First, let’s get some context on just how grand this structure is. It was the largest man-made structure for nearly 4,000 years and it stands at 479 feet tall. It’s estimated that around two million stone blocks were used to make the Great Pyramid. This is an unbelievable feat, especially given the lack of advancements at the time. How on earth did they manage it?

The Learning Curve

In every creation, there’s always a certain amount of trial-and-error. To err is human, after all. The techniques used to construct these incomprehensibly labor-intensive creations were developed over the course of centuries. And, like modern-day engineers, they experienced their fair share of setbacks.

The first pyramid was developed from the simple rectangular “mastaba” tombs that were originally used in Egypt around 5,000 years ago. According to LiveScience’s report on pyramid-building techniques, the first advancement took place during the rule of Pharaoh Djoser (2630 B.C.). The planning of the structure has been attributed to Imhotep, a vizier, who evolved the structure from its original rectangular form to a 197 foot high pyramid with six layer and tunnels underneath.

The next innovation in pyramid building came during the reign of Snefru (2575 B.C.), who was the first to create smooth-faced or “true” pyramids, as opposed to the step pyramids that were made previously.

When we think of pyramids, we think of inexplicably flawless and imposing structures, but, like all great inventors, even the Egyptians made mistakes. During Snefru’s reign he constructed a total of three pyramids, one of which is referred to today as the “Bent Pyramid” because the angle of the pyramid changes part way up, giving it the appearance of being bent.

Creation can be a process that feels like you’re failing upwards constantly. It’s comforting to know that even the great Egyptians made mistakes and they learned from them, too. Snefru corrected the design flaw in the next two pyramids he built and passed down his knowledge to his son, Khufu, who would be the one to oversee the construction of what we now know as “The Great Pyramid.”

Materials

A great architectural triumph is only as good as it’s foundation. Which, in the case of the Egyptians, comes down to the specific metals and stones they used for the construction.

The outside of the pyramids in Giza were constructed using a rough yellow limestone. Build sites were chosen based on where prehistoric oceans had deposited the most of this material. They’d dig channels and pry the blocks directly from the earth. They even determined the size of the block based on the natural thickness of the limestone layers.

This is where things got trickier because the only metal the Egyptians had access to in terms of tools was copper (which is not a particularly hard metal).

Being the innovators they were, the Egyptians learned if they used sand or powdered rock as an abrasive, their copper tools would be able to cut through the limestone.

The inner chambers of the pyramid were constructed with granite, which is one of the harder rocks out there (because it contains quartz). This was probably the most painstaking part of building, they’d chip away at the granite by hand using dolerite hammer stones.

To give you an idea of just how time consuming this was, researchers have estimated that they’d make about 5mm progress per hour. This would mean you would have to spend a full day pounding against the rock over and over, just to chip away a few centimeters. Nowadays people are barely patient enough to wait for the office printer to warm up and the Egyptians spent entire days hitting one rock against another rock.

Once finished, the pyramids were covered with a layer of white limestone. Over time, this layer has weathered and gone, but in the past it would’ve made the pyramids appear a bright white color instead of the sandy brown we see today. It’s also speculated that the very top of the pyramid may have been covered with electrum, which is a mixture of gold and silver. But, again, time ruins all things. Get it…ruins?

Transportation

Sad to say for the Egyptians, but the invention of the wheel (though it happened before their time) never reached these worker bees. It probably would’ve made their lives a lot easier, but the Egyptians found other ways to move these huge tons of rock.

Let’s start with the outer rock: limestone. There are ancient drawings of Egyptians which show them moving huge monuments using sleds being pulled through sand. That may sound painstaking and inefficient, but in a recent study done by researchers at the University of Amsterdam in 2014, we discovered how they made this work more…well… humanly possible. The researchers found that sand has an interesting property where, if it’s wet with the right amount of water, it becomes slick so objects can be moved easier with fewer workers. This simple and resourceful technique cut their required pulling force by half.

If you can believe it, the granite was even trickier to transport. However, researchers have discovered records of boats that could’ve been used to float the stones down the nile when it overflowed into channels.

It’s safe to say that a person in modern day society couldn’t even begin to imagine this level of painstaking work and dedication. In fact you may even get tired for them just reading about this whole process. And we’re not even done. Once they got the supplies to the location there was the matter of actually getting the stones into place.

It’s widely agreed on that Egyptians used some sort of ramps to deliver the stone to its particular place on the pyramid. This may be the first and only time in your life where you’ll ever hear the phrase mysterious ramps, but these ramps are mysterious. This is actually where researchers speculate the most in terms of the pyramid constructing process as there’s no clear documentation of the ramp system used.

However, engineer Craig Smith created a detailed ramp analysis, calculating how many stones could be delivered with each design. Having done this analysis, he believes that Egyptians (most likely) extended a big wide ramp near the bottom, where most of the stones would go, and smaller spiral ramps at the top where fewer stones were needed.

Once the stones had been moved to where they were needed, wooden levers and round dolerite “ball bearings” were used to guide stones into place, where they were carved to an exact fit.

Workers:

Last but not least, no project can be completed without a good workforce. According to the show It’s Okay to be Smart, to build the Great Pyramid in 23 years, “an Olympic swimming pool worth of stone needed to be added every 8 days.” For this to be possible, it’s estimated that the Great Pyramid alone required 1,200 to 1,500 workers. It’s also estimated that, between the three pyramids built in Giza, a total of 10,000 workers were likely used.

Now, anyone who has even the most basic knowledge of pyramid-building will associate the labor with an… unwilling workforce (slaves). And this was what researchers assumed for the longest time. However, in recent years, Egyptologists like Mark Lehner have uncovered massive cities built to feed, house, and care for the builders. These cities were equipped with breweries, bakeries, tool shops and even evidence that families lived nearby. A 2013 study published by Richard Retting, the chief research officer of AERA shows that enough cattle, sheep and goats were slaughtered every day to produce 4,000 pounds of meat to feed the pyramid workers.

According to Redding, “They probably got a much better diet than they got in the village.” They even received honourable burials (something a slave wouldn’t have received). Given this recent evidence, Egyptologists now speculate that, rather than slaves, these were skilled workers that were employed to build and were treated fairly well.

It’s fascinating to see how an architectural process from over 4,000 years ago can still be so relatable to modern-day building and manufacturing. Although the tools and the means are very different, they require the same basic elements- materials, transportation, workers and learning.

If you’re a creator who gets discouraged from time to time, learning about the imperfections of the Greats can make you feel a lot better about your own journey. Who knows, maybe you’ll build the next “Great” (with a capital G) thing.

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To even begin to talk about the strongest metal, you must first understand the four different types of strength.

Strengths

One type of strength is called Yield Strength, which measures how well the material resists being bent or deformed. This is a particularly important factor for structural engineers, who will ideally want to build with a material that won’t bend when more weight is added. You don’t want your building to end up looking like the Leaning Tower of Pisa.

The next type of strength is Tensile Strength, which measures how much strength it would take to pull the metal apart. While a substance like cookie dough, for example, has a low tensile strength, something like graphene has one of the highest tensile strengths ever recorded.

There’s also Compressive Strength, which is how well the material withstands to being squeezed together or compacted. Styrofoam, as one example, has very little compressive strength and will break apart easily if squeezed or flattened. Compressive strength can be measured using Moh’s scale which measures relative hardness and resistance to scratching.

Finally there’s Impact Strength which measures the material’s ability to resist sudden force or impact without breaking. While bulletproof materials wouldn’t be a perfect ten in every category, they would have a high level of Impact Strength. On the other hand, while a diamond may score a 10 on Moh’s scale, it will shatter if struck by a hammer.

While it would be really convenient for there to be a metal that was a perfect ten in all four categories, unfortunately there isn’t one. Therefore, when choosing a metal you have to make a decision based on your particular project and determine which type of strength is most needed.

Scientists have, however, found a way to cheat the system a bit by creating alloys (or combinations of metals) that produce an even stronger metal. This process may sound a bit like a Marvel movie, but it has helped create extremely useful building materials.

Steel

One metal that makes the cut is steel, which is an alloy of iron and carbon (often in combination with other elements as well). It’s created by heating iron ore in furnaces where impurities are removed and carbon is added.

According to Metal Supermarkets, steel is one of the most common materials in modern day society with more than 1.3 billion tons produced each year. Most large buildings like skyscrapers, airports and bridges are held up by steel in some capacity. It’s the primary source for the automotive, infrastructure, building and weapons industries.

There are a few different types of steel, each with their own types of strength. Carbon Steel is the first, which combines carbon and iron and scores high on all four types of strength. It has a high level of yield and tensile strength with an overall score of 6.0 on the Mohs scale.

The next type of steel is Maraging Steel, which combines nickel and elements such as cobalt, titanium, molybdenum or aluminum. With a lower carbon content, this type of steel is known for its high yield strength, being anywhere between 1,400 and 2,400 MPa. It’s often used in rocket and missile skins, gas centrifuges for uranium enrichment, and fencing blades.

Another type is Stainless Steel, an alloy of steel, chromium, and manganese. This combination creates a corrosion-resistant material which has high amounts of tensile and yield strength. The corrosion-resistant element makes stainless steel a commodity for everything from kitchen accessories and cutlery to medical instruments to even ship containers and refuse vehicles.

The last type of steel is Tool Steel which, shockingly enough, is primarily used to make tools. This is steel alloyed with cobalt and tungsten and is used for its hardness and its ability to retain a sharp cutting edge. This is why it’s largely used for axes and drills.

In terms of practical use, carbon steel and stainless steel are most often used in the construction industry. Carbon steel is primarily used to make beams for structural framework, bridges, and plates for highway construction. Stainless Steel is one of the oldest known building materials: there are structures made centuries ago that still stand today. Many famous buildings (the Chrysler Building in New York, for example) rely on stainless steel. This metal is often found on roofing, structural applications, handrails and balustrade, architectural cladding and in drainage components.

It may be surprising to learn that steel is often used by Green builders on eco-friendly construction projects. According to How Stuff Works, this is partly because steel is long-lasting and durable; it doesn’t lose any quality each time it’s recycled. There is also less waste with steel projects compared to wood projects because you can weld small ‘offcuts’ together to use for smaller jobs.

Inconel

Another alloy known for its strength is Inconel. In fact, it’s not just an alloy- it’s a superalloy, combining austenite, nickel and chromium. This metal is known for its ability to withstand extremely high temperatures and harsh conditions. As a result, it’s primarily used in gas turbine blades, well pump motor shafts, chemical processing plants and nuclear pressurized water reactors.

Tungsten

One naturally occuring metal to make the list is tungsten, which has the highest tensile strength of any naturally occuring metal. It’s extremely rare and usually found in the form of chemical compounds. Of all natural metals, tungsten has the highest melting point and lowest vapor pressure. However, tungsten is brittle and has a lower impact strength, so it’s often used as an alloy rather than in its natural state.

Around half of all tungsten is used for the production of hard materials- primarily tungsten carbide, which is an alloy of tungsten and carbon. Tungsten carbide is used to make knives, drills, circular saws, and lathes. The metalworking, mining, construction, and petroleum industries rely heavily on tungsten carbide tools. The high melting point of tungsten makes it perfect for rocket and missile manufacturing.

Titanium

Also naturally occurring, Titanium has the highest tensile strength to density ratio of any metal. Though it is very corrosion-resistant, it scores lower on Moh’s scale of hardness so it’s often used as an alloy. It’s commonly alloyed with a range of elements, including iron, aluminum, and vanadium. Alloys made using titanium are strong and lightweight, which makes them perfect for the automotive, aerospace, military and industrial industries. A total of two thirds of the titanium produced is used for aircraft parts and, because titanium is also resistant to seawater corrosion, it can be used for propeller shafts and rigging.

While not commonly ranked among the strongest metals, there are a few others that are quite commonly used for their significant amount of strength and additional benefits in the construction industry.

Aluminum

While aluminum itself doesn’t often make the list of strongest metals, it’s often used as an alloy in order to increase the strength of a metal. Some common elements with which aluminum is combined are silicon, magnesium and copper. Aluminum-zinc alloys are some of the strongest alloys available today and are often used in the automotive and aerospace industries.

Aluminum can also be made stronger through processing- by using hot rolling or cold rolling- which is heat treating followed by rapid cooling. This process freezes the atoms in place, strengthening the metal. The other process is “cold worked” or rolling, stretching, forging or drawing to make the metal stronger. This inhibits the movement of atoms relative to each other.

Aluminum has appeal because it’s about one-third the weight of steel, meaning parts can be made thicker and stronger while still reducing the weight of a vehicle. It’s the second most used material by auto-makers according to The Aluminum Association. It’s also commonly used in window frames, streetlights, doors, planes, trains, buses, trucks and ocean liners. The metal is also used by the U.S. Army, NASA and U.S. Air Force.

Copper

As the oldest known metal used by man–dating back to ancient Egypt–there are many benefits to copper. It has a lower tensile strength, is extremely corrosion-resistant and is a super conductor for electricity. Copper is often used for refrigeration, air conditioning, cookware, computers, medicines, and piping.

There are two types of copper tubing. Rigid copper tubing is ideal for hot and cold tap water pipes in buildings. Soft copper, on the other hand, is frequently used to make refrigerant lines in HVAC systems and heat pumps. Copper ductile, a malleable metal, is resistant to corrosion from water and soil, and is also recyclable. Copper tubing is also easily soldered, forming lasting bonds.

This metal is also alloyed with brass and used in musical instruments, jewelry, construction and artwork.

Iron
The comic book nerds out there may automatically think of Iron Man, but fun fact: Iron Man’s suit isn’t actually made of iron. Speculations say it’s most likely made out of some kind of nickel and titanium alloy.

There are two different types of iron: cast and wrought iron. Essentially, cast iron is rolled, pour and molded while wrought iron is only rolled in the final stages of production. Cast iron is used in architectural projects (like the dome of the U.S. Capitol) while wrought is used for things like beams, trusses and girders.

From constructing the Empire State Building to making modifications to your home, knowing your metals is crucial. Even if you’re not a builder, this knowledge can allow you to find a new appreciation for buildings in your hometown.

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