Overhead Crane exam questions and solutions

what are the rails that are attached to the building columns on either side of the bay? - runways what is it called when the girders are not perpendicular to the runway rails? - skewing what is the use of reverse motor power to stop a forward moving load? - plugging what is the term used to indicate very short movement? - inching what are the power cables that are hung in drape curves on the crane called? - festoon what kind of braking uses Eddy current braking? - dynamic what kind of brakes are applied mechanically when the hoist is not powered? - electrical what kind of a brake uses foot pressire on a pedal? - mechanical what are the 3 types of crane braking? - mechanical, electrical, dynamic what is located on both sides of the bridge and trolley to prevent over travel? - bumpers how many wraps must be on a drum when the load block is at its lowest position? - 2 wraps what are the girders that are connected on each side of the bay that sits on the runway called? - the bridge ANSI standard for overhead cranes? - B30.2 what should be done before lifting the load? - determine the weight of the load A hoist limit switch is triggered when the block contacts and raises the weight, what is suspended from the counterweighted limit switch? - the weighted switch when should limit switches be checked? - the beginning of each shift operating the trolley over long distnaces with intermediate speeds may do what? - heat up the motor whenever possible you should keep one hand on what? - the hoist If you accelerate and stop gradually what does this avoid? - excessive draft on a three light system, what does the RED light indicate? - 1. Crane is not to be moved under any circumstances 2. Crane is not manned 3. Crane is out of service on a three light system, what does the GREEN light mean? - 1. Crane is operational 2. Crane is manned 3. Operator must be in cab What is the working range for a radio reception? - 120 to 160 ft what kind of service operates at LESS than 85% of the rated load with no more than 10 lifts an hour? - normal service on a hook block on an overhead crane, the hook may have how much twist and how much opening? - 10 degree body twist 15% opening what are the 3 motors that drive a standard overhead crane? - 1. Bridge 2. Trolley 3. Hoist what should be done before loading or unloading a crane? - centering How do you secure an overhead crane? - 1. Park the crane at an authorized platform 2. Secure the trolley next to the cab 3. Raise the hoist block just below limit switch. 4. Position controls to the off position 5. Open Mon switch 6. Turn on red light 7. Put on parking brake what kind of service is operating at 85% of the rated load and OVER 10 lifts per hour? - heavy service what is position 1 used for on the hoist controller? - unloaded hook what is position 3 on the hoist controller used for? - smooth start on heavy loads what is position 2 used for on the hoist controller? - smooth start of medium loads what is the OSHA standard for overhead cranes? - 1910.179 what components shall be provided for outdoor bridge cranes? - rail clamps and wind indicator what type of fire extinguisher should NOT be used? - carbon tetrachloride what procedures are used when the load approaches near or over personel? - A warning signal shall be sounded what is a hoist limit switch that is operated when the load block hits a lever pulling contacts apart interrupting the hoist and circuit? - the paddle type what is a hoist limit switch that is attached to a shaft in the hoisting mechanism? - the rotating gear type what are the three basic types of hoist limit switches? - 1. the paddle type 2. the weight switch 3. the rotating gear type what must be checked when lifting a heavy load? - the hoist brake