Abstract/Executive Summary

Rail transportation of goods in North America has steadily increased over the last 20 years for a variety of factors.  Some of these factors include:  increasing fuel prices, more dependence on coal by electric utilities, and an increase in trade between North America and Asia.  These factors together help contribute to:  “Trains now carry 41% of U.S. freight as measured in ton-miles, or one ton moved one mile, up from 35% in 1986, according to the Association of American Railroads, a trade group".^[1]  To handle the increasing freight requirements, railroad companies are investing heavily in new track construction and improvements to existing tracks.  Improvements to existing tracks can improve the reliability of service without having to go through the lengthy process of new construction. 

One area in particular that can have significant impacts on rail capacity is proper switch operation.  Dependable switch operation helps ensure the smooth flow of rail freight throughout the country.  Switch failure events are caused by a variety things including:  vandalism, debris, and snow and ice buildup.  To minimize failure events caused by snow and ice build up, railroad companies install snow melters in areas prone to these conditions.  Snow melters are operated either remotely by a railroad dispatcher or automatically through a variety of field sensors.  Remote operation alone is not sufficient because of the lack of local weather information the dispatcher has access to.  Automatic operation via microprocessor controls and field sensors helps minimize this shortcoming, but has limitations itself.  The greatest limitation is that the railroad company does not know when the snow melter is running or not when it is in automatic mode.

Enabling advancements in communication technologies and microprocessor controls are the primary drivers in the advancement of snow melter systems.  Wireless data transmission allows for the collection and dissemination of valuable operating conditions experienced by the snow melter.  While advanced microprocessor controls enable the control module to operate and monitor more equipment functions then ever before.   Together these advancements provide the platform for the creation of more reliable snow melters.  Railway Equipment Company, building on existing technology in combination with these new advancements, has developed a greatly advanced snow melter machine that will provide the railroad industry with greater control and visibility of their snow melters.  Utilization of this advanced snow melter will result in fewer train delays resulting from non-functioning switches caused by snow and ice build-up.  Additional benefits include:  reducing emergency service calls to maintainer, remote diagnostics of malfunctioning equipment, and reduced fuel consumption.  Finally, the data storage capabilities of the system allow for data analysis and comparison to outside data sources to more effectively operate equipment.  One example would be the ability to compare snow melter run data against National Weather Service data to ensure temperature sensing and snow detector sensors are functioning properly.

Introduction

Railway Equipment Company, a long time supplier of equipment to help support railroad companies’ infrastructure, has developed a new product that will increase the ability to control, monitor, and maintain snowmelt equipment.  The new product, SNO-NET, utilizes existing snowmelt technology in combination with advanced control and communication systems.  The communication and control capabilities of SNO-NET allow much more visibility into the operation of the snow melter equipment.  This increased visibility will allow the railroad company to more accurately assess:  the condition of the snow melter, when the snow melter should be on, and operating parameters of the snow melter.  The goal of this paper is to bring to the forefront inefficiencies resulting from current technology and processes and to show how utilization of the SNO-NET system will eliminate these inefficiencies while providing additional benefits.

Review of Current Practices

The snow melter equipment in use today is a sophisticated piece of equipment comprising of electrical, mechanical, and software components.  All together these components work towards the goal of keeping rail switches operating in snow and ice conditions.    

Process for Operation

Currently, snow melter equipment is turned on and off at the discretion of the railroad dispatcher.  When a dispatcher is informed of potential snow or ice conditions in a given area, the dispatcher will respond by turning the equipment on for a period of time until the weather has changed.  The dispatcher is typically informed of weather conditions by train personal or weather announcements over the radio.  While this information may provide reliable regional weather information, it is not well suited to detect localized weather conditions.  Because of this inherent limitation, the current weather advisory protocol alone is not sufficient to predict whether or not a snow melter should be off or on.  This shortcoming has been addressed to date by adding multiple sensors and controls to the snow melter.  These sensors include:  air temperature sensors, rail temperature sensors, and moisture detectors.  The controls are programmed to turn the snow melter on or off according to operator preset parameters.  The evolution of the integration of the controls and sensors has led to more intelligent and effective snow melter operation.

Process for Responding to Snowmelter Failure

Snowmelters require periodic maintenance and may experience failure events due to:  weather, rodents, fuel, vandalism, component failure, or power failure.  The maintenance and service of the snow melter is typically performed by a railroad employee, the maintainer, who is often physically located within a few hundred miles of the snow melter.  When a failure event occurs, the dispatcher receives notification via indication.  The maintainer is then notified by the dispatcher that the snow melter machine is not on when it should be.  The maintainer is then tasked with getting the snow melter up and running as soon as possible.  Only knowing the snow melter is not function properly and not knowing the cause, results in a site visit by the maintainer.  At this point the maintainer is able to inspect the unit and diagnose the problem.  If the maintainer is able to correct the problem the unit is placed back into service.  However, many times the failure event that occurred can not be corrected without additional resources.  These resources may include propane or other parts the maintainer currently does not have in his possession.  If this occurs, the result is a continued delay in the proper operation of the snow melter.  To help alleviate failure due to a lack of propane, railroad companies may rely on a propane vendor to manage the propane inventory.  The management service provided by the propane dealer creates added expense for both parties.  This added expense occurs because of the lack of communication from the railroad to the propane vendor regarding the amount of propane in the fuel tank.   

Opportunity for Technology Enhancement to Improve Snowmelters

The current processes by which snow melters are monitored and operated have significant opportunities for improvement.  Two primary areas of potential for improvement are communication and functional capabilities of the unit.  Communication can be improved by connecting the snow melter to a centralized system.  This system would link: the maintainer, the dispatcher, and whoever else could benefit from knowledge obtained from the snow melter.  Other interested parties could include:  propane vendors, replacement parts vendors, etc.  Functional capabilities of the unit can be enhanced to monitor and record more accurate and timely data.  Data to be recorded may include:  ambient air temperature, gas pressure, duct pressure, rail temperature, tank level, snow detector, and others.  The data could then be analyzed by the central system to determine if any conditions require some form of action by appropriate personnel.  For example, the system might send out a message to the propane dealer to come out and fill the propane tank if the tank has gone below a certain level.    

Description of SNO-NET System Provided by Railway Equipment Company

The SNO-NET system developed by Railway Equipment Company addresses many of the current shortcomings of the existing technology while providing additional benefits.  This system consists of a snow melter, advanced control module, database, web interface, and connectivity via multiple communication options.  The system represents a technical leap in how communication occurs between the various interested parties.  Two-way communication between the snow melter and various parties is now possible.  In addition to allowing communication from railroad personal to the snow melter, the SNO-NET system will allow the snow melter to initiate communications to railroad personnel, such as a text message to a pager or Blackberry, for the purpose of warning of a snow melter malfunction. It will allow railroad personnel to remotely monitor and control any snow melter in the system through a secure internet connection in order to better understand the condition of the snow melter. 

SNO-NET Operation

Installing the SNO-NET system will allow the railroad company to operate their snow melter equipment more effectively and economically.  Sensors and controls will be linked via two-way wireless communication to various affected parties.  An example of the connectivity can be found in Appendix A.  In this example the maintainer, dispatcher, and central database are all linked together.  Programmable user settings will determine which parties receive information according to their need.  The central network control system will analyze the data received from the snow melters to determine if any conditions require some form of action by appropriate personnel.  All information collected from the snow melter as well as all actions taken by personnel will be recorded, time/date stamped, and permanently stored in the database.  This permanent record can then be analyzed by railroad personnel and compared to other known factors including weather data, maintenance intervals, or propane delivery schedules.  Analysis of this data will allow the railroad to more intelligently set the control parameters to accommodate the local conditions a particular snow melter is experiencing.

Web Interface

Railway Equipment Company has developed administrator customizable web interfaces to interact with the snow melter equipment.  Administrators will log in using a secure username and password.  After logging in, the web browser will be directed towards their unique site.  The next step is for the administrator to set up the snow melters with information such as region, division, sub-division, postal code, switch name, and milepost.   Railroad administrators will have the ability to control which snow melters an individual user will have access to along with what information and control functions the user will have access to.  Some of the control functions that can be performed via the internet are:  turn the snow melter on or off, adjust the air temperature set point up or down, adjust the run timer up or down, adjust the snow run timer up or down, set the burner rate to high only, low only, or automatic, adjust the rail temperature set point up or down, reset the gas consumption meter, set the low gas level indication, and reset the run timer. 

Railroad administrators will have the capability to set up an “advisory matrix”.  The matrix will allow the administrator to enter individual user ID’s and designate which advisories each user will receive and the means by which the advisory will be communicated.  For example, the administrator could enter the user ID for the maintainer responsible for a particular snow melter.  For that user ID the administrator could then enter the maintainer’s preferred method of communication.  Communication alternatives include:  email alert, text messages, voice messages, or all alternatives.  Some of the advisories that will be communicated are:  snow melter not running when called for, snow melter running when not called for, low gas pressure, low propane tank level, low voltage, blown fuse, low air flow, high duct air pressure, high air duct temperature, motor overload tripped, low gas vaporization capability, and others. 

Usage Example

An administrator has set up an account for a maintainer that is responsible for a group of twenty four snow melters.  The maintainer is informed that there is a big snow storm that should reach his area within six hours.  The maintainer this logs into the central system via an internet connection and immediately has control over all twenty four of his/her snow melters.  Knowing the snow conditions are approaching, the maintainer will elect to turn on all twenty four snow melters simultaneously.  Within minutes the maintainer will have visual confirmation that the snow melters are either functioning properly or are failing to function.  If a unit is not functioning properly, the maintainer can then isolate the malfunctioning snow melter and begin trouble shooting the problem.

Conclusion

Railway Equipment Company has designed and developed a state of the art system, SNO-NET, that will allow snow melter users the opportunity to remotely monitor and control snowmelt equipment.  The system is a combination of proven snow melter technology with the latest advancements in communications and web interfaces.  Providing a communication link with snow melters gives maintainers the ability to interact with snow melter equipment without having to travel to site.  Enhanced snow melter controls and functions, provide the maintainer with more tools to ensure proper switch operation in adverse winter conditions.  The SNO-NET system will provide railroad companies with a dependable option for monitoring, controlling, and maintaining snow melter equipment. 

 ^[1] Wall Street Journal, "Traffic Jam on the Tracks", April 4, 2006