System and Practice of Rail/Weld Testing by Technical ... · PDF file01.08.2017 ·...

Vineet Gupta, SPB1, IRICEN

Sharad Kumar Agarwal, PB, IRICEN

Technical Audit of

System and Practice ofRail/Weld Testing by

USFD

Introduction

A three day technical audit was recentlyconducted in a zone.The audit was conducted by a team ofTrack Directorate and M&C Directorate ofRDSO (5 members) and Faculties of IRICEN(4 members).Three sets of USFD operator along withmachine and registers were audited in detail.Discussed with other operators and ADENs inparallel sessions.

Introduction

Important featuresof any testingsystem are

ReliabilityAccuracyStandardProcedure

System

Reliable

AccurateStandard

Introduction

Any testingsystem comprisesof

ManMachineMethod

Method

M/c

Man

Audit of Data

Railway Board circulated a check list vide No.CT/USFD, Dt.28-10-2014.Data Survey- Sample data of two blocksection from TMS was taken for study.Details

Length- 17 km Rail section- 52 kg, Roll year- 2003Route-B, Annual GMT- 22, Total GMT- 200Total reported defects- 34 DFWO, 63 OBS + OBS(W)

Audit of Data

Thus defective rail and weld wereidentifiedObservation

Few entries in the selected data wereearlier shown as OBS/OBS(w) but onlater date shown as GR/GW.Once reported as GW earlier history iserased.Similar to weld defect history rail defecthistory is also needed.

Audit of Data

Information on USFD machine in use e.g.M/c maintenance log book, probereplacement, M/c characteristics, settingfor temperature variation etc. are alsoneeded in TMS.While rail testing if OBS(w) is found and thesame is tested for weld and found to beDFW(O) then two entries are created in TMS.This may be shown together and countedas one defect.

Audit of Machine

As per Chapter 4 of USFD Manual, themachine shall be

Maintenance ScheduleVisually inspected DailyCalibration of M/c Once in a weekSensitivity setting of M/c Once in 3 daysChecking of the equipmentcharacteristics Once in a month

Sensitivity calibration againsttemperature variation Once in a month

Audit of Machine- Visual

Details of M/cThree rail tester M/c were examined.Make- M/s Paras Electronics (711D)Type- Digital DRT, RDSO approved. Two weld tester M/c were examined.Make- M/s E E C (DS322AT),Type- Digital, RDSO approved.

Audit of Machine- Visual

•

•••

••

ObservationDRT

Charging- Not adequate. Charged up to60%.Electronic units- Good.Trolley- Good.Probe and Shoe- Satisfactory-2, Notgood-1.Alignment cum Lifting Syst.- Satisfactory.Audio Alarm- Sounding.

Audit of Machine- Visual

•••

ObservationWeld Tester

Charging- Adequate.Electronic units- Good.Audio Alarm- Sounding.

Audit of Machine- Visual

Accessories- All but the following wereavailable, (however, availability of sparescould not be verified)-

IIW block- Not calibrated.Stepped Gauge- Not available.

Supply of Spares- (as informed bysupervisors)

Probe- Supply is good.Battery- Supply is good.

Maintenance Practice- Contractual, OK.

Audit of Machine- Calibration

Calibration blocks0º normal probe- 60x50x50 mm steel blockAngular probe- IIW block, as per IS:4904.

ObservationBlocks were available but without validationcertification. Validation may be got done fromEngine Development unit of RDSO.It was apparent that they were not in use.However, operators were proficient in doingcalibration.

Audit of Machine- Sensitivity

RailRail test piece was available andoperators were proficient in ensuring M/c sensitivity.

WeldWeld test piece was available but notconfirming to Para 8.4.1 and Fig. 20(a).However, operators were able to ensureM/c sensitivity but with difficulty andunreasonable gain.

Audit of Machine- M/cCharacteristics

Following seven M/c characteristics areto be checked as per IS: 12666 - 1988

For M/c- (i) Linearity of time base ± 1.25%, (ii)Linearity of amplification ± 3%, (iii) Resolution,(iv) Maximum penetration powerFor Probe- (v) Probe index ± 1 mm, (vi) Probeangle ± 1º, (vii) Dead zone- single crystal < 7mm, double crystal < 3 mm.

Note: Tolerances for railway are shown here andare more stringent than IS.

Audit of Machine- M/cCharacteristics

ObservationsIIW block was the major concern as stated supra.The record keeping was sketchy, without specific

values.A few operators were able to check all the

characteristics while others were unable to do allthe checks. Some of them were even unable toexplain the procedure orally.It is recommended to conduct hands-on

workshop to refresh and sharpen this skill.It is recommended that the incharge USFD, PWI

shall relieve other operators for a day, forchecking M/c Characteristics etc. and inchargeUSFD, PWI shall do test checking of work done byother operators.

Audit of Machine- TemperatureSensitivity

This is necessary to compensate for loss insignal strength due to rise in temperatureduring day.It needs temperature gauging andadjustment of gain.Observation

This checking is not being given dueimportance and records were not beingmaintained religiously by majority of theoperators.

Audit of Proficiency of Operators

All the operators were proficient in pickingand identifying the rail flaws.Some of the operators were findingdifficulties in hand probing includingtandem rig.The soft grease couplent was more viscousand resisting free movement of hand probe.Data feeding for saving A-scan is onlybeing done for IMR defects.

Audit of Proficiency of Operators

Reason for not maintaining A-scan appearsto be casual approach under the disguise oftime constraint. Time taken:- 7-8 min. for first time.Subsequent entries:- 2-3 min.However, machine key board need to bemore user friendly.

It is recommended to conduct hands-onworkshop to refresh and enhance proficiency.

Recommendations- 1 Audit

Introduce a system ofInternal Audit basedon the checklist givenby Railway Board.Internal Audit- Withinthe zone, Divisional in-charge of USFD teamof one Division shalldo technical audit ofother Division’s Team.

Recommendations-2 Training

Conduct FocusedWorkshop of shortduration (2-3 days) totackle one or twoissues.Give emphasis onlearning by Hands-onto sharpen the skill.Conduct RefresherCourses frequently.

Recommendations-3 Accuracy

Arrange Standard TestPieces as per relevant IScodes and RDSO manuals.Give emphasis on RegularValidation to improveAccuracy.Follow Prescribed ManualMethod to improveReliability.Timely check of M/c onnominated days forAccuracy (one operator tobe relieved by Incharge).Test Check by inchargeon nominated days .

Recommendations-4 Data

All data related toUSFD M/c (e.g. logbook, variouschecking) may bemaintain in TMS.TMS may alsocapture A-scanrelated to all defectsand archive it.User may able to doAnalysis of growthpatterns w.r.t. otherrelated parameters.

OPENTO

DISCUSSION