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Temporary Stair Rail Failure
The hand rail on a temporary stairway at a
construction site failed, causing bodily injury to a
workman. A typical temporary stair rail, constructed
of angle iron and wire cable is shown in Photograph
A.
Photograph A:
Overall view of temporary stair rail post as
normally used at a construction site.
An overall view of the
temporary stair rail post is shown in Photograph B.
In Photograph B, it will be noted that the post
attachment welds, denoted with white arrows, are the
subject of this accident investigation.
Photograph B:
Overall view of temporary stair rail post. Arrows
denote upper attachment weld.
A close-up view of the upper
attachment weld, shown to the left in Photograph B,
is shown in detail in Photograph C. It can be seen
that rather than make a complete weld, the welder
chose to weld over a long piece of welding rod. This
is extremely poor welding practice. Arrows in
Photograph C denote the improperly placed welding
rod, which was then welded over.
Photograph C: Close-up view of upper
attachment weld. Arrows denote location of weld.
A profile view, showing the
very small amount of weld bead and the fact that the
weld bead was intermittent, is shown in Photograph
D.
Photograph D:
Profile of weld bead showing a small amount of weld
bead and intermittent nature of weld deposit.
The lower post attachment weld
is shown in Photograph E. This weld was so small
that no areas of fracture could be found between the
weld bead and the adjoining stair structure to which
the post was supposed to be joined.
Photograph E:
Lower post attachment weld.
No metallurgical examination
was conducted because the post attachment welds were
so poorly welded that cutting for metallographic
examination would have probably caused the
attachment weld bead and welding rod to fall away,
thus spoiling a perfect jury exhibit.
The cause of the subject
construction site accident was inept and inadequate
welding of the hand rail post to the stairway
structure.
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Dr.
R. Craig Jerner, Ph.D., PE specializes in accident
investigation and metallurgical failure analysis,
with over 30 years experience as a metallurgical
consultant and accident investigator. He has
testified as a metallurgical expert in over 250
depositions and more than 70 court appearances. If you or someone you know should need the services of Dr. Jerner and J.E.I. Metallurgical, please visit our web site at the buttons below, or e-mail Dr. Jerner --- 