Tower cranes are one of the most recognizable, hard-to-miss pieces of construction equipment at any large site that we have all seen hovering above. First used for construction in the 6th BCE in Mesopotamia, our tower cranes have evolved through new mechanical drive systems and steel frames to allow us to build massive skyscrapers that scatter our cities.

Part of the questions we had on them was how something this tall yet slender manages to hold up heavy loads without toppling over. From our research into crane designs, it is done through a combination of structural design, balance through a counterweight system, and reasonable mechanical drive systems.

For our Mechanical Design Final Project, we built a modestly scaled, functional tower crane. A tower crane was chosen over other types of cranes because of its rigid, stationary structure that would maximize strength while simplifying the design process to focus only the tower crane’s main three directions of motion: a turntable for rotation (yaw), a winch that lifts or lowers a payload, and a trolley that carries a winch along the jib.

Our crane helps solve the issue of moving heavy objects. The crane allows us to pick up these heavy loads without risking injury and removing the need for more people.

Design Specifications:

Quantitative Requirements

Winch and crane must be able to lift up to 50 lbs
Turntable rotation around 6 RPM to keep our dynamic loads safe and manageable
Trolley must be able to travel 4-foot working length of jib
Entire structure must be able to fit through backdoors of the design studio (~ 9 feet)

Qualitative Requirements

Crane structure remain within the elastic limit under full load
Work under full load through battery power
Be simple to control through on/off winch controllers
Be cool as heck

Stretch Goals

Winch and crane can lift up to 150 lbs (approx. weight of an average person)
Infinite rotation of the turntable through a slip-ring integration
Crane control by operator through remote control via an integrated controller