Invention Awards: Ripsaw Tank Delivers Death at 60MPH

See the Ripsaw in action: An unmanned beast that cruises over any terrain at speeds that leave an M1A Abrams in the dust

Mean Machine: Troops could use the Ripsaw as an advance scout, sending it a mile or two ahead of a convoy, and use its cameras and new sensor technology to sniff out roadside bombs or ambushes John B. Carnett

Today's featured Invention Award winner really requires no justification--it's an unmanned, armed tank faster than anything the US Army has. Behold, the Ripsaw.

Cue up the Ripsaw’s greatest hits on YouTube, and you can watch the unmanned tank tear across muddy fields at 60 mph, jump 50 feet, and crush birch trees. But right now, as its remote driver inches it back and forth for a photo shoot, it’s like watching Babe Ruth forced to bunt with the bases loaded. The Ripsaw, lurching and belching black puffs of smoke, somehow seems restless.

Like their creation, identical twins Geoff and Mike Howe, 34, don’t like to sit still for long. At age seven, they built a log cabin. Ten years later, they converted a school bus into a drivable, transforming stage for their heavy-metal band, Two Much Trouble. In 2000 they couldn’t agree on their next project: Geoff favored a jet-turbine-powered off-road truck; Mike, the world’s fastest tracked vehicle. "That weekend, Mike calls me down to his garage," Geoff says. "He’s already got the suspension built for the Ripsaw. So we went with that."

Every engineer they consulted said they couldn’t best the 42mph top speed of an M1A Abrams, the most powerful tank in the world. Other tanks are built to protect the people inside, with frames made of heavy armored-steel plates. Designed for rugged unmanned missions, the Ripsaw just needed to go fast, so the brothers started trimming weight. First they built a frame of welded steel tubes, like the ones used by Nascar, that provides 50 percent more strength at half the weight.

Ripsaw: How It Works: To glide over rough terrain at top speed, the Ripsaw has shock absorbers that provide 14 inches of travel. But when the suspension compresses, it creates slack that could cause a track to come off, potentially flipping the vehicle. So the inventors devised a spring-loaded wheel at the front that extends to keep the tracks taut. The Ripsaw has never thrown a track  Bland Designs

Behind the Wheel: The Ripsaw’s six cameras send live, 360-degree video to a control room, where program manager Will McMaster steers the tank  John B. Carnett
When you reinvent the tank, finding ready-made parts is no easy task, and a tread light enough to spin at 60 mph and strong enough to hold together at that speed didn’t exist. So the Howes hand-shaped steel cleats and redesigned the mechanism for connecting them in a track. (Because the patent for the mechanism, one of eight on Ripsaw components, is still pending, they will reveal only that they didn’t use the typical pin-and-bushing system of connecting treads.) The two-pound cleats weigh about 90 percent less than similarly scaled tank cleats. With the combined weight savings, the Ripsaw’s 650-horsepower V8 engine cranks out nine times as much horsepower per pound as an M1A Abrams.

While working their day jobs — Mike as a financial adviser, Geoff as a foreman at a utilities plant — the self-taught engineers hauled the Ripsaw prototype from their workshop in Maine to the 2005 Washington Auto Show, where they showed it to army officials interested in developing weaponized unmanned ground vehicles (UGVs). That led to a demonstration for Maine Senator Susan Collins, who helped the Howes secure $1.25 million from the Department of Defense.

The brothers founded Howe and Howe Technologies in 2006 and set to work upgrading various Ripsaw systems, including a differential drive train that automatically doles out the right amount of power to each track for turns. The following year they handed it over to the Army’s Armament Research Development and Engineering Center (ARDEC), which paired it with a remote-control M240 machine gun and put the entire system through months of strenuous tests. "What really set it apart from other UGVs was its speed," says Bhavanjot Singh, the ARDEC project manager overseeing the Ripsaw’s development. Other UGVs top out at around 20 mph, but the Ripsaw can keep up with a pack of Humvees.

Over the Hill: Despite the best efforts of inventors Mike [left] and Geoff Howe, the Ripsaw has proven unbreakable. It did once break a suspension mount — and drove on for hours without trouble  John B. Carnett
Back on the field, the tank has been readied for the photo. The program manager for Howe and Howe Technologies, Will McMaster, who is sitting at the Ripsaw’s controls around the corner and roughly a football field away, drives it straight over a three-foot-tall concrete wall. The brothers think that when the $760,000 Ripsaw is ready for mass production this summer, feats like this will give them a lead over other companies vying for a military UGV contract. "Every other UGV is small and uses [artificial intelligence] to avoid obstacles," Mike says. "The Ripsaw doesn’t have to avoid obstacles; it drives over them."

Check out the rest of PopSci's 2009 Invention Award winners!

14 Comments

It's like Daleks: They don't navigate stairs, they level the building.

It looks like one of the tanks from world war 1 with a gun on top. P.s no really it dose.

SO COOL!!!!! I do agree with the comment about them looking a bit like being from World War I. When I first saw the picture, steampunk originally came to mind. It had kind of classic look to it. Definitely quite a sleaker look then most tanks(since they don't have to worry about protecting people inside driving it) and moves beautifully in the video.

Apples and oranges. For one thing, the M-1 packs a 120mm cannon, two M240s and an M2 vs. the Ripsaw's one M240. So, it traded firepower for speed. Obviously, without a crew to protect you don't need armor. But it cannot intimidate the way a tank can. And the composite armor of the M-1 would (if it could) laugh at the Ripsaw's lack of firepower.

It would be a good test to see of the Ripsaw's speed can help it evade a 120mm shell. Conversely, it would be a good test if the M-1's systems can track-lock-and-engage an evading Ripsaw.

I can see the value of the Ripsaw if the Army wanted an Unmanned Tank... scaled up to handle a 120mm cannon... then we'll talk comparisons.

The game is still horribly imbalanced ATM. It's severely biased towards casters, which I believe shouldn't be in the game at all. This ultimately led to me unsubscribing from the game. I like how Craig has time and time again referred to the game being "group" balanced, but when he references pvp in relation to gear, he is clearly talking about 1 v 1. The game, its designers, and directors continue to contradict themselves. I won't be resubbing unless there are some major class balance changes. Conan would be ashamed of this P.O.S.
When you wake up in the morning you have the choice to achieve anything you want. Do not waste another do reading stupid web comments...get out there and live life!
Zamora

Warhammer Europe Gold

I'd just like to point out that this is not intended to compare with the M1. It can't. It's intended for infantry support (james2). As such it doesn't need the punch of the M1, just the ability to get in and out quick. Plus it's cheaper than the other UGV.

Although, it is scarily terminator-ish.

'taking', all tanks have guns on top!
the ones in WW1 had most guns on side

Life imitating Art imitating WAR... anyone see the new Terminator Salvation..? Altho i do agree that unmanned is the way to go, more machines Less People...This is a strange world we are living in, getting stranger all the time.

Ripsaw's looks are the only simularity to WWI tanks. Ripsaw has an astonishing 14inches of suspension travel. WWI had no suspension. WWII had little... Current have between 4"-8" No tracked vehicle has ever acheived 14"... not even close. This coupled with their guide system allows for the high speed, while not throwing a track. Its also an exto skeleton structure making lighter and stronger. When it comes to offroad capability weight is everything. Many people compare Ripsaw suspension to a sherman... This couldn't be farther from the truth.... Ripsaw possesses a swept back dual-acting dogleg... Never seen before. I agree with James, Ripsaw was never intended to go head to head with another tank. But with its speed and a Javlin missile system on top, I wouldn't want to oppose it in any vehicle. I'm a tracked vehicle specialist (CAT) and have followed Ripsaw for a while. Congrats guys

So it's 10mph slower than an M1, not 18mph faster. The 42mph official top speed of the M1A1 and M1A2 is governed. With the governor disabled the M1 series can exceed 70mph.

Any engineer who said exceeding 43mph in a tracked vehicle was impossible simply doesn't know what they were talking about. Several current tanks can do so, including the M1 and the Leopard 2 when the governors are disabled. They are governed to improve safety and power pack lifetime.

I want to see it driving across a lake like snowmobiles do.

too innovative, too fast, too efficient, too inexpensive...will never survive DoD procurement!

@mawz

I'd say it is the fastest. While the M1 can top out at about 70MPR w/o the govenor on, you're almost certain to throw track going that fast. This little guy can go that fast without fear of losing track.

AND!

If i had to sit in that station for more than 15 minutes to control that thing, i'd seriously quit and risk Levenworth.

Ahh, Skynet, I knew ye well.

Kids, if I've said this once, I've said it once. Introduce a system that's remote controlled, and the bad guys can figure a way to hack it. Make it autonomous, and.....wait, isn't that what the REAL Cyberdyne Systems is trying to do?

Yes, Virginia Tech., there is a terminator.

Popular Science Photo Pool


Share your photos in the Pop Sci pool at www.flickr.com!

Subscribe for 2 free issues!

POP_embeddedForm_cover_May09.jpg