The see saw is made up of 36 x 72 tonne Precast concrete segments and 4 x 82 tonne precast concrete segments all sitting on just one concrete pier.

The 2920 tonnes does not count the two heavy cranes (Light and Lofty) which travel and traverse along the top of the see saw, not to mention the other construction materials.

Adelaide Northern Expressway Center Pier Steel Cage

The steel cage was pre-fabricated on site on top of the same formwork shuttering which will be used to form-up this 6 meter tall structure.

Construction Workers To Feed The Steel Cage Into The Base

Formworkers, steelfixers, riggers and supervisors work together feeding the cage into the base making sure that every steel bar in the cage is in the correct position in relation to the starter base steel.

Steel Cage Fixed Into Position

After the steel cage is fixed into position, the structure is ready to be enclosed by formwork shuttering. The finished concrete structure will be a narrow 600mm at the bottom and 1500mm at the top.

Mario, Steve, Ed, Deano and Marty at Sino Project WA

The Cape Preston Sino Project is south of Karratha in WA’s Pilbara Region.

Video length: 1:30

Possible Conclusions

• The crane was too small for this lift.
• The load was being hoisted up too quickly not allowing for the water to drain.
• Maybe the windows were not smashed before lifting which prevented the last bit of water from draining at bottom end of the lift.
• Maybe the crane was not equipped with safety alarms, or the alarms were faulty, or they were manually overridden and therefore ignored.

Thanks Purple B

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

This 80 tonne pre-cast concrete bridge span is being placed onto the headstock and concrete embutment by a crane parked in the dry (at the moment) Turner River bed. The river floods once a year during the wet season which everybody was hoping would not arrive until the bridge is finished.

Turner River Bridge Span

The bridge span arrived by rail on the existing track. The crane was positioned on the river bed in between the old existing bridge, and the new under construction bridge. After a few scares, the bridge was completed before the river flooded.

Crane operators/riggers/doggers Flocky and Rob along with the Franna crane they use here at the construction site at Prominent Hill copper and gold mine.

Flocky and Rob at Prominent Hill

Here’s a Crane Signals Chart so we can all use the same signals rather than some hybrid, made-up signals. Includes crane hand signals signs along with bell/whistle signals.

Download – crane-signals-chart.pdf – 81 KB

How To Download PDF Files

Formwork carpenters Lenny and Simon, and crane operator Craig position this concrete road barrier which will be used to anchor the bracing at one side of the column formwork. The brace on the other side will be anchored to the foundation.

Concrete Road Barrier To Brace Column Formwork