Sperry Rail International A Rockwood Company. Non-destructive Testing of Rail

Transcription

1 Non-destructive Testing of Rail Bob Crocker

2 Background Hither Green disaster November 1967 Section of rail at a bolted joint came away Caused by cracks growing from bolt holes Realisation that cracks too small to be detected by visual inspection could cause catastrophic failure Real NDT arrived

3 Overview Rail is an engineering structure like many others Strength and stiffness based on material properties and shape However, introduce a sharp tipped crack as a stress intensifier and all bets are off Huge holes have no effect as long as the radius is large

4 Network Rail Infrastructure Network Rail owns approximately 21,000 miles of track, therefore 42,000 miles of rail This is comprised of approximately 16,000 miles of continuously welded rail (CWR) and 5,000 miles of jointed track, so millions of welds and bolted joints This includes approximately 35,000 switch and crossing (S&C) units.

5 The Facts of Life Cracks can occur anywhere at any time miles and S&C to cover

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7 Outside Direction of Travel

8 Inside (1) Tache Ovales

9 Broken and Defective Rails Inside (2) Star Cracks

10 Welds

11 Outside NDT Surface Breaking Visual Magnetic particle Dye penetrant Mainly electromagnetic eddy current ac fm Lizard

12 Outside

13 NDT of Welds Specialist techniques such as GULS, and radiography. Ultrasonic Procedure U6. U6 requires two hand held probes mounted in a tandem jig. It takes around 40 minutes per weld and is notoriously unreliable and operator sensitive. THESE ARE ALL SPOT INSPECTIONS

14 NDT of Welds The task is to inspect the millions of welds in track routinely and frequently. Once they have survived the first few weeks statistically they do not fail. All routine ultrasonic rail inspection treats welds as plain line. Welds develop many defects that are similar to plain line defects and they are detected by the normal ultrasonic procedures.

15 Inside NDT Objective: find everything test it often pre-emptive crack detection defect management to replace crisis recovery How: comprehensive ultrasonic inspection

16 Who are we? The Worlds First Company to Provide the Railways with a Rail Flaw Detection Service Worlds Largest Rail Inspection Company Over 65 Years Experience in Rail Flaw Detection An Expanding Fleet of over 120 vehicles The Only Company Totally Focused to Rail Flaw Detection

17 - We ve been around awhile

18 Customer Base Europe North America Network Rail (UK) Amtrak LUL (UK) BNSF Sweden CSX Norway Norfolk Southern Germany Canadian Pacific Estonia Canadian National Finland New York Subway Switzerland India China

19 Horizontal Defects (0 Degree) A B C D E A B C D E

20 Transverse Defects Tache Ovales (0 and 70 Degree) A B A B A B A B

21 Hole-in-the-Web Defects (37 Degree) A B C D E A B C D E

22 RSU on Rail

23 RSU Tire 70 Degree Probe Coverage 37 Degree Probe Coverage 0 Degree Probes Coverage 0 Degree Probe 37 Frw Degree Probe 70 Rev G, C & F Degree Probes 70 Frw G, C & F Degree Probes 37 Rev Degree Probe

24 Side Worn Rail

25 Dipped Joint Inspection

26 Sperry UTU 2

27 RSU Mounting

28 Sperry 200 Rail Bound Non Stop Inspection Vehicle

29 Sperry Road Rail Vehicle

30 Land Rover

31 UTI and UTU 3 Due to enter service during summer Five ultrasonic vehicles. Rail bound vehicles covering >100 miles per night at 30 mph testing speed. Road rail vehicles working in possessions at testing speeds up to 20 mph.

32 Sperry Walking Stick

33 The Usual Pose

34 Benefits of an RSU Walking Stick Complete coverage of head cross section in one pass of the operator Inspects worn rail and through corrugation Inspects through rust, wheel burns and squats Can inspect severely head spread rail U16 Bolt hole inspection U17 Rail Foot corrosion monitoring

35 B-scan Presentation

36 Rail Depth Display Rail Depth Calibration

37 Test Procedures / Standards Integrated Manual / Mobile Inspection Common Rail Inspection Procedures Common Calibration Standards Common Defect Classifications Common Defect Detection / Rejection Levels Common Defect Reporting Systems Common Defect Location Systems

38 Typical Defect Reports

39 Electronic Verification

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43 Benefits Manual and Mobile Inspection working in harmony Reliable defect data Reliable defect database Reliable asset management information

44 Summary Specialist techniques such as GULS, Lizard and radiography for spot inspections such as S&C and Welds Frequent, comprehensive ultrasonic inspection of plain line, welds and joints using vehicles and walking sticks equipped with Roller Search Units Objective is pro-active defect management, rather than reactive crisis recovery

45 A Parting Thought!!!! The Most Important Defect is not the Smallest we can find but the Largest we miss.