Steel Shipping Drums Police Whistles Miniature Train Wagons Glass Blocks
Today, on "how it's made"... Steel shipping drums... Police whistles... Miniature-train cars... And glass blocks. The steel shipping drum was invented in the late 19th century for the oil industry, which needed an alternative to leaky wooden barrels. But those first steel drums also leaked from their soldered seams. Welding them proved to be the solution, giving this container an airtight reputation. It's a product that really delivers the goods. A punch press first cuts and forms the drum's bottoms in one swoop. A conveyer shuttles the bottoms down the line to a turntable. As a drum bottom rotates on the turntable, a nozzle sprays sealant onto it, coating it completely. Then the drum bottoms are stacked up. Meanwhile, another punch press shapes steel discs into tops for the drums. Rollers turn up the outer edge to a precise measurement. Next, steel fittings tumble down a vibratory conveyer to a machine that simultaneously punches threaded openings in the tops and inserts the fittings. One hole is for opening and closing the drum. The other is a vent. At this station, workers check the thickness of sheet steel that will be used for the body of the drum. The thickness varies depending on what the container is to hold. A machine called a shear slices the the coiled steel into sheets. The steel sheets then move on to a forming machine, where rollers curl them into the drum's shell. Automated pushers then move each shell through an electric-resistance welder. It generates heat to weld the side seam, bonding it from both the inside and the outside so it won't leak. The shells roll down to a machine called a flanger. The flanger stretches and presses on the outer rims at both ends, creating a lip. Then it's over to the beater. Its rollers bear down on the shells to make grooves called rolling hoops. These rolling hoops add rigidity to the shells. The shells now travel down another conveyer and merge with the drum tops. Automated pushers deliver a top to the base of a shell. The shell rotates in a spinning clamp as rollers curl the edges of the top and shell together. This creates an interlocked seam called a chime, which is then flattened by another roller. Mechanized arms flip the shells so the bottoms can now be installed. To join the bottoms to the shells, rollers form another chime. These interlocking seams are comprised of seven layers of steel, making them leakproof. That's critical, since the steel drums may be used to transport hazardous goods. The steel drums now move forward to a testing station. Here, inspectors inject air into each drum and check the seams for leaks. The seams have been soaked up, so if bubbles materialize, it signifies a problem. The steel drums then go for a whirl under the paint gun. It sprays them with enamel paint for a protective sheen. Black is the most common color for these shipping containers. But custom colors can be ordered, too. The steel drums then journey through an oven that bakes the paint to a hard finish. The thickness of the paint is gauged with a special tool that makes sure it's thick enough to withstand rusting. Workers plug both openings and put a temporary seal on the vent to prevent tampering. After that, these steel shipping drums are ready for the long haul. Next, get the blow-by-blow at a police-whistle factory. It was in the late 19th century that london police started using a special whistle to get attention. It was lightweight and had a piercing sound-- a real improvement over the hand rattles they had been using before. That same design is still used today. They may be a blast from the past, but there's nothing better for blowing the whistle on lawbreakers. The average traffic cop blows his whistle thousands of times a day, so the whistles have to resist a lot of spit. The whistle's body is made of high-grade brass tubing, in which two slots are punched. These are sound holes that will allow the noise to escape. Using hydraulic pressure, the brand name is stamped onto the tube. Next comes the mouthpiece. Rollers sculpt a piece of spinning brass into a shape that's a bit like an hourglass. With the mouthpiece complete, a hydraulic punch is used to bend a piece of brass into a part called the slab. The slab will be used to create two sound chambers inside the whistle. A loop is fitted on to an endcap to make the whistle easier to hang on to. A rotating press bends the loop's tab against the inside of the cap to fasten them together permanently. Next, an endcap is attached to the slab, and then the slab is forced into the cavity of the whistle, splitting it into two chambers. A police whistle actually produces two notes at once, giving it that distinctive timbre. These two separate sound chambers will produce two different pitches. Now the ends of the whistle are dipped in solder paste and then the looped cap and mouthpiece are hammered onto the pasted the solder paste is a special lead-free compound so the whistle-blower won't be exposed to toxins. Solder wires are also inserted in the whistle chambers before capping the ends. These solder wires will act in conjunction with the solder paste to seal the whistle in a process that happens next. The whistles move through an electromagnetic conduction coil, which heats them to a smoking 425 degrees. This causes the solder paste and wires inside to melt and flow into the whistle's seams. Each whistle is then dipped in an acid bath, which hardens the solder, sealing the whistle's seams. Next, the whistles are lowered into a nickel bath, where positively charged nickel ions migrate to the negatively charged whistles. Now it's time to make some noise. Each whistle is tested with compressed air. The tiniest pinhole will cause a whistle to fail, and that happens in 3% of them. Failure is a crushing experience. The rejects get flattened and sent to a company that reclaims the metal. On both land and sea, whistles are the sound of authority. Here, workers assemble a boatswain's pipe, used by naval officers to issue commands and salute dignitaries. There's a tiny hole in the ball at the end of this pipe. The player opens and closes that hole with his hands to change the whistle's pitch. And with that, production at this whistle factory comes to a screeching halt. Up next, all aboard. You're about to see how raw plastic is transformed into a miniature train car. Making miniature train cars is all about the details. Every feature is scaled-down to a fraction of the real thing, and nothing is too small to replicate. The miniature train car is more than just a toy. It's a work of art and a collectible. On a miniature train track, the past comes full circle with replicas of trains from days gone by. Craftsmen start with historical photos and drawings of actual train cars and scale them down to 1/48th size. They feed polystyrene pellets like these into an injection-molding machine. It melts the pellets into a thick paste. The four sections of the mold close and nozzles pump in the plastic. It oozes into all the grooves and hardens almost instantly into the shape of a train car. Then the excess plastic gets clipped off. Here's a view of how the four parts of the mold come together to shape melted plastic into a boxcar. They even create holes in the boxcar to attach accessories and they impress details like ridging that mimics the steel ribs of the life-size train car. More molds are used to replicate door rails, brake wheels, and other accessories. The assembler clips the parts off the framework and files down the rough sections. That is the brake wheel she's snapping onto the end of the model. Using a hobby knife, she trims excess plastic from the train car's step. She then glues a steel weight to the bottom of the train car to make it 1/48th the weight of the real thing. Making something to scale is a bit of a balancing act. Finally, she attaches air-brake tanks to the underframe of the car, and it's time to spray-paint the model train car vivid orange. It's a color that would have been used on an actual boxcar, combined with white. For that two-toned look, the model is held in a paint shield, which protects the orange sections as they spray on the white. This technique ensures the paint job has clean lines. The car is left to dry overnight. Not all paint jobs are so flashy. This car is basic black, the perfect canvas for white lettering. A pad picks up the ink from letter engravings on a printed plate and transfers the image to the car. Metal wheels now roll off a revolving conveyer. They funnel into mechanisms that press-fit them onto each end of metal axles. The wheel-and-axle assemblies drop into a bin below. Two sets of wheels are now installed on a plastic framework. The framework is then attached to a coupler, the device that links train cars. The wheels-and-coupler assembly are screwed on to one end of the car. Then the process is repeated on the other end. The couplers are snapped together to connect two train cars. In the world of train models, a little grime is just fine. A misting of paint makes the cars look dusty and aged on purpose. The painter layers colors to get just the right effect. This technique adds the element of realism to the model train car. It's all a matter of preference. Some hobbyists prefer this weathered look, while others like their model trains shiny and new. The model train cars have now rolled off the assembly line, and they're ready to hit the tracks for a whistle-stop tour of another era. Coming up, the hot scoop on one of the world's favorite building blocks. When it comes to building materials, glass blocks are clearly a classic. In the 1920s and '30s, they were a cornerstone of the art-deco style of architecture. Today, glass blocks are still popular for creating walls, windows, and stunning design features, a stylish way to build a privacy barrier that still lets in light. Glass blocks aren't just decorative. They insulate from heat, cold, and noise. Production begins with just four ingredients-- recycled glass pieces called cullet, sand, soda ash, and limestone. A computerized system portions out each one and feeds them into a melter. This giant furnace heats the batch of ingredients to a fiery 2,700 degrees, transforming them into molten glass. The melter pumps out enough molten glass to make one half block at a time. Automated shears slice just the right amount. The gob of glass then slides into a waiting mold. A plunger pushes the gob down, spreading glass throughout the mold cavity. Its waffled surface imprints that pattern into the glass. A blast of ambient air cools down the molten glass drastically, from 1,800 degrees to 1,100 in just a few seconds. This way they don't lose their shape when a retractable arm extracts them from the mold and lays them on a conveyer belt, leading into a sealing machine. This is where two half blocks join together to form a full block. Entering the machine, each piece passes over a series of burners that keep the glass temperature constant. Sudden cooling could crack or shatter the glass. The machine then slowly reheats the half blocks until their edges start melting. Next, they enter the part of the machine called the squeeze station. Here, an automated press forces a top half and bottom half together. Their melted edges fuse, forming a single block. The blocks now travel into a leer, an oven that cools the glass at regulated temperatures over several hours. This annealing process prevents cracking and allows the glass time to set properly. The glass goes in at about 1,800 degrees. Coming out, it's down to 175. The blocks are now ready for inspection. Workers use digital-alignment gauges to make sure both halves are flush. Then they run a straight piece of steel along the block's surface to check for any distortion. Every block must meet precise standards for both size and shape-- a 71/2-inch square that's 4 inches thick. Building with glass blocks is similar to building with bricks-- you use mortar to stick them together. To prep the blocks for mortaring, workers now place each one onto a separate station. As it spins, nozzles spray the edges with liquid vinyl. This coating will help the mortar stick to the glass surface. Just one last step. An ink-jet printer applies the product code along with the manufacturing date and time. The quality-control department runs samples through an impact test. A worker drops a weight through a tube onto the side of the block. This verifies the strength of the sidewall and the seal between the two halves. Finally, the glass blocks are ready for shipping. Workers pack them into cardboard boxes that have block-sized sections to keep them safe during transport. Glass blocks come in so many shapes, sizes, and patterns that the design possibilities are endless. Both practical and beautiful, it's no wonder they're so popular with builders and decorators alike.