1. Introduction to Tower Crane Project
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

2. What are Cranes? Cranes Are… Cranes Are Used For… Transportation
Lifting machines that can move loads vertically or horizontally
Used to move heavy loads by taking advantage of mechanical advantage
Cranes Are Used For…
Transportation
Construction
Manufacturing
Construction
Manufacturing
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

3. History of Cranes 515 B.C. – Pulley Crane used in ancient Greece
1500 B.C. – Shaduf used in early Egypt to lift water
515 B.C. – Pulley Crane used in ancient Greece
357 A.D. – Treadwheel Crane used in Rome
480 A.D. – Crane use declines with fall of Western Roman Empire
1225 A.D. – Treadwheel Cranes are re-introduced in Europe during the Middle ages
1340 A.D. – Slewing Crane used for dockside loading
1700’s – Steam Crane ushers in the modern era
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

4. Types of Cranes Mobile Fixed Paved Surfaces Rough Terrain
Mounted on a moveable base, usually some existing vehicle type (trucks, tractors, etc.)
Fixed
Stationary; usually erected in place
Paved Surfaces
Rough Terrain
Tower Crane
Luffing Crane
Rail
Water
Air
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

5. Review: Mechanical Advantage
Levers
Pulleys
M.A. = number of strands supporting the load (minus the strand where the force is applied)
1st
2nd
3rd
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

6. Pulley Crane Investigation
What simple machines are in use?
What is the mechanical advantage of:
Just the pulley setup?
Just the lever?
The combined setup?
What is the tension force, L, in Newtons?
What is the applied force, F, in Newtons?
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

7. Tower Cranes Fixed Parts Stationary; usually erected in place Base
Slewing Ring (Turntable)
Tower
Boom
Counterbalance
Load Line
Lifting Hook
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

8. Degrees of Freedom
Used in statistics, physics, chemistry and mechanics
Mechanical DOF
The set of independent translations and/or rotations that describe the position of a body or system
What’s a translation?
What’s a rotation?
For an independent body in general motion,
For a system, we usually say DOF is the sum of the number of independent translations and rotations that are possible.
A translation is a linear movement without rotation.
where d is the number of dimensions.
A rotation is an angular movement about some axis.
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

9. Tower Crane (Sketchup Model)
How many degrees of freedom are in the Sketchup model?
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

10. Design Process Define the Problem Brainstorm, Research, Generate Ideas
Explore Possibilities
Develop a Design Proposal
Make Model/Prototype
Test and Evaluate
Refine the Design
Communicate the Solution
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

11. Constraints on the Engineering Design Process
(A constraint is a limit or restriction.)
Safety – is the product safe to use/construct?
Reliability – will it work consistently over time?
Cost – is it affordable?
Quality Control – does it meet customer requirements?
Environmental Concerns – does it harm the natural or human environment negatively?
Manufacturability – can it be made?
Maintenance – how easily can it be maintained or upheld?
Ergonomics – how efficiently can the human body utilize it?
4/24/2017
Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith