95 Years of Failure & Damage Analysis

Way back in 1924, Walter G.  Haag, a civil engineer who had graduated from Drexel Institute in Philadelphia in 1899, established his own consulting office in Dallas, Texas. He created Haag Engineering to determine facility values after losses (similar to the work Haag Construction Consulting performs today). Soon, clients began to ask Mr. Haag how the facilities were damaged.  Thus, he began to perform engineering origin and cause evaluations. The term “forensic engineering” was not used back then. (In fact, Professional Engineer licensing wouldn’t even start until 1937.) 

Mr. Haag hired Charles Wayne Parish in 1946. Mr. Parish, a World War II veteran and engineer in the Air Force, assumed increasing responsibility in the company and purchased it from Mr. Haag during 1956. Under Mr. Parish’s direction, Haag expanded its area of operation from North Texas to the world. He added Research & Testing capabilities in the early 1960s, which published a historic ice ball impacting study on wood roofing in 1963. Along the way, Haag Engineering has expanded to include Haag Construction Consulting, Haag Education, Haag Research & Testing, and Haag Technical Services.

As we celebrate Haag’s 95th anniversary in 2019, we thought it would be fun to take a look back at a few of the many noteworthy projects completed by Haag staff. During each month in 2019, this blog will feature noteworthy projects, as selected by our senior staff. We are fortunate to have several employees still with Haag who started in the 1970s, and one—my predecessor as Haag’s president & CEO, John Stewart (featured below)—who will be celebrating 50 years with Haag!

No company can endure, let alone prosper, for 95 years without talented, dedicated employees and loyal clients.  Further, Haag would not have been able to prosper without a commitment to quality and integrity.  As I like to say, we’re not good because we are old, we are old because we’re good. For turning 95, we still feel pretty spry!

Thank you to all the people who have contributed in any way to Haag’s pending 95th anniversary. That includes clients of our services and products, current and past employees, and all those who have spread a good word about Haag.

—Justin Kestner, P.E., President & CEO of Haag Global

Imperial Sugar- Sugar Dust Explosion

by John D. Stewart, P.E., Principal Engineer Emeritus

Around 7:00 am on February 7, 2008, a massive explosion occurred in the center of the Savannah Foods/Imperial Sugar facility, destroying or extensively damaging all three sugar silos and the packaging buildings that surrounded the silos. Sugar dust was believed to have been ignited by operating machinery. Many buildings outside the center of the plant also was extensively damaged. Investigations by government agencies as well as private experts concluded that the event was caused by an explosion of sugar dust followed by a fire wherein the sugar in the silos and throughout the area burned. Tragically, 14 individuals were killed in the blast and some 40 others were burned or injured.

Savannah Foods in Port Wentworth, Georgia, was founded in 1915 by Benjamin Alexander Oxnard and Richard H. Sprague when they moved their entire sugar refining operation, including more than 300 employees and their families, from St. Mary’s Parish in Louisiana to Port Wentworth. The refinery took in raw sugar and processed it into refined sugar and various other sugar products.  The Savannah Sugar Refinery began melting sugar on July 7, 1917.  In 1997, Imperial Sugar Corporation acquired Savannah Foods & Industries, Inc., which at the time was the second largest sugar refiner in the industry. Savannah Foods & Industries marketed its sugar under the Dixie Crystals® brand.

The Port Wentworth refinery included many large buildings, various tanks, and additional equipment for processing the sugar.  Sugar was brought into the facility by ship and sent out by rail, truck, and ships.  Among the facilities were three very large reinforced concrete silos located in the center of the packaging and storage area and used for storage of bulk refined sugar.  These silos, constructed in 1935, were approximately 130 feet tall by 40 feet in diameter arranged in an east-west line and were capable of holding about 3 million pounds of sugar each.  A large 4-story building to the north was the North Packaging Building.  Another 4-story building to the south was the South Packaging Building.  North and South Palletizing areas were to the west of the silos.  The main refining and raw sugar storage facilities were east of the silos.  Other buildings were south of the silo/packaging area.

Above, a 2008 image after the explosion and a 2019 oblique image of the same area. The centers of both images cover most of the areas of major damage.

Following the February 2008 explosion, Haag engineers were engaged by the insurers to evaluate the scope of damage and cost of repairs to the facility resulting from the event.  Haag also monitored the repair work during the several year period of restoration. Haag’s role beyond evaluation of the scope of damage was to monitor and separate extensive upgrades of the rebuilt facility from needed repairs. The extensive upgrades of the facility took it from an old processing unit to a state-of-the-art processing and packaging plant.

Haag engineers were on site from shortly after the explosion until the repairs were completed and the plant restarted in late 2009.  Haag was closely involved in the evaluation of the scope of damage.  Knowing that the facility would be extensively modified during the restoration it was critical to prepare a detailed scope of work including estimates of repairs for facilities that would not be rebuilt in kind.  Haag also was closely involved in all discussions about all changes, extensive upgrades, and reconfigurations of the facility to ensure that costs charged to the insurers of the facility were fair and represented the costs to restore an equivalent facility despite the many changes.

Ultimately, the loss cost insurers approx. $345 million out of total insurance coverage of $350 million. Total of physical damage and business interruption well exceeded $500 million.

John D. Stewart, P.E., is Principal Engineer Emeritus at Haag Engineering Co. and served as Haag’s President for more than 30 years (1982 – 2014). Mr. Stewart has been with Haag Engineering Co. since 1969. His engineering expertise includes evaluating and determining the scope of damage and repair options following failures, including at industrial plants, oil refineries, chemical plants. He has analyzed electrical failures, lightning damage, and electronic and computer equipment failures.

Mr. Stewart graduated from the University of Texas at Arlington with a Bachelor of Science degree in Electrical Engineering. He is a licensed professional engineer in the states of Texas and Arizona, and a member of the Institute of Electrical and Electronic Engineers (IEEE), the American Institute of Chemical Engineers (AIChE), the National Fire Protection Association (NFPA), the International Association of Arson Investigators (IAAI), the National Society of Professional Engineers (NSPE), and the Texas Society of Professional Engineers.

Bird’s Eye View—A Guide to Aerial Lifts

Aerial Lifts—now called Mobile Elevating Work Platforms (or MEWPs)—provide a safe way for viewing parts of a roof or building envelope. They can help you safely access elevated parts of structures. Haag’s resident MEWP expert, Anthony Bond, P.E., breaks down the types, components and uses of lifts.

Aerial devices have a variety of names given to them throughout the years. Common names for aerial devices include Cherry Pickers, Man Lifts, Bucket Trucks, Aerial Lifts, Aerial Work Platforms (AWP), and Elevating Work Platforms (EWP). The new American National Standards Institute (ANSI) group of standards (A92.20, A92.22, and A92.24) name these aerial devices Mobile Elevating Work Platforms. The definition provided by the new ANSI standards for Mobile Elevating Work Platforms or MEWPs is a “machine/device intended for moving persons, tools, and material to work positions, consisting of at least a work platform with controls, and extending structure and a chassis”.

There are several different types of MEWPs including truck-mounted aerial devices, trailer-mounted aerial devices, boom lifts, scissor lifts, and bridge inspection/maintenance devices. The typical types of MEWPs that we see on construction sites are scissor lifts (Group A, Type 3) and boom lifts (Group B, Type 3). Group A are MEWPs with platforms that move vertically, and stay inside the tippling lines. Group B are all the other type MEWPs with platforms that extends past the machine’s chassis. Type 1 MEWPs can only be driven in the stowed position, and Type 2 MEWPs can be driven with the platform elevated from a point on the chassis. While Type 3 MEWPs can be driven with the platform elevated from the chassis.

MEWPs have three basic assemblies: chassis, extending structure, and platform. For boom lifts, the extending structure is a boom assembly that either telescopes, articulates, or a combination of the two. Booms lifts are raised via a lift cylinder and extends by an internal cylinder, sometimes aided by wire ropes or chains. Boom lifts have an extending structure (typically boom-type) that positions the platform outward and upward beyond the chassis. While scissor lifts have an extending structure or scissor mechanism that elevates the platform vertically via a lift cylinder.

In order to select the type of MEWP for a specific job, some features of the MEWP to consider include its platform height, platform reach, platform capacity, working envelope, turning radius, and machine weight, as well as the MEWP’s overall dimensions. Platform height is the vertical distance from the ground (surface that the MEWP is on) to the floor of the platform. Platform reach is the horizontal distance from the center of rotation to the outboard railing of the platform. Platform capacity is the rated load that the platform can carry, which includes the total weight of the operator, tools, materials, and anything else that is within the platform that is not originally part of the MEWP. Working envelope is the operating range that the boom/platform maneuvers within as designed. This is usually illustrated by a range or reach diagram. Turning radius is the smallest circle that the MEWP can make. Scissor lifts typically have a smaller turning radius than boom lifts. Machine weight is the weight of the machine as configured by the manufacturer. Scissor lifts are typically less than 6,000 pounds, while boom lifts can weigh as much as 50,000 pounds or more. The overall dimensions of MEWPs vary tremendously. A 150-foot boom lift is approximately 40 feet long, 10 feet tall, and over 16 feet wide with its axles extended. Whereas a 20-foot scissor lift is approximately 8 feet long, 7 feet tall, and 3 feet wide.

Performing a worksite inspection will determine the required characteristics for the MEWP, while keeping in mind the limitations and restrictions of the worksite. Worksite limitations and restrictions can include overhead obstructions such as power lines that require minimum safe distances, height/width restrictions caused by the route the MEWP must travel, limits to safe travel for the MEWP due to hazards such as surface conditions (unlevel surfaces such as ramps, depressions, drop-offs, or holes), and surfaces that cannot support the weight of the MEWP (sidewalks, vaults or enclosures below ground).

Training requirements for MEWPs (aerial lifts) are provided within OSHA regulations. OSHA requires that, “Only trained and authorized persons are allowed to operate an aerial lift.” OSHA’s Fact Sheet for Aerial Lifts indicates that training include the following: “Explanations of electrical, fall, and falling object hazards; Procedures for dealing with hazards; Recognizing and avoiding unsafe conditions in the work setting; Instructions for correct operation of the lift (including maximum intended load and load capacity); Demonstrations of the skills and knowledge needed to operate an aerial lift before operating it on the job; When and how to perform inspections; and Manufacturer’s requirements.”

When safely operated by trained professionals, using Mobile Elevating Work Platforms/Aerial Lifts will help make your job safer.

Anthony E. Bond, P.E., is a Principal Engineer and aerial device expert. Mr. Bond has been with Haag for more than 10 years, and has 25 years of active involvement in the aerial device industry. He specializes in determining the cause and extent of aerial device accidents and responsibilities of involved parties (manufacturer, owner, dealer, user, operator) as defined by aerial device national consensus standards. He testifies in depositions and trials as an aerial device and crane expert. Mr. Bond gained valuable experience from his employment as a design engineer and engineering manager for an aerial device and crane manufacturing company. His structural designs and analyses include booms, pedestals, carriers, and outriggers, as well as hydraulic cylinders. Designs also include hydraulic, electrical, and control systems for product development of aerial devices. Under his direction as an engineer manager, the research and development team fabricated and assembled prototype models for testing prior to releasing new aerial device models for production. He is a licensed Professional Engineer in 26 states, and a member of the American Institute of Steel Construction (AISC), American Society of Mechanical Engineers (ASME), National Society of Professional Engineers (NSPE), Society of Automotive Engineers (SAE), and Scaffold Industry Association (SIA).

Seen and Unseen….The Benefits of Desaturation Testing

By Steve R. Smith P.E.

Have you ever been examining a built-up roof and encountered a mark which was not easy to identify? Identification of hail-caused damage to a roof can be as simple as following standard hail inspection procedures. Look for hail spatter and dents in soft metals. Examine less well supported components and examine test areas on the roof (a procedure developed by Haag Engineering Co. in the 1970s).

Sometimes, however, there are conditions observed on the surface of the roof that appear similar to a hail-caused condition but may or may not be related to hail. Also, it is not uncommon for two separate parties to have differing opinions on whether or not a hail-caused condition has compromised the roof covering.

When you find questionable marks on a roof, desaturation analysis of roofing samples can provide invaluable information. Desaturation can help determine if a particular feature is hail-caused and if the water-shedding ability or long-term service life of a roof has been compromised. Haag Engineering’s laboratory, established in 1963, has been performing desaturation analysis on roofing samples for decades. Desaturation can determine conclusively if a bituminous roofing sample has been compromised by hail.

Desaturation works like this: lab personnel use equipment and chemicals to extract the reinforcements from asphalt built-up roofing (ABUR), coal tar built-up roofing (CTBUR), modified bitumen membranes (mod-bit), asphalt roll roofing, and asphalt shingles. Then, they examine the reinforcements to identify fractures, or the absence of fractures, and determine if the fractures present are characteristic of damage associated with hailstone impacts. Desaturation can also help identify the constituents of a roof, including the number of roofing plies, the types of roofing plies, and the quantity (weight) of the inter-ply asphalt.

Haag’s lab examined an ABUR sample for the effects of hail, see photos below. When the bitumen was removed, our analysis revealed fiberglass reinforcements from the ABUR system, and several organic reinforcements from the previous roof system that was left in place and overlaid. There were no hail-caused fractures in the fiberglass reinforcements, but a hole was observed in one of the organic plies. We noted the hole was only present in the uppermost organic ply, which is not consistent with an impact-caused fracture. Instead, the hole was characteristic of a weathering-related condition in the older roof system.

Figure 1: Desaturation of ABUR – fiberglass and organic reinforcements

Hole was found in the uppermost organic ply only

Organic ply below the top organicply did not contain a hole,indicating the hole was a weathered condition on the oldroof, rather than an inpact-caused fracture

Now let’s look at a mod-bit sample. This sample exhibited a discrete region of missing granules that was thought by some to be a hail-caused bruise. There were no fractures visible in the top or bottom surfaces of the sample prior to desaturation. We noted the exact location of the area of interest so that we could examine the same area after desaturation, which revealed the reinforcement was intact.

Figure 2: Desaturation of mod-bit – scrim-type reinforcement

Mod-bit prior to desaturation	Area of interest observed on                     the top surface
Scrim-type reinforcement extracted by desautration	Close-up of reinforcement at the area of interest revealed no damage to the reinforcement (the structural element of the roof)

Finally, let’s examine a mod-bit sample that shows the effects of impact by large hail. Our laboratory personnel installed a mod-bit sample on a test panel to replicate the as-installed support conditions for the sample and performed ice ball impact testing to show the effects of hail impact. The sample was impacted by three ice balls, ranging up to two inches in diameter. The two-inch diameter impact is highlighted in blue (Figure 3). Desaturation of the sample revealed a fracture at the two-inch diameter impact location.

Figure 3: Desaturation of mod-bit impacted by ice balls – polyester reinforcement

Mod-bit prior to desaturation	Impact testing setup	Sample after impact testing
Sample after desaturation (top side up)	Bottom side of reinforcement after desaturation	Close-up at fracture caused by a 2-inch diameter ice ball impact

In all examples, desaturation was able to conclusively determine if the reinforcements had been fractured by hail. Desaturation also allowed us to identify constituent components and even provided insight on the condition of the previous roof system (Figure 1). Hail-fractured reinforcements ultimately result in a loss of water-shedding ability and/or reduction of the remaining service life of the roof. Knowing if the structural components of a roof had been compromised by hail is paramount in determining appropriate remediation procedures.

Since desaturation is destructive testing, Haag Research and Testing personnel carefully document test specimens during all phases of testing. We photograph and even video record (if requested) to document specimen conditions and preserve the evidence. Proper maintenance of the chain of custody of evidence is another important consideration.

Steve R. Smith P.E. is the Director of Research & Testing. Mr. Smith is based at Haag’s national headquarters in Flower Mound, TX, and can be reached at ssmith@haagglobal.com .