What is FEM standard for crane?
FEM is the European Federation of Materials Handling that, like HMI & CMAA, publish standards for the material handling industry. The FEM standards use a couple of main factors to determine the hoist duty classification: load spectrum and average daily operating time.
How is crane deflection calculated?
To measure your deflection, divide the span of your specific system (the length in inches or centimeters) by the deflection limit defined for that type of crane. For example, he deflection for a 34-foot bridge on a workstation bridge crane can be determined by first changing the unit of measurement from feet to inches.
What is a crane runway beam?
The crane runway beam section of overhead cranes can consist of a rolled I-section, either with or without side reinforcements for supporting horizontal loads, an I-section that has been welded together or a box girder.
What are the major considerations in the design of cranes?
Mechanical principles
There are three major considerations in the design of cranes. First, the crane must be able to lift the weight of the load; second, the crane must not topple; third, the crane must not rupture.
What is FEM classification?
Definition. FEM classification. The European Federation of Materials Handling and Storage Equipment is an association of constructors and experts setting common rules for the design and use of handling equipment, including lifting equipment.
What is FEM in hoist?
Selecting the correct hoist for your operation. The European Materials Handling Federation, known as ‘FEM’, are a standards body for the material handling industry and are publishers of the FEM Hoist Duty Classifications.
What is the maximum deflection allowed on a beam?
According to North American rack design standards 1,2 , the vertical deflection of beams loaded by pallets should not exceed the length of the beam (L) divided by 180. For a typical 8-foot-long beam, this would represent a maximum deflection of approximately 0.5 inches.
What is the allowable deflection?
Deflection is the bending or “sag” caused by loading. Allowable deflection is generally expressed as a fraction of the span, in inches. All structural members will deflect or flex under load.
What is span of crane?
The crane span is the measured center-to-center distance between the runway beams. One of the most important measurements you can provide during an overhead crane consultation is the crane’s span.
What is girder in crane?
A crane girder is a preformed metal beam on which the crab or hoist head of a traveling overhead crane runs. Such girders are typically “I” profile beams that may be reinforced at various points depending on the loads and crane configuration involved.
What are four specifications for the crane?
Specifications Cranes require separate values for bridge and hoist speed and acceleration. You must enter Speed (Empty), Speed (Full), and Accelerate and Decelerate values for bridge movement along the rails and hoist movement across the bridge.
What type of structure is the crane tower?
frame structures
Tower cranes and communication towers are examples of frame structures. Frames are made from bars joined together to form a ‘framework’. This is one of the most economical ways of building structures. Some modern buildings have a frame structure which can only be seen during construction.
How are cranes classified?
There are two main categories of cranes: static cranes and mobile cranes.
What is H4 duty cycle?
H4 (heavy use) – High volume of heavy loads, frequently near rated load in steel warehousing, machine and fabricating shops, mills, and foundries. Total running time not over 50% of the work period.
What is Crane duty classification?
Crane duty classification is done as per the crane load condition and the grades of crane used. The principle of classification lies in the frequency of different cases, average load, and having the same crane life at the same level. The crane classification helps improve the generality level of crane parts too.
How is deflection calculated?
Generally, deflection can be calculated by taking the double integral of the Bending Moment Equation, M(x) divided by EI (Young’s Modulus x Moment of Inertia).
How do you calculate beam size?
Calculate the maximum bending moment for the wooden beams. The bending moment is the length of the span times the weight to be supported divided by 8. For a beam spanning a 12-foot room and supporting a weight of 600 lbs., the maximum bending moment would be 12 x 600/8 = 900 foot-pounds.
What is maximum beam deflection?
To calculate the maximum deflection of a beam with a combination of loads, we can use the method of superposition. The method of superposition states that we can approximate a beam’s total deflection by adding together all the deflections brought about by each load configuration.
What is CT and LT in crane?
LT motion : Long Travel Motion. CT motion : Cross Travel Motion. Bridge : the structural portion on which the trolley/crab moves. LT End carriage : Structure which houses Long Travel Wheels. CT End carriage : Structure which houses Cross Travel Wheels.
What is crane hook height?
The hook height represents the required dimensions from the crane hook to the floor when the crane hook is at its highest position. This vital measurement determines how high the runway must be from the floor and directly related to the clear interior height of the building or structure.
What is LT and CT in crane?
How is crane capacity calculated?
Measure geometric components
- The standard calculation for maximum crane capacity is (r)(hC)/100.
- R = Radius between the ground and load.
- hC = Lifting height multiplied by the capacity.
What is the working radius of crane?
The ’ft. ‘ indicator on the left axis represents the radius, the distance from the center pin to the center of the load. EXAMPLE: You need to lift a load of 15 tons (30,000 pounds) a distance of 25 feet. The distance is measured from the center pin of the crane to the center of the load.
What supports a tower crane?
MAST OR TOWER: The mast is connected to the base, and it is the supporting structure that gives the crane its height. The mast has a large triangulated lattice structure, which gives the crane its strength.
How are tower cranes supported?
The base support is located at the bottom of the tower and often attached to a concrete pad on the ground. Alternatively, the base support may be attached to a steel grillage or ballasted chassis set on the ground or on top of an existing structure.