Axle Load Checkpoints (ALC) in Denmark 21.05.2013 Presented by Tom E. Thøgersen, Banedanmark, Teknisk Drift IT - Transition & Integration The Annual Danish Rail Convention 2013
Introductions Wheel/rail interface, Denmark: No measurements/knowledge today about the real forces generated in the wheel/rail interface during operations Track tonnage estimated on the basis of theoretic gross weight of trains, not what the trains really weigh Defects on train level are manually reported by engine drivers and train personnel (what they hear during operations), i.e. subjective judgments 2
Introductions Wheel/rail interface, Denmark: Despite all this: What happens in this very same interface is most likely resulting in the biggest spendings on renewal and maintenance budgets Renewal spendings 2012, Banedanmark (mill. DKK) Track: 65% of total spendings Maintenance spendings 2012, Banedanmark (mill. DKK) Track: 41% of total spendings 3
Introductions Problems from high forces and impacts in the wheel/rail interface Loss of lifetime and acceleration of defect developments for both rolling stock and infrastructure components (a lose-lose situation) How to detect and prevent the formation of high forces and impacts for the benefit of all actors? Forces Forces Accelerated track geometry deterioration Stresses/defects on suspension, axles and other vehicle components, further wheel defect developments Further rail defect developments (crack propagations), rail fatigue (loss of lifetime) Impacts of some defect types are even enforced by increased speeds Other effects: Increased noise and decreased passenger comfort 4
Introductions The classic ALC-systems typically measure the vertical quasi-static og dynamic forces in the track from each train wheel passing the measurement site at a certain constant speed: Parameter Static force (Q): Reasons/what can be deduced from the data (examples) More reliable sums of gross tonnage for the track Axle load/the weight of the cargo/ how many passengers onboard Asymmetric weight distribution 9,134,756 ton Other related reasons (examples) - - - Dislocated cargo - Incorrect cargo-loading Q static Diagonal imbalance in the bogie Right Left - Damaged suspension - Twisted bogie-frame Dynamic force (Q): Out-of-round wheels: - Brake defect/brakes are activated - Wheel bearing defect - Defect on primary suspension - Poor welds/insulated Q dynamic Ovality Wheel flat/ material fallout Polygonization joints in the track contribute to wheel defect formations 5
Agenda 1. Most important milestones achieved and ahead in the project 2. The working principle of ALC-systems 3. Why ALC-systems in Denmark? 4. The ALC-type solution and installations to be applied by Banedanmark 5. Applications and expected gains from the ALC-systems 6
1. Most important milestones achieved and ahead in the project ALC-test on the S-line (Østerport- Nørreport) Final business case for ALC on the mainline Workshop #1 with stakeholders (needs and requirements) Workshop #2 with stakeholders (1 st draft req. specification) EUtender process Select supplier Installation of remaining ALC measurement sites ALC-test on the mainline (Glostrup- Høje Taastrup) Evaluation of ALC-tests. Mainline chosen to be the primary target for installations Project approved in Banedanmark, 4.95 mill. DKK for the first installations incl. SCADAsurveillance First 4 ALC measurement sites chosen Chosen to expand test period on Little Belt Bridge 1 year Final draft req. specification for enquiry EU-tender preparation Approvals for installations Installation and trial run of first ALC measurement site 7
2. The working principle of ALC-systems A typical ALC-installation consists of Approach tracks and lead-on/lead-off tracks at both ends of the measurement area Wireless or wired data transmission Measurement area (4-12 m, depending on system type) Cable crossings/ducts for neighboring tracks that may also be measured Sensors on rails (typically on rail web, under rail foot or embedded in rail) Sensor cables Cable trench RFID-reader for vehicle identification (optional) HW/SW-cabinet for analyzing measurements 8
Light intensity 2. The working principle of ALC-systems Example: The ATLAS FO system from SST AG (tested by Banedanmark) A B C D A Rest B Wheel approach (rail up-bending) Time C D Maximum rail bending (when wheel is directly above sensor) Defect (dynamic oscillations) The measurement range of each sensor is 3.5 m at both sides, so each dynamic impact is actually detected by multiple sensors, which each contribute to the defect analyses 9
2. The working principle of ALC-systems 10
3. Why ALC-systems in Denmark? Approximate number of ALC measurement sites in European countries 15+ 25+ 1 (test) 15+ = None or unknown 3 45+ 20+ 10+ 15+ 5+ 30+ 1+ ALC measurement sites have been used in many European countries at least since the year 2008 Reports about o Reductions in track maintenance costs o Reductions in rail breaks o Increase in lifetime of components o Lower wheel maintenance costs o Better running comfort o Etc. Examples: o o The Netherlands: Yearly savings in the area of 10% on track maintenance costs and approx. 25% on wheel maintenance from an almost 100% coverage of traffics Austria: Business case expecting yearly savings in the area of 3,5 mill. EURO on track maintenance costs for coverage of 10,000 km track 11
3. Why ALC-systems in Denmark? Example studies on the influence of high forces/impacts Empirical studies on high force influences from Modern Railway Track indicate the significance of the variable P Constants β basically indicate that 1 axle of 450 kn force deteriorates the track corresponding to 8 axles with half that force (225 kn) The β/α-ratio further indicates that the high forces mainly contribute to rail surface defects developments and track geometry deterioration The influence of speed Deutsche Bahn AG investigated the influence of wheel flats from freight wagons (Gv) on track maintenance costs at different speeds Costs rise with an increase in speeds For low number of wheel flats For high number of wheel flats 10-20% increase in track maintenance costs for wheels with higher number of wheel flats at comparable speeds 12
3. Why ALC-systems in Denmark? Learnings from tests in Denmark Mainline test, Albertslund: Period of 1 month, high traffic density, 134,568 axles/5,382 trains measured, main goal: Examine the level of wheel defects and axle loads Most important results from the test on the mainline Axles with one or more of the defects/excesses: 1. Wheel defect left and/or right 2. Exceeding max allowed wheel force on one or both wheels (190/200 kn) 3. Exceeding max allowed axle load (22,5 ton) 6,10 % (equal to every 16 th axle passing the test site) Axles with wheel defect left and/or right: 5,98 % (equal to every 17 th axle) Axles exceeding max allowed wheel force on one or both wheels: 1,39 % (equal to every 72 th axle) Axles exceeding max allowed axle load: 0,14 % (equal to every 705 th axle) S-line test, Østerport: Period of 3 weeks, high traffic density, 86,568 axles/7,988 trains measured, main goal: Examine the level of axle loads from single-axle S-line coaches o Generally OK axle loads and low levels of wheel defects, however test was run in spring period where wheel defect levels are lower 13
4. The ALC-type solution and installations to be applied by Banedanmark Interfaces towards operations/maintenance No disturbances to traffic operations (unless intended to) or inherited systems of Banedanmark Identification processes No significant disturbances to track maintenance operations (grinding, tamping, change of rails etc.) Banedanmark s ALC-solution Measuring/detection functionalities Accuracy, static forces: Max. +/- 5% uncertainty for at least 95% of measured wheels at speeds up to 200 km/h Accuracy, dynamic forces: Max. +/- 30 kn uncertainty for at least 95% of measured wheels at speeds up to 200 km/h Measurements of same quality in both driving directions User functionalities and GUI RFID-readers for the recognition of individual locomotives/vehicles (defect developments etc.) Distribution of measurement results to TOCs on the basis of train numbers Search and analysis functionalities for determining loads and defect developments Alarm notifications/data few sec. after passage Results on axle loads, dynamic forces and wheel defects measured - in real-time 14
4. The ALC-type solution and installations to be applied by Banedanmark ALC-site #3 Middelfart- Snoghøj 2 tracks on mainline ALC-site #2 Høje Taastrup- Glostrup 2 tracks on mainline 1-2 tracks on S- line (possible alternative: ALC-site #5, Østerport-Nørreport Positioning of the ALC measurement sites Initially we plan for 4 ALC-sites (possibly 5) From just the first 4 sites around 47% of approx. 12,000 weekly trains on the mainline are measured With a total of 12 future sites, nearly 85% of passenger trains and 90% of freight trains on the mainline are measured ALC-site #5 alone would achieve measurement of some 90-95% of all S-line trains ALC-site #4 Tinglev-Rødekro 1-2 tracks on mainline ALC-site #1 Kastrup-Tårnby 2 tracks on mainline (Note: If agreement with S&B is reached) No. of trains and traffic coverage on a weekly basis on mainline 15
4. The ALC-type solution and installations to be applied by Banedanmark IT- network structure 16
5. Applications and expected gains from the ALC-systems Main applications and gains 1. Better estimates of MGT for fatigue calculations of tracks and bridges 2. Include results on dynamic forces from wheel defects in the fatigue calculations for better judgments on deterioration levels and life-expectancies 3. Real-time surveillance of wheel defects with a view to impose e.g. speed reductions on trains with most critical ones (when feasible in relation to traffic operations and punctuality) 4. Making the data available for TOCs' maintenance workshops o Rough estimate: Expect around a 3.5 mill. DKK reduction in yearly track maintenance costs from the initial traffic coverage if most critical wheel defects are reduced to a minimum (not including savings of TOCs) No plans of using the ALC-systems for safety purposes A need for safety application (prevention of incidents) could require a more expensive ALC-type solution (higher density of installations, accuracy, availability, MTBF etc.) However, no incidents with injuries or high material costs in DK for the past two decades that could have been prevented by the ALC-type system, thus no need for such safety barrier 17
Thank you for your attention!? 18