WRA2 Water Rocket Dragster General Design Parameters
- Rocket Dragster must use Water as its primary reaction mass.
- Rocket Dragster must use compressed ambient atmospheric air as its energy. Other gasses, phase change (steam) are not permitted. (see section II for special rules regarding bottled air).
- Pressure Vessel of the Rocket Dragster must be constructed from lightweight nonmetallic materials.
- Rocket Dragster must be launched from a stationary position on a fixed launcher. (Slingshots,trebuchets, catapults, cannons, and all other forms of launcher boost assist are forbidden). Launch tubes are allowed as long as the internal pressure of the rocket is the only supply of energy.
- Rocket Dragster must be completely scratch-built using single components such as wheels, bolts, and screws, wood, plastic. Items such as cameras, servo motors, and RC control mechanisms are allowed. (Manufactured RC cars are prohibited).
- Record attempts must be recorded by ground-based video to validate each run. It is required proof the run actually happened. (if using bottled air is used then the 10 minute max pressure hold must be shown).
- Rocket Dragster must carry an onboard video camera.
- Rocket Dragster must be free wheeling (no forms of power to turn the wheels other then the air pressure in the pressure vessel.
Bottled Air Rules
- Only bottled atmospheric air is allowed. No exotic gasses, cryogenics or combustibles.
- Tanks must be certified. (copies of tank certifications will be provided and filling station receipt).
- All local laws must be complied with for handling pressurized tanks as well as any certifications that the operator may need will also be provided upon a record submission.
- To prevent "stomp rockets" the rocket must remain pressurized to full launch pressure for a period of no less then ten (10) minuets. (The video camera will show both the tank and the Rocket Dragster on the launcher during this 10 minute period).
- Bottled air pressure source must be located at the minimum safe distance of 50 Feet (15 meters) from the launcher (this allows the bottle air pressure source to be safely controlled in the event of an emergency).
Safety Rules
- All WRA2 Water Rocket Safety Rules must be followed.
- All pressurized portions of the Rocket Dragster must be contained inside a wire mesh cage.
- The cage can be no closer then 2 inches to any pressurized component.
- The cage can mounted on the dragster or as part of the launcher.
- The cage shall be constructed of welded mesh with openings no larger then 0.5in (1.3cm) and a wire thickness of no smaller then 0.02 in (0.5mm).
- All spectators and crew must be located behind the launcher during pressurization and launching.
- Do not launch your water rocket powered dragster towards any moving vehichles, animals, or people.
Pressure Vessel Rules
- Pressure vessel must be entirely fabricated by the rocket builder.
- Pressure Vessel cannot be constructed using any portion of an existing high pressure enclosure. (i.e. no Paintball tanks, CO2 tanks, SCUBA tanks, Propane Tanks, etc.). The object is to engineer and build your rocket yourself.
- Pressure Vessel may not be fabricated from metal.
- Nozzle, and internal couplings can be made from lightweight metal.
Reaction Mass Rules
- Reaction Mass must be primarily ordinary tap water.
- Thrust must come from expelling reaction mass, not from air discharge. That would be considered an Air Cannon projectile.
- Water Reaction Mass must fill a minimum of 20% of the volume of the Pressure Vessel. Token amounts of water added in an attempt to qualify an air cannon projectile as a water rocket dragster are not allowed.
Dragster Distance World Record Competition Rules
- Distance is calculated as the average of two runs (one in each direction)(180 degrees) within a 2-hour period using the same marked course. This prevents using terrain or winds an an advantage. Results must be repeatable!
- The same Rocket Dragster must be used for all averaged runs. The only portions of the Rocket Dragster which can be replaced are expendable or consumable items. (batteries, tape, deployment chemicals, water, etc..) Items which are damaged in any record attempt must be repaired and reused. Any competing Rocket Dragster must be sturdy enough to survive multiple launches.
- Track must be marked in 10 Meter or 10 yard intravals.
- Markings must be visible in videos.
- Distance will be measured brom the last marker to the point perpendicular to the centerline where the car comes to a stop.
- Centerline will be defined as the direction the launcher points.
This criteria was inspired by high profile competitions such as the Ansari X-Prize and most land speed competitions.
Dragster Speed World Record Competition Rules
- Speed will be calculted as the average time of two runs (one in each direction)(180 degrees) within a 2-hour period using the same course. This prevents using terrain or winds an an advantage.
- The same Rocket Dragster must be used for all averaged runs. The only portions of the Rocket Dragster which can be replaced are expendable or consumable items. (batteries, tape, deployment chemicals, water, etc..) Items which are damaged in any record attempt must be repaired and reused. Any competing Rocket Dragster must be sturdy enough to survive multiple launches.
- Time will be calculated using the onboard video from the time the dragster starts moving until it completes the specified distance.
- The specified distance will be 150 feet ((45.7m).
This criteria was inspired by high profile competitions such as the Ansari X-Prize and most land speed competitions.
Filing a Record Claim
- Videos for each speed or distance run.
- Detailed still photos of the finished Dragster.
- Time and date for each speed or distance run.
- If using bottled air: copies of the tank and operator certifications.
- Onboard Videos from each speed or distance run.
- Design drawings.
- Detailed still photos of the dragster being constructed.
All record claims must be filed to the WRA2 Contest Submissions for public review.
Items required:Optional Items:
Maximum file size 45MB per file.
Questions & Answers
- If you have any questions about the rules or if your rocket is eligible for world record competition, please post them in the WRA2 Competition Q & A forum for a prompt answer. Remember that if you are in doubt, ask before you build.