Speed Record

NALSA NEWS FLASH- New Landsailing Speed Record !!!!!!!!!!!!!!!!!!!!! 3/16/99
March 15, 1999 - Ivanpah Dry Lake , Primm, NV

Yesterday Bob Schumacher (pilot) and Bob Dill (designer/pilot) achieved a new world record in landsailing hitting 108.8 miles per hour (175.5 kph) in 25-35 mph winds. Many runs were made in the 90's and over 100 with Bob Dill and Bob Schumacher alternating as pilots in the "Iron Duck" solid wing, three wheeled landyacht. This US achievement replaces the former world record of 94.7 mph (152.7 kph) held by Bertrand of France.

Bob Dill has been developing the Iron Duck for over 7 years in his hometown of Burlington, Vermont.

Measurement team was headed by Kent Hatch, President of the North American Land Sailing Assn. (NALSA).

More speed attempts are possible as the NALSA America's Landsailing Cup Regatta begins March 21-26, 1999 at the Ivanpah dry lake site on the California side of Primm, NV, 35 miles south of Las Vegas, Nevada.
(See follow up note. Editor)

Yacht notes may be read here.

NALSA
c/o Kent Hatch
1680 Manzanita Ln
Reno, NV 89509
775-825-1530 contact phone
775-825-5626 Fax
kent@hatchrealty.reno.nv.us

Reported by Mark Harris, NALSA, American 5 Square Meter Assn., SALA
2027 Valencia Way
Sparks, NV 89434

Editors follow up.

On Saturday March 20th, on the day before the America's Landsailing Cup Regatta, the 'Iron Duck' was once again piloted to a new and higher speed. In front of an enthusiastic crowd the Duck was pushed to a top speed of 116.7mph (187.7kph). Below are photos of the 'Iron Duck'. Details of the sailing conditions, and yacht information are below.

Jim Hart US93
NALSA webmaster.

The Iron Duck, March 1999

· Fastest pilot: Bob Schumacher: 116.7 mph, March 20, 1999
· Second fastest run: 115.0 mph
· Second fastest pilot: Bob Dill: 112.3 mph
· Probable wind speed during the fastest runs: 25-30 mph.
· General Configuration: Asymmetric, port tack favored
· Length: 39 ft
· Wheel base: 30 ft
· Width: 23'
· Track (outside of tires): 22'
· Weight: 1600 lbs. (after capsizing the Wood Duck in 1994, adding extra steel was too easy)
· Moderate aerodynamic hold-down from the axles.
· Construction Materials:
· Tubular metal frame
· White ash axles
· Volvo spindles, hubs and wheels
· Plywood, foam and fiberglass fairings
· Wing: Hot wire cut foam under 1/8" plywood in the back and fiberglass over the nose.
· Field assembly: Duct tape
· Wing Height: 23 ft
· Cantilevered mast
· Wing :71 sq. ft without flap, chain driven from hand wheel.
· Flap: 15 sq. ft, external type, 0014 section, pivot axis: 4% forward of wing tail.
· Wing section: NACA 0014.5 (scaled from a 0012)
· Wing chord/profile: 40" with elliptical top 5 feet
· Wing pivot axis: 17.5% of chord length
· Side Tires: 14" wheel, 23" diameter: very sticky dirt track tires or high performance street tires.
· Tire pressure: 35 to 50 psi
· Tire life: ½ to 2 days.
· Front Tire: 5x5 airplane tire
· Steering: double cable, foot operated.
· Designer: Bob Dill
· Design inspiration and advice on winged landyachts: Clarence Rothtock (Scorpion), Phil Rothrock (all his boats), Chauncey Griggs (Schazaam), Kent Hatch (several boats).
· Builders: Bob Dill, Anders Toft, Bob Schumacher, Jerry Manock.
· Hot wire team: All the Dills and anyone else I could talk into this tedious job.
· Time invested: About 4000 hours since 1993.
· Construction Cost: About $6000 for two boats (labor rate =$0.00/hr).
· Travel/Transport Cost: About $10,000 since 1994.
· Sponsor: The Robert Dill Charitable Fund for Overweight Birds (any and all donations gladly accepted)

Measurement:
Measuring things accurately in the field is always a challenge. NALSA recently developed a set of regulations for speed record attempts with these problems in mind. They are designed to assure that the measurement methods used for determining records are scientifically and ethically valid. The regulations require that a calibrated, high accuracy Primary Measurement Method be used to get the 'official' measurement data. One or more secondary methods are used to back up the primary measurements and assure that there are not any false readings.
In our case we designated the NALSA Stalker Radar as the primary method. The Stalker is the best sports radar available. We had four secondary methods including an older (shorter range) Stalker Radar that I own, two Avocet 45 speedometers and a Garmin II+ GPS. The radars agreed very well over a large number of runs. The speedometers read about 5% low at the highest speeds. This is consistent with losses observed in this speed range in bench tests run on the Avocet 45 (see article in the NALSA newsletter). The GPS accuracy spec is +/- 0.5mph.
Its maximum reading was 2 mph higher than the primary radar measurement. We believe this was the top speed of the boat during its fastest run. We considered both radar and a timing trap for primary measurement. We have been using radar in the US for several years. FISLY currently prefers a timing trap. They both have about the same overall accuracy.
The main objection to radar is that it gives a peak value rather than an average over a distance. We have found that relatively heavy boats at their peak speed do not change speed much in the time it takes to traverse a 50 meter trap (less than a second). That was very clear when you watched the radar gun as the Duck was approaching.
We chose radar for several reasons. Radar is easy to set up and calibrate. There is tractability of the calibration to the National Institute of Standards and Technology. Radar also has a long history of holding up to court challenges in the prosecution of speeding tickets.
When used properly, it is very unlikely to give false readings. Radar also updates quickly so we were able to record multiple readings on many runs. It can be pointed at the incoming boat no matter what direction it is coming from. We came in at a wide range of approach angles trying different things to maximize speed. Adjusting a trap to match the constantly changing optimum approach angle would have required a lot of down time. On a beach this would be less of a problem because the boat is restricted to a relatively narrow path. Also, the wind on an ocean beach tends to be much more uniform in velocity and direction than winds tumbling over our desert mountains. An important safety feature of radar is that it has enough range to allow the boat to stay well away from the measurement station. An obvious way to get killed in this game would be to hit the motor home at 100+ mph. On the wide open playa or on ice, we believe radar is clearly the best measurement method.
If you have questions, comments or suggestions I can be reached at bobdill@hotmail.com.

Bob Dill

PS: (February 2001) NALSA has adopted the use of high performance GPS with data logging as a primary measurement method. It offers lower measurement uncertanity and considerably more data than radar as we have been using it. While radar allows the yacht the be measured from a distance GPS allows the course to be completely free of vehicles, a distinct safety advantage. See the NALSA Regulations for Speed Record Attempts (Revision 1, Sept 2000)

(Thumbnails will link to larger pictures)

No, it's not bent. It's meant to be that way!