Jan 5th Flashcards
Name 3 ways modern cranes differ from those in ancient times that were powered by man or beast
- Ability to mobilize
- Ability to lift heavier loads
- Ability to specIalize
What are the 5 basic characteristics of all mobile cranes ?
- Adjustable boom length
- Adjustable boom angles
- Ability to lift and lower loads
- Ability to swing loads
- Ability to travel about a job site under their own power
Within the broad category of mobile cranes there have evolved the 9 basic types and configurations, list them.
- Boom truck
- Industrial cranes
- Carrier mounted lattice boom cranes
- Crawler mounted lattice boom cranes
- Carrier mounted telescopic boom cranes
- Crawler mounted telescopic boom cranes
- Rough terrain cranes
- Mobile tower cranes
- Heavy lift mobile cranes
What is the one difference in boom trucks from all other mobile cranes?
They are mounted on a commercial truck chassis that has been specially strengthened to accept the crane.
What are the two common configurations of boom trucks ?
- Telescoping boom
2. Knuckle boom
Name 8 components of a boom truck
- Telescoping boom section
- Base/heel section
- Boom lift cylinder
- Commercial truck chassis
- Swing circle
- Pedestal
- Rear outrigger/stabilizer
- Front outrigger/stabilizer
Name 6 components of a knuckle boom truck
- Commercial truck chassis
- Knuckle boom
- Hydraulic cylinder (could be more than one)
- Swing circle
- Pedestal
- Stabilizer
Where would an industrial crane possibly be used ?
In industrial locations where working surfaces are significantly better than those found on most construction sites.
How does a carrier mounted crane differ from a boom truck ?
It is specifically designed for crane service and the heavy loads these cranes are required to withstand. The undercarriage provides a stable working platform , using high quality steel plate the cranes weight and strength ratio is increased.
What is the function of a swing circle ?
The swing circle or roller path of the carrier is an external or internal gear with which the swing pinion on the revolving upper structure meshes to provide swing motion
Describe 3 functions of the outrigger system
- Push the tipping axis further from cranes centre of gravity
- Provide a stable base
- Provide a method of levelling the crane
What does the the front/fifth outrigger provide ?
Better stability towards the front of the crane allowing for full 360 degree chart
What’s the main difference between a stabilizer and outrigger system ?
Stabilizer system provides support while still using tires and frame , while outriggers lift all tires off the ground
Put the following connected sections in proper order going from the frame up.
Swing circle
Turret
Pedestal
- Pedestal
- Swing circle
- Turret
What is the “lever” of the crane ?
The boom
What is the function of the boom lift cylinder ?
Provides the effort of the booms lever, allows the boom to move up and down effectively.
What provides the booms fulcrum?
The boom foot pins
Name three things the base/heel section of the boom provide
- Allows all telescoping sections to slide in and out of it
- Provides and attachment point for the boom foot pins to the turret as well as an attachment point for the boom lift cylinder
- A convenient place to Store the jib
Does a pinned boom generally give more or less capacity than a full power hydraulic boom and why?
A pinned boom provides more capacity due to having less components at the tip
Name two disadvantages of a pinned boom.
- Fixed positions
2. Almost never able to scope out with load on
What is the purpose of the upper boom head sheaves ?
To provide the wire rope a method of transitioning from the top of the boom to the hook
What do the lower boom head sheaves provide?
A mechanical advantage
What is the job of the auxiliary or rooster sheave ?
Prevent the two hoist lines from becoming entangled
Name two functions of a jib
- Produce greater clearance between the forward edge of the boom and the jib hook.
- Reach higher
