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Alex Wilson Memorial LectureA L Sonneveld MD TERMI-MESH Sydney Pty Ltd
Keywords: AINDT Alex Inaugural Sonneveld Wilson
The AINDT has decided to incorporate the Alex Wilson Memorial Lecture as a permanent part of the program of all AINDT national conferences. Clearly it is to honour the memory of Alex Wilson, but by inference it honours the other significant people in the formation of our Institute. It will provide a platform for significant statements on NDT and related activities to be delivered to audiences comprised of persons to whom the address should resonate and then generate a response. It is only fitting in this inaugural address that the focus is on Alex himself.
I am delighted to have been asked to present the inaugural lecture in honour of my old friend and colleague, Alex Wilson. Sadly Alex passed away before he was aware that the Australian Government had recognised his achievements and posthumously awarded him an AM, Member of the Order of Australia on Australia Day 26/1/2000. The award citation was a precis of what our current Federal Secretary, Col Hocking, published in our NDT journal
Alex Wilson, the main instigator in the formation, and principle driving force behind the development, of the AINDT passed away on 17 May 1999 aged 79 years. A generous and forthright man who had a strength of conviction to see an idea in which he believed, grow from its origins to an effective national institute to the benefit of all Australians.
Alex was born at Prahran in Victoria on 10th December 1919. He gained his ASTC in Metallurgy in 1943. He has since gained a number of honorary awards, including Fellow, Australasian Institute of Mining and Metallurgy and Honorary Member of AINDT.
He has held numerous honorary positions with various technical societies over the years, including
I have included in the conference proceedings an address presented by Alex to our NSW AINDT Branch on 8th August 1989.
I commend that you read his story which is a reflection of the development of NDT in Australia over the past 50 years paralleled with Alex's pioneering spirit, his preparedness to have a go, his insatiable search for knowledge, his compassion and understanding of people and his volunteering commitment to so many organisations mentioned earlier. His poignant address deserves international recognition in these proceedings.
Early in 1963 Alex along with Don Fifer and Phil Onions germinated the idea of an Association. Soon Messrs Auberson, Gillespie, Spence and Robinson joined with them and formed a committee. Alex was elected as the first President. The inaugural public meeting with 250 people in attendance met on 30th May, 1963 giving formal birth to the NDTAA.
In March 1965 Alex addressed 50 people at the University of Melbourne and the Victorian chapter was created with Tol Goldfinch as Chairman and Bob Sheldon as Secretary.
In August 1967 a National organisation was created with Alex Wilson elected the first Federal President and Jim Cole as Secretary / Treasurer. March 1969 saw the creation of the SA Branch under Lyall Heard as President and Gerry Savage - Secretary.
The Qualifying Board , now called Certifying Board under the Chairmanship of Irwin Ferris was constituted in September, 1971. Alex Wilson was a founding member and remained on the board for the next 9 years.
1973 saw the establishment of the Western Australia Branch with Jim Shannon President and Dick Taylor Secretary.
Alex and Keith Stanton, Deputy Registrar of NATA conducted a successful NATA assessment of my Metlab NDT laboratory in Brisbane early in 1973. Their support and encouragement prompted me to stimulate the formation of a Queensland Branch of NDTAA which occurred in April 1973 under the Chairmanship of Brian Stott. Vince Preston, Robin Malcolm, John Fletcher, Neil Schuler and Derek Payne all assisted with the creation of this new Branch. Can you can imagine how proud I am that 28 years later the Queensland Branch is hosting this 10 A-PCNDT in this wonderful Brisbane Convention Centre.
At this point it would be appropriate to congratulate the Queensland Branch Steering Committee chaired by Robin Malcolm for organising this wonderful conference. Particular thanks must go to John Maccarone - Federal President AINDT
I have presented a thumbnail sketch of how, when and who started our Institute under the tutelage of Alex Wilson.
I have informed you of how it started, but who has carried the baton over the past 38 years? The attached spreadsheet (Table 1) acknowledges those individuals who have contributed to our Institute; you will notice that Alex Wilson is up there with Lyall Heard, Keith Stanton, John Maccarone, Gary Martin, Toll Goldfinch, Jim Cole and the current President of A-PCNDT Mr Derek Olley.
I was Federal President 1981 - 1983 when the 4th Pan Pacific Conference on NDT was held at the Manly Pacific Hotel In Sydney Australia. I welcome back to Australia all those delegates, who visited Sydney 18 years ago in November 1983.
Recognition for Federal activities does not reflect the grass root contribution at Branch level however there are too many people to mention. Naturally there are many personalities that have helped create and shape our industry over the past 35 years that weren't necessarily involved with the Institute, namely Alex Kerr, Reg Philips, Bill Jenkins, Fritz Boegel, Keith Jackson, Charles Pope, Don Searle, Arthur Harvey, Norm Gallagher, Stan Ambrose, Col Rumble, Mike Hordern, Alan Virgo, Gabe Timms, Neville Chrimes, Dave Minotti and Phil Hearns, to mention a few.
Analysis of Table 1 reveals that only 12 of the 32 are currently active in the Institute and some of those people have already been involved for 20-30 years and can not go on forever. The concept of Succession Planning must be included into the long term Strategic Plan because suitable committed people will be pivotal to the growth, prosperity and posterity of the organisation. We must ensure what Alex Wilson started in 1963 survives 2001 and beyond.
More energy required extra fossil fuelled power stations and an improved electricity transmission grid. The Snowy Mountain Hydro Electric Scheme sprang to life with the infusion of migrants from all over the world.
Bass Strait oil and gas was discovered and the country entered a whole new era less dependent on imported oil.
Many government departments (shipyards, electric power industry, Defence, etc ) had the personnel and funds to dabble in NDT of armaments, munitions, pressure vessels then along came the Hifar Reactor at Lucas Heights which brought the first commercial NDT contractors to Australia about the time Alex Wilson started the NDTAA.
In the beginning, there was ETRS and METLAB, both progressively expanded around Australia with varying degrees of success. These two privately owned companies trained and spawned most of the NDT technicians throughout the 70's supporting heavy engineering, steel making, general manufacturing, mining, power and petro- chemical industries. Cooper Basin natural gas was piped to Adelaide, Sydney, Canberra and Newcastle; most of these pipelines were X-rayed by either ETRS or Metlab.
The North West Shelf Woodside North Rankin field brought many international players to Western Australia to compete for large contracts. Most of the NDT outfits now either cease to exist or have gone home. Some regional companies slowly but progressively consolidated their market share by investing in specialist equipment and specific market segments eg Pilbara NDT, C W Pope and Intico.
NATA took the initiative early in the piece to introduce NDT laboratory registration, inclusive of industry based endorsed technician and technologists. Essentially this practice still exists, however new personnel must possess AINDT Certifying Board recognition in relevant categories. Whilst Alex Wilson was separate from commercial companies he was actively involved with NATA assessments and the general improvement of knowledge and expertise in the industry. He personally supported and encouraged many young professionals to take up a career in NDT. Whilst he retired from ECNSW now Pacific Power in 1982 he continued to work as a consultant and still regularly attended AINDT committee meetings and social functions until his passing.
Without any local development and manufacture of NDT equipment, Australia has been host to gear from UK, Japan, USA and Continental Europe; making it expensive and difficult to service. The current low value of the Australian dollar makes equipment even more expensive. Previously most equipment operated by NDT companies was adaptable enough to service various customers and industry sectors whereas today expensive specialist equipment can often be limited to 1 - 2 customers.
NDT technology is constantly being improved and new methods developed, particularly in an effort to keep pace with the development of new materials (ie. composites) and applications. Advances in the use of lasers and imaging technology (including video, holography and thermography) have made non contact NDT more viable in many situations.
Optical fibres and new piezo-electric materials are allowing the creation of intelligent materials and structures which can not only monitor themselves but may even respond to their environment. Computer advances have allowed signal processing techniques and expert systems to be used which enhances the quality of the information obtained using traditional and new NDT methods.
20 years ago I penned some verse about computers and the need to CHANGE. It is a shame I didn't heed my own advice! Nevertheless I shall recite this verse for you now:
The demise of manufacturing and the competitive nature of petro-chemical processing in Australia today have seen traditional markets very much depressed. However mining exports, LNG plants, defence and the aerospace industries provide continuity of work.
Technical society membership is stagnant; attendance at functions and conferences is substantially reduced compared with 20 years ago primarily due to alternate attractions in life eg. sports, entertainment, the Internet etc. We could do with an infusion of Alex Wilson's foresight, honesty, enthusiasm, commitment, dedication and tenaciousness.
Alex lived for 79 years with a major spinal deformity, a miracle in itself. He often had difficulty sleeping, he regularly used the floor as his desk as it was more comfortable. A workaholic by nature he still found time to devote to his own and his extended family. If there was a Para Olympics for engineering knowledge, public service and administration, he would have won Gold time and time again.
|Name||State||Federal Council Meetings||Recognition Status within AINDT||QB / Certifying Board Meetings||Current AINDT Involvement|
|1||L S Heard||SA||22||Honorary||18||Retired|
|2||A R Wilson AM||NSW||19||Honorary||10||Deceased|
|3||K N Stanton||Vic||-||JHC||26||Deceased|
|4||J Maccarone *||Qld||14||Honorary||9||Active|
|5||A L Sonneveld *||NSW||22||Honorary||-||Active|
|6||T E Goldfinch||Vic||8||Honorary JHC||14||Retired|
|7||G Martin *||Vic||16||Honorary||5||Active|
|9||R Everett OAM *||Vic||6||Honorary||13||Active|
|10||R S Gilmour||Vic||12||Honorary JHC||6||Retired|
|11||J H Cole||Vic||18||Honorary||-||Deceased|
|12||D Olley *||Qld||18||Honorary||-||Active|
|13||P Sheedy *||NSW||5||Honorary||12||Active|
|15||G Williams *||WA||8||Honorary JHC||8||Active|
|16||E J Owen *||NSW||14||-||-||Active|
|19||G Barber *||WA||10||-||-||Active|
|20||M Callanan *||WA||10||-||-||Active|
|21||R W Sheldon||Vic||9||-||-||Retired|
|22||R Keld *||Vic||9||-||-||Active|
|26||D Barnett *||NSW||-||-||7||Active|
|27||R A Carter||S A||7||-||-||Deceased|
|28||D E Fifer||NSW||7||Honorary||-||Retired|
|29||J O Currie||NSW||-||-||6||Deceased|
|31||R W Taylor||WA||6||-||-||Retired|
|Table 1: AINDT Historical Meeting Schedule & Current Industry Activity of Committed People|
JHC is the coveted James Henry Cole Award -
The award has been created to perpetuate the memory of James Henry Cole, one of the founders of AINDT. Jim, who was Federal Council Honorary Secretary and Treasurer until his death, was an untiring worker for the Institute. The recipients have made a significant contribution to Non-Destructive Testing in Australia.
|Table 2: Past & Present Personnel Deployment by Australian State|
Children playing an electronic game,
Controlling LCD characters in each frame,
Chasing themselves with high scores to lay claim,
Challenge any adult to achieve same.
Computer or alternatively microprocessor,
Configuration of digits and numbers galore,
Confusing to some, that's for sure,
Collating life's detail more and more.
Consider the cash registers whenever you buy,
Calculator's abound, the business ally,
Chip development accelerates, never to die,
Capable of anything, not 'Pie in the sky'.
Change is upon us, they've sown the seed,
Courage and conviction is what we need,
Confident that we may well take heed,
Creating a new school or N.D.T. breed.
College courses can help you keep abreast,
Commit yourself now, not much to request,
Consolidate knowledge and pass the test,
Concede it is fruitful time to invest.
Complacent people will think for a while,
Contemplating these thoughts as futile,
Content to sit back and smirk or smile,
Confounding what will be the future style.
Conventional testing certainly isn't spent,
C.R.T.'s are necessary, even though ancient,
Circumstances are changing by the moment,
Cultivating test repeatability and advancement.
Contest my words, call them untrue,
Consequently, you will try nothing new,
Conduct a thorough literature review,
Changes are happening, what about you?
NON-DESTRUCTIVE TESTING-A LIFETIME OF DISCOVERY AND ADVENTURE
An address to NSW Branch, AINDT,
by Alex Wilson 1989
How many of the industrial radiographers present are aware that Victoreen and his associates developed the condenser dosimeters only 63 years ago? 1926 ! Did any of you know it was only in 1934 that Irene & Joliot Curie first discovered "artificial radio-activity"? It is probably even more surprising to know their references were to "radio-" nitrogen, magnesium and silicon!
Twenty six years ago, I became involved in creating a technical society, now the A I N D T , though my interest in non-destructive testing "sparked off" 34 years earlier in 1929, the period of my opening remarks, and just one year after the formation of ICRP - the International Council for Radiation Protection.
In 1929, stripped to my silken shimmy shirt, I was let into a semi-dark room, firmly lashed down to a cold metallic table in the midst of what appeared to be a four-poster bed with wires strung around the post tops, told to hold my breath for fifteen long seconds, and then subjected to a minor fire-works display. Sparks flashed above and around me and I had the option of being terrified or fascinated, I chose the latter! The end result of this adventure was a shadow-graph of the compaction damage to my lumbar spine suffered many years previously. The machine involved in that diagnostic procedure had a consumable anode devoid of cooling and delivering X-rays of debatable quality from electrons whacked by about 100 kv and at very low milli-amp current. Exposure time was of the order of 10 seconds. Note, such a procedure was very much in its early stages of development.
My next close encounter was with a 400 kVp unit used in Defence Research Labs, located at the DeHaviland aircraft plant in Lidcombe, when I was investigating the development of sound, crack and porosity free high-conductivity copper castings to convey sea-water coolant when inserted in the shaft section of iron blast furnaces at Port Kembla Steelworks in the mid-40's.
In 1954, I joined the Electricity Commission of NSW, charged with the task of establishing a metallurgical service to that large heavy engineering organisation. My interests rapidly focussed on detection of fabrication and in-service deterioration and faults, first in metals, and later in a full range of engineering materials. I studied welding with particular attention to recognising faults developed by the various welding methods and the means to correct and eliminate them. With this knowledge and the ever-present awareness of the vagaries of metal solidification, I learned what to look for and where and how to find the evidence to establish corrective action to prevent potential failure or recurrence of such deterioration. By heeding the fundamentals of material science it is not necessary to develop complicated and possibly damaging procedures, it is far more logical to seek simple preventative and corrective action to avoid in-service failures.
Thus was born my active and continuing interest in non-destructive testing. My philosophy may be crystallised as follows:
"Seek only what you need to know for a reliable assessment, then give sound advice for correction, where required, in simple unambiguous language clearly understood by your audience." Many tests, both physical and chemical, are performed on the basis of tradition or habit, contribute nothing to an assessment and may display ignorance of the factors significant for corrective action.
The fascination of N-DT is in the ever expanding knowledge and the pursuit of accuracy in measurement and precise location of significant features of materials under examination.
I ran the gamut of X-ray equipment in Australia, from 100 to 400 kVp, and glimpsed Linacs in operation in America and Japan examining steel welds up to 26 inch (650 mm) thick in nuclear containment vessels. Of the isotopes applied to industrial radiography I handled radium, radon, cobalt, caesium and iridium. The early handling methods were crude by comparison with modern procedures, so gave rise to some ingenuity in the development of methods to limit personal dosage. (We applied the ALARA principle, i.e. As Low As Reasonably Achievable). The initial procedure involved use of a fine gold chain attached to the isotope encapsulation which was hoisted by a fishing line to a distant cup pre-attached, generally by a magnet, at the desired point for exposure. Next, we had simple metal rods screwed on one end to mate with a secondary encapsulation of the isotope. In the late 50's Falk and other suppliers produced remote control devices for projecting a "pencil" with isotope attached - - - this was O.K. until the pencil fell off and hurtled down a penstock, for instance! So we developed a belt and braces arrangement comprising a bayonet cap and sprung socket attachment on the end of aluminium tubing. More recently, with the application of appreciably higher energy containing isotopes, there have been many developments of remote handling devices, some good - some not quite so, but with which industrial radiographers are familiar.
During the Summer of 1954/55 I had an interesting challenge in a request to examine a triple drum boiler at Yanco in the Murrumbidgee Irrigation Area. Armed with a couple of radon "needles" (normally used for radio-therapy in the treatment of cervical cancer) Harry Beadle and I sped off from RPA Hospital to our southern appointment with the 40 plus year old veteran boiler. To complete the exercise, we converted a local country dunny into a darkroom having an ambient over 40°C and proceeded to bend all the rules for film processing. There was no running water, and we managed to denude all the local domestic refrigerators of their iceblocks. It was very rewarding to produce clear proof of extensive caustic embrittlement (cracking) ahead of a potential catastrophic boiler explosion.
A further testing of the rules involved radiography of steam range piping in service at 565°C. It was necessary to air-cool the isotope, Co 60, and protect the film by an interposed water-cooled cassette carrier. The pipework was 350mm diameter x 70mm wall, at pressure of 2500psi. We did get pictures! I drew the line at using Cs 137 as it, being a comminuted source, was too dangerous, quite apart from its marginal possibility of penetrating the mass of steel involved.
The stewards of a Sydney horse racing club presented a suspect hot saddle for advice. A high voltage "buzzer" coil and associated devices were revealed. It was possible to identify the important items, their branding and almost certain source of purchase in Singapore and Hong Kong! Exit amazed stewards.
Drug detection by X-ray procedure is well known, despite its limitations, but when it is a matter of internal bodily concealment there is a problem of human rights, one cannot X-ray a person without their knowledge and consent. It is in fact possible to examine a person sitting on a bench to establish the presence or absence of hidden material within the body but there is some difficulty in identification by density difference between what may be there and what should not! (unless it is wrist watches!)
In the mid 50's some work was done on examination of wood poles in electric power distribution systems. The critical zone is between ground level and to a depth of about 4 feet, where the effects of soil moisture and its contents are most damaging. The energy supply for the X-ray machine was available directly overhead, but it was a bit tricky making connection for free 240 volt supply. A decade or so later it was a lot safer and easier to connect to a 7.5 hp Honda generator. The power pole exercise was rather expensive as it entailed excavating a fairly large pit around the pole to accommodate the X-ray machine. In soft ground this was feasible, but with so much of Sydney on a sandstone plateau, preparation costs could be absolutely prohibitive. A much more economic approach is by ultra-sound using probes at 20kH and above. Very useful information has been revealed in initial testing but more development of procedures and interpretation is needed to establish with certainty the difference between acceptable and rejectable items. When the source of large straight timber poles "dries up", it may be too late to do anything but moan and proceed to fabricate poles in metal or other materials at greatly increased cost. Avoiding premature rejection of existing poles is economically desirable in all States of Australia.
In the lab, we developed an X-ray procedure for extracting a clear reproduction of a finger print from a multi coloured cardboard box and then from a slab of human skin some 12 hours after strangulation pressure was applied. Inter faction unrest within the Police Department led to passing our discovery to Scotland Yard rather than the local forensic group. The procedure had a potential for application to strangling cases such as the Thorne kidnap and murder which occurred just as we completed refinement of the test.
X-ray procedures have developed extensively since my first encounter in 1929. fifty nine years later, I watched CRO screens presenting a moving picture of a controlled probe searching my cardiac arteries and the valves between chambers of my heart. Spell binding stuff! A couple of weeks earlier I had witnessed a modern ultra sound examination of the same personal equipment, I mean my heart and its surroundings, of course. A different spread of information was revealed, notably the performance of the valves in detailed presentation, together with details of flow rates and quality of performance.
This was a far cry from earlier work in ultra sound which was initially directed, in UK and Europe, to studies on pig fat distribution in bacon production (on the live pig). Remarkable developments have led to the accurate prediction of sex of the foetus as well as its physical well being or otherwise. There has been an enormous leap in the information available in studies of most major organs and other parts of homo-sapiens and other animals.
Let's turn to ultra-sonics applied to inanimate materials.
Following the explosion of the first turbine operating on steam power produced by nuclear plant at Hinkley Point in Wales, UK, a panic was averted when it was clearly established that the cause was stress corrosion cracking initiated in the surface of keyways of the shrunk-on turbine discs carrying the turbine blades on the composite low pressure rotor. (It had no association with the nuclear aspects of the power stations). Alan Virgo did some remarkably good developmental work using a German Lehfeld U/S unit, originally designed for clinical diagnostic applications. His results allowed me to predict with accuracy the depth of penetration of cracks into the keyway surfaces, their distribution, orientation and lengths. Return to service or direction to dismantle was based on this assessment. On dismantling, grinding to progressively remove cracks confirmed the predicted dimensional and location data. NOTE. The composite low pressure rotors came from all States of Australia (except N.T.) and North Is. New Zealand. They comprised shafts up to 8 or 10 metres long and 500mm diameter on which were shrink mounted and keyed 10 to 12 bladed discs ranging from 250 to about 1500 kgm each.
Turbine studs linking half cylinders for operation at red heat, 560°C continuous, are bored through their centre. A probe mounted on a controlled rotary support and linked to depth of movement within the stud can achieve a "picture" of crack development at or near the cylinder joint line, propagating from thread roots. The test is performed at ambient temperature but with the stud under full preset operating tension. Crack growth continues in service until a reject / replace limit is reached, just as is applied to the periphery of rivet holes in the periodic inspection of aircraft. With reliance on the accuracy of measurements and their reproducibility, unnecessary or too early replacement of expensive parts is avoided.
Cladding. The simple forms of cladding refer to inter bonded continuous sheets of metal or materials and the search is for continuity of bond whether it is a metal composite bearing or a portion of duplex wing structure of an aeroplane. It becomes more complicated to test when the composite is a sheet to which a honeycomb is attached as for the nose cone of a re-entry vehicle. It is claimed that NASA designed a test procedure before they developed and fabricated that composite material.
Twenty years ago, steam drums weighing over 200 tonnes were fabricated with nozzles attached by a then acceptable weld design incorporating unfused lands. Reheat cracking initiated in such zones and could have progressed to catastrophic failures. In Australia, all nozzles in such drums were ultra sonically tested to define the extent of cracking and a programme of weld replacements, without removal of the nozzle, carried to complete restoration. No second repairs were required in NSW, whereas in UK, on drums of the same origin (manufacture) there was a 40% rework requirement. The remarkable performance locally was due, in large measure, to the progressive hot magnetic testing during progress of welding --- dry powder technique was adequate as local preheat maintained in the weld proximity did not exceed 250°C. The sonic probe manipulator developed for pre and post testing of the welds was rather unique but was later substantially developed for remote controlled testing of nuclear plant.
All the foregoing is rather spectacular when compared with the pre 1954 Kelvin Hughes Mark V with its CRO display about 60mm diameter and using massive probes in the separate modes of transmitter and receiver! Who could imagine tackling an ultra-sonic exercise now without mini probes, focussed twin crystals and the highly developed battery operated units with which we are so familiar and take for granted.
Magnetic testing, with dry or wet particles, is a simple procedure which may be applied at ambient temperature, or up to 400°C within certain test limitations and particular care of the equipment above 60 to 80°C. In hot work the operator also needs special consideration, as with testing during replacement of boiler drum end. The drum was preheated to 180°C and the wet magnetic system was being attempted (against my advice). The contractor laughed when a fire extinguisher was demanded, but went quiet two minutes later when the operator was brightly illuminated.
An unhappy situation developed when I offered to demonstrate wet magnetic to a friend from USA on a boiler drum defective weld examination. He insisted on running his trial first, using a 110 / 120 volt magnetic bridge with dry powder (at room temp.). With 240 Volt supply the equipment failed promptly, of course, so we proceeded with my 240 bridge and the wet suspension method. I still had difficulty in conveying the interpretation "lack of fusion", as opposed to his preconceived notion of "cold weld" - a term unique to USA in those days used to describe the situation where metal does not fuse! (but hangs together?). The Yank and I are still good friends! Note, it is not permissible to cable 240 volt power into a boiler drum, but one can achieve that objective using a combination of step up and step down transformers.
In 1954 I observed metallurgists at NSW Railway laboratory testing locomotive steam pressure cylinders using a kerosene soak followed by mopping off and coating the surface with whiting (mag. carb), the old kero and whiting test for cracks indicated by bleed out - a forerunner to dye pen testing! As a back-up test, magnetic powder, suspended in a kero/light oil mix, was applied to areas close to a permanent magnet, the test was of limited reliability. Well, steam locomotives are rapidly joining the memories of these early developments. It may of be interest, however, to realise that the aircraft industry was making extensive and reliable use of red and fluorescent dye penetrant tests during the 50's.
Dye penetrant testing has now progressed to the point where we are very conscious, I hope, of the need to clean up after testing, particularly in the case of austenitic stainless steels which are subsequently subject to services temperatures exceeding 600°C in the bore and nearer 1100°C on the outer surface. Contaminants in "trace" proportions create the source of stress corrosion or corrosion fatigue cracks which can proceed rapidly to failure of pressure parts.
Thermo vision, based on infra-red inspection procedures, has made great strides in detecting hot spots in electrical circuitry on high voltage power lines, (using helicopter surveys) and in switch yards at terminals and switch points. Similarly, in iron and steel plant, cement kilns and in the oil refining and chemical industries where insulating linings may deteriorate, the system is an invaluable detector of impending disaster.
For the recently acquired F/A.18 Hornet Fighter aircraft a non metallic honeycomb cladding has been developed for an engine couling. Its purpose is to delay an engine disintegration from a few seconds to a few more to enable the pilot to achieve ejection without incineration (immediate cremation!). The technique involves sensing retained heat in the base metal some time after a hair dryer has warmed the metal surface, any defective bond zone stands out like the proverbial ---.
Warning, don't view your girlfriend through an infra-red detector, even when she has her clothes on! Thermo vision equipment sure is sensitive to very small temperature differences.
Acoustic emission is rapidly progressing in the detection of crack propagation in structures subject to significant stress variation from pressurising, plastic or brittle distortion or from other causes. The procedures are particularly useful in studies of pressure vessels and hydraulic lines during fabrication, testing and in service. Likewise, buildings and bridges subject to appreciable earth movement, e.g. the Stanwell Park Viaduct. Some brilliant work has been done on that project by Brian Wood of CSIRO.
In 1976, when I directed the failure in brittle mode of a 14 tonne forged pressure vessel for Australian Welding Research Association, Brian, assisted with his then rather limited acoustic emission equipment on the day of reckoning when I disintegrated the vessel into about 30 pieces and a few fragments at 9000psi. The emission records went dumb just before the moment of truth! The many fractures propagated at the speed of sound from my predicted initiation sites but the acoustic emission equipment was inadequate in availability of triangulations to catch the messages. Well, that was the early days of acoustic emission in Australia.
It was a far different story in March 1986, when I set out to destroy another large pressure vessel, this time in ductile mode, after it had served as a steam receiver and distributor for 40 years in Whyalla steel plant. In this test, the vessel commenced to leak at 16Mpa (over 5000 psi) as we were recording over 2000 acoustic emission "events" per minute !!! This aspect of the investigation, again conducted by Brian and his mates, was most revealing. It told me exactly when and where each end of the vessel developed and progressed cracks up to 50mm deep, almost full circle around the manhole end plate sealing welds in the heat affected zone of the drum plate side of these welds. It revealed all significant progressive crack developments, their fairly precise locations and direction of propagation. It also presented information regarding progressive heavy distortion radially outwards of the drum barrel and longitudinally (full circumference) in the rolled over portion of the drum ends. Note this vessel was 6 metres long by over 1 metre diameter.
Well such is progress in a few short years. The success of this latter pressure vessel investigation led Brian to fame with hydro-penstock junction studies and the local railway viaduct problem mentioned earlier.
The "spy-in-the-sky", whether it be a super jetplane or a satellite, furnished with a super camera, reveals much information non-destructively but leaves no doubt about the precise location of marijuana crops growing (concealed) in corn fields.
Non-destructive testing, in whatever form of test, demands our respect for the energy we handle or release. Who wants to lose a hand, eyesight or even a whole body, lock stock and barrel, because of carelessness or lack of knowledge of the effects of ionising radiation? I have not enjoyed seeing all those things happen to others. Prevention of such disasters and, more directly, the control of and use of irradiating apparatus and of those responsible for such activity is an important aspect of the many functions of the Radiation Advisory Council in New South Wales, of which group I have been a member for 16 years.
It was a bit disconcerting to be handed 100 17"x14" films for comment, and reply that 8 appear to be of vertebrates (human or animal), and 92 unreadable! They were claimed to be medical, diagnostic, of limbs and other parts of busy (?) girls from Kings Cross. So, not all dud radiographs come from industrial radiographers who have been temporarily banished to the desert. The unfortunate aspect of the foregoing story is the fact that a person has forgotten the ALARA principle and respect for the Hypocratic Oath.
The Rad. Advisory Council is vitally interested in new developments in the use of ionising and non-ionising radiation in the service of mankind. CAT scanning has been established and accepted by the medical profession. The machines have proliferated appreciably beyond real need, unfortunately over servicing is a result and efforts are in hand to encourage a return to an ethical approach. I repeat, not all the naughty boys are in industrial radiography!
The most recent developments on the medical scene are magnetic resonance imaging (MRI) and bone mineral densitometery. Indiscrete approach to the former equipment when operating will wreck all your credit cards by rendering them inoperable and the latter is "discriminatory" because it is directed at females only. Bone density measurements use 75 kVp X-ray at high ma and search for information about calcium content and distribution in particular. However, until reproducible data can be assured, with reliable and skilled interpretation, the study of osteoporosis in women of advancing age should remain, for the time being, in the restricted research area. The R.A.C. is maintaining a watchful eye on these developments.
The hottest news, of interest to industrial radiographers, is that a Ministerial Minute will be tabled in State Parliament shortly, concerning the New South Wales Radio-active Substances Act of 1959. This out-of-date legislation will be rewritten in a manner more appropriate to the current technology, and will be gazetted as the Radiation Control Act of NSW. It will make reference to non-ionising radiation too.A final anecdote. I cannot forget the three sugar-bags of prime Murray Cod jagged from a prohibited area at Hume Hydro-power Station during my radiographic inspection of penstock welds in the late 50's The enterprising fisherman had "borrowed" one of my "non-passare" signs and lashed it to the only access to his operations and effectively blocking inspection by the local ranger! The real sting was in the fact that I did not receive a single fish for supper.
If I have learned anything in all the foregoing, may I repeat, it has been to develop and adopt the following guideline --- "Seek what you need to know to establish sound advice to a client, then give it to him in a language he can comprehend and without any ambiguity."
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