Retrotechtacular: The Deadly Shipmate

November 27, 2024 by Dan Maloney 33 Comments

During World War II, shipboard life in the United States Navy was a gamble. No matter which theater of operations you found yourself in, the enemy was all around on land, sea, and air, ready to deliver a fatal blow and send your ship to the bottom. Fast forward a couple of decades and Navy life was just as hazardous but in a different way, as this Navy training film on the shipboard hazards of low-voltage electricity makes amply clear.

With the suitably scary title “115 Volts: A Deadly Shipmate,” the 1960 film details the many and various ways sailors could meet an untimely end, most of which seemed to circle back to attempts to make shipboard life a little more tolerable. The film centers not on the risks of a ship’s high-voltage installations, but rather the more familiar AC sockets used for appliances and lighting around most ships. The “familiarity breeds contempt” argument rings a touch hollow; given that most of these sailors appear to be in their 20s and 30s and rural electrification in the US was still only partially complete through the 1970s, chances are good that at least some of these sailors came from farms that still used kerosene lamps. But the point stands that plugging an unauthorized appliance into an outlet on a metal ship in a saltwater environment is a recipe for being the subject of a telegram back home.

The film shows just how dangerous mains voltage can be through a series of vignettes, many of which seem contrived but which were probably all too real to sailors in 1960. Many of the scenarios are service-specific, but a few bear keeping in mind around the house. Of particular note is drilling through a bulkhead and into a conduit; we’ve come perilously close to meeting the same end as the hapless Electrician’s Mate in the film doing much the same thing at home. As for up-cycling a discarded electric fan, all we can say is even brand new, that thing looks remarkably deadly.

The fact that they kept killing the same fellow over and over for each of these demonstrations doesn’t detract much from the central message: follow orders and you’ll probably stay alive. In an environment like that, it’s probably not bad advice.

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Retrotechtacular: The TV Bombs Of WWII

November 14, 2024 by Dan Maloney 40 Comments

Anyone who was around for the various wars and conflicts of the early 2000s probably recalls the video clips showing guided bombs finding their targets. The black-and-white clips came from TV cameras mounted in the nose of the bomb, and were used by bombardiers to visually guide the warhead to the target — often providing for a level of precision amounting to a choice of “this window or that window?” It was scary stuff, especially when you thought about what was on the other side of the window.

Surprisingly, television-guide munitions aren’t exactly new, as this video on TV-guided glide bombs in WWII indicates. According to [WWII US Bombers], research on TV guidance by the US Army Air Force started in 1943, and consisted of a plywood airframe built around a standard 2000-pound class gravity bomb. The airframe had stubby wings for lift and steerable rudders and elevators for pitch and yaw control. Underneath the warhead was a boxy fairing containing a television camera based on an iconoscope or image orthicon, while all the radio gear rode behind the warhead in the empennage. A B-17 bomber could carry two GB-4s on external hardpoints, with a bulky TV receiver provided for the bombardier to watch the bomb’s terminal glide and make fine adjustments with a joystick.

In testing, the GB-4 performed remarkably well. In an era when a good bombardier was expected to drop a bomb in a circle with a radius of about 1,200′ (365 meters) from the aim point, GB-4 operators were hitting within 200′ (60 meters). With results like that, the USAAF had high hopes for the GB-4, and ordered it into production. Sadly, though, the testing results were not replicated in combat. The USAAF’s 388th Bomber Group dropped a total of six GB-4s against four targets in the European Theater in 1944 with terrible results. The main problem reported was not being able to see the target due to reception problems, leaving the bombardiers to fly blind. In other cases, the bomb’s camera returned a picture but the contrast in the picture was so poor that steering the weapon to the target was impossible. On one unfortunate attack on a steel factory in Duren, Germany, the only building with enough contrast to serve as an aiming point was a church six miles from the target.

The GB-4’s battlefield service was short and inglorious, with most of the 1,200 packages delivered never being used. TV-guided bombs would have to wait for another war, and ironically it would be the postwar boom in consumer electronics and the explosion of TV into popular culture would move the technology along enough to make it possible.

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Retrotechtacular: Making Enough Merlins To Win A War

October 25, 2024 by Dan Maloney 16 Comments

From the earliest days of warfare, it’s never been enough to be able to build a deadlier weapon than your enemy can. Making a sharper spear, an arrow that flies farther and straighter, or a more accurate rifle are all important, but if you can’t make a lot of those spears, arrows, or guns, their quality doesn’t matter. As the saying goes, quantity has a quality of its own.

That was the problem faced by Britain in the run-up to World War II. In the 1930s, Rolls-Royce had developed one of the finest pieces of engineering ever conceived: the Merlin engine. Planners knew they had something special in the supercharged V-12 engine, which would go on to power fighters such as the Supermarine Spitfire, and bombers like the Avro Lancaster and Hawker Hurricane. But, the engine would be needed in such numbers that an entire system would need to be built to produce enough of them to make a difference.

“Contribution to Victory,” a film that appears to date from the early 1950s, documents the expansive efforts of the Rolls-Royce corporation to ramp up Merlin engine production for World War II. Compiled from footage shot during the mid to late 1930s, the film details not just the exquisite mechanical engineering of the Merlin but how a web of enterprises was brought together under one vast, vertically integrated umbrella. Designing the engine and the infrastructure to produce it in massive numbers took place in parallel, which must have represented a huge gamble for Rolls-Royce and the Air Ministry. To manage that risk, Rolls-Royce designers made wooden scale models on the Merlin, to test fitment and look for potential interference problems before any castings were made or metal was cut. They also set up an experimental shop dedicated to looking at the processes of making each part, and how human factors could be streamlined to make it easier to manufacture the engines.

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Retrotechtacular: Powerline Sagging And Stringing In The 1950s

August 17, 2024 by Dan Maloney 13 Comments

While high-voltage transmission lines are probably the most visible components of the electrical grid, they’re certainly among the least appreciated. They go largely unnoticed by the general public — quick, name the power line closest to you right now — at least until a new one is proposed, causing the NIMBYs and BANANAs to come out in force. To add insult to injury, those who do notice the megastructures that make modern life possible rarely take a moment to appreciate the engineering that goes into stringing up hundreds of miles of cable and making sure it stays up.

Not so the Bonneville Power Administration, the New Deal-era federal agency formed to exploit the hydroelectric abundance of the Pacific Northwest of the United States, which produced this 1950 gem detailing the stringing and sagging of power lines. Unsurprisingly, the many projects needed to wire together the often remote dams to the widely distributed population centers in an area that was only just starting to see growth began in the BPA’s offices, where teams of engineers hunched over desks worked out the best routes. Paper, pencil, and slide rules were the tools of the trade, along with an interesting gadget called a conductor sag template, a hardware implementation of the catenary equation that allowed the “sagger” to determine the height of each tower. The conductors, either steel-cored aluminum or pure copper, were also meticulously selected based on tensile strength, expected wind and ice loading, and the electrical load the line was expected to carry.

Once the engineers had their say, the hard work of physically stringing the wires began out in the field. One suspects that the work today is much the same as it was almost eighty years ago, save for much more stringent health and safety regulations. The prowess needed to transfer the wires from lifting sheaves to the insulators is something to behold, and the courage required to work from ladders hanging from wires at certain death heights is something to behold. But to our mind, the real heroes were the logistics fellows, who determined how much wire was needed for each span and exactly where to stage the reels. It’s worth sparing a moment’s thought for the daring photographer who captured all this action, likely with little more than a leather belt and hemp rope for safety.

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Retrotechtacular: Ford Model T Wheels, Start To Finish

July 18, 2024 by Dan Maloney 20 Comments

There’s no doubt that you’ll instantly recognize clips from the video below, as they’ve been used over and over for more than 100 years to illustrate the development of the assembly line. But those brief clips never told the whole story about just how much effort Ford was forced to put into manufacturing just one component of their iconic Model T: the wheels.

An in-house production of Ford Motors, this film isn’t dated, at least not obviously. And with the production of Model T cars using wooden spoked artillery-style wheels stretching from 1908 to 1925, it’s not easy to guess when the film was made. But judging by the clothing styles of the many hundreds of men and boys working in the River Rouge wheel shop, we’d venture a guess at 1920 or so.

Production of the wooden wheels began with turning club-shaped spokes from wooden blanks — ash, at a guess — and drying them in a kiln for more than three weeks. While they’re cooking, a different line steam-bends hickory into two semicircular felloes that will form the wheel’s rim. The number of different steps needed to shape the fourteen pieces of wood needed for each wheel is astonishing. Aside from the initial shaping, the spokes need to be mitered on the hub end to fit snugly together and have a tenon machined on the rim end. The felloes undergo multiple steps of drilling, trimming, and chamfering before they’re ready to receive the spokes.

The first steel component is a tire, which rolls down out of a furnace that heats and expands it before the wooden wheel is pressed into it. More holes are drilled and more steel is added; plates to reinforce the hub, nuts and bolts to hold everything together, and brake drums for the rear wheels. The hubs also had bearing races built right into them, which were filled with steel balls right on the line. How these unsealed bearings were protected during later sanding and grinding operations, not to mention the final painting step, which required a bath in asphalt paint and spinning the wheel to fling off the excess, is a mystery.

Welded steel spoked wheels replaced their wooden counterparts in the last two model years for the T, even though other car manufacturers had already started using more easily mass-produced stamped steel disc wheels in the mid-1920s. Given the massive infrastructure that the world’s largest car manufacturer at the time devoted to spoked wheel production, it’s easy to see why. But Ford eventually saw the light and moved away from spoked wheels for most cars. We can’t help but wonder what became of the army of workers, but it probably wasn’t good. So turn the wheels of progress.

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How To Lace Cables Like It’s 1962

May 20, 2024 by Donald Papp 34 Comments

Cable harnesses made wire management a much more reliable and consistent affair in electronic equipment, and while things like printed circuit boards have done away with many wires, cable harnessing still has its place today. Here is a short how-to on how to lace cables from a 1962 document, thoughtfully made available on the web by [Gary Allsebrook] and [Jeff Dairiki].

It’s a short resource that is to the point in all the ways we love to see. The diagrams are very clear and the descriptions are concise, and everything is done for a reason. The knots are self-locking, ensuring that things stay put without being overly tight or constrictive.

According to the document, the ideal material for lacing cables is a ribbon-like nylon cord (which reduces the possibility of biting into wire insulation compared to a cord with a round profile) but the knots and techniques apply to whatever material one may wish to use.

Cable lacing can be done ad-hoc, but back in the day cable assemblies were made separately and electrically tested on jigs prior to installation. In a way, such assemblies served a similar purpose to traces on a circuit board today.

Neatly wrapping cables really has its place, and while doing so by hand can be satisfying, we’ve also seen custom-made tools for neatly wrapping cables with PTFE tape.

Retrotechtacular: How Not To Use Hand Tools

May 6, 2024 by Dan Maloney 48 Comments

Whatever you’re doing with your hand tools, by the US Army’s lights, you’re probably doing it wrong. That seems to be the “Green Machine’s” attitude on pliers and screwdrivers, at least, the main stars of this 1943 War Department training film on the horrors of tool abuse.

As kitschy as the film might be, they weren’t wrong. That’s especially true about the dreaded slip-joint pliers, which seem to find their way onto everyone’s list of unloved tools and are shown being used for their true purpose — turning nuts and bolt heads from hexagons into circles. Once that gore is wrapped up, we’re treated to the proper uses of pliers, including the fascinating Bernard-style parallel jaw pliers. We can recall these beauties kicking around the bottom of Dad’s tool kit and being entranced by the mechanism used to keep the jaws parallel and amplify the force applied. Sadly, those pliers are long gone now; Tubalcain did a great review of these pliers a few years back if you need a refresher.

A selection of screwdrivers gets the same treatment, complete with dire warnings against using them as prybars and chisels. Also against the Army Way is using the wrong size screwdriver for the job, lest you strip the head of the screw or break the tool itself. It has to be said that the Plomb Tool Company of Los Angeles, which produced the film, made some fantastic-looking screwdrivers back in the day. The square shanks on some of those straight screwdrivers are enormous, and the wooden handles look so much more comfortable than the greebled-up plastic nonsense manufacturers seem to favor these days. Also interesting is the reference to the new-fangled Phillips screw, not to mention the appearance of a Yankee-style spiral ratcheting screwdriver, another of Dad’s prized acquisitions that thankfully is still around to this day.

What strikes us about these military training films is how many of them were produced. No subject seemed too mundane to get a training film made about it, and so many were made that one is left wondering how there was any time left for soldiering after watching all these films. But really, it’s not much different today, when we routinely pull up a random YouTube video to get a quick visual demo of how to do something we’ve never tried before. The medium may have changed, but visual learning is still a thing.

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