Battery-Electric Ships: Coming Soon To A Harbor Near You?

When ships moved from muscle- and wind power to burning coal and other fossil fuels for their propulsion, they also became significantly faster and larger. Today’s cargo ships and ferries have become the backbone of modern civilization, along with a range of boat types. Even though tugs and smaller pleasure vessels are a far cry from a multi-thousand ton cargo or cruise ship, one would be hard-pressed to convert these boats back to a pure muscle or wind-based version. In short, we won’t be going back to the Age of Sail, but at the same time the fossil fuel-burning engines in these boats and ship come with their own range of issues.

Even if factors like pollution and carbon emissions are not something which keep you up at night, fuel costs just might, with these and efficiency regulations increasing year over year. Taking a page from alternative propulsions with cars and trucks, the maritime industry has been considering a range of replacements for diesel and steam engines. Here battery-electric propulsion is somewhat of an odd duck, as it does not carry its own fuel and instead requires on-shore recharging stations. Yet if battery-electric vehicles (BEVs) can be made to work on land with accompanying low ‘refueling’ costs, why not ships and boats?

A recent study by Lawrence Berkeley National Laboratory (LBNL) researchers Hee Seung Moon et al. as published in Nature Energy claims that a significant part of US maritime traffic can be electrified this way. Yet as a theoretical model, how close does it hit to the harsh realities imposed by this physical world which we live in?

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Blinded By The Light: The Problem With LED Headlights

Having a good set of (working) headlights is a crucial feature of any motor vehicle, assuming you want to be able to see the road ahead of you when there’s a lack of sunshine. Headlights are also essential to be noticed by other cars and traffic participants, but if installed improperly they can end up blinding an opposing driver with potentially fatal results. This is a major worry with LED lamps that are increasingly being installed in cars, often replacing the old-style halogen bulbs that have a very different color spectrum and beam patterns, to the dismay of fellow road participants.

This headlight glare can also be simulated in driving simulators, as in a 2019 article by [B.C. Haycock] et al. where the effect is of course diminished because displays can only get so bright. Of note is that it’s not just LED lights themselves, but also taller vehicles and misaligned headlights, all of which makes it important that the angle of your car’s headlights is proper. You want to see the road in front of you, after all, not illuminate every house in the nearest settlement two klicks away.

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Fairey Rotodyne in flight

Versatile, Yet Grounded: The Rotodyne Revisited

When it comes to aviation curiosities, few machines captivate the imagination like the Fairey Rotodyne. This British hybrid aircraft was a daring attempt to combine helicopter and fixed-wing efficiency into a single vehicle. A bold experiment in aeronautical design, the Rotodyne promised vertical takeoffs and landings in cramped urban spaces while offering the speed and range of a regional airliner. First flown in 1957, it captured the world’s attention but ultimately failed to realize its potential. Despite featured before, new footage keeps fascinating us. If you have never heard about this jet, keep reading.

The Rotodyne’s innovative design centered around a massive, powered rotor that utilized a unique tip-jet system. Compressed air, mixed with fuel and ignited at the rotor tips, created lift without the need for a tail rotor. The result: a smoother transition between vertical and forward flight modes. Inside, it offered spacious seating for 50 passengers and even had clamshell doors for cargo. Yet its futuristic approach wasn’t without drawbacks—most notably, the thunderous noise produced by its rotor jets, earning complaints from both city planners and residents.

Despite these hurdles, the helicopter-plane crossover demonstrated its versatility, setting a world speed record and performing groundbreaking intercity flights. Airlines and militaries expressed interest, but escalating development costs and noise concerns grounded this ambitious project.

To this day, the Rotodyne remains a symbol of what could have been—a marvel of engineering ahead of its time. Interested in more retro-futuristic aircraft tales? Read our previous story on it, or watch the original footage below and share your thoughts.

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Behold A Geared, Continuously Variable Transmission

When it comes to transmissions, a geared continuously-variable transmission (CVT) is a bit of a holy grail. CVTs allow smooth on-the-fly adjustment of gear ratios to maintain a target speed or power requirement, but sacrifice transmission efficiency in the process. Geared transmissions are more efficient, but shift gear ratios only in discrete steps. A geared CVT would hit all the bases, but most CVTs are belt drives. What would a geared one even look like? No need to wonder, you can see one for yourself. Don’t miss the two videos embedded below the page break.

The outer ring is the input, the inner ring is the output, and the three little gears with dots take turns transferring power.

The design is called the RatioZero and it’s reminiscent of a planetary gearbox, but with some changes. Here’s how the most visible part works: the outer ring is the input and the inner ring is the output. The three small gears inside the inner ring work a bit like relay runners in that each one takes a turn transferring power before “handing off” to the next. The end result is a smooth, stepless adjustment of gear ratios with the best of both worlds. Toothed gears maximize transmission efficiency while the continuously-variable gear ratio allows maximizing engine efficiency.

There are plenty of animations of how the system works but we think the clearest demonstration comes from [driving 4 answers] with a video of a prototype, which is embedded below. It’s a great video, and the demo begins at 8:54 if you want to skip straight to that part.

One may think of motors and gearboxes are a solved problem since they have been around for so long, but the opportunities to improve are ongoing and numerous. Even EV motors have a lot of room for improvement, chief among them being breaking up with rare earth elements while maintaining performance and efficiency.

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A Self Balancing Bike For Crash Dummy Billy

We aren’t sure there’s enough information in the [We Make Machines’] video to easily copy their self-balancing bike project, but if you want to do something similar, you can learn a lot from watching the video. Building sufficient gyros to keep the bike stable required quite a bit of trial and error.

There are some tricks to getting a stable heavy weight to rotate without a lot of vibration and problems. The gyros go on the rider’s saddle, so you aren’t going to be able to ride in the normal fashion. However, a substantial motor drives the wheels so there’s no need to pedal.

The first attempt to self-balance stayed stable for about 10 seconds. Some of it was fine-tuning code, but noise from the gyros also threw off the angle sensor. A higher-quality sensor seemed promising, but it didn’t really fix the problem. Instead of using PID, the guys tried an LQR (Linear Quadratic Regulator) algorithm. Once that was sorted and a servo allowed for steering, it was time to let the bike roam free.

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Retrotechtacular: 1980s Restoration Of San Francisco’s Cable Car System

The cable car system of San Francisco is the last manually operated cable car system in the world, with three of the original twenty-three lines still operating today. With these systems being installed between 1873 and 1890, they were due major maintenance and upgrades by the time the 1980s and with it their 100th year of operation rolled around. This rebuilding and upgrading process was recorded in a documentary by a local SF television station, which makes for some fascinating viewing.

San Francisco cable car making its way through traffic. Early 20th century.
San Francisco cable car making its way through traffic. Early 20th century.

While the cars themselves were fairly straight-forward to restore, and the original grips that’d latch onto the cable didn’t need any changes. But there were upgrades to the lubrication used (originally pine tar), and the powerhouse (the ‘barn’) was completely gutted and rebuilt.

As opposed to a funicular system where the cars are permanently attached to the cable, a cable car system features a constantly moving cable that the cars can grip onto at will, with most of the wear and tear on the grip dies. Despite researchers at San Francisco State University (SFSU) investigating alternatives, the original metal grip dies were left in place, despite their 4-day replacement schedule.

Ultimately, the rails and related guides were all ripped out and replaced with new ones, with the rails thermite-welded in place, and the cars largely rebuilt from scratch. Although new technologies were used where available, the goal was to keep the look as close as possible to what it looked at the dawn of the 20th century. While more expensive than demolishing and scrapping the original buildings and rolling stock, this helped to keep the look that has made it a historical symbol when the upgraded system rolled back into action on June 21, 1984.

Decades later, this rebuilt cable car system is still running as smoothly as ever, thanks to these efforts. Although SF’s cable car system is reportedly mostly used by tourists, the technology has seen somewhat of a resurgence. Amidst a number of funicular systems, a true new cable car system can be found in the form of e.g. the MiniMetro system which fills the automated people mover niche.

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The Hovercraft Revolution And Finding The Right Niche For A Technology

In the world of transportation, some technologies may seem to make everything else appear obsolete, whether it concerns airplanes, magnetic levitation or propelling vehicles and craft over a cushion of air. This too seemed to be the case with hovercraft when they exploded onto the scene in the 1950s and 1960s, seemingly providing the ideal solution for both commercial and military applications. Freed from the hindrances of needing a solid surface to travel upon, or a deep enough body of water to rest in, hovercraft gave all the impressions of combining the advantages of aircraft, ships and wheeled vehicles.

Yet even though for decades massive passenger and car-carrying hovercraft roared across busy waterways like the Channel between England & mainland Europe, they would quietly vanish again, along with their main competition in the form of super fast passenger catamarans. Along the English Channel the construction of the Channel Tunnel was a major factor here, along with economical considerations that meant a return to conventional ferries. Yet even though one might think that the age of hovercraft has ended before it ever truly began, the truth may be that hovercraft merely had to find its right niches after a boisterous youth.

An example of this can be found in a recent BBC article, which covers the British Griffon Hoverwork company, which notes more interest in new hovercraft than ever, as well as the continued military interest, and from rescue workers.

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