04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

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

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

Transportation

Construction

Manufacturing

04/18/23Baltimore 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 Empire1225 A.D. – Treadwheel Cranes are re-introduced

in Europe during the Middle ages1340 A.D. – Slewing Crane used for dockside

loading1700’s – Steam Crane ushers in the modern

era

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

Mobile•Mounted on a moveable base, usually some existing vehicle type (trucks, tractors, etc.)

Fixed•Stationary; usually erected in place

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

Paved Surfaces

Rail

Air

Rough Terrain

Water

Tower Crane Luffing Crane

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

Part 1: 8 mins Part 2: 10 mins

LEVERS PULLEYS

M.A. = number of strands supporting the load (minus the strand where the force is applied)

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith

L

F

d

d

F

LM.A.

1st

2nd

3rd

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?

04/18/23Baltimore Polytechnic Institute Engineering Practicum –

Dr. Smith