Cruise Ship-Lengthening Surgery: All The Cool Companies Are Doing It

September 10, 2024 by Maya Posch 58 Comments

Sliding in an extra slice of cruise ship to lengthen it. (Credit: Silversea cruises)

The number of people going on cruises keeps rising year over year, with the number passengers carried increasing from just over 3.7 million in 1990 to well over 28 million in 2023. This has meant an increasing demand for more and also much larger cruise ships, which has led to an interesting phenomenon where it has become more economical to chop up an existing cruise ship and put in an extra slice to add many meters to each deck. This makes intuitively sense, as the segment added is fairly ‘dumb’, with no engine room, control systems, but mostly more rooms and cabins.

The current top-of-the-line cruise ship experience is exemplified by the Icon class that’s being constructed for the Royal Caribbean Group. The first in this line is the Icon of the Seas, which is the largest cruise ship in the world with a length of 364.75 meters and a gross tonnage of 248,663. All of this cost €1.86 billion and over two years of construction time, compared to around $80 million and a few months in the drydock. When combined with a scheduled maintenance period in the drydock, this ‘Jumboization’ process can be considered to be a great deal that gives existing cruise ships a new lease on life.

Extending a ship in this manner is fairly routine as well, with many ships beyond cruise ships seeing the torch before being split. A newly built segment is then slid in place, the metal segments are welded together, wires, tubing and more are spliced together, before the in and outside are ready for a new coat of paint that makes it seem like nothing ever happened to the ship.

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Self Driving Cars Learn From Our Eyes

September 8, 2024 by Al Williams 14 Comments

[Michelle Hampson] reports in IEEE Spectrum that Chinese researchers may improve self-driving cars by mimicking how the human eye works. In some autonomous cars, two cameras use polarizing filters to help understand details about what the car sees. However, these filters can penalize the car’s vision in low light conditions.

Humans, however, have excellent vision in low-lighting conditions. The Retinex theory (based on the Land Effect discovered by [Edwin Land]) attributes this to the fact that our eyes sense both the reflectance and the illumination of light. The new approach processes polarized light from the car’s cameras in the same way.

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A photo of a white dog with curly fur riding a black skateboard with grey motors under the front deck. There are blue squares on the top of the deck that she is standing on to steer the board.

An Electric Skateboard For The Dogs

September 6, 2024 by Navarre Bartz 1 Comment

What’s a dog to do if they want to do some accessible skateboarding? [Simone Giertz]’s three-legged pup, [Scraps], got the chance to try a LEGO Technic board for her thrills.

This electric LEGO skateboard features six motors and paw pedals to let [Scraps] steer while [Giertz] remotely controls the speed of the board. While it’s not a particularly fast ride, it does let [Scraps] live out her dreams of being a YouTube dog skateboard celebrity.

A video from [Giertz] wouldn’t be complete without a life lesson, and this time it was the importance of rest to the creative process. Sometimes when a solution eludes you, it’s just time to take a break. The steering mechanism, in particular, was giving her trouble but became simple the next morning. We’re also treated to an adorable shot of [Scraps] napping when the initial shoot of her riding the board wasn’t going as planned.

Want to try your hand at making your own skateboard? How about a deck from recycled plastic, tank treads instead of wheels, or is a rocket-powered skateboard more your speed?

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A tricked-out kids' Jeep in black and silver.

Driven To Over-Engineer A Kids’ Car

August 29, 2024 by Kristina Panos 10 Comments

You know, it feels as though it’s getting more and more difficult to compete for Father of the Year around here. And [Jon Petter Skagmo] just laid down a new gauntlet — the incredibly overly-engineered kids car.

While the original plan was to build the entire car from scratch, [Jon] eventually opted to use an off-the-shelf car that had a dead battery.

While the original architecture was quite simple, the new hardware has just about everything a kid could want in a tricked-out ride, most of which is accessible through the really cool dashboard.

We’re talking headlights, a music player, a siren, a selfie video cam that doubles as two-way communication with the driver, and even a garage door opener that uses an MQTT connection.

Under the cute little hood is where you’ll find most of the electronics. The car’s brain is a Raspberry Pi 3B, and there’s a custom daughter board that includes GPS/GNSS. This was originally meant to geofence [Baby Girl Skagmo] in, but Dad quickly realized that kids are gonna kid and disabled it pretty soon after.

This isn’t the first high-tech rebuild of a kiddie car that we’ve seen here at Hackaday. Makes us wish we were quite a bit smaller…

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Building A Small Gyro Stabilized Monorail

August 27, 2024 by Lewin Day 12 Comments

Monorails aren’t just the core reason why The Simpsons remains on air after thirty-six seasons, twenty-six of which are unredeemable garbage. They’re also an interesting example of oddball rail travel which has never really caught on beyond the odd gadgetbahn project here and there. [Hyperspace Pirate] recently decided to investigate the most interesting kind of monorail of all—the gyro stabilized type—on a small scale for our viewing pleasure.

The idea of a gyro-stabilized monorail is to use active stability systems to allow a train to balance on a single very thin rail. The benefits of this are questionable; one ends up with an incredibly expensive and complex rail vehicle that must always run perfectly or else it will tip over. However, it is charming to watch in action.

[Hyperspace Pirate] explains how the monorail vehicle uses control moment gyroscopes to keep itself upright. The video also explains the more common concept of reaction wheels so the two systems can be contrasted and compared. It all culminates in a wonderful practical demonstration with a small 3D printed version of a 20th-century gyro monorail running on a 24″ track.

If you’re studying mechanical engineering this is a great project to pore over to see theoretical principles put into obvious practice. Video after the break.

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Tech In Plain Sight: Speedometers

August 22, 2024 by Al Williams 29 Comments

In a modern car, your speedometer might look analog, but it is almost certainly digital and driven by the computer that has to monitor all sorts of things anyway. But how did they work before your car was a rolling computer complex? The electronic speedometer has been around for well over a century and, when you think about it, qualifies as a technlogical marvel.

If you already know how they work, this isn’t a fair question. But if you don’t, think about this. Your dashboard has a cable running into it. The inner part of the cable spins at some rate, which is related to either the car’s transmission or a wheel sensor. How do you make a needle deflect based on the speed?

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Open Source Liquid Rocket Reaches For The Sky

August 20, 2024 by Tom Nardi 30 Comments

Since the very beginning, solid-propellants have been the cornerstone of amateur rocketry. From the little Estes rocket picked up from the toy store, to vehicles like the University of Southern California’s Traveler IV that (probably) crossed the Kármán line in 2019, a rapidly burning chunk of solid propellant is responsible for pushing them skyward. That’s not to say that amateur rockets powered by liquid propellants are completely unheard of … it’s just that getting them right is so ridiculously difficult that comparatively few have been built.

But thanks to [Half Cat Rocketry], we may start to see more hobbyists and students taking on the challenge. Their Mojave Sphinx liquid-fueled rocket is not only designed to be as easy and cheap to build as possible, but it’s been released as open source so that others can replicate it. All of the 2D and 3D CAD files have been made available under the GPLv3 license, and if you’re in the mood for a little light reading, there’s a nearly 370 page guidebook you can download that covers building and launching the rocket.

Now of course we’re still talking about literal rocket science here, so while we don’t doubt a sufficiently motivated individual could put one of these together on their own, you’ll probably want to gather up a couple friends and have a well-stocked makerspace to operate out of. All told, [Half Cat] estimates you should be able to build a Mojave Sphinx for less than $2,000 USD, but that assumes everything is done in-house and you don’t contract out any of the machining.

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