Safety? That's for Hackaday trolls!

A project log for HoistInsight - A brain for your crane

Utilizing GPS tracking, point-to-point networking and mobile devices to increase safety and improve efficiency in crane hoist operations.

salokcinsalokcin 08/20/2014 at 04:390 Comments

I'd like to start with a little anecdote about a recent near-incident my father (the crane operator) encountered.

My father was nearing completion on a job for NASA in New Orleans, LA. He was flying handrails (for stairs) in the blind. His flagman radioed to him that the load was in position above the target, it was time to start lowering the load.

The conversation with the flagman (over the radio) went something like this:

Flagman: "Cable down"

Dad: <Starts slowly cabling down...>

Flagman: "More... more... more..."

Dad: <Continues cabling down...>

Flagman: "Cable down!"

Dad: <Cables down a little bit more, then stops>

Dad: [Realizing he's cabled down enough to put the load on the floor when it's going up on the 2nd floor stairs] "That should be enough!"

Flagman: <Grabs on the tagline attached to the handrail and begins to pull.> 

At this point the handrail releases and falls nearly 60' straight vertical before crashing into the ground, still with slack on the cable. I'll leave it to someone else to calculate the force involved with a ~100 lb. handrail falling 60' unimpeded. Suffice it to say that anyone caught by that handrail on the way down would likely no longer be among the living.

You see, what the flagman failed to realize is that the handrail had become snagged on some other structures higher up. The flagman continued to tell the crane operator (my father) to lower the load, apparently thinking he was being ignored. At the same time, the operator continued to lower the load, thinking he was perhaps off on his estimates of how low the load needed to be placed.

It wasn't until the operator looked over at the cable spool beside him and saw it completely slacked that he knew there was a serious issue -- the crane was no longer supporting the weight of the load! At the time he radioed the flagman to inform him of the situation, the flagman was tugging on the tagline to move the load.

While the crew was lucky enough to escape tragedy this time, it could be only a matter of time before this situation ends much worse than it did!

With the intuitive interface of HoistInsight, it will be VERY apparent to the operator that as he's cabling out his load is not descending. This very scenario could have been caught with only a couple feet of slack on the line versus 60'+ slack on the line -- potentially meaning the difference between someone making it home for dinner or perhaps not making it home at all.