Month: October 2020

12 Engineering Mistakes That Worked Out

Not everything created matches the blueprint. There are times engineers finish a project before realizing there's a big problem with their design.

Problems arise from poor project management and bureaucracy too. Mistakes happen, and plans change. Mistakes can doom a construction project, but not every mistake is a failure.

We'll take a look at a few that turned out all right.

Gisborne Railway

The landscape comes at a premium in New Zealand. It's one of the world's smallest countries, and building large-scale transport isn't easy — especially when the left-hand doesn't know what the right is doing. 

Because of this, the Gisborne Airport has a functional railway line that crosses the main runway, which sounds like a recipe for disaster.

However, despite the two different types of vehicles moving close enough to each other to make you nervous — there has never been an accident. It does help that the airport is a small, regional facility and the only planes that fly from there are small ones, used for private flights or flights to Australia.

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The Walkie Talkie 

There are some incredible and unique buildings in London, England. Architects with outstanding skills are sought out regularly and paid millions to use their talents. One such structure is a building that has been nicknamed The Walkie-Talkie — because of its unique shape.

Sadly, the skyscraper located on 20 Fenchurch Street was voted the worst building in the United Kingdom in 2015. The shape of the building led to some accidents nobody saw coming. 

The glass front reflects the sunlight so intensely that it set a carpet in a neighboring building on fire in 2013. It also melted the roof on a luxury car on the street below it. During the high winds, the curved surface creates a wind tunnel strong enough to knock pedestrians over. 

Despite all of these incidents, the building still stands and is adored by Londoners.

Sydney Opera House

Australia Sydney Opera House isn't just one of Australia's most iconic buildings, but one of the most iconic buildings in the whole world. Most people love the building's design. So, many are surprised to hear that it is a classic example of bad project management. 

In 1959 the foundations were laid, and construction was supposed to be finished in 4 years and cost around $7 million. It took 14 years to build, and by its opening day, it cost over $100 million. 

The issues began when the government ordered the construction work on the outer shells before the architect, Jørn Utzon, had finalized the design, which meant the designer had to supply updated plans to builders while in the middle of the building process. All the chaos led to some mistakes getting made, of course. 

In the mid-1960s, with construction delayed by disagreements and impracticalities, Utzson was frustrated and resigned from the project — and took his original designs with him, which meant other designers had to come in and finish the project without Utzson's blueprint. It's a miracle it ever got finished at all. 

Baku Railway Highway

In Baku, Azerbaijan, there are some interesting choices on railway crossing placement. Trains cross onto busy highways without warning, nearly crashing into the many passing cars. Images of this went viral in 2016, prompting the Baku government to reconsider the design and remove the railroad. 

The area is much safer now, making it hard to believe anyone ever thought that placement was a good idea. 

Railway Market

If you visit Mae Klong in Thailand, you will find one of the largest fresh seafood markets in Thailand, the Mae Klong Railway Market, conducting business along an active railway line — in the same place. Six trains run directly through the street every day. The street vendors have to quickly get out of their way when they approach. 

Luckily, the vendors have it down to a science. They know the times the trains run through, so they get out of the way ahead of time. The train running early or late hasn't proven dangerous so far. But the railway market is known as the most dangerous market in the world. 

The only reason it hasn't been closed down is the sheer stubbornness of the traders. 

The John Hancock 

A famous building in Boston, Massachusetts, has gone by many names over the years. Most people call it the John Hancock Tower. But it's also gone by 200 Clarendon Street, The X Building, and The Hancock. It's also known for its shoddy construction work. 

Built-in the 1970s, the person in charge of securing the windows and window frames on the skyscraper did a poor job. As a result, several window frames have fallen out of the window frames and plummeted to the busy sidewalk below. Thankfully, no one was hurt.

This situation was one of many embarrassments for the architects after they finished the building in 1976. It was supposed to have been completed in 1971, and the five-year delay sent the project $100 million over budget. 

When it did open, it swayed so much in the wind that occupants suffered from motion sickness. Luckily, the issues were resolved. 

 Walt Disney Concert Hall

The Walt Disney Concert Hall, which sits in Downtown Los Angeles, California, is another example of buildings that didn't get completed on time and do not turn out as intended. 

Construction began in 1992, sparked by a $50 million donation from Lillian Disney — the widow of Walt Disney. It didn't welcome its first guests until 2003. By that point, it had cost $274 million. The parking garage cost $100 million on its own.

Nearly every cost provided at the design stage came in below the estimated costs. The project stalled entirely between 1994 and 1996, as they sought additional funding to complete the project. 

When resumed, the expensive, initially planned lavish stone exterior was substituted with stainless steel, which proved problematic. While most of the building's exterior had a matte finish, the Founders Room and Children's Amphitheater were designed with highly polished mirror-like panels. The concave walls reflected and intensified the sun, which heated the nearby sidewalks to 140 degrees Fahrenheit and nearly blinded neighboring residents.

After about a year, they sandblasted the offending panels’ gleaming surface, eliminating the unwanted glare, thus resolving the issue.

Chicago Aon Center

The Aon Center in Chicago, Illinois, once known as the Amoco Building, is 1100 feet tall and the 4th most massive skyscraper in Chicago. In 1973, when the building was constructed, it stood as the 4th tallest in the whole world. 

The buildings' impressive height made it's opening a significant affair in the city, but it almost didn't make it to its opening date due to numerous construction issues. The building was constructed with Carrara Marble, and marble that thin had never gotten used to clad a building before. A 350-pound piece of the marble fell to the ground on Christmas Day in 1973. It crashed through the roof of the Prudential Center.

In 1985, an inspection discovered major cracks and signs of bowing on some of the building's central panels. The building had to be strapped in stainless steel to prevent the marble from falling off. Later, from 1990 to 1992, the building was refaced with Mount Airy white granite at an estimated cost of over $80 million, which was well over half the building’s original price, without adjustment for inflation.

Brooklyn Bridge Park

In 2010, there was a new playground installed at Brooklyn Bridge Park that had some flaws. The design included metal climbing domes that were supposed to be one of the primary forms of entertainment for the children. With its shiny chrome design, it looked futuristic in style. Somehow, the team forgot how hot steel gets when the sun's out.

On the hottest day, the climbing domes would become so hot that the children playing would receive immediate burns.

Following complaints, officials decided to plant trees close to the domes to provide shelter. However, critics said the trees don't completely solve the problem. They quickly installed temporary tents over the metal domes to keep them cool.

But they didn't work. The family of a toddler scorched by playground equipment in Brooklyn Bridge Park won a $17,500 settlement from the city. The tents were already in place at the time of the toddler's accident.

Following the girl's injury, officials closed off access to three steel climbing domes. Four months after children began getting their hands scorched on the brand new Brooklyn Bridge Park Pier 1 playground, park officials finally replaced the three steel climbing domes.

Venice Glass Bridge

Santiago Calatrava designed a glass bridge in 2008 in Venice. However, they didn't prepare it for many people to walk over it. 

After several pedestrians fell and became injured, he got fined $150,000. The designer informed the city that the bridge's glass steps would need replacing once every 20 years. Instead, eight of them required replacing four years after the bridge opened. 

When it rains, the glass makes it impossible for a person to balance while crossing. It is aesthetically appealing from a distance, but you want to think twice before walking across it.

China Train in Apartment Complex

Chongqing, China, has a train line that runs directly through the middle of an apartment building. Not only does the passenger train pass through the 19-story residential building, but it also has a transit stop there.

No one knows whether to call this a triumph or disaster when it comes to design. It's convenient for those living in the apartment building, but the train's constant passing must be causing structural damage. 

The exciting part about it is that the nine-story apartment complex was there before the monorail was. In 2004, the city wanted to expand its railway service. They originally intended to tear the apartments down. 

But, they reconsidered and found another way to do it. Due to the changes, the complex apartments have increased in value due to the novelty and convenience. 

Nail Houses

In China, nail houses are houses marked for construction work. Residents sometimes get offered three or four times what the home is worth for them to get removed, but the nail houses are the ones that still stand when the owners refuse. You'll see them pop up amid a construction project, such as a road.

One notable example is a nail house in Wenling, China, a five-story home left in the middle of a new road. The owner, Luo Baogen, and his wife agreed to accept the "vastly inflated" price of $41,000. Now his place is demolished, but there are many more all over the country.

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Extreme Engineering: Megastructure-Building Machines

There is something gratifying about watching machines build masterpieces. When it comes to the mega-sized ones, it gets even more enjoyable. 

Have you ever wondered what it takes to build some of the world’s largest skyscrapers? Are you curious about what type of equipment it takes to lay the foundation for a bridge underwater? Sometimes it seems like they do the impossible. But with a few large tools, they manage to complete some miraculous structures. 

Let's look at several of the world's most powerful megastructure-building machines and how they do what they do.


SLJ900/32 Segmental Bridge Launcher

When you think about bridge construction, you may envision large cranes lifting each section into place as they build the structure, and you wouldn't be wrong. This isn't the only way now. There is a massive machine in China that redefines bridge construction as we know it.

The SLJ900/32 Segmental Bridge Launcher is 580 tons and manufactured by the Beijing WowJoint Machinery Company. 

It drives onto the bridge's pillars, lowering a pneumatic support structure, anchoring the machine to the first pillar, which allows it to extend itself out to the second and third pillars. It then deposits the girder it's carrying. 

From here, the workmen can weld everything into place while moving onto the next girder. The transport relies on 64 wheels split into multiple sections, rotating 90 degrees to steer on space-confined ground. 

The development of this machine has a fast-tracked infrastructure development in China.

 24,000 miles of railway track is planned for construction by 2025. More than the combined railway structures combined in the European Union — which rests at 13,841 miles.


Tunnel Boring Machines

Have you ever wondered how engineers dig road, rail, and utility tunnels without disturbing the busy cities above? Tunnel boring machines make this possible.

One example is the ongoing construction of Australia's Forestfield-Airport Link. It currently requires the use of two tunnel boring machines designed by the German company Herrenknecht. The devices cost about $20 million each. 

They have 39-foot radius rotating cutter wheels, helping them efficiently break material away from the tunnel's rock walls. The gravel is then transferred to the belt conveyor system, while the hydraulic system pushes the machine forward. 

Reinforced concrete segments are installed, matching the tunnel's curvature. These segments form rings that support the tunnel as the machine bores. Once each concrete ring is complete, the machine's hydraulics can push against the new ring to propel it forward.

In Australia's airport link project, they are placing around 9000 rings along the project's 5-mile plus tunnels. 

In order to avoid vibrations that would cause significant disruption above, technology like this needs to move very slow. Because of this, Australia's Airport project started in 2017, won't be finished until late 2020.


Tower Cranes

Cranes are one of the most miraculous machines that city-dwellers see every day. Making the most of their machines in every way, one of the world's leading crane companies, Liebherr, always put their engineers and machines to the test. 

Sometimes they have large celebrations where they get giant cranes to lift smaller cranes. But where their cranes are most impressive is in practical application, particularly with tower cranes.

Construction site ground space is a precious commodity. Having multiple vehicles and lifting equipment can be more of a hassle than a help. Tower cranes remove that complication by hosting all lifting and moving activity, using airspace above the site, which frees up the ground room. 

Depending on the series, Liebherr's tower cranes can lift as high as 1500 feet for specialized constructions of exceptionally tall buildings, such as St. Petersburg's Lakhta Tower. 

While most tower cranes aren't quite that tall, the shorter ones are still pretty impressive. Some of them can lift loads of up to 42 tons. They do this with incredibly thick, steel lifting cables with thinner strands around the large central core to distribute the weight. 

The modular design of tower cranes means they get quickly erected by other smaller cranes and disassembled similarly. For ease of use, the tower cranes typically get built into the megastructures they create. Some tower cranes can even climb while inside a building — reaching higher as construction progresses.


Georgia Nuclear Power Plant

Sometimes you need something that can reach farther than even tower cranes can reach. The Georgia Nuclear Power Plant can reach up to 3200 acres. In large planes, crawler cranes are the weapon of choice for several reasons. 

Units 3 and 4 of the Georgia Vogtle Expansion Project had nuclear containment roofs weighing in over 900 tons apiece. They were 135 feet in diameter and 37 feet tall. 

The Lamson LTL 2600 fits the job. It can lift to 1200 tons.


AASTA Hansteen Rig Spar

You ever wondered how an oil rig is constructed so far out at sea? The world's largest oil rig, the AASTA Hansteen, was built in South Korea and measured in at 656 feet long and 164 feet in diameter. It weighs over 46,000 tons. 

The rig needed transporting from Korea to the coast of Norway. The Boskalis Dockwise Vanguard is a semi-submersible transport vessel, which can sink over 90 feet beneath the water, allowing heavy machinery to float onto the platform instead of being lifted.


Thien Ung Project

Oil workers need to have a place to live and store at sea while working on oil rigs. They do this on top of the rig. Of course, none of it ever gets built in the middle of the ocean. 

The top of the Thien Ung KK TNG Field Rig is one example. Built offshore, the project required a 4200-ton topside, with an 850-ton living quarter. 

At the time, they used the world's most massive nautical lift installation—the Asian Hercules III. It was an offshore heavy lift sheer leg crane. This self-propelled instrument is 350 feet tall and can carry over 5000 tons.


Wikinger Wind Farm Installation

If you'd ridden a plane in the past few years, you may have seen some offshore wind farms in the sea. Onshore wind turbines can reach 575 feet in height, but onshore they can get 853 feet. They need an array of mega machines to put them into place. 

In 2017, the Wikinger Wind Farm Installation used over 70 turbines off Germany's coast to work. The Fred Olsen Windcarrier was used to complete the most fundamental stages of the project. The mega-machine is a jack-up vessel, a ship that contains four self-elevated basilisks sitting on the ocean floor that push the boat above the waves.


Wiggins Island Tandem Cranes

The goal behind the Wiggins Island Coal Export Terminal design was to export over 120 million tons of coal from Australia's east coast every year. 

To do this, coal stacking bridges are an essential component and mobile cranes with rotational flexibility. For the 1.1 mile project, they called for two Lamson LTL 2600 transit lift cranes working in tandem to lift the gigantic structures into place. 

Once they got everything moved, it was a matter of welding everything in place.



Ever wonder how the legs of bridges get built right in the middle of the water? The process involves sheet piling and cofferdams. 

Sheet piling involves the interlocking and overlocking of substantial steel beams, a method involved in producing large cylinder structures formerly known as cofferdams. These objects get dropped into the water where the structure needs building, and the water gets drained out — allowing a dry area for construction workers to create. 

The cofferdams are lifted and then floated into position with large cranes. In some cases, the shape, weight, and height of the cofferdam make it difficult for this kind of positioning. In these cases, the cofferdams may be launched straight off a slope right into position.

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Engineering at Home: Build a Mousetrap Car

Did you know there are simple and fun crafts you can make to share engineering at home with your kids? Building a mousetrap car is one of those simple crafts, and it's fun for all ages. Building a mousetrap car is so enjoyable that there are events all over the nation for mousetrap car races!

And here I bet you thought that mouse traps were only good for catching mice.

We know engineers like to take things apart to see how they work. They want to teach their kids the same thing. While a simple mousetrap car may not go very far or very fast, it will show you how stored potential energy becomes kinetic energy.

When you’re finished with this project, you can try building a more complex mousetrap car by changing a few things. Think about what you could do to design the car to go a longer distance and go faster. Consider the wheel-to-axle ratio, inertia, the rate of energy release, and friction. These areas might help get your creative juices flowing for future improvements to your mousetrap car.

Here are a few other things to consider when creating a mousetrap car for speed and distance. 

Long Distance Mousetrap Car

  • Smallest fraction for mechanical advantage

  • Reduce friction 

  • Reduce weight 

Faster Mousetrap Car

  • Largest fraction for mechanical advantage

  • Good traction in rear wheels

  • Reduce friction

  • Reduce weight

  • Reduce rotational inertia

Let’s dive into the instructions now, shall we?

Safety Note: Before you begin, please note that mouse traps are dangerous. If one snaps back on your hand while you’re holding it, it could cut you, or worse, break your finger. This project requires adult permission and supervision to complete.

Supply List

  • 2 - 4” X 10”  pieces of heavy cardboard: other dimensions will work, but this is an excellent place to start.

  • 4 - DVD’s or CD’s: Recycle old ones that no one watches or listens to. You can also use new ones found at an office supply store if you cannot use old ones. 

  • 4 - 1/4L (19/32”) Beveled faucet washers: You can find these washers at most hardware or home improvement stores in the plumbing department. 

  • 2 - 3/16” Dowels that are  6” long: If you change your cardboard’s dimensions, these dowels will need to be scaled up or down accordingly. 

  • 1 - ¼ inch dowel that is 10“ long

  • 2- drinking straws

  • Masking or duct tape

  • Zip ties: An assortment of 4” will work

  • String

  • Hot glue

  • Scissors

  • Ruler


Build the Body of the Mousetrap Car

Before you begin, visualize your mousetrap car. You’re going to need to create a body that’ll form the frame of your car, wheels, and an engine to power everything.

Cut a rectangular notch about 1” x 2” on one short side of each cardboard piece so that the notches overlap. The cardboard becomes the frame of your car.

Then place the two pieces of heavy cardboard on top of each other and use your masking or duct tape to tape them together, making a double-thick, heavy-duty piece of cardboard.

Make sure your notches line up.

Tip: If you’re going for distance with your mousetrap car and not speed, you’ll need to lighten the load as much as possible. You can cut holes in the frame to do this.


Prepare the Mouse Trap

Once you’ve gotten your cardboard taped together, you’ll need to attach the straws. Using your ruler, measure the short side and the two sections on either side of the cutout. You’ll need to cut your straws to match these lengths and hot glue them in place.

Be sure the straws are parallel to each other and the leading (short edge) of the cardboard, making the underside of your mousetrap car.

While your glue is drying, prepare the mousetrap. Take your trap and remove the small pieces that make up the release trigger. These are called the bait holder and wire bail.

Get 2 or 3 4” zip ties and secure the ¼” dowel to the snap arm. You can reinforce this arm with your tape or hot glue. Be sure your dowel is pointing forward, away from the notch you placed in your cardboard. Also, make sure that the dowel lines up with the notch center when it’s pulled back.

Get your string and attach a piece to the end of the ¼” dowel with another zip tie. You want your string to reach a bit longer than the hook on the rear axle. Tie a small loop at the end of your string. You want your loop to just reach the hook on the rear axle.


Prepare the Wheels

Now to prepare the wheels for your mousetrap car. Put a piece of tape over the hole in the center of the DVD or CD you are using. Turn the DVD or CD over and put a beveled faucet washer into the center, sticking it to the tape.

Then, use a generous amount of hot glue to hold it in place. Do this for all 4 of your wheels.


Add the Axles and Wheels

Once all of your hot glue has dried, you’re ready to start adding the axles and the wheels to your mousetrap car’s body.

Slide the 3/16” dowels into the straws and then press a wheel onto each end of the dowel.

If you have difficulty getting the dowels through the tape, rounding or slightly sharpening the dowel ends can help make this part a little easier.

Once you have attached all four wheels, do a test run and see if your mousetrap car rolls straight. If it doesn’t, you may need to straighten your straws.


Attach the Hook

Now that you’ve gotten your wheels on and your mousetrap car is rolling straight, it’s time to attach the hook to the rear axle.

Attach a 4” zip tie to the center of the car axle exposed by the notch in the heavy cardboard and cut it short, about ¼ inch, which will be the hook for your string. Use a dab of hot glue to hold it in place.

And now you’re done!  Attach the string to the hook and wind it backward. Put your mousetrap car on the ground and let go. It should start rolling away.

Now you can take some time to get to know your mousetrap car. You'll want to roll your vehicle to test it multiple times. Watch its performance. If it's not rolling smooth or veering off to the right or left, take some time to adjust it. You'll want to get it right.

Once you understand how the mousetrap car works, you can experiment with different materials.

Tip: To make your mousetrap car more durable, use lightweight wood instead of heavy cardboard.

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A set mouse trap is full of potential energy. When released, it gets converted into kinetic or motion energy. Your mousetrap car’s design allowed that energy to be transferred to the axel to make the wheels turn.

When the mousetrap in your car snapped closed, it yanked the string forward. As the string got pulled, friction between it and the axle caused the axle to rotate, which turned the wheels and moved the car forward.

Wasn’t that fun?

Hopefully, everyone had a great time putting together their mousetrap car and learning about potential and kinetic energy. Now the mousetrap car makers can build their science fair project, share the ideas with their friends, or even better, join the mousetrap car races.

We’re not only engineers, but we’re parents, too! That’s why we created this post.

We understand what it’s like to want to teach your kid how fun engineering is. We know how great it is to be a hero and help your child win with the best science fair project or now, the mousetrap car races.

Now that your kids are excited and want to learn more engineering fundamentals, you'll want more kid-friendly ideas for projects you can do together.

Let us send you more articles like this one by signing up for our newsletter, and we’ll share more step-by-step project ideas that you can share with your kids about engineering.

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