Re: Would like to know your opinion (URGENT Reply by 13th Feb) Dear Friend,
The first and sencond steps are ok but may be with some acceptable risk.
The third and fourth steps involve safety aspects.
Even assuming that you have long enough retractable cable where you can move to a safe distance for cranking (which itself is doubtful) and operators are rotated to keep down to acceptable exposure levels, the question of physical safety involved in constant handling of the boom in a cordinated sequence at the given heights with a technician hanging at the end, needs very carefull attention. I personally do not accept the risk.
There is one way you can make it work without taking the risk. You should employ a mototorized camera with a long enough connecting cable linked to a control panel located at the ground/base level.
Long back I have operated a French camera with an electrical controle panel with more than 20 metres connecting cable but that was a Co-60 source.
The placement of the source guide tube should be controlled from the ground only with sutably designed locators aided with enhanced vision through binaculars and/or with the help of ccd camera.
The loctors should fix the boom to the tank wall to prevent movement(expected at those heights) during exposure.
Still the risk is present in placement of the film. This may perhaps be minimised by placement of a long pack with staggered films that are exposed individually but collectively retrieved.(complimentary pack is placed in the repeat step)
The film placement also can be done in some ways without actually the technician going up by using electro meagnetic devices.
All of this costs money.In the end it may work out to be cheaper to erect the scafolds
Good luck for whatever you do.
P V SASTRY
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: Hi friends I had one opinion till now from Nigel Armstrong. Thanks (Nigel). The arrangement is as follows:
: 1) Inside to paste film using scissors lift.
: 2) Outside move the boom lift close to wall and guide tube tiedto one of the bars on Scissors lift.
: 3) After setting up the source he flew into another boom lift with a crank unit.
: 4) Move as much you crank cable allows you and expose and retract the source.
: I am fed up speaking to this guys. I am with my technicians and trying to convince them to put up staging. Can anybody pls let me know if they have experience how the usual and normal setup is in the radiography of storage tanks.
: Pls reply by 12 or max by 13th feb as I have to hold my final discussions with them.
: : If gamma radiography is requested to perform on Storage tanks, it needs a good platform and structure. Our client requested using two snooker lifts to perform this task one to place the PROJECTOR and another to place a CRANK/DRIVE ASSEMBLY assembly. QUITE SCARY RIGHT! But client says "WHY CANNOT PERFORM? GIVE REASONS? YOU CAN DO ALL SAFETY EVALUATIONS REQUIRED AND PERFORM THE TASK IN THIS MANNER. I REQUEST THE READERS TO HELP ME WITH THEIR OPINION:
: : A) DOES ANYWHERE ANYBODY DO THIS KIND OF ARRANGEMENT?
: : B) IF DONE WHAT ARE ALL PRECAUTIONS TAKEN AND EVALUATION NECESSARY
: : C) PLS GIVE ME SOME HINTS TO CONVINCE THIS IS NOT THE WAY.
: : I thank all readers and those replying to this message in ADVANCE. your opinion would matter in decission making
: : Thanks
: : Mohiuddin
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