Posts Tagged ‘Dark Territory’
“Operating a railroad safely requires signaling.”
Major suppliers sell major signaling systems to major railroads for major bucks. But what about those small freight railroads, even those with some passenger service? Do they really require the traffic control systems that are offered to them; the ones that involve extensive investment in wayside infrastructure, communications, and back office systems? Additionally, what about those railroads that are being planned for difficult terrain subject to extreme weather, a lack of power, theft of equipment, and a lack of trained maintenance personnel? Do they need to confront these hardships on top of extensive investment and on-going maintenance costs to provide for a safe railroad?
While signaling does provide for safe operations, that is not its purpose. Signaling is used to provide capacity. It is possible to operate a railroad very safely without signaling, as well evidenced in North America. Specifically, nearly half of the freight trackage in N.A. operates as non-signaled territory (albeit only 20% of the traffic) meaning that there are no track circuits, no wayside or cab signals, and no code lines as required in Centralized Traffic Control (CTC) systems. The only technology requirement is that of some form of wireless communications that can be either commercial (satellite, cellular) or private network sufficient to provide for voice communications. That’s it for the infrastructure.
As to the vitality (i.e., the integrity of train movement), as noted in the post “There’s nothing vital in dark territory.”, the computerized conflict checking process is the simplest of a traffic control process that doesn’t permit two trains to be in the same portion of track at the same time. In a way, this is not unlike the most ancient traffic control system based upon track occupancy referred to as token block. The key difference is that dark territory is programmed whereas token block’ vitality can be readily compromised by lack of discipline with the manual efforts required; indeed this is the case in some countries where it is still in use.
The only issue with dark territory is the time required for the iterative, manual process of the dispatcher transmitting the movement authorities to the train crew followed by the rolling-up of the authorities once the train crew has reported the train’s progress. With such a simple process, a decent size freight or passenger railroad can operate safely. Additionally, there are even ways to tweak dark territory operation to improve capacity even further, e.g., digital transmission of authorities, automatic roll-ups, embedded signals (without CTC), and the ability to throw switches from the locomotive. Lastly, with the combination of dark territory and Positive Train Crew (PTC), the railroad is assured of a safe operation both as to dispatcher errors and train crew errors respectively.
Also, Dark territory is really, really inexpensive. However, don’t expect those major suppliers or consultants to share its existence with small to medium railroads. First of all, those supplier don’t have a dark territory deliverable or mindset, and second, there is nothing for them to sell as to infrastructure and complex back office systems.
The team of railroad professionals at Maendeleo Rail is well experienced with dark territory operations as well as PTC. We can readily address the alternatives as to processes and wireless technologies, as well as determine the level of throughput that can be delivered for freight, passenger, or mixed traffic. Since we’re independent of any suppliers, and instead look to partner with railroad operators, we provide low cost, highly efficient solutions.