Failsafe Audible Signal Power Assisted Switch for Railroads

This application claims the benefit under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 63/464,331, filed on May 5, 2023, which is incorporated herein by reference.

Not applicable.

The present disclosure generally relates to railroad signal systems. More specifically, the disclosure relates to a vital railroad switch system for use in dark territory.

Railroad signal systems are generally comprised of wayside signals, power operated switches, vital track circuits, and “vital” field logic implemented in either relay-based systems or solid-state devices. The term “vital” is a term used in the railroad industry to indicate known performance and reliability parameters (i.e. failsafe, redundant, etc.). The signal systems provide for the safe control and movement of railway vehicles through the operation of the signals and switches. This control is predominantly accomplished through centrally controlled systems where a dispatcher remotely controls the signals and switches.

However, the majority of railroad track is considered “dark” territory, meaning it is outside of the range of central control. Movement of railway vehicles in dark territory is governed by verbal communication and authorization, issued by a dispatcher, thereby maintaining the safe separation and movement of the railway vehicles. While the dispatcher gives the authorization to operate a switch or use a track, the dispatcher can not confirm the status of the signals and switches or control their operation in dark territory.

One area in dark territory where a vital switch may be used is in a passing siding. Passing sidings in dark territory allow for meets and passes without requiring trains to stop and manipulate a switch manually. An approaching train can command the switch, upon the authorization of the dispatcher, using a remote signal, typically DTMF codes transmitted via VHF or UHF radio. LED indicators (signals) indicates the status of the system as the train approaches.

The railroad industry typically remotely controls these particular switches with vital functionality. This vitality is desirable due to the switches being utilized on main track (i.e. mainline) within dark territory, where main track allows trains to operate at speeds greater than visual stopping distances. That is, if a signal visually observed by the train indicates an incorrect position of a switch, the train would not be able to stop before reaching the switch.

While this system works for mainline/siding junctions where ‘vital’ operation is warranted, there are situations where transfer to a railyard may not necessitate vital switches at all junctions. For example, in a railyard transfer, the switch from the mainline to the railyard may be vital, but the switches within the railyard are non-vital. Integration of the vital mainline switch with non-vital railyard switches would allow safe operation of the vital functions while increasing efficiency. Therefore, it would be advantageous to develop a system providing improved functionality for use on portions of track where not all switches are vital.

According to embodiments of the present disclosure is a system that allows for the control of railyard switches and mainline switches together, while maintaining the vital features of the mainline switch. A processor in the system will designate a yard track or a route to the yard track and provide the route with a unique identifier. The system operates the yard switch on the route, then controls the mainline switch if, and only if, the yard switches achieve the proper position.

100 101 101 101 110 110 111 According to embodiments of the disclosure is a systemfor controlling switches, particularly a group of vital and non-vital switches. The switchescan be of the type known in the railroad industry and move between ‘Normal’ and ‘Reverse’ positions, where the Normal position maintains a route along a mainline trackand the Reverse position transfers a train off the mainline trackto a siding, railyard, or other auxiliary track.

101 111 100 101 In dark territory, the locomotive sends a request to query (or throw) the switch machinefrom up to two miles in advance of the sidingwhile on approach. Once a request is made and the switch move is completed, the locomotive crew receives a vital audible message on their radio from the control systemnotifying them that the switchis lined and locked for their requested move.

101 100 101 101 101 100 By way of further detail, the switchmay be commanded by a remote signal issued by an approaching train, typically Dual Tone Multiple Frequency (DTMF) codes received via a VHF or UHF radio. A command received by the systemcan cause movement of the switchfrom the Normal or Reverse positions. If the switchis not already in the correct position, it is controlled to the correct position. Once the correct position is achieved, the switchis time locked and the systemindicates the position via LED indicators (signals) and an audio transmission via a radio system.

101 100 Improper positioning of the switch, erroneous signals, or incomplete movement between Normal and Reverse positions can lead to train derailment, collisions, and other potential risks to life and equipment. As a result, the following functions of the systemcan be vital: (A) position indicators; (B) audio messages conveying either Normal or Reverse positions; (C) time locking; and (D) track circuits/occupancy/locking.

111 110 110 111 101 101 101 101 110 111 101 111 1 FIG. The main purpose and use of these control systems is for passing sidings in dark territory, which is a type of track configuration having a siding linebranch from the mainline track, as shown in. The mainline trackand a siding trackare connected by a switchand determines the route the train will take. The switchesallow for meets and passes without requiring trains to stop to manipulate the switch. It is understood that when the switchis lined and announces Normal that the train will remain on the main trackand not enter or depart the siding track. It is also understood that when the switchis lined and announces Reverse that the train will either enter or depart the siding track.

101 101 111 101 101 110 111 2 FIG. Not all mainline switchesin dark territory connect to passing sidings. Many mainline switcheslead to rail yards that have a plurality of tracks, as shown in. For a train to enter into or depart from a yard track from the mainline not only must the mainline switchbe controlled, but also any intervening yard switchesbetween the mainline trackand the desired yard trackmust be controlled as well. In prior approaches, existing switches on the mainline do not interface with, or work in conjunction with, the yard switches and they must either be controlled by a separate system or the train must stop in order for them to be manipulated manually.

100 101 101 101 101 The systemof the present disclosure allows for the control of the yard switching apparatusand mainline switching apparatustogether while maintaining the vital features of the mainline switch. The yard switchesmay or may not be vital.

3 FIG. 3 FIG. 100 100 105 105 105 100 105 101 101 111 110 101 101 shows the systemaccording to one embodiment. As shown in, the systemmay comprise a processor or preprocessor, which can be a separate processoradded to an existing switch or integrated as a processing unit within an existing processorof the system. The processorreceives the decoded commands received by the switchwhere the commands designate: (A) the mainline switchas Normal; or (B) a yard trackto connect to from the mainline track, where the connection is designated as a route having a unique identifier and the route includes both the mainline switchand the yard switch.

100 12 12 3 FIG. 3 FIG. 3 FIG. By way of further detail, the systemshown inprovides audio messages with vital reliability by use of discrete audio boards for the recording and playback of individual messages. Each audio board contains only one message, and is equipped with a trigger, audio output, and push to talk output. The messages are triggered by a program logic controller (PLC). The PLC can be implemented as a hardware, firmware, software, as a system of relays, or other similar controller devices. Routing the audio output of each board through the Normal switch repeater (NWP), Reverse switch position repeater (RWP), and third relay approach stick relay (ASR) provide the vital audio functions as shown in. In, Brefers to a positive 12 volts and Nrefers to negative 12 volts.

101 105 101 101 100 101 110 101 To maintain the vital operation of the mainline switch, the processorwill control the yard switchon the route first and if, and only if, all of the switchesachieved proper position, then the systemwill pass the command to control the mainline switchto go to the Reverse position, directing the train off the mainline track. Further, the command to the mainline switch would designate the route that is being set. This command can either be discrete inputs to the switchwhere each input designates a specific route or communicated digitally or numerically.

101 101 101 101 111 101 4 FIG. To achieve this functionality, an existing switchwithout separate PLCs for yard switches(as shown in) would be extended to include a plurality of “reverse” audio messages, where each message would correspond to the mainline switchbeing Reverse and the yard switchesbeing lined to a particular track. All other features and functions of the existing switchwould be maintained.

When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps, or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The invention may also broadly consist in the parts, elements, steps, examples and/or features referred to or indicated in the specification individually or collectively in any and all combinations of two or more said parts, elements, steps, examples and/or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein.

Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure. Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.