Pre-1700's: Trebuchets

Trebuchets were most commonly used in the Middle Ages. The trebuchets fired many different projectiles, some which weighed over three hundred pounds! Most of the projectiles were stones used to take down walls during sieges and battles.

Although trebuchets were designed differently from one another they all had the same basic idea for how they were operated. First the trebuchet is pulled back, usually by two men turning a wheel or a crank because the base of the trebuchet and the end that does not have the sling were very heavy. When the trebuchet is fully pulled back, the ammunition is loaded in the sling and the ropes are cut which releases the built up tension and send the ammunition catapulting forward

Trebuchets were built primarily out of wood and stone because they were a common resource during the Middle Ages. Because there were many different varieties, designs, and innovations with siege weapons during this time, the cost of a trebuchet during this is unclear. Trebuchets were later replaced in favor of gunpowder and metal, but, during their prime, they were the most accurate and powerful siege weapons of war.

Cannons from the 1800's

The Athen's Double Barreled Cannon is just one of the cannons from the 1800’s. It was originally designed to shoot a chain shot (two cannonballs linked together by a chain). The two cannonballs spin together and create massive amounts of damage. Originally developed by the Spanish, chain shot was used by the Spanish to take out masts on the high seas.

Designed by John Gilleland, this cannon was actually constructed at the Athens Steam Company (hence the name) and cost around $3500 to make. The bore diameter (is the diameter of the smallest point of the cannon's bore, which is the area the projectile travels through as it is shot) was 3.67 inches, and the entire cannon weighed between 1300 to 1400 pounds. The cannon, however, was a failure because the ammunition would not fire properly, often destroying the ammunition, and although the cannon never saw production for the war, several army personnel commented that it shot regular cannonballs and grapeshot very well.

Modern-Day Cannons: 1900's to Now!

The M40A3 bolt-action sniper rifle is just one of the many examples of modern day cannons. Designed in 1996 by Jack Cutty and Neill Goddard, and released in 2001, the M40A3 is primarily used in the Marines for long action defensive combat. This rifle can fire one bullet up to 1000 m (1094 yd), and has a five round detachable box magazine (ammo cartridge). This type of sniper rifle is produced at around $1500 per rifle.

Procedure: How We Made Our Cannon

Step 1. Cut two and a half inches off of the first can.
Step 2. Tape a cannon lid to the end you jus cut off.
Step 3. Tape the part that you cut off in the beginning to the bottom of the tennis ball can where you just taped the cap
Step 4. Place the second cap on to the front of the second can
Step 5. Cut out a hole in the second can so that you will be able to lay the first tennis ball can on top of it.
Step 6. Place the first can on the second can, so that its laying in the hole at a 40 degree angle.
Stepn7. TAPE IT!!!

Our Goal Was... (What We Wanted To Accomplish)

Our goal is to craft a cannon that will launch a foam ball using 18 inches of tape, 2 mL of 99% ethanol, scissors, and two tennis ball cans (including lids).

Hypothesis: We believe that if we coat the inside of the cannon with the ethanol, and place a semi-permeable surface between the foam ball and the chamber, that when we ignite the ethanol it will produce an exothermal reaction, shooting the foam out of our cannon.

Design & Process

1. We chose a 40 degree angle for the balance between lift and initial velocity

2. The chamber in the bottom was placed there for three reasons: The first for the ethanol to have a higher concentration. The second was so that we could make our cannon's barrel shorter, and the third was so that it could build up more pressure in the chamber before it releasing to the foam ball.

3. The second can does nothing for the chemical reaction. All it does is stabilize the first can.

4. The chemical formula for ethanol is C2H5OH. It creates a combustion reaction (the ethanol and oxygen in the air combust in reaction to heat and produce water and carbon dioxide):
C2H5OH + O2 -----> H2O + CO2

5.Gay Lussac's law states that temperature and pressure are directly proprtional to each other (when the temperature rises, so does the pressure and visa versa). When the ethanol in the tennis ball can ignited, the temperature rose quickly and so did the pressure. The spike in temperature and pressure shot directly to the weakest link, i.e. the foam ball.

6. The launch formula:

R= distance projectile goes through the air= 0
V= the initial velocity= 0
Theta= measure of the lunch angle= 40 degrees
g= gravitational constant= about 32.2 ft/sec

There were three likely causes of what the cannon SHOULD do:
1. The cannon would launch the foam ball.
2. The back chamber of the cannon would shoot off.
3. An exo-thermic reaction would take place and the cannon would melt :(