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Re: Choice between intermittent and continuous fillet weld in Crane girder ( I beam with channel top)

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I was involved in design of Industrial Buildings for over 26 years between 1974 and 2000.
We designed several hundred welded crane girders for crane capacities from as low as 10 tons upto 250 ton for grider spans from 6 meters to 24 meters and crane spans upto 40 meters.
We always specified continuous fillet welds for the flange to web connection of the girders and a special section would be drawn making this clear.
 
This issue of the contractor proposing to use intermittent fillet welds in lieu of  continuous welds was also a routine situation. They would attempt to sneak it in while submitting  the shop dwgs but as part of our check list, we always corrected this and  we insisted on changing to continuous fillet welds before approving the shop dwg.
 
We got tired of explaining why we insisted on continuous fillet welds and prominently mentioned that the welds were to be continuous in the drawings even while issuing for bidding.
 
It was our experience that contractors used to bring up issues of possible distortion to persuade us to change our specs and allow intermittent welds.
We found that the real issue was simply more time and effort involved (and hence more money) which they did not want to project.
One contractor even furnished calcs to justify intermittent welds and tried to get our spec over ruled by the client . He tried to convince the client that we were increasing costs needlessly.
 
We found that good and experienced contractors who followed proper welding sequences were able to provide continuous fillet welds without any noticeable distortion.
 
While we did occasionally relax our specs with regards to stiffeners, we never approved intermiitent fillet welds for the flange to web connection of a crane girder subjected to heavy  and moving / dynamic concentrated point loads
 
Hope this helps.
Vish
 


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