CSCS Crawler Crane flashcards
CSCS Crawler Crane · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Crawler crane base
- A crane with a rotating upperworks mounted on two endless crawler track assemblies, providing mobility and load spreading without outriggers.
- Load moment indicator
- A device that senses load and radius, computes load moment, compares it to the rated chart, and warns or locks out before an overload occurs.
- Boom angle effect
- As boom angle decreases toward horizontal, radius increases and rated capacity decreases; lower angles also increase boom bending loads.
- Pendant lines
- Fixed-length wire rope or bar assemblies that support the boom from the upperworks and transfer boom loads into the crane structure.
- Rated radius definition
- The horizontal distance from the crane's rotation center to the vertical line through the load's center of gravity, used to read the load chart.
- Ground bearing pressure
- Total weight carried by a track divided by the effective track contact area, expressed in psf or kPa and compared to soil allowable capacity.
- Out-of-level limit
- Manufacturer's maximum allowable crane slope, commonly about 1 percent, beyond which chart capacities are invalid and stability is reduced.
- Tipping axis
- The line about which the crane tips, typically the track edge or outrigger line; the crane tips when load moment exceeds resisting moment.
- Crane mats purpose
- Timber or steel pads that spread track pressure over a larger area so the subgrade's allowable bearing capacity is not exceeded.
- Pick-and-carry rating
- A separate charted capacity for traveling with a load, valid only on firm level ground with the boom in the specified travel position.
- Total load calculation
- Load weight plus sling and rigging weight plus hook block or headache ball plus below-the-hook devices, all deducted from gross chart capacity.
- Next longer radius rule
- When the actual radius falls between charted values, use the next longer radius and its lower capacity; never interpolate capacity upward.
- Structural versus stability
- Rated capacity is the lesser of the structural limit of boom, pins, and rope and the stability limit for that radius and configuration.
- Parts of line
- The number of rope falls supporting the load; required line pull equals total load divided by parts of line.
- Loaded radius change
- Boom deflection and load swing increase the operating radius beyond the unloaded geometric radius, reducing actual capacity.
- Sling leg tension
- For a two-leg bridle, tension per leg equals half the load divided by the sine of the leg angle from horizontal.
- Choker hitch capacity
- A choker hitch is typically rated about 75 to 80 percent of the sling's vertical capacity because the choke reduces strength.
- Sling angle factor
- Multi-leg sling capacity is multiplied by the sine of the angle to horizontal; 60 degrees gives about 0.866, 45 degrees about 0.707.
- Shackle rating basis
- Shackle working load limit is based on the pin or bowl strength, and the hook must have a functioning safety latch.
- Center of gravity control
- The load's center of gravity should be below or at the lift point; off-center lifts require tag lines and calculated load control.
- Anti-two-block test
- A daily function check that confirms the device stops hoisting before the hook block contacts the boom tip.
- Boom pin inspection
- Verify all boom and lacing pins are fully inserted and secured and pendant lines are properly tensioned before lifting.
- LMI calibration check
- The load moment indicator must be calibrated and zeroed for the installed boom and counterweight configuration; a bypassed LMI removes the crane from service.
- Wire rope rejection
- Rope is removed from service for broken wires exceeding the specified count per lay, kinking, crushing, bird-caging, or heat and corrosion damage.
- Daily pre-shift inspection
- A documented check of rope, sheaves, hook and latch, boom pins, tracks, fluids, brakes, and limit switches before each work shift.
- Designated signal person
- One qualified person directs the operator by hand or radio; the operator obeys only that person except for stop signals from anyone.
- Stop signal rule
- The operator stops immediately on a stop signal from any person, then resumes only when directed by the designated signal person.
- Trial lift procedure
- Lift the load a few inches, verify stability, brake holding, and rigging, then proceed with the full lift.
- Swing control technique
- Start and stop swing smoothly and use the boom to move the load; do not drag loads or swing the load ahead of the boom.
- Power line contact response
- If the crane contacts energized lines, the operator stays in the cab and warns others away until the line is de-energized.
- Emergency exit from crane
- If fire forces exit after line contact, jump clear without touching crane and ground together, then shuffle away with feet together.
- Suspended load exclusion
- No person may stand or walk under a suspended load, within the swing radius, or between the load and a fixed object.