SANJEEV RATHORE :SSE/PWAY/USFD/DHG STAR-CRACK SANJEEV-KUMAR-RATHORE S.S.E./PWAY/USFD/DHG DIV:AHMEDABAD WESTERN RAILWAY 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

BOLT-HOLE CRACK (STAR-CRACK) BOLT HOLE CRACK IS DETECTABLE BY NORMAL PROBE SINCE THEY OBSTRUCT THE PATH OF SOUND WAVES AND LEAD TO DROP/LOSS OF BACK WALL ECHO. IF THE CRACKS ARE SO LOCATED THAT THEY ARE UNABLE TO BE SCANNED BY 0°PROBES DUE TO SMALLER SIZE OR ORIENTATION,SUCH CRACKS MAY NOT BE DETECTED IN INITIAL STAGES OF THEIR DEVELOPMENT. FOR DETECTION OF BOLT HOLE CRACKS,37°PROBE ARE IDEAL.THIS IS BECAUSE THE CRACKS DEVELOPING FROM BOLT HOLES ARE GENERALLY OBLIQUE AND PROPOGATE IN THE ZIG-ZAG MANNER 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

SANJEEV RATHORE :SSE/PWAY/USFD/DHG FIGURE:STAR-CRACK-1 FIGURE-1 FIGURE-2 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

FIGURE-STAR-CRACK=2 SANJEEV RATHORE :SSE/PWAY/USFD/DHG 11/22/2018

SANJEEV RATHORE :SSE/PWAY/USFD/DHG FIGURE-STAR-CRACK-3 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

FIGURE-STAR-CRACK-4 SANJEEV RATHORE :SSE/PWAY/USFD/DHG 11/22/2018

BOLT-HOLE CRACK(STAR-CRACK BY O°,4MHZ BOLT-HOLE WITHOUT CRACK BOLT- HOLE WITH CRACK PRESENTED BY SANJEEV RATHORE S.S.E.(PWAY)/USFD/DHG 11/22/2018

STAR- CRACK NOT DETCTABLE BY 0°PR4OBE 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

BOLT HOLE CRACK BY 37°PROBE PROBE=37°PROBE(F/B) FREQUENCY=2MHZ RANGE=200MM PLACE=PROVIDED IN SINGLE RAIL TESTER IN PLACE OF NON GAUGE FACE 70°PROBE(F/B) SENSITIVITY SETTING=THE PROBE SHOULD BE DETECT A 5MM LENGTH SAW CUT AT THE BOLT HOLE LOCATION ORIENTED AT 53°AS SHOWN IN FIGURE.BY BOTH FORWARD &BACKWARD PROBE. THE AMPLITUDE OF SIGNAL SHALL BE ADJUSTED TO 60% OF FULL SCEEEN EIGHT PROCEDURE= THE 37°PROBE F/B SHALL BE FIXED IN RAIL TESTER IN PLACE OF NON GAUGE FACE 70° PROBE WITH SUITABLE PROBE HOLDER SO THAT THE PROBE RUNS ON CENTRAL PORTION OF THE RAIL HEAD ROUND FREQUENCY=ONCE IN A YEAR BEFORE WINTER DURING NORMAL TESTING AS DUE 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

STAR-CRACK - BY 37°PROBE SANJEEV RATHORE :SSE/PWAY/USFD/DHG 11/22/2018

FIGURE SHOWING BEAMPATH OF37°PROBE SANJEEV RATHORE :SSE/PWAY/USFD/DHG 11/22/2018

DETECTION OF STAR-CRACK SANJEEV RATHORE :SSE/PWAY/USFD/DHG 11/22/2018

CLASSIFICATION OF RAIL DEFECT FOR 37°PROBE TYPE OF PROBE TYPE OF DEFECT OSCILLOGRAM PATTERN CLASSIFICATION (A) 37° PROBE SENSITIVITY SET AT 5MM SAW CUT ORIENTED AT53° BOLT HOLE CRACK 1) IN FISH PLATE ZONE 2)IN TUNNEL&APP 3)MAJOR BRIDGE AND APPROACHES 100M EITHER SIDE FLAW ECHO SHOWING MORE THAN 10% HORIZONTAL AND 20% VERTICAL HEIGHT IMR (B) 37° PROBE SENSITIVITY SET AT 5MM SAW CUT ORIENTED AT53° BOLT HOLE CRACK OTHER THAN LOCATION (A) 1)HORIZONTAL=MORE THAN 15% &VERTICAL=MORE THAN 40% 2)HORIZONTAL=MORE THAN 10% &VERTICAL=MORE THAN 20% ……… THAN OPEN FISH PLATE AND CHECK (P)…ANY CRACK FOUND VISUALLY ………………..= Q)…NO VISUAL CRACK FOUND………………………-= OBS 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG

SANJEEV RATHORE :SSE/PWAY/USFD/DHG STAR-CRACK DETECTABLE-PROBE 1) 0°PROBE,4MHZ 2) 37°PROBE,2MHZ 11/22/2018 SANJEEV RATHORE :SSE/PWAY/USFD/DHG