here are the rules :
http://www.sciencenc.com/event-help/exa ... 4rules.pdf
DESCRIPTION: Prior to the tournament, teams construct and test up to two rockets designed to stay
aloft for the greatest amount of time.
TEAM OF UP TO: 2 IMPOUND: No EYE PROTECTION: Safety Spectacles TIME: 10 min.
1. EVENT PARAMETERS:
a. Teams must design, build, and bring up to two rockets to the tournament (only 1 launch allowed per
rocket). Parts from one rocket must not be used on another rocket. Teams must wear eye protection
during the loading, launching, and retrieving of their rockets. Teams may also bring their own
funnels, measuring devices and other necessary tools to prepare their rockets.
b. Event supervisors must provide the launcher and water. They may also provide funnels and
measuring devices.
2. CONSTRUCTION PARAMETERS:
a. PRESSURE VESSEL: The rocket pressure vessel is the part of the rocket that attaches to the
launcher and is filled with water and air. The pressure vessel must be made out of a single 2-liter or
less plastic carbonated beverage bottle with a neck/nozzle opening internal diameter of
approximately 2.2 cm (a 1/2 inch Schedule 40 PVC pipe must fit tightly inside the nozzle opening).
i. LABELS may be removed from the bottle but labels must be presented at the safety
inspection to prove the bottle is carbonated. Rockets without labels must not be launched, this
is a safety issue.
ii. PLEASE NOTE: Many soda manufacturers have recently changed their bottles. The inside of
the neck of the bottle now has a ridge that will prevent the bottle from going on the launcher
on many brands. See the event help webpage for assistance in checking if yours will fit.
iii. STRUCTURAL INTEGRITY: The structural integrity of the pressure vessel must not be
altered. This includes, but is not limited to: physical, thermal, or chemical damage (e.g.,
cutting, sanding, using hot or super glues). Alteration to the structural integrity of the pressure
vessel is a safety violation of the rocket and it must not be launched. Event supervisors must
assess the structural integrity by looking through the nozzle and sides of the bottle for
discoloration, bubbles, thinning or cuts in the walls. Rockets violating this rule must not be
launched, this is a safety issue.
b. MATERIALS: Only tape must be used to attach fins and other components of
the rocket together. Glues of any type must not be used anywhere on the
rocket. Metal of any type and commercial model rocket parts are prohibited
anywhere on the rocket. Rockets violating this rule must not be launched, this
is a safety issue.
c. NOSE CONE: Rockets must use a blunt or round nose with a minimum radius
of 1.25 cm, for safety (see Figure 1). Teams must not use a nose that is sharp,
pointed, or consisting of a rigid spike regardless of the material used. Rockets
violating this rule must not be launched, this is a safety issue.
d. FINS and OTHER PARTS: Fins and other parts added to the pressure vessel
must be 5 cm or higher above the level of the bottle’s opening to ensure rockets fit
on the launcher (see Figure 2).
e. ENERGY SOURCE: Explosives, gases other than air, chemical reaction,
pyrotechnics, electric or electronic devices, elastic powered flight assists,
throwing devices, remote controls and tethers are prohibited at any time. All energy imparted to the
rocket at launch must originate from the water/air pressure combination. Rockets violating this rule
must not be launched, this is a safety issue.
f. RECOVERY SYSTEM: Any free-fall recovery system is allowed provided it does not violate any
other rule; however, the recovery system must be judged as safe. Example: a parachute.
3. THE COMPETITION:
a. All rockets must be launched using the launcher and water provided by the supervisor.
b. Only one launch is allowed per rocket. If a team wishes to use both launches, they must have 2
rockets.
North Carolina 2014 rules
Bottle Rockets B/C- rev. 8/1/13
c. Teams must arrive at the competition site ready to launch. Teams must bring and wear safety glasses
for loading, launching, and retrieving their rockets. Teams must also present labels from the pressure
vessel if labels were removed. Following the safety inspection of each rocket, teams will add water
to each rocket. When called to launch, the teams will have a total of 10 minutes to launch 1 or 2
rockets brought to the competition (only 1 launch per rocket). Only rocket(s) launched before the
time expires will be scored.
d. All rockets will be launched at 60 psi. Once the rocket is pressurized, no contestant may touch or
approach the rocket.
e. Time aloft is recorded in tenths of a second. Timing begins when the rocket separates from the
launchers and stops when any part of the rocket touches the ground, goes out of sight, or comes to
rest on a tree, building, or other obstruction.
f. Event leaders are strongly encouraged to use three independent timers on all launches. The middle
value of the three timers must be the officially recorded time.
4. SCORING:
a. Ranking within each tier is determined by the greatest time aloft of a single rocket.
b. Rockets that violate a safety related construction rule (2a – 2f) will not be launched and will receive
participation points only.
c. Ranking within each tier is determined by the greatest time aloft of a single rocket flight. Tiers:
i. Tier 1: Rockets launched without any violations
ii. Tier 2: Any launch with competition violations, or a non-safety construction
violation.
iii. Tier 3: No launches were possible due to violations, participation points only.
d. Ties in tiers 1 and 2 are broken by the better score of each tied team’s other rocket.
and here is the score sheet
http://www.sciencenc.com/event-help/sco ... 2014NC.pdf