5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

What are Cranes? Cranes Are… 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 5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith Transportation Construction Manufacturing

5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith 2 mins

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 5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith

Types of Cranes Mobile Mounted on a moveable base, usually some existing vehicle type (trucks, tractors, etc.) Fixed Stationary; usually erected in place 5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith Paved Surfaces Rail Air Rough Terrain Water Tower Crane Luffing Crane

5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith Part 1: 8 mins Part 2: 10 mins

LEVERSPULLEYS  M.A. = number of strands supporting the load (minus the strand where the force is applied) 5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith 1 st 2 nd 3 rd

 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? 5/20/2015Baltimore Polytechnic Institute Engineering Practicum – Dr. Smith