Dragonator

A Dragonator is any steam-powered melee cannon used to repel medium to large-sized monsters. While the developer and time of development are unknown, the Guild regularly installs them in strategic locations to repel large monsters. Dragonators consist of at least three pieces. The machinery, the weapon, and the control unit. Little is known about the machinery, other than the fact that it uses pressurized steam to launch the weapon. The steam is provided by a coal-fed fire. The location of the fire is unknown, presumable under or behind the weapon. The weapon itself consists of massive rod-like objects which are propelled by the steam at high velocities at the target area. The weapon can be as simple as stone rods, or as complex as spiky, spinning drills. There can be multiple rods launched from each Dragonator. The control unit is where the cannon is fired from.

Operation
While the internal machinations of Dragonators are a mystery, they are quite user-friendly and easy to operate. A large button is usually placed somewhere relatively safe, but still within view of the machine, for targeting purposes. All one needs to do is simply press the button when the time is right. (note that some buttons may require a Pick Axe to press) There will be a short period of waiting while the steam is building. During this time, hunters may hear the whirring of steam or the clanging of machinery. After the steam has built, the weapon of the Dragonator is propelled forward at massive velocity. Anything in front of the weapon will be devastated. Once all of the momentum has left the weapon, it will be retracted back into the wall or structure where it came from, and begin recharging. Dragonators take a long time to build up enough steam to fire again. Because of the melee nature of these cannons, it is advisable to wait until the monster is very close before activating them.

Known Dragonators
Fortress - Located in area 5 on the wall of the Fortress. This one consists of 2 narrow, pointy, spinning spikes on either side of the door, making for 4 total. The controls for it are located directly above, between the other siege weapons.

Castle Schrade - Located in the back of the second area, with the controls directly above. This one consists of one giant spinning spike with a bouquet of smaller spikes around it. This one is used exclusively on the black Fatalis, and can be both tricky and dangerous to use.

Town - Also known as Dondruma, the Dragonator here is located in area 3, on the Northern face of the Southern wall. This one is made of two huge, iron spears that spring from the wall. The controls are directly above it on top of the wall.

Land Arena - There is a Dragonator in the Monster Hunter 3 Land Arena. It is located on the North-East wall. The controls are situated on a small shelf just West of the weapon portion. This weapon consists of four giant, iron spears that spin when launched. However, this Dragonator is not active for every quest in the arena.

Great Desert - Arguably the most advanced Dragonator. This one is a single, giant, metal, spinning harpoon with barbs. Not only that, it is mounted on the front of a sand ship. The controls are located at the front of the ship, and require a Pick Axe to activate. Due to the nature of the quest, the Dragonator is moved at different times during the quest.

Underwater Ruins - Possibly the oldest known Dragonator. It is located in area 3 of the Underwater Ruins. It is used solely against the Naval Deus. The weapon is two pairs of stone rods that jut out of the wall when fired. The button is just above the weapon. This one requires a Pick Axe to operate. It is currently unknown how this one operates underwater.

Trivia

 * In Monster Hunter, the player collects and delivers coal to power the Dragonator located at The Fortress.
 * Even though steam power is a rather modern technology in the Monster Hunter world, there is an ancient Dragonator in the Underwater Ruins. This means either steam is not as modern as previously thought, or some other mysterious power is used to operate the underwater Dragonator.  There is currently no explanation.
 * When using a Dragonator, a players view is switched to a panoramic view of the Dragonator weapon while it fires. This view can sometimes be obstructive of play, and some players opt to skip it.