Ground-Effect Vehicle To Carry Passengers Around Hawaii

January 27, 2024 by Bryan Cockfield 29 Comments

Although Hawaii used to have a ferry service to access the various islands in the archipelago, due to environmental and political issues, air travel is now the only way to island-hop. Various companies have tried to fill this transportation gap, but have all been stymied for one reason or another. The latest to attempt to solve this problem is a unique one, however. The Hawaii Seaglider Initiative is currently testing a ground-effect vehicle for inter-island passenger service that hopes to use the unique characteristics of this type of aircraft to reduce costs and limit environmental concerns.

The Seaglider, with backing from the Hawaii state government and various corporate interests like Hawaiian Airlines, is actually an amalgamation of three different types of vehicle. It’s capable of operating like a normal, hulled boat at low speeds but has a hydrofoil for operating at higher speeds. Beyond that, its wings give it enough lift to leave the water but stay in ground-effect flight, flying low to the water to reduce drag and improve lift when compared to an aircraft flying out of the ground effect. The efficiency gains from this type of flight are enough that the Seaglider can use electric motors and batteries to make the trips from island to island.

While the ferry is not yet in service, flight testing of the vehicle is scheduled for this year. Ground-effect vehicles of this type do have a large number of obstacles to overcome, whether they’re huge military vehicles like the Ekranoplanes of the Soviet Union or even small remote-controlled crafts, including difficulty with rough seas and having to operate in a harsh salt water environment.

San Francisco Sues To Keep Autonomous Cars Out Of The City

January 26, 2024 by Maya Posch 32 Comments

Although the arrival of self-driving cars and taxis in particular seems to be eternally ‘just around the corner’ for most of us, in an increasing number of places around the world they’re already operational, with Waymo being quite prevalent in the US. Yet despite approval by the relevant authorities, the city of San Francisco has opted to sue the state commission that approved Google’s Waymo and GM’s Cruise. Their goal? To banish these services from the streets of SF, ideally forever.

Whether they will succeed in this seems highly doubtful. Although Cruise has lost its license to operate in California after a recent fatal accident, Waymo’s track record is actually quite good. Using public information sources, there’s a case to be made that Waymo cars are significantly safer to be in or around than those driven by human operators. When contrasted with Cruise’s troubled performance, it would seem that the problem with self-driving cars isn’t so much the technology as it is the safety culture of the company around it.

Yet despite Waymo’s better-than-humans safety record, it is regarded as a ‘nuisance’, leading some to sabotage the cars. The more reasonable take would seem to be that although technology is not mature yet, it has the overwhelming advantage over human drivers that it never drives distracted or intoxicated, and can be deterministically improved and tweaked across all cars based on experiences.

These considerations have been taken into account by the state commission that has approved Waymo operating in SF, which is why legal experts note that SF case’s chances are very slim based on the available evidence.

Cockpit of a Hawker Siddeley Trident with the moving map display

A Live Map Display In A 1960s Airliner

January 23, 2024 by Danie Conradie 4 Comments

We tend take GPS navigation for granted these days, so it’s easy to forget that it became only available in the last few decades. Aviation navigation used to be significantly more challenging, so how was the Hawker Siddeley Trident, a 1960s airliner, fitted with a live updating map display? In a fascinating dive into aviation history the British Airliner Collection has spun up an insightful article on the magic behind these moving map displays.

Without access to satellite navigation or advanced electronics, engineers had to get creative. Enter the Trident’s moving map display, a marvel of ingenuity that predated the GPS systems. Using a combination of Doppler radar and some clever mechanics, pilots could accurately determine their position without relying on any external signals.

The system makes use of four Doppler radar beams, arranged in what was known as the Janus array. This configuration corrected for errors caused by changes in altitude or wind drift, ensuring accurate ground speed readings. The movable antennas mounted under the cabin floor could adjust its orientation to maintain alignment with the actual direction of travel, calculating drift angle precisely. Combined with compass information and flight time from a known start point to to indicate the current position with a pointer on a rolled paper map. The system was well ahead of it’s time, and significantly easier to use and more accurate than the Decca radio navigation system in use at the time.

It’s mind boggling to see the solutions engineers came up with without much of the digital technology we take for granted today. Gyroscopes for inertial navigation, the cavity magnetron for radar and radial engines were all building blocks for modern aviation.

Thanks for the tip [poiuyt]!

Could Solar-Powered Airships Offer Cleaner Travel?

January 23, 2024 by Lewin Day 93 Comments

The blimp, the airship, the dirigible. Whatever you call them, you probably don’t find yourself thinking about them too often. They were an easy way to get airborne, predating the invention of the airplane by decades. And yet, they suffered—they were too slow, too cumbersome, and often too dangerous to compete once conventional planes hit the scene.

And yet! Here you are reading about airships once more, because some people aren’t giving up on this most hilarious manner of air travel. Yes, it’s 2024, and airship projects continue apace even in the face of the overwhelming superiority of the airplane.

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Learn Sailing Mechanics Without Leaving Dry Land

January 20, 2024 by Danie Conradie 31 Comments

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.

Tech In Plain Sight: Windshield Frit

January 18, 2024 by Al Williams 29 Comments

You probably see a frit every day and don’t even notice it. What is it? You know the black band around your car’s windshield? That’s a frit (which, by the way, can also mean ingredients used in making glass) or, sometimes, a frit band. What’s more, it probably fades out using a series of dots like a halftone image, right? Think that’s just for aesthetics? Think again.

Older windshields were not always attached firmly, leading to them popping out in accidents. At some point, though, the industry moved to polyurethane adhesives, which are superior when applied correctly. However, they often degrade from exposure to UV. That’s a problem with a windshield, which usually gets plenty of sunlight.

The answer is the frit, a ceramic-based baked-on enamel applied to both sides of the windshield’s edges, usually using silk screening. The inner part serves as a bonding point for the adhesive. However, the outer part blocks UV radiation from reaching the adhesive. Of course, it also hides the adhesive and any edges or wiring beneath it, too.

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Möbius Tank’s Twisty Treads Became Bendy

January 14, 2024 by Donald Papp 14 Comments

[James Bruton]’s unusual Möbius Tank has gotten a little more unusual with the ability to bend itself, which allows it to perform turns even though it is a single-track vehicle.

The turning radius isn’t great, but three-point turns are perfectly feasible.

The Möbius Tank was a wild idea that started as a “what if” question: what if a tank tread was a Möbius strip? We saw how [James] showed it could be done, and he demonstrated smart design and assembly techniques in the process.

He’s since modified the design to a single-track, and added a flex point in the center of the body. Two linear actuators work together to make the vehicle bend, and therefore give it the ability to steer and turn. A normal tread would be unable to bend in this way, but the twist in the Möbius tread accommodates this pivot point perfectly well.

It works, but it’s not exactly an ideal vehicle. With the tread doing a 90-degree twist on the bottom, there isn’t a lot of ground clearance. In addition, since the long vehicle has only a single tread, it is much taller than it is wide. Neither does it any real favors when it comes to stability over uneven terrain, but it’s sure neat to try.

Even if it’s not practical, Möbius Tank is wild to look at. Check it out in the video, embedded just under the page break.

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