Pin: A pin acts as a fix axis for an object, in which allows it to rotate 360 degrees around its axis depending on the amount of force acting on the object. Pins are usually used in door hinges, and or other object in which a rotation is necessary to create a reaction. A pin itself cannot make an object to move unless an external force is acting on the object.

Hinge/pin: Hinges are objects mainly used in doors. Is a system that by the use of a pin, it allows it to rotate in the direction of the force acting on the object connected to it. Hinges cannot make an object move unless an external force is acting on it.

Gear wheel: A gear wheel is a useful mechanism in which when held by a pin or other type of connections, allows it to rotate around its axis. In a series of gears you can created a mechanism that allows a far away object to move. Gears can be use to create an object to move on a path.

Arch structure: An Arch structure is a slanted semi circle, thick at the base and thin in the middle. This when applied to a structure, it allows for a great loading capacity. The Arch works by directing the loads from the center out into its ends. The center piece of the arch is very important because it allows for this load distribution to happen.

Truss system structure: A Truss is a system of number of straight members, in which are ether connected by pins, welded; screw...etc at the ends. This connection allows for a great deal of load capacity because each member distributes the load around the system, in which creates a static system. During this force distribution the truss system is able to endure both internal compressive and tensile forces. This system also allows trusses to span greater distances. The longer the truss the bulkier they need to become. A truss is generally thin at the bases and thick in the middle.

Tension Cables: Tension cables are members carrying only tensile forces. No compression is used on this member, which means there is no buckling. When failure is reach there is only rapture. Because of the great capacity of load, tension cables can reach great lengths, hence why they are widely used in bridges.

Air Hydraulic: This system can ether mechanically or by an external force, allows control movement of the object to a certain direction. The pressure system also allows the object to return to its original place in a control motion, and without the use of an external force. As the Small member pulls out of the big member air is suck in the system, on the small member is release, it slowly pushes the air back out until it reaches normal state. A spring is use in this system as well to facilitate the movement.

Pulley system: This system works by strapping one end of the cable to either an engine or a heavy object, and at the other end placing the object that wants to be moved. The cable goes though a wheel or a series of wheel that will guide the direction of the movement.

BRIDGES	Air hydraulics	Pulley system	Gear wheel
ARCH	The hydraulic system will make a section open up. This system will allow a section of the arch connected by a Hinge/pin to rotate in and out in a control motion. Also air hydraulics will be use to push up one track section to meet the rest of the track. As it returns, no extra energy is needed because the pressure in the air hydraulics will return to its normal state automatically. When the arch opens up tension cables must be applied to support the structure	Pulleys will act as the external force pulling on the section of the arch structure, when it’s time to pull back the arch, the air hydraulic will return the arch to its normal position. The pulleys will also pull the section of the platform. This movement is allowed by gears sticking out at the platform ends. Thus when pulley the gear will allow for an easy control movement. Also no energy is needed to return the platform to its original position because the track is on an angle thus allowing the weight of the platform to work on the movement on the way down.	The gears will allow the platform to move up and down the track place on the arch structure.
TRUSS	Air hydraulics can be use to move a certain section of the truss in the desire direction, but because or the length established in the design requirements, the truss would need to be relatively thick. Most likely the truss would have to be placed above the platform, which the platform would be hanging from tension cables connected to the truss	The pulley can pull the section of the truss and platform in motion. It can be ether an independents cable or it can be integrated in the tension cables	The gear wheel can allow for the mechanism to take place
TENSION CABLES	Little movement can happen with tension cables, the cables only have structural value if they are always in tension, therefore second system such as truss or arch must be introduce to act as second structural support for the bridge. As the cables stay in tension, it can provide a good control movement for the bridge opening	This system can be integrate to the tension cables to act as one, and act as the tensile force acting on the bridge section to open up. Or an individual pulley system can create the movement.	The gear wheel can allow for the mechanism to take place