New York City Crane Collapse 2016 WHAT may have gone wrong?

Let me say I do not know exactly what occurred and I am only providing a number of theories based on my many, many years as an engineer, trainer, and safety professional. In the days ahead the facts will come to the surface.

First I would like to say how sorry all of us feel for anyone that has suffered a loss because of this terrible incident and I look forward to the day this NEVER happens.

I have always said that both Bay Crane & GTI are 2 of the best in the business and are responsible for a large portion of NYC skyline as safe contractors. The art of Cranes & Rigging have been around for centuries and I say “art” because of the balancing act is as simple as 2 small kids in a Park on a “Titer Totter” or even as massive as the NASA moving a Shuttle into place. Over the past 20 years we have a need to use lighter steel and smaller outrigger spreads while increasing the reach into the sky and adding more counter weight to offset the massive 300-500 foot boom that stretches into the sky. For this reason I once defined -

Safe “Crane engineering” as the ability to accurately engineer the radius of your crane, height, boom, ground conditions, net capacities of the load, both static/dynamic & wind without the use of a calculating device within a given time frame with less than 1% of error. Now I came up with this in 1999 when I was sitting in my first NCCCO class so if a couple of the 1000 (so called) experts want to re write my definition, go ahead. The point is the engineering that goes into the crane work these days is amazing. Now as you know with any other type of engineering “safety factors” or margins are built into the manufactures load chart to offset human mistakes. On average about a 25% margin is written into the manufactures load chart to offset wind & human error to name a few. The problem is some well- intentioned people may try and play "Crane God" and take it upon themselves to use the safety margin* in order to make that 1 pick that is just dipping into the safety factor. The point is in most crane catastrophes one or more of the items listed below will always and I do mean always be the reason for the collapse.

Some questions that will need to be answered

• *Was the crane operated within the manufactures “safe working margin”?
• Was the Crane lowered in the proper sequence?
• Did the engineering allow for wind gust or sustained winds?
• Was the total wind sail calculated based on the massive size of the Boom?
• Was the operator familiar with this crane?
• Did the LMI or computer have a human moment? (Malfunction due to ice or snow)
• Did a component of the crane fail IE, Beckett, and Wire Rope?
• Was the counterweight sufficient enough for the amount of Boom?
• Did a safety preplan meeting reveal what not to do?

As always we aim to learn from our mistakes so that we never repeat pain again. Our deepest sympathies go out to the friends and families affected by this tragedy.

Darrell L Fullerton