Manual chainfalls failure

[Dagger]

24ft truss line with 7 lekos rigged with
2x 1/ 4 ton manual chainfalls 18ft up in air

Rigger bagged the chains and left the venue without safetying truss.( or chainfalls)

The rig will stay up for 5 days.

My question are how

- acceptable not to safety? ( i have always safety the truss or.chainfalls.

- how likely is it that chainfalls will fail??
( chain will come down)

Thanks

 

[josh88]

How are they connected in the structure? A lot of what we've done having to make points and using either motors or chain hoists, spanset the truss, choking the top and bottom rung to a shackle, to the hoist. Then the pick point is made with spansets to a shackle to the hoist, or steel cable to shackle to the hoist.

 

[porkchop]

Really difficult to say without seeing it in person. In general I would prefer to see truss with a safety if the audience is below it. If it's not over the audience I see safeties less often.

As far as the chain falling, if the bags used are in good repair, designed for the application, and used properly then you're very unlikely to see chain rain. It's up to the rigger.

 

[TimMc]

Depends on the chain fall and about 3 other things, but if *you* are the client you should instruct the riggers to safety the truss. If they push back you need different riggers.

I don't think I've had a rigger who would refuse to add safety steel and most would suggest it if they thought there was any chance of hoists slipping or failing.

 

[gafftapegreenia]

I guess the only thing I don’t love is two points for a 24’ truss. Maybe three is overkill but i was taught redundancy.

 

[Milt Hathaway]

I guess the only thing I don’t love is two points for a 24’ truss. Maybe three is overkill but i was taught redundancy.

Using more than two lifting points on a straight run of truss is not any safer and requires the use of load sensors to determine proper load distribution among the lifting points. Better to achieve 'redundancy' by assuring proper equipment and structural safety margins on the two points used.

 

[egilson1]

Another issue with chain falls is the breaks which are often not designed for suspending loads for prolonged periods of time.


Ethan

 

[danTt]

Would you prioritize transfering load/adding a secondary safety on a manual chain hoist over standard BGV-D8 chain motors? Neither are "rated" for suspending loads over people, although I think we can all agree that we see D8 motors used for stage truss quite regularly.

 

[danTt]

Using more than two lifting points on a straight run of truss is not any safer and requires the use of load sensors to determine proper load distribution among the lifting points. Better to achieve 'redundancy' by assuring proper equipment and structural safety margins on the two points used.

This is a fantastic general rule that certainly applies in this situation, but I'd contribute for the archives that there are certainly times when using three or more points is going to be safer. If you have a 70' foot length of truss, for example, you're probably not going to want to try and find truss engineered to let you suspend it from two points. You'd certainly want to consider synchronized motors/load cells as these scenarios grow and develop, but they do exist.