Rapperport Associates, Inc

Engineering and Materials Consultants
8 Wallis Court Lexington, Massachusetts 02421

Rapperport Associates’ engineers offer a level of expertise in failure analysis that is matched by few firms. Our success can be credited to an extraordinarily talented team – a team with impeccable credentials and a wealth of experience. Rapperport Associates has earned the trust of over seventy five insurance companies and hundreds of law firms and has been retained on billions of dollars in losses since inception in 1974.

Our team of engineers and scientists is drawn principally from Stanford University, Massachusetts Institute of Technology and University of California Berkeley. Many of our engineers are nationally recognized experts in their fields and as a team we provide exceptional capability in all aspects of failure analysis. Our use of stunning graphics to present solutions to complex analyses sets us apart. We have been engaged on many large loss accidents and have an enviable track record. 100% of our cases over the last ten years have resulted in favorable settlements for our clients.

Failure Analysis - Selected Cases

Failure Analysis • Big Dig Tunnel Collapse
A 38 year old woman was killed when a section of the concrete suspended ceiling in the eastbound Interstate 90 (I90) connector tunnel in Boston, Massachusetts detached from the tunnel roof and fell onto her vehicle. Rapperport Associates, Inc. was retained to conduct a failure analysis of the roof panel collapse. 

Failure Analysis • Tesoro Refinery Explosion
Rapperport Associates was retained to conduct a failure analysis of the equipment involved in this massive explosion.

On April 2, 2010, the Tesoro Refining and Marketing Company LLC petroleum refinery in Anacortes, Washington, experienced a catastrophic rupture of a heat exchanger in the Catalytic Reformer / Naphtha Hydrotreater unit. The heat exchanger, known as E-6600E, catastrophically ruptured because of High Temperature Hydrogen Attack (HTHA). Highly flammable hydrogen and naphtha at more than 500 degrees Fahrenheit (ºF) were released from the ruptured heat exchanger and ignited, causing an explosion and an intense fire that burned for more than three hours. The rupture fatally injured seven Tesoro employees who were working in the immediate vicinity of the heat exchanger at the time of the incident. To date this is the largest fatal incident at a US petroleum refinery since the BP Texas City accident in March 2005.

The NHT unit at the Tesoro Anacortes Refinery contained two parallel groups, or banks, of three heat exchangers (A/B/C and D/E/F) used to preheat process fluid before it entered a reactor, where impurities were treated for subsequent removal. The E heat exchanger was constructed of carbon steel. 

At the time of the release, the Tesoro workers were in the final stages of a startup activity to put the A/B/C bank of heat exchangers back in service following cleaning. The D/E/F heat exchangers remained in service during this operation. Because of the refinery’s long history of frequent leaks and occasional fires during this startup activity, the CSB considered this work to be hazardous and non-routine. While the operations staff was performing the startup operations, the E heat exchanger in the middle of the operating D/E/F bank catastrophically ruptured.*

Failure Analysis • Sculpture Pedestal Collapse
Tullio Lombardo’s statue of Adam was the centerpiece of the Metropolitan Museum of Art’s newly installed Renaissance exhibit. Carved around 1490 for the tomb of the Doge of Venice, purchased by the Museum in 1936, it was their most important Italian Renaissance sculpture and one of the most important Italian sculptures outside Italy. On October 6, 2002 after the museum had closed for the evening, guards discovered the sculpture shattered on the marble floor. The wood pedestal had collapsed sending the prized sculpture crashing to the floor. The value of the sculpture was estimated at $40 to $80 million.

Rapperport Associates was retained to conduct a failure analysis of the pedestal.

Failure Analysis • Silk Air 185 Aircraft Accident
On December 19, 1997 a Silk Air Boeing B737-300 aircraft departed SoekarnoHatta International Airport, Jakarta with 104 aboard (97 passengers, 5 cabin crew and 2 cockpit crew). The aircraft took off in daylight with good weather conditions and climbed to 35,000 feet. The voice and data recorders were deactivated with no abnormal data then, according to radar information, the aircraft suddenly dropped 400 feet in 8 seconds and continued in a rapid descent initiating in-flight breakup followed by complete disintegration of the aircraft upon impact with the Musi River. All 104 persons on board were killed. Although 73% of the wreckage was recovered, most of the samples consisted of small highly distorted parts. Rapperport Associates was engaged to develop a simulation of the final flight path based on flight recorder data, radar information and debris field Silk Air 185 wreckage scatter. 

Failure Analysis • Scaffolding Collapse
One worker was killed and a co-worker was seriously injured when the tower climbing work platform they were working from collapsed sending them plummeting 85 feet to the ground below. A third worker managed to escape injury by leaping over the parapet onto the building’s roof. The workers were removing water table stone from the roof façade of an eight story building when the accident occurred. A bay window protrusion extending the full eight stories of the building hindered worker access to the building directly from the central work platform. Cantilever extensions had been bolted to the central work platform to accommodate the bay window protrusion. Rapperport Associates was engaged to determine the cause of the failure. Finite element stress and buckling analyses were conducted and verified with full scale testing. It was determined that the structure failed by buckling and not as a result of weld failure

Failure Analysis • Roof Truss Failure
A worker sustained serious head injury when an 80 foot wooden truss fractured during building construction and struck him. A reconstruction of the rigging configuration combined with a dynamic finite element stress analysis of the truss stresses generated during construction showed that the failure occurred from improper rigging when the truss was being lifted into position and not as a result of a manufacturing defect.

Failure Analysis • Deterioration of Celcon Plastic Water Pipe Fittings
Our firm was selected as experts for the insurance defense group in Hoechst Celanese Corp. vs. National Union Fire Insurance Company et. al. This matter related to the premature field failure of residential plastic pipe fittings throughout the southern and western regions of the United States and involved losses of hundreds of millions of dollars. Our firm was engaged to determine if premature fitting failures would be expected based on the available file documents. We inspected failed fittings, performed stress analyses, analyzed file test data, and reviewed thousands of documents to assess whether or not Hoechst Celanese knew or should have known that the fittings were unlikely to survive the intended service life expectancy prior to releasing the product. Acetal resins are sensitive to chorine and low levels of chlorine in potable water supplies (1-3 ppm) can be sufficient enough to promote stress corrosion cracking. Widespread failure of acetal fittings in potable and hot water supplies resulted in one of the largest class action lawsuits in the US when acetal plumbing fittings cracked and caused flooding of homes. The accompanying photograph illustrates chlorine attack in the threaded portion of an acetal fitting. Chlorine attack caused the material to become brittle and resulted in crack initiation at the thread roots. The discoloration on the fracture surface was caused by deposition of carbonates from the hard water supply, indicating that the joint had been partially cracked for a while prior to component failure.

Failure Analysis • Pallet Rack Collapse
A massive pallet racking system used by R. R. Donnelly Corporation to store printed catalog matter suddenly collapsed resulting in the complete destruction of the pallet racking system and loss of the stock. The facility consisted of 12 racks, each 66 feet high (10 bays) and 228 feet long. Although the property loss was substantial, amazingly, no one was injured. Some failed welds were observed in the wreckage and there was a question whether weld failure precipitated the collapse or whether the welds failed as a result of the severe structural deformation associated with the collapse. Rapperport Associates was retained to determine the cause of the failure. A buckling analysis indicated that the structure was overly flexible structure due to inadequate cross bracing and failure was caused by global buckling. A stress analysis of failed welds confirmed that the weld failures resulted from the high loads of the collapsing structure and were not the initiating event

Fire and explosion investigation

Rapperport Associates has provided failure analysis, fire and explosion investigation and accident reconstruction services for losses totaling billions of dollars since 1974.

Our team of distinguished engineers and scientists is drawn principally from Massachusetts Institute of Technology, Stanford University and University of California Berkeley. We combine state-of-the-art computer modeling, laboratory testing and forensic graphics to solve complex problems and present cases in a clear and understandable manner.

We also offer comprehensive fire investigation services including field investigation, fire modeling and testing as well as fire protection evaluation and assessment. We can perform complex computer modeling to predict hazards such as radiant heat flux, fire growth, smoke production, fire plume and ceiling jet temperatures and velocities, toxic species production and depth of the hot upper layer. We can model fire growth, steadystate burning and decay for intact and impaired sprinkler system activation. The computer models can also be used to study the effects of ventilation changes, and thus, changes in interior environment conditions as the interior and exterior fire suppression activities are conducted. 

An overview of some selected projects and a partial client list is provided below. You can also visit our web site at www.rapperport.com for additional information.

Fires and Explosions

1. Fires at Malden Mills Textile Plant
wo separate fires occurred at the Malden Mill textile plant in Lawrence, Massachusetts. The latter, a catastrophic fire, destroyed approximately one square block of the textile production facility resulting in total damages of approximately $500 to $800 million, making it one of the costliest industrial fire losses in United States history. Rapperport Associates was retained to investigate the cause and origin of both fires.

2. Mill Fire 
A devastating fire swept through a 400,000 square foot mixed use business complex in Massachusetts, once the third largest yarn mill in the U.S. Although 400 firefighters from 66 communities responded to the blaze, the complex was completely destroyed. The property and business losses suffered by 65 businesses following the fire were estimated to be many millions of dollars.

3. Pressure Vessel Explosion
A massive 220,000 lb steel pressure vessel exploded sending fragments, some in excess of 30,000 lbs, hundreds of feet. A 2,000 pound fragment was found resting on railroad tracks a quarter mile away. The roof and walls of the plant were blown off from by the force of the explosion. Reconstruction of the plant cost more than 17 million dollars. Rapperport Associates was retained to determine the cause of the explosion. Testing in various aqueous environments was conducted on the subject vessel steel to characterize the material properties. A thermal finite element stress analysis was performed to determine operating stresses. A scanning electron microscopy (SEM) examination was performed to identify the crack initiation sites. The data indicated that improper cooling water treatment resulted in stress corrosion cracking which dramatically reduced the life expectancy of the vessel.

4. Nitroglycerine Pump Explosion
A pump explosion killed two workers during the mixing process of nitroglycerine with various polymers to manufacture heart patches. The pump fragments were recovered and carefully analyzed. Rapperport Associates was retained to determine the cause of the accident. A detailed examination of the fragment damage yielded clues to the failure sequence and ultimately to the cause of the failure. A pump redesign was proposed and built, eliminating the design flaw that resulted in collection of fugitive nitroglycerine setting the stage for the explosion.

5. Fire at Shenandoah Industrial Rubber Company:
Two workers were severely burned at an industrial tank lining facility in Roanoke, Virginia. We developed a computer model to determine regions where combustion could have occurred during contact cement application. This two fluid, gravity stratified, computational fluid dynamics model of hydrocarbon vapor formation was verified with smoke experiments conducted in the actual plant. The results ruled out ignition from an overhead heater pilot or exhaust fan blade/shroud contact as claimed. The ignition source was demonstrated to be within the tank, where a cigarette lighter was found.

6. Magnesium dust explosion:
Rapperport Associates, Inc. was retained to investigate and analyze a massive magnesium dust explosion. A nonlinear structural finite element analysis was performed to determine the maximum pressures developed during the explosion event.



Our clients include prominent law firms and insurance companies nationwide. A partial listing of the insurance companies that have retained our services is given below:

Acadia Insurance
Ace Property and Casualty Co.
AIU Insurance Co.
Am International Marine Agency, Inc.
Allstate Insurance Co.
American International Adjusting Co.
American Motorists Insurance Co.
Arbella Insurance, Co.
Atlantic Mutual Insurance, Co.
California Union Insurance Co.
CIGNA Insurance Co.
CNA Insurance Co.
Chubb Group of Insurance Companies
Columbia Casualty Co.
Commerce Insurance Co.
Commercial Union Insurance Co.
Fireman’s Fund Insurance 
First State Insurance
Genesis Underwriting Management Co.
Gibraltar Casualty Co.
Great American Insurance Co.
Hanover Insurance Co.
Hartford Accident & Indemnity Co.
Hartford Insurance Co.
John Hancock Property and Ins. Co.
Insurance Company of North America
Kemper Insurance Co.
Lexington Insurance Co.
Liberty Mutual Insurance Co.
Lloyd’s of London
London Market Insurance Co.
Mt. Hawley Insurance Co.
National Union Fire Insurance Co. of Pittsburgh
New England Insurance Co.
New England Reinsurance Co.
The North River Insurance Co.
Northland Insurance Co.
Northwest Property and Casualty Insurance Co.
Prudential Reinsurance Co.
Royal & Sun Alliance Insurance Co
Scottsdale Insurance Co.
Specialty Risk Services
Travelers Property Casualty
Twin City Fire Insurance Co.
United National Insurance Co
United States Fidelity & Guaranty Co
Wausau Insurance Co.
Winterthur International
Zurich Insurance Co