SmartPlug Rail Force Monitoring Device Presented by: John Kidd QinetiQ North America Technology Solutions Group June 14, 2011 2009
Thermal Loads in Welded Rail Continuous Welded Rail (CWR) Thermal expansion of rail steel Welded rail constrained (no bolted/expansion joints) Develop longitudinal forces in rail Rail Neutral Temperature (RNT) High rail temperatures cause compression Low temperature tension Rail neutral temperature occurs in the transition between tension/compression, when the rail has no force 2009 2
Monitoring Status of CWR Track RNT changes with time (daily, seasonally, etc.) SmartPlug captures RNT value SmartPlug Monitors changes in RNT and rail temperature High rail force can cause track failure SmartPlug calculates rail force (using RNT and rail temperature) SmartPlug sends alert for track failure or high risk of failure 2009 3
Data Measurement Changes in RNT and rail force are calculated from measured parameters (longitudinal strain and rail temperature) Attaching strain gages to rail with strain gage welder Measuring rail strain with strain gage indicator 2009 4
RNT Determination at Rail Cut Actual value of RNT is determined by measuring the strain while the rail is cut (no tension/compression) Gap is cut into rail and rail is pulled together prior to weld to elevate RNT Rail Cut / Rail Gap SmartPlug measures rail temperature SmartPlug calculates proper gap for target RNT 2009 5
De-Stressing Operations during Field Weld Prototype Sensor Units Hydraulic tensors pull rail together to elevate RNT Field Weld (Cooling) SmartPlug measures changes in strain and rail temperatures Hydraulic Tensors SmartPlug calculates RNT (post-weld) and monitors changes in RNT 2009 6
Proof of Concept Prototypes (Wayside Access) Includes strain and temperature sensors Printed circuit board with processor and local memory for data storage Short range RF communications(15-50 feet range for wayside application) 2009 7
Prototype Data (collection) Rail Force/RNT Data Collection Field Weld/De-Stress Operations 2009 8
Rail Temperature and RNT (F) Prototype Data 150 130 Rail Temp RNT 110 90 70 50 30 0 200 400 600 800 1000 1200 1400 Time (Hrs) 2009 9
RNT and Rail Temperature (Degrees (F)) Prototype Data (Rail Temp and RNT prior to field weld) 160 February 25 - April 7 (Bolted w/joint bars untill April 5, then De-stressed & Welded) RNT shoots up while de-stressed with tensors, then welded 140 Slight drop in RNT when tensors are released 120 New stress (tension) is distributed locally into undisturbed rail with rail traffic, causing RNT to taper off to "equilibrium" 100 Prior to weld, RNT is free to increase w/rail temp (due to slop in bolted connection) 80 60 40 20 RNT Rail Temp 0 0 100 200 300 400 500 600 700 800 900 1000 Time (Hours after installation) 2009 10
Tr & RNT (degrees), strain (microstrain) Prototype Data (Rail Temp, RNT, Rail Force) DATA - POST WELD 180 160 140 120 100 80 60 40 20 0 RNT Rail Force Rail Temperature 0 50 100 150 200 250 300 Time (hours) 2009 11
New SmartPlug (Specifications) System Specifications Dimensions: Weight: Battery Life: Power Usage: Range: 1.2 x3 x14 6 Lbs. 1 year 26 mamp seconds 1 mile Operating Frequency: 140 240 MHz Strain Gages: 350 Ohm Operating Temperature: -40F to 180F Zero Calibration: Performed at rail cut, maintained after battery replacement Data Storage: 6 months data storage at 1 hour data collection frequency Installation: Magnetic, non-destructive Sensor Unit Mounts on Rail Performance Specifications Calculates recommended rail gap and displays Real-Time graph of RNT during destressing operations Monitors for track failure at 10 Minute intervals sends message immediately Sends dailey data for track status 2009 12
New SmartPlug Communications Schematic Established long range communication path for data Chain of sensors perform condition and failure monitoring Data is sent to tower Tower uploads data to web accessible database Query data for location, rail force, high rail temperatures, etc. 2009 13
New SmartPlug Data Paths to GIS Database 2009 14
Field Testing for Communications Range Field tested long range communications signal Achieved > 1 mile range on both tangent and curved track Develop webaccessible GIS and database for all sensor data Graphical display of sensor and calculated data for maintenance prioritization and risk analysis Tangent track range test Curved track range test Monitor for track failures and send e-mail and phone calls to emergency contacts 2009 15
SmartPlug Database/GIS (Specifications) Database for all SmartPlug data will work off of a GIS platform Web accessible Sort and Query functions Graphical Display Data (rail temp., RNT, rail force versus time) Lat/Lon GPS and milepost locations Data from track charts and other site data Google-Earth type birds eye views Current and forecasted site weather data Uploads data from sensors and data dump from roving collector units Auto-send alert function (phone/e-mail) for track failure conditions 2009 16
SmartPlug Thank You. 2009 17