CPC Construction Equipment & Temporary Structures Flashcards
6 cards from real CPC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPC Construction Equipment & Temporary Structures flashcards as text
What is the primary factor that determines a crane's rated lifting capacity at a given radius?
Answer: Boom angle and load radius
A crane's rated capacity decreases as the load radius (horizontal distance from center of rotation to load) increases due to increasing overturning moment.
Which excavation support system uses horizontal steel members braced against the trench walls with no external tiebacks?
Answer: Braced cut (internally braced excavation)
A braced cut uses internal struts or cross-lot bracing between opposite trench walls to resist lateral earth pressure without external anchors.
What is the maximum safe working angle for a suspended scaffolding rope on a swing stage scaffold?
Answer: No more than 15 degrees from vertical
OSHA requires suspension ropes on two-point (swing stage) scaffolding to be plumb (vertical) or no more than 15 degrees from vertical to prevent swinging.
A tower crane's 'out-of-service' wind speed rating is important because:
Answer: It defines the wind speed at which the crane must be weathervaned and unloaded
Out-of-service wind speed ratings define when a tower crane must be placed in free-slew (weathervane) mode with no load to reduce wind-induced forces.
What is the purpose of a 'shoring' system in below-grade construction?
Answer: Temporarily support loads above while permanent structure is built below
Shoring provides temporary vertical support for structural loads above an excavation while the permanent foundation or structure is constructed below.
Which type of dewatering system lowers the groundwater table by pumping from a series of closely spaced small-diameter wells connected to a header pipe?
Answer: Wellpoint system
A wellpoint system uses closely spaced shallow wells connected to a vacuum header, effectively lowering the groundwater table across the entire excavation area.