How is such a small vehicle that connects to an airplane able to push it and direct it away from the terminal?
In: 52
The tug just needs to overcome the rolling resistance of the aircraft, some gravity if there’s an incline (like for drainage), and wind. That is all tremendously less force than equivalent to the weight of the aircraft.
An example though, a 747-400 can weigh up to 910,000 lbs at takeoff. The rolling resistance of the aircraft could be around 0.02 (a unitless value). On a level surface with no wind you could move the aircraft with a force of 18,200lbs of force.
The tug just needs to weigh enough to get a grip on the concrete to be able to push that hard. That’s determined by the coefficient of friction between the tires and ground (perhaps 0.8). So the tug would weigh around ballpark of 23,000 lbs. So the tug is massively lighter than the aircraft. Then to make the force needed (the 18,200lbs) you use gearing to increase the engine torque and turn the wheels.
Ford did a gimic commercial like this scenario, except it was a pickup pulling train cars. It may have been 1,000,000 lbs of train, but the rolling resistance of steel wheels on steel tracks is comically low. Thus, a 6000lb truck was able to move a 1,000,000lb chunk of train.
Latest Answers