With regard to the accident in Austin, and the comments made, please remember the following points:

1. A mast climber is a 'moving platform' not a 'fixed scaffold'

2. When 1926.451 was enacted mast climbers were not in use in the US.

3. OSHA defines an 'enclosed platform' as a platform where the leading edge is 14" or less away from the face of the work, negating the requirement for a front handrail if these conditions are met. This is achieved by 'planking' around the building profile. The Austin unit was 'planked' in this way.

4.The accident was caused by the following scenario. The front edge planking, which sits on top of steel box-section 'slides' which are extended and retracted to allow the unit to pass protrusions such as balconies, was not retracted properly. The unit was driven up, and the two furthest left slides collided with the underside of the balcony, something that would not necessarily be noticed by the operators because of the slow platform speed, the jobsite noise and the fact that the operators were probably around the central 'mast' area while it was moving. This movement continued until a. the slides bent (can be seen on the video), b. the platform twisted at the far left end, (again evident), and finally, c. the bolts holding the platform to the drive unit sheared, causing the platform, and the operators to fall.

Its also worth mentioning that while within the 'confines' of a 'enclosed platform' there is no requirement to either 'tie-off' or to attach a lanyard from a body harness to the platform itself. In fact it would be very difficult to hang tie-off ropes from the top of the building in this instance because of the protrusions, the balconies and the platform canopies etc.

This seems to be a training issue. Clearly there should be job specific advice on how to retract and extend these slides, and only those authorized to do so should have been on the platform.

Question is, did the supplier train the operators properly, and was the progress monitored in return visits.

Kevin

Thanks for the reply. I appreciate you providing this type of information that I hope will make jobsites a little safer.

There is a lot of potential for lessons learned from this tragedy. The various videos, if nothing else, should provide some unique opportunities in terms of reconstructing what happened.

Thanks again.