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Episode 1.8: Righty Tighty, Lefty Loosey: How the Ancient Greeks Screwed the World (script)

Hi. I’m Keith Decent and this is From the Ground Up. A podcast about how we make what we make, the materials, the tools, and the stories behind the things we build.

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August 24th, 1986, Port of Rotterdam, the Netherlands. The dredging ship, Triton, is working through the night, creating a trench around some wreckage it had accidentally come upon back in early May. Triton is one of many ships tasked with excavating the Slufter, a future disposal site for contaminated silt, a byproduct of natural processes and the operation of the port.

As part of a preservation effort for archaeological discoveries, any shipwrecks found during the operation must be removed carefully and cataloged. The sudden pitch change in the typical clattering cacophony of the ship’s pumps can only mean one thing. There’s another blockage. When the system is cleared, the stoppage turns out to be wooden debris. Not just wood but also coal. Heaps of coal. This is not the same wreckage they were working on. This was an entirely different ship.

The wreck is carefully dug out over the course of several weeks. Half of a timber hull is raised from the depths, cataloged, and reported on. If the wreck as too new to be culturally significant, then the site would be archaeologically abandoned. This turned out to be the case, as the ship, now marked SL 4, was estimated to have been built between the end of the 18th century and 1850. Back then, this area was an open sea port with hazardous sand embankments, instead of the man made haven it had been built into since the 1960s. Until then, the only protection for ships was the guiding beacon of an old, stone lighthouse called Stenen Baak.

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March, 1864. Rough seas. A cargo ship had left Rotterdam on it’s way to Hull when it encountered a storm only a few miles into its journey. Captain Hans Claus Marten had ordered his crew to return to port, but it was too late. A sudden stop jostled every man on board. The dull scraping sound of wood on sand. They were stuck, and it wasn’t long before the vessel sank into the murky depths. The 31 crew members were rescued, and the captain of the rescue ship commissioned a painting of the event. The canvas showed it all. The jagged waves tossing the ill fated ship. The blustering winds filling its sails, sending it spinning uncontrollably toward the sandy banks. An old, stone lighthouse in the distance.

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The ancient kingdom of Syracuse, in what is modern day Sicily, about 240 B.C.E. Archimedes stands on the deck of the Syracusia, a ship he designed and had built by order of his King, Hieron II. It was huge. There’s no other word to describe it. It was the largest ship ever built at the time and had enough room for 1942 passengers, and 1800 tons of cargo. The ship was more of a floating castle, boasting cabins, a library, a reading room, a gymnasium, a chapel dedicated to the goddess Aphrodite, a dining room and a bath. But, like a Greek bath, so think more public wading pool than claw foot tub. The ship had an 18 foot catapult and guard towers on the top decks. It was a serious piece of naval equipment. One of the most interesting features of the Syracusia, however, was that it’s massive bilge, the area in the very bottom of the ship that collects water from all of the above decks. Drainage, spillover from rough seas, that sort of thing. Well, the bilge on the Syracusia could be emptied by just one man.

What should have taken several men hours of hard labor could be accomplished by one man with medium effort thanks to a device Archimedes has invented a few years prior, the Archimedes Screw.

The device itself is a cylindrical shaft, with a flat surface spiraled, on edge, up it’s curved outer wall. The screw sits in a hollow tube, allowing the pump to raise liquids and granular materials from a low lying supply area. Really, a quick search will show you pictures of what I’m describing, but I think you get it. The device was great for moving grain out of a silo or trough, and also excelled at pumping water.

There are accounts of the ancient peoples before Archimedes’ time using screws for irrigation. Its told in some records that the Hanging Gardens of Babylon were kept watered through such means. However, The Greek polymath was the first to on record to have designed one, so it gets his name.

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Britain, 1839. Francis Pettit Smith stands on the deck of the SS Archimedes. The ship, the first of its kind, has been the culmination of a lifelong fixation on boats and propulsion. As a child, Smith would have dreamed of this moment, finally launching a full sized version of one of his models into the sea. But the farmer turned shipwright had yet to prove his invention not only seaworthy, but worthy of the attention of the British Navy.

Smith’s ship, named for the legendary, ancient Greek inventor, had a revolutionary propulsion method. It housed a steam engine, which was nothing new as American Robert Fulton had already invented his steam paddle ship. Smith’s vessel, however, was driven by a screw.

He took Archimedes’ Screw, and figured that, when submerged in water, it would propel itself. He was right. The British admiralty, however, had misgivings, thinking a screw powered ship would be too difficult to steer for an ocean voyage. In September of 1837 he had taken a smaller, test version of the screw ship out to sea. When a storm blew in and dark seas surrounded the Francis Smith, as he had named the tiny, wooden-propellered boat, it kept chugging right along, unfazed by what would normally cause a sailing ship great trouble. Upon witnessing this, seasoned officers in the British Navy showed renewed interest in his invention, prompting the admiralty to request he built a full sized version.

Smith got right to work. He gathered investors and builders, and before too long, the SS Archimedes was launched on October 18, 1838. 125 ft long, 22 ½ feet wide, and weighing 237 tons of English Oak, the boat was built with the sleek, slender lines of a schooner, making it a as beautiful as it was powerful. After a few changes to the machinery and gearing, the ship took its maiden voyage and never looked back. It traveled far and wide, suffered major setbacks, and was put up in trials against some the fastest ships on earth, proving itself swift, capable, and dependable, time and time again. It inspired the design of seafaring vessels for centuries to come, and is seen as one of the most technologically important ships ever built.

However, it was never bought by the Navy. Smith and his company of investors, The Ship Propeller Company, sold it off as a commercial vehicle. From this point, it’s life it’s difficult to find reliable reports on what happened to the SS Archimedes. It ran aground in Beachy Head in 1840. Disappearing and reappearing in public records, usually with less and less of its machinery until after a stop in Sunderland, it was finally stripped of all it’s mechanics and propulsion. It was last heard from in 1864, caught in a storm off of the Port of Rotterdam.

This was to be the final fate of one of the most important ships in history. A faded visage of its former glory, the SS Archimedes was now an old, creaky sailing vessel. Stripped away years ago of the one thing that could have saved her from the storm. A revolutionary propulsion system designed and built by a farmer, and based on an invention from the one of ancient world’s greatest minds.

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Plato, in Book 6 of The Republic, described his ideal leader, the so-called “Philosopher King.” He must be a wisdom seeker, a lover of knowledge, intelligent but grounded enough to prefer a simple life. A complicated leader with few complications. It is widely believed that Plato based these archetypes on his friend, a genius mathematician named Archytas of Tarentum.

Not solely an academic, but also a statesman, Archytas wasn’t just “of” Tarentum, he basically ran the place. The citizens elected him “Strategos,” which is basically a form of military governor. Tarentum had a rule barring successive appointments, but Archytas was so efficient and so beloved that they decided to make an exception, 6 times.

A learned disciple of Pythagoras (you may be familiar with his theorem? A squared plus b squared equals C squared?), Archytas has numerous mathematical proofs and inventions attributed to him. He invented a sort of flying machine, shaped like a dove, which could propel itself from a lower perch to a higher one using a jet of steam. Among those inventions, he is also widely credited with inventing the screw, in wooden form. Because of these achievements, and a lifetime devoted to solving the working mysteries of the world, Archytas is considered the father of mechanical engineering.

Since their invention, wooden screws, with an internally cut thread, were used for early clamps and presses. One of the first widespread applications of the screw was to press grapes for wine. Pliny the Elder, an ancient Roman statesman and historian, tells that screw presses and clamps were in use as early as 60 AD. They started out as wood, but were later manufactured, individually and by hand, from metals such as bronze or silver.

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Screws remained hand-cut until about the late 18th century. Artisans of the time, like Jesse Ramsden, had managed to make lathes to cut screws and screw threads, which allowed them to increase precision and output. However, each machine was different, and so were the screws they put out. Each crafter had a preference for the angle of the thread planes and the shape of the valleys between them. It wasn’t until Henry Maudslay invented the first industrially viable, and widely available screw cutting lathe in 1797, that the fasteners started to become standardized. It was another practitioner of Archytas’ discipline, mechanical engineering, who pushed for the complete standardization of the screw. Sir Joseph Witworth, former apprentice to Maudslay, had taken off to start his own business manufacturing lathes and other machine tools. His machines became famous for their high degree of precision manufacturing. Witworth had high standards, and is often credited with having invented the “thou.” Basically his reputation for exactitude was so widely known, that no one has any trouble believing that he was the first person to work in thousandths of an inch.

In 1841, Witworth became tired of being the only one with standards. In order to repair a product, you had to know what type of screw was used, which company manufactured it, and then had to have the correct replacements on hand. Pieces of engines just fit together better when there’s only one type of screw thread being used. He developed a method of standardization that set the thread angle at 55 degrees with a uniform pitch and shape. It later became adopted nationally, as the British Standard Witworth. Its popularity was due in large part to its adoption by British railway lines, then later, manufacturing, as it streamlined assembly and repair processes, greatly increasing efficiency and reliability of products. Repair work could now be outsourced to specialty shops that only had to stock one type of screw, but could service machines and engines from multiple different manufacturers and companies.

Witworth’s screw design was more efficient, but it’s actual manufacture was not. It required two kinds of lathe and three kinds of cutters. In 1864, a few months before the USS Archimedes ran aground off the coast of Rotterdam, on the other side of the Atlantic, American William Sellers was presenting his invention in a paper delivered at the Franklin Institute in Philadelphia. He proposed a screw thread that had flat roots and crests, making it machinable using just one lathe and cutter. He set his thread angle to 60 degrees, which was easier for machinists and mechanics to cut. As president of the Franklin Institute, Sellers was uniquely positioned to pitch his idea as the new US national standard. The Institute lobbied the US Army, the navy, and the master mechanics of the largest railroads.

Each country having its own standard was well and good until World War II came along and showed that, in the coming age of globalization, an international standard was required. Canada, the US, and Great Britain jointly developed the Unified Thread Standard, with a 60 degree thread profile based on the inch.

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Screws, despite which standard they are manufactured to, all have one thing in common. Just like people who write, produce, and record their own podcasts, they need to be driven. Early on in the industrial revolution, screws were slot headed. A single channel was cut across the head of the screw, into which would fit a flat-headed screwdriver or screw-gun bit.

The two biggest problems with slot head screws is that it takes an extra second or two to properly align your driver head with the screw, and they are extremely susceptible to what is called ”cam-out.” This is when the amount of torque becomes too great and the driver head slips out of the screw head, possibly damaging the work piece, the screw, the driver, and, as in one famous case, the person holding the tool.

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1907, Montreal. Canadian inventor and salesman, P.L. Robertson, is doing a demonstration on a street corner of a spring-loaded screwdriver. It’s not exactly his dream job, but it pays the bills. He had a slew of un-to-minorly successful patents in his design portfolio, but this would prove a fateful day.

While showing the ease with which one can drive a screw with a spring loaded driver, its flat head slipped out of the screw’s slotted head, badly injuring Robertson’s hand. He decided, unsurprisingly, what the world needed was a screw driver that wouldn’t slip out of it’s slot and maim people. He decided upon a square-drive system, which had been used before but never optimized for production. He applied for the patent right away, and received a loan to start his own manufacturing company. Robertson figured out that if he tapered the square slightly, he could cold stamp the recess into the top of the screw with a die, which enabled production on a mass scale. His sales prowess did the rest and the Robertson Screw quickly gained popularity in Canada.

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Henry Ford, one of history’s greatest optimization and efficiency nerds, had a plant manufacturing Model Ts right across the river from Detroit, in Windsor, Canada. Ford noticed this plant was saving $2.60 per car, at what shook out to about 2 hours worth of assembly time. What he discovered, upon investigating, was the Robertson Screws were driven more reliably and quicker than the old slot headed ones. Over the general manufacturing time of the vehicle, the second or two saved per screw by using Robertson’s design, multiplied by the 700+ screws used in the Model T, meant big savings.

Wanting to keep this manufacturing edge all to himself, Ford met with Robertson. Ford wanted to manufacture the screws under a license. Unfortunately, Robertson had already been taken advantage of by foreign investors once, and was reluctant to sign any deal in which he did not control the production of his screws. Both went home empty handed. Robertson continued to expand and grow in popularity in Canada, and the car manufacturers to the South kept using slot headed screws, for a little while, anyway.

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Portland, Oregon, 1935. The deal is sealed and Henry F. Phillips has just purchased a design for a self-centering screw from a local mechanic, John P. Thompson. Thompson had tried and failed to market his design to manufacturing and tool companies. Phillips thought he might be able to do better, given his background in sales and engineering. He was right.

He formed the Phillips Screw Company, patented a modified version of Thompson’s cruciform

design, and right away he was able to convince companies all over the US of its capabilities. Not as protective of his work as Robertson, Phillips licensed his design to just about anyone who was willing to pay. The screw was soon found in hundreds of assembly lines and thousands of products, including the GM assembly plant for Cadillacs and, later, Ford’s plants as well. By 1939, 20 companies worldwide were manufacturing Phillips’ screws, and the Phillips Screw Company grossed a fortune, never having had to manufacture any screws or drivers.

Phillips Head Screws and drivers came to dominate the American marketplace. Eventually finding their way from industrial applications to the homes and toolboxes of handymen, homeowners, and craftspeople. By the middle of the 20th century, it was nearly ubiquitous.

Many driver and screw designs have evolved over the last century or so. And each has their own merits and drawbacks. Despite what a boastful Canadian woodworker, or a 1930s assembly line worker might tell you, there is no perfect screw for every situation. However, thanks to great minds like Archytas and Archimedes, and great entrepreneurs like Phillips and Robertson, the value of the screw is well-known. The simple machine that makes the things we use and the things we make, makeable.

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Until next time, this is Keith Decent saying, later makers.

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