Formwork Blog

Posts Tagged ‘New South Wales – NSW’

Location: A Construction Site In Sydney Australia on the 26th of September, 2008

Brand new (nine day old) 250 tonne Leibher Crane crashes through concrete floor on a Sydney Construction Site. I have not been told of any injuries or fatalities. If you know anything about this incident, your comments are welcome.

Photo 01 – Crane Crash 26-September-2008 Sydney

It would appear that the concrete floor did not have enough Back Propping underneath, and I cannot make out if large enough Sole Boards were used (if any) under the outrigger pads.

This concrete floor would also have a safe working load limit. If the crane exceeded the safe working load limit, the entire path where the crane traveled should be back propped underneath in order to increase the safe working load of the floor.

Photo 02 – Crane Crash

In most cases, a crane coordinator from the crane hire company usually sees things like this in advance and makes the necessary arrangements. At other times, experienced crane operators, riggers and doggers are competent enough to anticipate back-propping requirements.

Photo 03 – Crane Crash

The next photo reveals an outrigger pad with no sole-boards underneath it!

Photo 04 – Crane Crash

To me, Sole Boards are standard and should be placed underneath outrigger pads whenever the crane is setup. I was always told that outrigger pads can penetrate concrete floors and to always use sole boards underneath outrigger pads when setting up a crane.

Photo 05 – Crane Crash

Tip: Always position plenty of back-propping under a concrete floor directly underneath the outriggers, and always use big solid sole-boards underneath the outrigger pads in order to distribute the weight over a larger area.

Even when sufficient and correct back-propping is in place, outrigger pads have been known to penetrate concrete floors where sole boards have not been used.

Extra Sole Boards In order to distribute the weight over a larger area, it can be a good idea to stack two rows (instead of just one row) of hardwood sleepers under the specific outriggers which will be under the most load.

If you are ever unsure, ring the crane coordinator and demand an official decision.

Thanks for the photos Joe