Fire and Explosion

Chicago River West Event

Overpressure event in low pressure gas distribution system resulted in explosions and fires covering an area of Chicago bounded by the Kennedy Expressway, the Chicago River, and Kinzie and Cortez streets.  Fourteen houses and three commercial buildings were damaged; there were four injuries and four deaths.  Lead investigating engineer determined that either a worker turned a bypass valve in the wrong direction, or debris in the bypass valve became dislodged (see NTSB report PB93-916501).

Dust Explosion in Petrochemical Plant

An explosion occurred while three workers were dumping a “supersack” of chemical additive into a hopper.  All three were sprayed with melted additive and badly burned.  An extensive investigation showed the accident scenario and cause.  It was determined that two dust explosions occurred in rapid succession (not an unusual occurrence in dust explosions), and that the cause was failure to ground the “supersack” during pouring. 

House Fire

Explosion in Air Compression System

A distribution pipe in a high pressure industrial air system detonated, sending shrapnel across an occupied area, seriously wounding a worker.  Widespread damage occurred to the high pressure air compressor and other components.  Extensive inspection, testing and literature research showed that the explosion originated in the distribution pipe, and that the cause was a buildup of oil-coated granular rust particles in the pipe.  The initiating cause was most probably static electric discharge in a filter.

Parking Garage Gas Explosion

A massive gas explosion occurred in a parking garage under construction in Monterrey, Mexico, causing extensive damage, 25 injuries and nine deaths.  The facts showed that the explosion happened as workers were attempting to light an industrial water heater.  All associated gas equipment, including the water heater and its components, were suspected as causes.  Document review, analysis and testing led to two important conclusions: a) the design of the water heater and its associated installation would have conducted gas away from the area if it had leaked, and b) the source of the gas was a pipe intentionally opened for a significant time shortly before the explosion.

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Workplace Safety

Intermodal Transport Operations

Transfer of shipping containers between trucks and railcars resulted in alleged injuries.  Loading cranes and other equipment were named as causes.  The workplace and work techniques were surveyed.  It was determined that the alleged injuries resulted from a failure to follow established work procedures.

Worker Struck by Falling Drilling Pipe

A water well driller was struck by pipe that fell out of a lifting harness as he was lifting it.  Issues were raised about the safety designs of the drilling rig, including the pipe handling mechanism and guarding.  It was determined that the pipe fell because the driller failed to place the pipe in the lifting harness properly, that he failed to place himself in a safe position, and that the guarding furnished with the drilling rig met industry practice.

Static Electricity During Wet and Dry Conveying

A major service company developed equipment and procedures for preventing static electric discharge during conveying of wet and dry materials.  These procedures and the associated equipment were reviewed and several minor changes were suggested.

Safety During Grit Cutting

A major service company was concerned with spark emission during high pressure grit blasting and cutting.  An in depth literature survey showed that such spark generation could ignite hydrocarbon vapors under some conditions.  The recommendation was made to follow “hot work” procedures during grit blasting and cutting.

Use of Caustic Washing Solutions

Labeling and warning of commercial dishwashing products were called into question after workers received skin irritation injuries after using the products improperly and without adequate personal protection.

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Oil Field and Offshore

Explosion on Lift Boat

An explosion occurred in the port engine room of a lift boat, elevated alongside an offshore production platform in the Gulf of Mexico.  There were few injuries, but the lift boat was irreparably damaged.  Investigation showed that natural gas from the platform backed up an air hose which had been used to operate control valves on the platform.  There was no check valve to prevent flow from the platform to the lift boat.  Once inside the engine room, the gas was exposed to a number of ignition sources.

Determine Failure Mode of Oil Field Packer

A downhole  oil field packer was examined to see why it failed to set on several attempts.  Tool marks (from wrench teeth) were found on a close-tolerance component of the setting tool, and it was concluded that this prevented sliding movement which was necessary to set the packer.

Worker Injured During Drilling Rig Erection

During rotation of the A frame of a land based drilling rig, the A frame tore loose and struck a worker in the face.  He fell off the rig floor and was severely injured.  It was determined that the crane operator failed to operate the crane properly, and tore the A frame anchor bolts loose.  A key part of this investigation was the use of single point perspective to determine that the crane operator was pulling at an improper angle when the incident occurred.

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Design

Heavy Truck Transmission

A major trucking firm suffered numerous transmission breakdowns, allegedly caused by oil leakage from a defectively designed gasketed bolted joint.  The transmission manufacturer requested a review of the design of the gasket and bolted joint.  Analysis showed the joint was designed and performed properly.  Operation and repair records indicated that the breakdowns were due to inadequate maintenance.

Soot Blower Drive

A soot blower manufacturer claimed infringement of intellectual property concerning the means for indexing the lance on its soot blower.  Indexing causes the lance to follow different spiral paths on inward and outward travel, to better sweep the surface being cleaned.  Analysis showed that all drives of a certain type indexed the lance as a consequence of operation, without any need for particular mechanical means to cause indexing.

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Premises Liability

Trip in Store Aisle

A customer allegedly tripped over merchandise in the aisle of a dollar store, as she was squeezing past her companion’s shopping cart.  Examination of the store and its records established that the aisles were of adequate width and the store had a written procedure for keeping its aisles clear.

Person Struck by Falling Toilet Paper Holder

It was alleged that a customer in a restaurant was struck on the foot when the cover of a large toilet tissue dispenser fell off the wall of a toilet stall.  The person was diabetic and died after the alleged incident.  A lawsuit claimed that the alleged injury contributed to her death.  Investigation revealed that the person’s version of the incident was inconsistent with the dimensions of the toilet stall, and that the restaurant had no record of a problem with the toilet tissue dispenser.

Person Struck by Falling Temporary Fence

A pedestrian was struck when a temporary construction fence was pulled over by a skater on roller blades.  She suffered a significant ankle injury, with surgery required.  The fence was not anchored with sandbags, as it should have been for a fence located in a pedestrian area.

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