How Not to Get Stuck in the Sand Dunes

December 24, 2007

As you saw in the video highlights from last year’s Dakar (three posts ago), even the pros find it hard not to get stuck in the sand dunes.  No matter how fast you are on hard surfaces, the sand will get you.  And this year we have extra sand, most of the Dakar will take place in Mauritania, which is mostly dunes.  This beauty was taken in Marzuga, Morocco:

Morocco 199

The Desert Warrior is optimized to drive on sand: it is very light to begin with, and by operating on diesel it carries less fuel (about 200 kg); when you get to the dunes you need to deflate the tiers, to about 1 bar, so the tier flattens out and has better grip.   The Desert Warrior has separate front and rear differential locks, pneumatically activated by the driver. But then you still need to be able to read the terrain, to know from which direction the wind blows , and how to cross the dunes.

Egg Cartons in the Dessert

Think of sand dunes as a (soft) egg carton: a series of bowls, each bowl is surrounded by ridges.  The bottom of the bowl is flat and firmer to drive on, the ridges are steep and soft.                                              November 2007 070 You got to drive over a ridge to get to the next dune.  Most times you cannot drive on the ridge line itself (too narrow, you will roll over), and you cannot just drive straight up to the ridge: you will lose too much momentum (too steep, too soft) and get stuck in no time. 

Morocco 195What to do, then? When we trained in Morocco Paul and Beady showed us a technique they use to drive over dunes.   It is very effective, and, believe him or not, Martin claims that in their 2007 Dakar he and Paul didn’t have to shovel themselves out of the sand even once.

Dune Surfing

What you do is try to “surf” the dune.  When you’re at the bottom of the bowl, drive around in circles and gather as much speed as you can; with more speed you build momentum that allows you to get higher on the dune’s ridge, about 2/3 of the way up; but you drive parallel to the ridge, not perpendicular.  Once you have enough momentum and you’re high enough, lift your head and look for a crossing spot, typically a lower saddle between two peaks (remember the egg carton?).  Keep your momentum to get to the ridge line, and as you crest the ridge, immediately lift your foot from the accelerator, brake gently, and pick your route into, and out of, the next bowl.  As you descend into the next bowl you build up momentum, and so forth for the next 200 miles 🙂

Check out this slide-show to get a sense of what I’m talking about:

This “surfing” technique is very effective and fun, once you get it.  It doesn’t always work, though, as the sand may be too soft, the dune too steep, or you just don’t have enough speed; remember that you can always trade-off height for speed (for those of you who are pilots, I’m sure you get exactly what I’m talking about).   so, if you find yourself on the ridge, your momentum just died, and you feel you will get stuck in the sand any second now, just turn your steering wheel towards the bottom of the bowl, and accelerate (that’s right) downwards; with enough speed and a bit of luck, by the time you get to the bottom you have enough momentum to start the maneuver all over again (and if it didn’t work, well, start digging!).

See how Nadav gets out of a messy situation after he got the the top of the ridge but lost all his momentum (there may be a bug here; if this window doesn’t show a slideshow, just click on the “x” mark on the top right corner):

BTW, both slides shows where created by Slide.com.  I’d be interested in your comments, which style did you like best, the “Slide Show” or the “8 mm”?  Let me know by leaving a comment on this post.


Team O’Neil Rally School: Blah, Blah, Blah, …Accelerate!

December 22, 2007

If you want to have a few days of sheer fun and learn how to spin a car into a turn like a Hollywood stuntman,  drive up north to Littleton, NH, and spend a few days with the folks at Team O’Neil Rally School.  This is what my friend Ilan Segev (middle, maroon shirt) and I did last summer, as I was looking for ways to prepare myself for the Dakar.

June 2007 103

Tim O’Neil, an accomplished rally racer, opened this school in the wooded hills of NH to teach high speed driving on loose surfaces to policemen, fire fighters, but also to rally enthusiasts who want to develop their driving skills and acquire some of the professional really techniques.   A 2 days course is probably the minimum, but if you have a bit more time a 3 or 4 days’ course will get you much more in terms of confidence and improvement.

The basic technique they teach is Left Foot Braking.   As “civilians” drivers, we either step on the gas, or on the brake, but not both (and so we use the same right foot for both).  In rally driving, you want to be able to keep the right foot on the accelerator, while applying pressure to the brakes with your left foot; by doing that, you will transfer weight from the rear to the front wheels, and give the front wheels slightly more traction than the rear wheels.   And so, in rally, when you get to a tight corner at a high speed, you do not lift your foot off the gas; rather, you steer the wheels ever so slightly “into” the turn, and gently apply pressure to the brakes; the front wheels will dig into the loose surface you’re on, and the car’s rear will spin, or throw itself outside of the turn; this gives you a much tighter turn, and you do not lose much speed during the maneuver:

Sounds easy enough?  The first few runs will give you a good scare, your instincts will tell you to lift your foot off the gas, or to slam the brakes as you head into a 90 degrees turn at 60 miles/hour…  but the instructors at Team O’Neil are very calm about the whole thing, have tremendous amount of patience, and before you know it you will be spinning on the muddy ground, more or less in control, and I guarantee you will be loving every minute of it!

Here is a video of a beautifully executed rally turn that my friend Ofer Shoshan sent me:

Once you master this basic technique, you start combining different elements into more complicated maneuvers; a lot of judgment has to be applied to the right level of braking, steering, speed, etc., given the conditions.  This, for example, is a typical rally maneuver you may have to use on a winding track with increasingly tight turns: 

Team O'Neil breaking in turn

Check out some more neat videos on Team O’Neil web site.

This is definitely in the category of “kids, don’t try this at home”.  The techniques are powerful and fun to try once you mastered it all, but you cannot do any of that with your “civilian” car if it has ABS, and in reality you need to learn from a professional in a controlled environment.   I highly recommend spending a few days with Tim, Chuck, Wyatt, and the rest of the folks at Team O’Neil.  They can be reached at 603-444-4488, or on their web site.

Next time: How not to get stuck in the sand


Help Dror Cohen get to Dakar

December 16, 2007

While almost every one that participates in the Dakar deserves some credit either as a hero or as a nutcase or both,  this year one of the competitors deserves a little bit more credit than anyone else.  His name is Dror Cohen.

Dror Coehn

A former F-16 pilot, Dror had a traffic accident at the age of 24 that left him paralyzed from the waist down.  Not one to be deterred easily, Dror has since become an extreme sports competitor.  He already won the Olympic Gold medal in sailing in Athens, has taken up rock climbing, Bungee jumping, skiing, and in recent years got into off-road racing and the Dakar.  Watch the following YouTube clip about Dror’s life story; it is in Hebrew, but you will get the point.

Dror first entered the Dakar in 2002 and has done quite well until he Dror carhad to drop due to mechanical problems.  Since then he has been building a unique vehicle that will allow him to compete effectively and hopefully to finish the race.  Nadav visited Dror and the folks who build the car for him in Israel, and says it is beautiful, powerful machine with an automatic transmission,  a 400 hp Chevy engine, and a cabin for 3 (Dror as the driver and two co-pilots).

Designing a special vehicle and recruiting a full crew to help out with mechanics and logistics is a very expensive undertaking.   You can help by going to Dror’s website; there, you can chose any area on the car’s hood, pay for the space, and upload a picture or a message.  Or you could just contact Dror and dror@drordakar.com.


Cool 2007 Dakar video

December 14, 2007

Check out some of the 2007 Dakar videos on YouTube. This one is quite good, it is from Day 7, the first day in Mauritania. Watch how they all struggle in the dunes, pros and amateurs alike.  It is going to be a lot of fun!


RallyRaid UK and the Desert Warrior

December 9, 2007

Last summer I was driving in the English countryside, somewhere between Manchester and Huddersfield.  It was raining and it was foggy and I was partly lost.  I was on my way to the headquarters of RallyRaid UK, so I was looking for some high-tech building, with a lot of glass and chrome, with employees in white coveralls, maybe the quite hum of precision machinery, as befits the high-end specialized driving machine that the Desert Warrior is.  All I could see is sheep, lots of them.  There were farm houses too and some sheds.  It took me a while to figure out that one of those sheds was indeed the world-wide headquarters of RallyRaid UK.

 October 2007 131

And this is just like Paul Round (right) and Beady Jones (left) ,the inventors and developers of the Desert Warrior,  who are down to earth, incredibly nice, and fun-to-be-with folks, with a huge passion for the Dakar and off-road racing, that without much fanfare developed a great desert vehicle that this year will participate in the Dakar for the 6th straight year.

Why RallyRaid UK?

Nadav and I considered a bunch of options when we decided to try and do the Dakar. We talked to people who modified production vehicles and concluded that while it was the lowest cost option, it probably won’t get us to Dakar given the heavy weight that could become a drag in the sand, and the (relatively speaking) weak structure. We also talked to folks in the US who offered to build us a Baja 1000 machine, but realized that while those are incredibly fast and agile vehicles, they are not designed for the sustained punishment and marathon conditions of the Dakar (the Baja 1000 takes about 24 hours vs. the Dakar’s two weeks).  After talking to a few specialty shops that focus on the Dakar, we picked RallyRaid.

The first reason, and in retrospect the less important one, was that the car that they make, the Desert Warrior, is really an awesome machine, optimized for the Dakar and for dune driving in particular. Paul and Martin 2006 car It is on its 6th anniversary, thus benefits from a lot of first hand and real life experience as the RallyRaid folks participate in the Dakar every year themselves and always return with new ideas for improvements (this year’s race will be Paul Round’s, the man behind RallyRaid, 10th Dakar).

The second and more important reason is that we learned that you can really trust those folks who are motivated not strictly by commercial interests but rather by the love of the Dakar and the desire to see more and more Desert Warriors complete the Dakar. With that comes a very helpful package of in-race support truck with spare parts and mechanics, and an off-race mechanical and logistics support that is invaluable. Add to that the fact that they are the biggest group of English (I should probably say non-French) speaking competitors and support staff, and you have a wining proposition for the non-French speaking, serious amateur. Over the last two years Paul, Beady, and Martin have become our good friends and mentors, and if we ever get to Dakar they will have a lot to do with that.

How it all started

Ten years ago Paul Round June 2007 086 sold his business successfully, but was bored to death; one evening while watching the Dakar on TV with his son Mark, they decided to give it a try; without much preparation and with zero support, they got an old Land Rover, and joined the Dakar. Mark was the driver; Paul was the navigator, as well as his own mechanic and support crew. Not deterred by an almost fatal wheel bearing failure while still in Spain, by having to drive on 4 flat tiers in the sands of Mauritania, by a car that was just too heavy and hence got bogged down in the dunes over and over again, and by many sleepless nights (you get none if you insist on being your own mechanic; mechanics typically work while drivers sleep and vice-versa), somehow they emerged from the desert two weeks later in Dakar, exhausted but victorious.

Paul (middle, next to Nadav) fell in love with the Dakar, and was determined to develop a better vehicle and the right support system.  He teamed up with Beady Jones (on the right, after losing a front wheel while driving 110 km/hr off road), an avid off-road motorcycle racer, and a gifted mechanic, electrician, computer hacker and overall a multi talented dude.   

October 2007 047October 2007 010

In recent years Martin Coulson (left) joined the team and takes care of client relations and with a multitude of organizational nightmares.  The first Desert Warrior hit the Sahara sands in 2003, and continued to improve ever since. RallyRaid produces only a handful of vehicles each year, and organizes a group of clients, more like friends-of-the-firm, to compete in the Dakar.  Each client gets a dedicated mechanic, as well as in-race support provided by a 4×4 race truck filled with spare parts and driven by expert mechanics.

The Desert Warrior

Looking from the outside, the Desert Warrior looks a bit like an SUV, somewhat similar to a Land Rover. But beneath the fiberglass shell you will find a unique structure, best described as a large roll cage, or a very strong, ruggedized dune buggy. When I visited the shop Paul pointed to a pile of 2” and 3” metal pipes and said: “this is your car”. I thought he was joking. He wasn’t. June 2007 225 After putting together the roll cage, the guys add a BMW 3 Litter, 225 hp, Diesel engine, and a Land Rover power train. Almost everything else is custom made or assembled specifically for this vehicle.  On top of that they overlay a fiberglass body, but it could look like almost anything you want it to look like. Similarly, although you may think that the “BMWs” in the race are modified X3s, the “Mitsubishi” are Outlanders, or that Robby Gordon really drives a Hummer (and therefore you ought to go and buy one for yourself), they are definitely not. Like the Desert Warrior, they are all specially designed roll cages and frames, made to look like one of the models of the car company that sponsors that team.

The diesel engine is a great choice for the amateur who wishes to complete the race first and foremost, and cares less about winning. It may be a bit slower than the gasoline engines on hard surfaces, but produces a lot of torque at relatively low RPM, which is just what you need in the sand. June 2007 093 It is also much more economical.  So you either take less fuel (and thus your car weighs less), or, you fill it up and then can do almost 2x the distance that the gasoline driven cars do. E.g., on road conditions, the Desert Warrior will do 8 km/l (~20 m/gl), and can cover 1,800 km (~1,125 miles) on a full tank; in the sand, it will still get a respectable 4 km/l (~10 m/gl) and 900 km (~562 miles) respectively. A turbo charger provides excellent acceleration and power, but is super sensitive to sand (we will carry a spare turbo in the vehicle, just in case).

The 5 speed, close ratio gear box, with max 400 bhp & max 800 ft nm torque, provides great dynamic range. A pair of separate front and rear diff locks, pneumatically controlled, helps a lot in the sand. The twin Fox shockers have a 12” front and rear suspension travel, and make the vehicle fly over hard surfaces. Given the desert temperatures and the workload, everything in this car is cooled separately by its own circulation and radiator systems: fuel, engine oil, gear and power steering oil, the air from the turbo, and of course the engine coolant. Except, of course, the cabin: no Dakar vehicles have air conditioning… We will be driving on BF Goodridge A/T tires, that are relatively soft and could change the tire profile at lower air pressure; June 2007 237 this is what you want in the sand, where you drop the air pressure to 1 or even 0.5 bar for greater traction. The down side of this type of a tire is that it gets punctured easily; for that reason, and just for good measure, the Desert Warrior carries 3 spare tires and is equipped with hydraulic jacks on both sides.

Overall we feel that we have made a good choice of vehicle and an equally good choice of partners in the form of the RallyRaid UK team. Of course, we will be wiser and more experienced after the race, so stay tuned.

Next time: how to prepare for the race, and what I learned from the folks at Team O’Neil in New Hampshire.