OH CR4P!

Perhaps the most infamous hazardous waste site in the U.S., Love Canal stands as a staunch reminder of what irresponsibility and bad public policy can bring about.

Love Canal began as a vision by William T. Love, a venture capitalist of the 1890's. His dream was to use a three-block tract of land on the eastern edge of Niagara Falls, New York to build a "power canal" to supply cheap hydroelectric power to the region. However, economic depression, along with Nikola Tesla's invention of A.C. current, ended the project shortly after it began. The canal was left as nothing more than a huge hole.

(<-- Infrared aerial view of Love Canal in 1978 - Credit: NYSDOH)

In 1942, Hooker Chemical and Plastics Corporation made a deal with the current land-owners allowing the company to dump their chemical wastes into the site. By 1950 they had finished the dumping of 20,000 tons of hazardous and deadly chemicals, a long list including: hexachlorocyclohexane pesticide (Lindane), chlorobenzenes, chlorinated hydrocarbons, benzene, chloroform, trichloroethylene, methylene chloride, benzene hexachloride, phosphorous rocks, polychlorinated biphenyls, and 1, 3, 7, 8- tetrachlorodibenzo-para-dioxin (or just dioxin). Simply put, it was a big mess.

In 1953, shortly after the site was capped and sealed, the district school board approached Hooker C&P with a request to purchase the land and build a school. Despite warnings from the company on the risks to public health and safety, the school board prepared eminent domain cases in order to claim the property. In the end, Hooker C&P agreed to sell the land for only $1.00 in return for being freed from any liability. The school board sold a portion of this land to housing developers and to the city of Niagara Falls.

Construction proceeded for the school despite contractors unearthing pits of chemicals. Although no official investigations were done, ongoing health concerns and strange odors were reported in the community as it was developing. It wasn't until the late 1970s that heavy rain and snow falls produced high groundwater levels which triggered the surfacing of many of the buried chemicals. Noxious fumes began permeating the air, oily substances began leaking into basements, and surface water became contaminated. By 1978, the site received national attention, and remedial cleanup began in addition to relocating and compensating those in homes surrounding Love Canal.

For many this was not enough. Studies conducted in the area linked the disaster site to diseases, birth defects, and chemical burns suffered by some of those in the immediate area surrounding the Love Canal, specifically those 230 adults and 134 children living in homes on the property.

(Love Canal protester - Credit: EPA -->)

When playing the blame game, people seem to point fingers from all sides. From an engineering standpoint, Hooker Chemical and Plastics Corporation did a poor job handling the chemicals they dumped, considering the dangers they presented. Many were strewn out without being encased in barrels or containers, while others probably shouldn't have been allowed in a landfill at all. In the company's defense, however, the impermeable clay soil and clay cap used to enclose the Love Canal was carefully constructed, and was likely more than adequate to hold the chemicals and prevent leaching on its own. Reports indicate that the subsequent construction of a school, sewer system, and houses resulted in the puncture and leaching of the enclosure - construction that came about despite warnings from Hooker C&P.

Regardless of who is at fault, one lesson from this debacle is clear - prudence is a necessity when dealing with hazardous chemicals and waste sites. While many regulations and laws (e.g. Superfund) have been established since Love Canal, engineers and public policy makers alike should not forget the event. Since 1988, the area around Love Canal has been deemed uninhabitable, and goes to show that the consequences of poor hazardous waste management can last a lifetime.

Editor's Note: Past posts on CR4 regarding the Love Canal incident can be found at these links.

Happy Birthday, Love Canal

Love Canal - Reason.com

The Love Canal Disaster - Online Ethics Center

I was in study hall when it happened. An announcement came over the loud-speaker that a plane had hit the World Trade Center. I didn't even know much about what that building was, except that it was big and important; I couldn't really grasp what they had said. But shortly after, we were all sent home from school. I watched the rest of the horrible events unfold on TV for hours that day.

In tribute to this day of remembrance and those who lost their lives in the tragedy, I thought it would be fitting and appropriate to take a look at the engineering achievement behind the Twin Towers.

The Project

The conception of the world trade center is attributed to David Rockefeller, a grandson of the famous John D. Rockefeller. In the 1950s and '60s, Rockefeller was looking to bring new life to lower Manhattan through new construction, and constructing a trade center would no doubt bring about economic growth. It would also enhance the value of the Chase Manhattan Bank tower, another one of Rockefeller's projects.

Rockefeller commissioned The Port of New York Authority to head up the project in 1960; their own Guy Tozzoli managed the entire design and construction process. Minoru Yamasaki, the team's chief architect, came up with the twin tower concept and the basic layout for the entire complex, which consisted of office and hotel space, an exhibit hall, a securities and exchange center, and shops.

Design and Construction

The World Trade Center towers, the masterpieces of the complex, used a unique "tube" design, where all support columns would be located at the perimeter and the core of the building. Basically, each tower was a box within a box joined by horizontal trusses on each floor. On each floor, the outer box was made of 14-inch wide steel columns with aluminum facing, while the inner box consisted of 47 heavy steel columns which went all the way down to a spread footing structure beneath the tower basement. Each column in the spread footing design rested on a cast-iron plate above steel grillage and a concrete pad. Once in place, this whole bottom structure was drowned in concrete.

(Images Credit: HowStuffWorks)

This innovative design provided incredible stability. The inner structure was completely dedicated to supporting the incredible vertical loads, while the outer structure reinforced all the horizontal loads resulting from wind. In addition, the tube concept allowed for a more open floor plan, since all the columns and support was located in the center and edges of the building.

Constructing the Twin Towers was also a true feat, considering it was a logistical nightmare. Not only was the engineering incredibly difficult, but the space for the construction site and materials was limited. In order to manage this and keep the project moving at a decent pace, the 200,000 tons of steel had to be supplied by just-in-time delivery. The process moved chunk by chunk from the inside out; inner steel tubing was built to a certain height first, followed by perimeter wall, the floors, and the anodized aluminum facing. On April 4, 1973, the WTC complex opened its doors - 13 years or more after the project began.

September 11

It took about an hour for Tower 2 to collapse after being struck by an airliner on the morning of September 11. Tower 1 followed only 40 minutes later.

A combined effort by FEMA and SEI/ASCE was coordinated to investigate what exactly happened and what caused the collapse. The entire report can be found here. To sum up, the crashes involved two 395,000 pound Boeing 767s flying about 470 mph (Tower 1) and 590 mph (Tower 2). The impact wrecked floors, damaged columns at each building's core, and destroyed as many as 36 (Tower 1) and 32 (Tower 2) vertical columns around each tower's perimeter. In each crash, the jet fuel ignited and resulted in a massive fireball. This caught much of the office equipment and building materials on fire, which continued to fuel the flames until the collapse.

(Image Credit: BBC News -->)

Most skyscrapers would presumably have toppled within seconds just from the initial crash. But remarkably, the twin towers managed to hold up against the incredible stress put on the remaining columns of the building. The FEMA report claims that without the onset of the fire or any additional loads, the building would have remained intact indefinitely. But the +2,000°F fire, which spread across multiple floors and over a large area, was more heat than the columns and trusses could handle. When enough steel had been weakened and stressed from the heat, the result was catastrophic failure. The remaining supports gave way, sending some twenty stories crashing down on the intact portions below where the planes had hit. The rest, as they say, is history.

Looking Back

The Twin Towers were certainly built in a spirit of excellence. They were remarkable technological achievements that showcased the hard work and driving spirit of this great country. It is in this spirit that we honor the victims of these attacks and remember the bravery shown by rescue workers on that day, from the first responders to those involved after the collapse. It's unconditional sacrifice like this which we should look to, sacrifice which gives us hope for the future.

References

How the World Trade Center fell - BBC News

The World Trade Center - HowStuffWorks

World Trade Center Disaster - Engineering.com

Sometimes weather disasters go beyond the scope of what we could ever imagine or prepare for. Such was the case with the China floods in 1931, the Bhola Cyclone in 1970, and the more recent Indian Ocean Tsunami in 2004. But was it the same for Hurricane Katrina in 2006? Was New Orleans (its worst victim) completely at the mercy of such a huge storm, or could something more have been done to defend it?

The Storm

This past week marks the seventh anniversary of Hurricane Katrina's landfall, a deadly Atlantic hurricane that formed in 2005 and lasted from August 23 to August 30. This force of nature took 1,836 lives and, with $81 billion in damages, claimed its place as the most financially destructive natural disaster in history.

The storm first threatened the city of New Orleans while in the Gulf of Mexico on August 26. A voluntary evacuation was issued on August 27, and a mandatory evacuation was called a day later as the storm grew to a Category 5. New Orleans experienced intense winds, rain, and flooding over the next several days. The eye of the storm missed the city, but this fact meant very little to the many areas of the city which suffered catastrophic damages.

Perhaps the worst damage in New Orleans was done to the Lower Ninth Ward. Storm surge flood waters poured into this residential area from multiple places due to levee failures, and completely destroyed most of the houses. I remember visiting the Lower Ninth in the spring of 2009, nearly four years later, while helping with some ongoing restoration projects. Empty lots, a few restored buildings scattered about, and streets leading to nowhere were all that remained of the old neighborhood. Here are some photos I took:

Disaster Prevention: What/Who Went Wrong

Roughly 49% of the city of New Orleans has an elevation below sea level, not conducive for easy flood prevention. Since the flooding from Hurricane Betsy in 1965, the Flood Control Act of 1965 was put in place to initiate flood prevention strategies, including projects by the Army Corps of Engineers. The complete project plan for the city was projected to take about 13 years, but by the early 2000s was given a completion date of 2015 (40 years since its inception). In October 2002, Scientific America declared New Orleans was "a disaster waiting to happen".

A year after the storm, the Independent Levee Investigation Team released a report on the levee failures in New Orleans. According to their reports, while some flooding was inevitable due to the hurricane design levels authorized by Congress (Category 3 level), the catastrophic failure of major portions of these levees could have been prevented. Most of the fault was due to the incompleteness and inadequacy of portions of the outer levees. When these outer levees failed, waters surged through swamp areas intended to absorb what would have been normal overtopping, and passed easily over secondary levees not designed for such massive flows.

(Broken levee. Photo Credit: FEMA)

There were a number of reasons why these floodwalls and levees failed. For one, multiple sections were still well below design grade at the time of the storm due to the lack of funds provided to the Army Corps for the project. Other sections contained large portions of erodible and lightweight sands rather than hard and compact clays designed to resist water erosion. Many breaches also occurred at junctions between dissimilar sections and "complex" intersections; places where collaboration between multiple design teams is needed to do the job right.

In sum, the investigation team had this to say:

"The New Orleans regional flood protection system failed at many locations during Hurricane Katrina, and by many different modes and mechanisms. This unacceptable performance can in many cases be traced to engineering lapses, poor judgments, and efforts to reduce costs at the expense of system reliability. These, in turn, were to a large degree the result of more global underlying "organizational" and institutional problems associated with the governmental and local organizations jointly responsible for the design, construction, operation, and maintenance of the flood protection system, including provision of timely funding and other critical resources."

Sharing the Blame

Unfortunately, unacceptable performance was a nearly universal characteristic for those in leadership roles involving disaster prevention/relief in New Orleans. Most troubling was the evacuation "plans" for the city, which (although effective enough to evacuate 80% of the city's population) had no solution for the elderly, disabled, or others without means to leave on their own. As a last ditch solution, places such as the Louisiana Superdome were opened up to those who could not evacuate. But the problems that occurred there are another story…

References

Independent Levee Investigation Team Findings (pdf)

Hurricane Preparedness for New Orleans - Wikipedia

Among hazardous chemicals and substances handled in industry, gases are often the most dangerous. In addition to being harder to contain than liquids or solids, many gases are invisible and odorless, forcing workers to rely on sensors and meters to detect leaks.

But surprisingly, amongst all the toxic, corrosive, and otherwise nasty gases that exist in industry, the most deadly of them all is the one we breathe in the most - nitrogen.

(Credit: Nitrogenfree.com -->)

Nitrogen (N₂) is an inert and invisible gas that makes up about 78% (by volume) of the air we breathe. The lungs don't absorb any of it, and it comes right back out when we exhale along with carbon dioxide (CO2), as discussed in ChelseyH's newest Medical Mystery blog post. No interactions, no suffocation, no problems.

Nitrogen Asphyxiation

But don't let that fool you. Things get dangerous fast when nitrogen concentration rises and oxygen levels fall in a closed environment. It only takes about a 2% dip from normal oxygen levels to create a breathing environment that is fatal within a short period of time. Victims of nitrogen-rich environments often don't know what's wrong until it's too late, because normal breathing is still taking place; carbon dioxide is still being released, so the buildup which causes suffocation doesn't happen. The incident, termed 'nitrogen asphyxiation', results in a lack of oxygen which impairs judgment, coordination, and the ability to exert strength. In extreme cases, even just one breath can result in unconsciousness.

Just how prevalent is the nitrogen problem? Accidents involving nitrogen asphyxiation cause nearly 8 deaths per year in the U.S. The CSB (U.S. Chemical Safety and Hazard Investigation Board) reports that between 1992-2002, 85 incidents occurred, resulting in 80 deaths and 50 injuries. Of these, perhaps one of the most tragic was an accident at a Valero Refinery in Delaware City, Delaware.

The Fatal Valero Asphyxiation Incident

On the night of November 5, 2005, a pipe elbow had been removed on the top of a hydrocracker which was shut-down for maintenance. Nitrogen had flowed into the reactor and exited from the covered opening, which was marked with a "Danger: Confined Space" sign but had no signs for nitrogen hazards. Nitrogen dangers in the report for the installation crew had been marked N/A.

(Credit: CSB)

Down in the opening, workers noticed a roll of duct tape in the reactor, which needed to be removed in order for work to continue. However, entering the reactor to remove it would require obtaining a special crew and permit, which would cost a lot of time and money. This was incredibly inconvenient considering the reinstallation was scheduled to be completed that night, and a crane needed for the operation had just become available for that short window of time.

In an attempt to save time, a worker tried retrieving the tape with a long wire, but to no avail. There are two plausible scenarios of what happened next: either the worker got close to the edge of the reactor hole, or he decided to climb down into it. In either case, in an attempt to retrieve the duct tape the worker ended up breathing in oxygen-deprived air and quickly collapsed down inside the reactor.

An eyewitness saw that the foreman and a contractor were peering down the hole when the first worker collapsed. The foreman quickly grabbed a ladder, inserted it into the hole, and climbed down to attempt a rescue. He too collapsed inside the reactor. The contractor then quickly declared an emergency on his radio.

Over 10 minutes since the first victim collapsed, emergency crews had responded and found the oxygen levels within the hole to be below 1%. Using breathing apparatuses and harnesses, they retrieved the workers from the reactor, but attempts to revive them were unsuccessful. It was later estimated that the men died around 3 minutes after falling unconscious within the reactor.

Lessons Learned

In an investigation of the incident, the CSB determined that current industry safety guidelines, company training programs, and OSHA standards were not enough to adequately warn workers about the dangers of low-oxygen hazards. Properly informed and trained workers would know not to enter such confined spaces without safety equipment such as oxygen level meters to detect O2-deficient environments. They would also know not to attempt a rescue of a fellow worker without essential breathing equipment or first purging the area of the harmful gases.

(Credit: RKI Instruments -->)

As always, industry should strive for safety as a number one priority in any potentially dangerous work environment. Nitrogen-related accidents like that at the Valero refinery can be prevented through proper safety equipment, thorough reporting, adequate warning signs, and sufficient training in the workplace.

References

CSB: Valero Refinery Asphyxiation Incident

CSB Safety Video: Hazards of Nitrogen Asphyxiation

The Texas City Oil Refinery is the second largest in the state of Texas, and the third biggest in the U.S. Up until early 2005, the 1200-acre facility processed up to 460,000 barrels of crude oil every day, and from a distance it seemed like the plant was in good order. Unfortunately, it wasn't until after the worst refinery explosion of the decade that the facility's major safety procedure and safety culture flaws were revealed.

Incident

On March 23, 2005, operators had started up the raffinate splitter tower (gasoline component separator) section of the ISOM unit used to increase the octane of gasoline, and began filling it with hydrocarbon fluid. Abnormal pressure built up in the tower due to an abundance of fluid, and relief valves opened to allow the components to escape to the "blowdown" drum. Shortly thereafter the filled drum ejected fluid and vapor in a "geyser-like" stream out the vent stack into the air. While workers alerted to the cloud rushed to shut-off all hot-running equipment, a contractor attempted to turn on his diesel pick-up truck. Operators ran to him in an attempt to stop him, but once the fuel content in the air had diluted to the UEL (Upper Explosion Limit), the engine provided an ignition source, resulting in a huge vapor cloud explosion. The fireball injured 100 people and killed 15, including some workers in a trailer parked near the process unit. They were in a meeting, and were unaware of the situation.

(Fire extinguishing operations after the explosion. -->)

Cause

The direct cause of the incident was the poor operation and condition of the raffinate splitter tower, and its flawed blowdown system. In 1997, the atmospheric blowdown was replaced with an identical one due to budget constraints, despite safety regulations prohibiting that type. Between 1994 and 2004, apparently eight similar cases of flammable emissions from the blowdown vent occurred, but no corrective action was taken. In addition, operators involved with the raffinate splitter tower did not follow standard (timely) procedures for discharging the fuel during the restart, and ignored the open maintenance orders on the tower's instrumentation. The alarm meant to warn workers of excess liquid in the unit was disabled.

Many other safety problems could be considered causes of failure. A number of other alarms and safety sensors were disabled, malfunctioning, or non-existent. Poorly trained control operators worsened the situation by opening the discharge valve, allowing hot discharge to flow through a heat exchanger and pre-warm the inlet fluid. Safety protocols for equipment and vehicle placement were also not being followed by some of the staff, including the guest contractors.

For a complete breakdown of the disaster and its causes, check out this video by CSB (the Chemical Safety Board).

Lessons Learned

On top of the casualties, BP (the owner of the refinery) had $1.5 billion in expenses and lawsuits to take away as a hard learned lesson on process safety. Among the refinery's most fatal flaws was its inadequate safety culture; disaster investigators concluded the facility nurtured an environment in which workers were neither well-informed of nor well-encouraged to speak up about safety issues. On top of this, leadership did not take control to properly train workers and operators on emergency procedures and situations. Replacing the actual blowdown system, as well as the numerous malfunctioning safety systems, alarms, and sensors were also not a high priority under a tight budget. The lack of alarms was the reason that some people remained unaware of the emergency that was taking place until after the explosion.

This horrible accident is just another example of how important it is to keep safety a priority in the workplace. Establishing and following standard work safety practices, doing routine tests and maintenance of safety systems, and encouraging open communication among workers are all important aspects of a safe work culture. Furthermore, investment into work safety should be considered synonymous with investments towards quality work and quality product. As we have seen in numerous case studies, the bottom line is a very thin line to walk alone; companies with a misplaced emphasis on it are setting themselves up for a dangerous fall.

References

Texas City Refinery Explosion - Wikipedia

What Went Wrong: Oil Refinery Disaster - Popular Mechanics

When it comes to land warfare, no piece of machinery is more widely known or feared than the armored tank. These beasts combine a number of different technologies (e.g. combustion engines, armor plate, continuous track) to create a mobile fortress with some intense firepower.

(<-- Credit: Thehistorybluff.com)

Tank technology made its first formal appearance around the time of World War I, but played a much more significant role in the developments of World War II. Between these two time periods, a variety of innovative tanks were developed. But along with the renowned Sherman and Tiger tanks, there were a number of lesser known designs and proposals that just didn't make the cut…

The Russian Tsar Tank

In the early stages of tank development, a lot of designs were lacking in functionality. The one that stands out the most perhaps was the Russian Lebedenko, also known as the "Tsar Tank". This 40 ton monster sported two very large spoked wheels (nearly 9 meters in diameter) attached to a hull with a centrally placed turret equipped with the desired weaponry. The hull tapered down at an angle and attached to a double wheel at its rear to provide the steering.

See the resemblance? (Credit: Fastboy (Wikipedia user) | cannonsuperstore.com)

The tricycle design, which to me looks pretty similar to an old-fashioned howitzer or 6-pounder, along with the massive wheels, was supposed to give the Lebedenko the ability to go virtually anywhere it wanted to. Unfortunately, the weight of the machine was miscalculated by near 50% due to the use of a thicker metal, and during a test run the back wheel got stuck in soft ground. The project was deemed to be too expensive to continue, and was cut before the design engineers were given the chance to add more powerful engines. The wheels of the Tsar were also considered to be too vulnerable to artillery fire.

Corkscrew Tank

Years after the failed tricycle design, the Russians were still looking to unlock the key to all-terrain tank mobility. In 1950 they had another proposal - the corkscrew tank. Riding on two large spinning corkscrew "wheels", the corkscrew tank was supposed to be more versatile, capable of traversing terrain such as snow and ice with greater ease than a traditional track-style tank (something pretty important during the snowy winters in Russia). Check out this video to see it in action.

(Credit: WebUrbanist dot com-->)

The tank suffered from a number of severe flaws, however. While its massive corkscrews were more than capable of grinding through snow and ice, they weren't able to move through normal terrain (flat ground, tarmac). The weight of the corkscrews also made the vehicle quite slow and incredibly hard to maneuver. Its poor steering and instability (apparent in the video) made it very susceptible to rollovers.

Flying Tank

Because air-drop paratrooper operations were a large part of World War II, there was a big incentive to develop a tank that could be flown and dropped into enemy territory. Having tanks on the ground behind enemy lines would provide a huge tactical advantage in surprise airborne operations like the famous Operation Market Garden. A number of different models were attempted by Russia, England, Japan, and the U.S., including those with detachable glider wings and others that would be carried by heavy bombers and dropped with parachutes.

(Credit: Gajitz)

Surprisingly, some designs actually had successful test flights, including the A-40 (KT-40) developed by the Soviet Union. Unfortunately these projects never saw production due to the weight limiting factor. In order to fly successfully, tanks had to be stripped of most of their plating and armament, making them tin cans in the midst of German armor. Nowadays, with access to stronger and lighter weight materials, we have aircraft that can airlift tanks to where they are needed on the battlefield.

References

Antonov KT Flying Tank - Unreal Aircraft

When the Military's imagination gets away from them - US Infrastructure