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KELSAFE '94 Root Cause Analysis Workshop Disclosure Number: IPCOM000217286D
Publication Date: 2012-May-04

Publishing Venue

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   KELSAFE '94 Root Cause Analysis

Subject: Workshop #I - Falling Crane Incident

_ -

Workshop #2 -


Classroom type arrangement with two large dry ink boards and overhead projector.


The intent of the session is as follows:

0 Demonstrate root cause analysis via actual example

0 Demonstrate the benefits of using the process


Outline when to use it

Issued selected witness statements llom the actua process by workshop leaders.


Explanation of intent and participant selection

0 Root cause analysis demonstration

Actual results



Document package from actual study inc.dent and coawed through the

- 10 mins.

50 mins.

- 10 mins.

- 5 mins.



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I Was informed this mornin

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The existing vessel is being modified in a mini-shutdownand most all of the mechanical work has been completed. Stress relieving of the vessel was in progress with burners located at manholes. A faster heatup had been decided for this vessel as opposedto the identical vessel modified earlier. A chimney and damper had also been added to the top of the vessel to help regulate the flow of hot gases inside the vessel.

A problem developed with the lower burner at 8:30a.m., Saturday morning. The burner was sending out black smoke which was also visible from the stack. The burners were then remotely shutdown and the problem was being investigated. Our fad, the contractor for this work and a vessel inspector went up on a platform to try to seewhat was the problem. They noticed that there was still some small flames at the burners from the residual gas in the gas lines. At this point, the contractor opened the damper

onthe stack fully and an explosion inside the vessel was heard. The plate holding the lower burner pealed back from the vessel and the hot gases escaped the manhole, bounced off of the platform they were standing on and went up their pants legs. There did not appear to be a flashback of flames, only hot gases.

This was over in a very short time and the men got down off the vessel. One had an area onthe calf which was red, similar to a bad sunburn. He was treated at the site and continued to work. He had no blisters or burns other than those noted.

The contractor had a red area from the ankle to the knee and he did have blisters form quickly. He was transported to the hospital emergency roomand was treated there. He returned to work after treatment.

The inspector was unhurt.

A complete investigation was started immediately and a meeting of all the Kellogg and Client Project Team was convened and the incident captured. The heat treatment procedure was also modified to heat up slower than previously agreed. There apparently was some residual hydrocarbons which were driven out of some coke materials in the vessel which could not be removed. The new damper and stack held these hydrocarbons inside the vessel longer and allowed a combustible mixture to be availa...