INNOVATION / MODIFICATION OF EXISTING PARAS MAKE DRT FOR TESTING OF RAILS FOR NBC & GFC TESTING SIMULTANEOUSLY 1. SYNOPSIS 2. INTRODUCTION 3. MODIFICATION OF TROLLEY & PROBE ATTACHEMENT 4. PROBE CONNECTIONS AND DIGITAL CONTROL 5. CALIBRATION AND SENSITIVITY SETTING 6. PROPOSED METHOD OF TESTING 7. FIELD TRIAL 8. FINANCIAL AND PHYSICAL SAVINGS 9. MERIT AS COMPARE TO CONVERTED SRT FOR GFC 10. LIMITATIONS

SYNOPSIS Rail defect inspection technology covers : Rail defect inspection technology covers : i)Inspection frequency. i)Inspection frequency. ii)Inspection methods. ii)Inspection methods. These two factors are playing most important part of Rail defect management system. These two factors are playing most important part of Rail defect management system. This article covers the modification of existing DRT (Paras Make) for testing of rails for NBC as well as GFC testing simultaneously. In which above two factors of rail defect management system are taken in to account. So that the testing cost can be saved and both testing can be carried out with available resources. This article covers the modification of existing DRT (Paras Make) for testing of rails for NBC as well as GFC testing simultaneously. In which above two factors of rail defect management system are taken in to account. So that the testing cost can be saved and both testing can be carried out with available resources.

INTRODUCTION Total annual workload of USFD testing on Western Rly. (after Nov.’07) is Km. Total annual workload of USFD testing on Western Rly. (after Nov.’07) is Km. The requirement of Nos. of operators to cope up this workload is 85 Nos. (including LR) The requirement of Nos. of operators to cope up this workload is 85 Nos. (including LR) Present availability of operators Present availability of operators A) No. of trained operator - 57 Nos. A) No. of trained operator - 57 Nos. B) Existing cadre of operator - 50 Nos. B) Existing cadre of operator - 50 Nos. Arrangement made for training of operator:- Arrangement made for training of operator:- i) Allotment of seats for training at RDSO up to Sec.’07 including extra allotment of 12 seats = 16 Nos. i) Allotment of seats for training at RDSO up to Sec.’07 including extra allotment of 12 seats = 16 Nos. ii) No. of operators being trained by out side agency at W.Rly. = 22 Nos. ii) No. of operators being trained by out side agency at W.Rly. = 22 Nos.

Contd. Arrangement made for creation of cadre of operators & trollymen Arrangement made for creation of cadre of operators & trollymen Creation of 18 Nos. of posts of PWIs along with trollymen is already vetted by HQ Finance & creation of another 17 Nos. of posts of PWIs along with trollymen is under process. Creation of 18 Nos. of posts of PWIs along with trollymen is already vetted by HQ Finance & creation of another 17 Nos. of posts of PWIs along with trollymen is under process. Requirement of machines SRT = 42 Nos. (including one spare Requirement of machines SRT = 42 Nos. (including one spare at Each division) at Each division) DRT = 16 Nos. DRT = 16 Nos. Availability of Machines SRT = 29 Nos. Availability of Machines SRT = 29 Nos. DRT = 16 Nos. DRT = 16 Nos. To fulfill requirement of SRT, 13 Nos. of new SRT ( GFC detector are being procured (P.O. issued ) and 7 Nos. existing m/c are being retrofitted at division level. To fulfill requirement of SRT, 13 Nos. of new SRT ( GFC detector are being procured (P.O. issued ) and 7 Nos. existing m/c are being retrofitted at division level.

Contd. The work load which can be out sourced on CC+6+2 & CC+8+2 routes in alternative round is (including NBC+GFC) The work load which can be out sourced on CC+6+2 & CC+8+2 routes in alternative round is (including NBC+GFC) Keeping in view the above increased requirement of man power and machines, efforts has been made at W.Rly by Shri R P Potdar & Shri Manoj Vyas PWI USFD to make necessary modification in existing DRT m/c so that it can perform NBC & GFC simultaneously. The results are promising & RDSO is requested for examination of technical aspect. This will reduce the workload by Km on W.Rly. Subsequently a saving of operators by 26 Nos. & trollymen by 35 Nos. Keeping in view the above increased requirement of man power and machines, efforts has been made at W.Rly by Shri R P Potdar & Shri Manoj Vyas PWI USFD to make necessary modification in existing DRT m/c so that it can perform NBC & GFC simultaneously. The results are promising & RDSO is requested for examination of technical aspect. This will reduce the workload by Km on W.Rly. Subsequently a saving of operators by 26 Nos. & trollymen by 35 Nos.

Contd. At present with DRT we are doing testing as below – At present with DRT we are doing testing as below – either – either – NBC through rail testing. NBC through rail testing. OR OR GFC through testing as a separate round. GFC through testing as a separate round. We are doing testing of GFC by converting existing (DRT) trolley and by shifting 70º F/B probes by 8 mm towards Gauge face, but with this only GFC testing can be done and for NBC testing additional DRT with operators and staff will be required. It is very difficult to maintain NBC as well as GFC testing frequency with available manpower and machines. We are doing testing of GFC by converting existing (DRT) trolley and by shifting 70º F/B probes by 8 mm towards Gauge face, but with this only GFC testing can be done and for NBC testing additional DRT with operators and staff will be required. It is very difficult to maintain NBC as well as GFC testing frequency with available manpower and machines. Hence this little trial is conducted by this unit after modification of existing Paras make DRT. The trial is satisfactory. The detailed procedure of testing and modifications is described as below :- Hence this little trial is conducted by this unit after modification of existing Paras make DRT. The trial is satisfactory. The detailed procedure of testing and modifications is described as below :-

MODIFICATION OF TROLLEY & PROBE ATTACHEMENT GFC probe attachment :- GFC probe attachment :- Probe carriage arrangement is modified and extended with steel bracket of length 55 Cm and this is totally detachable and attachable arrangement. Probe carriage arrangement is modified and extended with steel bracket of length 55 Cm and this is totally detachable and attachable arrangement. Whenever require this arrangement can be attached with overlap of 15 Cm by bolts and both GFC as well as NBC testing can be done simultaneously. Whenever require this arrangement can be attached with overlap of 15 Cm by bolts and both GFC as well as NBC testing can be done simultaneously. Probe holding assembly for GFC probe :- Probe holding assembly for GFC probe :- Single crystal probe of 70º F/B housed in same assembly is additionally attached with extended bracket by modified probe holder and `U’ clamp by bolts (see photograph). The `U’ clamp is modified in such a way that its holding central bolt / rod is shifted by 8mm from centre. Hence 70º F/B for GFC testing will always scanning the rail as per desired norms. Single crystal probe of 70º F/B housed in same assembly is additionally attached with extended bracket by modified probe holder and `U’ clamp by bolts (see photograph). The `U’ clamp is modified in such a way that its holding central bolt / rod is shifted by 8mm from centre. Hence 70º F/B for GFC testing will always scanning the rail as per desired norms.

NOW THE MODIFIED TROLLEY IS HAVING FOLLOWING ARRANGEMENT NOW THE MODIFIED TROLLEY IS HAVING FOLLOWING ARRANGEMENT 0º – 4 MHz probe ahead of trolley. 0º – 4 MHz probe ahead of trolley. 70º F/ B 2 MHz S/C probe in middle position to scan central cross section of rail. 70º F/ B 2 MHz S/C probe in middle position to scan central cross section of rail. 70º F/B -2MHz S/C probe in rear of trolley wheel with extended bracket. This is GFC probe with modified probe holder shifted towards Gauge face by 8 mm. 70º F/B -2MHz S/C probe in rear of trolley wheel with extended bracket. This is GFC probe with modified probe holder shifted towards Gauge face by 8 mm. Contd…

Present USFD DRT Electronic unit is having 06 channels as below : Ch.No. 1Left side 70 degree Forward. Ch.No. 2 Left side 70 degree Backward. Ch.No. 3Left side 0 degree Normal. Ch.No. 4Right side70 degree Forward. Ch.No. 5 Right side 70 degree Backward. Ch.No. 6Right side 0 degree Normal. Now if we attach additional GFC probe 70 Degree F/B we require 02 channels. To fulfill this condition we have to make following arrangement of connections. Ch.No. 1- Connection of GFC 70 degree forward as well as backward probe in only one socket. Ch.No. 2-Connection of NBC 70 degree forward as well as backward probe in only one socket. Ch.No. 3- 0degree - 4 MHz as existing system. Ch.No. 4- Same as channel No.1 Ch.No. 5- Same as channel No.2 Ch.No. 6- Same as channel No. 3 This is the modified connection arrangement with control rear panel (See figure [1])panelfigure PROBE CONNECTIONS AND DIGITAL CONTROL

CALIBRATION AND SENSITIVITY SETTING Horizontal calibration for all channels to be carried out as per available instructions. Horizontal calibration for all channels to be carried out as per available instructions. Sensitivity setting & vertical calibration : Sensitivity setting & vertical calibration : i)GFC Probe Ch.No.1 Forward/Backward in same channel. Sensitivity setting is carried out on 5mm dia hole peak of 60 % full screen height. Sensitivity setting is carried out on 5mm dia hole peak of 60 % full screen height. a) For forward GFC probe programme No.1 - Ch.No. 1. a) For forward GFC probe programme No.1 - Ch.No. 1. b) For backward GFC probe programme No.2 - Ch.No. 1 accordingly gain values to be saved. b) For backward GFC probe programme No.2 - Ch.No. 1 accordingly gain values to be saved. ii)NBC probe Ch.No. 2 forward/backward in same channel. Sensitivity setting carried out on 12mm dia hole - Peak of 60 % full screen height. Sensitivity setting carried out on 12mm dia hole - Peak of 60 % full screen height. a) For forward NBC probe Programme No.1 - Ch.No.2 a) For forward NBC probe Programme No.1 - Ch.No.2 b) For backward NBC probe Programme No.2 - Ch.No. 2 accordingly gain values to be saved. b) For backward NBC probe Programme No.2 - Ch.No. 2 accordingly gain values to be saved. iii)Ch.No. 3 Now MHz D/C probe for bottom 5 mm dia hole. Peak of 60 % full screen height in programme No.3 iv)Same procedure is repeated for Ch.No. 4, 5 & 6 v) As per RDSO letter No CT/USFGD- dt – We have to increase gain by 6 dB ( for GFC 70º probe) – As both forward & backward probe are connected with one BNC connector in one channel. It is difficult to display both gain value in one programme. Hence it is decided that for Ch No.1 – Prog. 1 & 2 from 02 gain values which is higher in taken for safer side and by adding 06 dB it is saved in Ch.No.1.Prog. No.3 and same thing repeated for Ch No.4. We have to increase gain by 6 dB ( for GFC 70º probe) – As both forward & backward probe are connected with one BNC connector in one channel. It is difficult to display both gain value in one programme. Hence it is decided that for Ch No.1 – Prog. 1 & 2 from 02 gain values which is higher in taken for safer side and by adding 06 dB it is saved in Ch.No.1.Prog. No.3 and same thing repeated for Ch No.4. Now for Ch.No.2 is already the higher gain value from Prog.No.1 & 2 is to be saved in Prog.No.3. This is for central probe 70º F/B same thing is repeated for Ch.No.5. Now for Ch.No.2 is already the higher gain value from Prog.No.1 & 2 is to be saved in Prog.No.3. This is for central probe 70º F/B same thing is repeated for Ch.No.5.

PROPOSED METHOD OF TESTING Now actual through testing is carried out by taking Prog.No.3 in which 70º F/B probe – GFC & central having safer gain and actual gain of 0º normal probe. Now actual through testing is carried out by taking Prog.No.3 in which 70º F/B probe – GFC & central having safer gain and actual gain of 0º normal probe. During testing if any defect arise the categorization of defect can be done as below :- During testing if any defect arise the categorization of defect can be done as below :- 0º normal probe – detectable flaws can be marked easily by using Prog.No.3 echo pattern of Ch.Nos.3 & 6. 0º normal probe – detectable flaws can be marked easily by using Prog.No.3 echo pattern of Ch.Nos.3 & 6. But for 70º F/B central & GFC probe there is some modification as below : But for 70º F/B central & GFC probe there is some modification as below : As any moving echo is seen on screen during testing. As any moving echo is seen on screen during testing. First it should be analysed by Ch.No.1 OR 2 and Ch No.4 OR 5 depending upon whether this flaw is detectable by GFC probe or NBC probe. First it should be analysed by Ch.No.1 OR 2 and Ch No.4 OR 5 depending upon whether this flaw is detectable by GFC probe or NBC probe.

If the flaw will be from GFC probe then by observing its movement i.e. from right to left and left to right. It can be decided that whether it is from forward or backward probe. If the flaw will be from GFC probe then by observing its movement i.e. from right to left and left to right. It can be decided that whether it is from forward or backward probe. While doing classification of defect as per GFC norms by reducing 6 dB it should be marked. Hence by changing Prog.No.3 to 1 for forward & Prog.No.3 to 2 for backward probe defect can be classified. While doing classification of defect as per GFC norms by reducing 6 dB it should be marked. Hence by changing Prog.No.3 to 1 for forward & Prog.No.3 to 2 for backward probe defect can be classified. If the flaw is from central 70º F/B probe then by observing its movement from right to left & left to right, it can be decided that whether it is from forward OR backward probe. If the flaw is from central 70º F/B probe then by observing its movement from right to left & left to right, it can be decided that whether it is from forward OR backward probe. Then by changing Prog.No.3 to 1 & Prog. No. 3 to 2 actual height of NBC peak can be observed and defect can be classified as per actual height. Then by changing Prog.No.3 to 1 & Prog. No. 3 to 2 actual height of NBC peak can be observed and defect can be classified as per actual height.

FIELD TRIAL The field trial testing was carried out with modified DRT / 201 / 75 between NDB - DWD section. Looking to the working of probe system and trolley working, it was found satisfactory. The field trial testing was carried out with modified DRT / 201 / 75 between NDB - DWD section. Looking to the working of probe system and trolley working, it was found satisfactory.

FINANCIAL AND PHYSICAL SAVINGS i)By one DRT 1200 ETKM track can be tested with two operators and supporting staff in one year whether it will be either NBC or GFC testing. i)By one DRT 1200 ETKM track can be tested with two operators and supporting staff in one year whether it will be either NBC or GFC testing. ii)But by this modified system same 1200 ETKM can be tested for GFC as well as NBC simultaneously i.e ETKM can be tested by two operator in one year. ii)But by this modified system same 1200 ETKM can be tested for GFC as well as NBC simultaneously i.e ETKM can be tested by two operator in one year. iii)i.e. work load of one DRT with two operators and supported staff can be saved. iii)i.e. work load of one DRT with two operators and supported staff can be saved. iv)i.e. approximately 26 nos of PWI’s and 35 nos of Trollymen can be saved on account of rail testing in a year with existing machine. iv)i.e. approximately 26 nos of PWI’s and 35 nos of Trollymen can be saved on account of rail testing in a year with existing machine.

MERIT AS COMPARE TO CONVERTED SRT FOR GFC i)The rated out put is double as that of SRT with GFC. i)The rated out put is double as that of SRT with GFC. ii)DRT trolley conversion is easier than SRT and locally possible. ii)DRT trolley conversion is easier than SRT and locally possible. iii)Alignment of probe is shifted position towards gauge face is comparatively better than SRT. iii)Alignment of probe is shifted position towards gauge face is comparatively better than SRT. iv)Even dedicated SRT of GFC testing are also giving problem of gain setting for 6 dB by potentiometer arrangement. iv)Even dedicated SRT of GFC testing are also giving problem of gain setting for 6 dB by potentiometer arrangement.

LIMITATIONS i)It requires various sets of calibration in different programme. Hence require sufficient practice and field trial before testing. i)It requires various sets of calibration in different programme. Hence require sufficient practice and field trial before testing. ii)As both forward and backward probe connected in single socket, the flaw can be identified by only its movement on screen (instead of channel) whether it is detectable either by forward probe or back probe. ii)As both forward and backward probe connected in single socket, the flaw can be identified by only its movement on screen (instead of channel) whether it is detectable either by forward probe or back probe. iii)As this is multi-channel electronic unit and both forward and backward probe connected in single socket, the testing is to be carried out with single gain value for 70 ° GFC & central probe. iii)As this is multi-channel electronic unit and both forward and backward probe connected in single socket, the testing is to be carried out with single gain value for 70 ° GFC & central probe.

CONCLUSION Looking to the testing procedure, the testing of central and GFC probe is carried out by common gain. But this gain is most safer gain as the value is maximum gain of GFC probe + 6dB and maximum of forward & backward central probe. Hence there is not a single chance of missing any flaw for GFC or NBC testing. And at the time of classification we are marking by observing peaks in different programme hence there are also no chances for wrong marking or over marking. Looking to the testing procedure, the testing of central and GFC probe is carried out by common gain. But this gain is most safer gain as the value is maximum gain of GFC probe + 6dB and maximum of forward & backward central probe. Hence there is not a single chance of missing any flaw for GFC or NBC testing. And at the time of classification we are marking by observing peaks in different programme hence there are also no chances for wrong marking or over marking. Hence looking to the testing procedure and expenditure made on modification of equipment, it is most economical testing procedure and can be implemented easily with available resources. Hence looking to the testing procedure and expenditure made on modification of equipment, it is most economical testing procedure and can be implemented easily with available resources.