CT Crane Operator flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Rated capacity

The maximum load a crane may lift at a specific radius, boom length, and configuration as published in the manufacturer's load chart, before deductions for rigging and block.

Load moment

The product of load weight and horizontal radius from the crane's rotation center; it measures the tipping effect and is the basis for stability-limited capacity.

Anti-two-block device

A safety device that stops hoisting when the hook block approaches the boom tip, preventing rope damage, block failure, and load loss.

Outrigger float loading

The force transmitted through an outrigger float to the ground, which must be spread over mats and kept below soil bearing capacity to prevent tipping.

Sling angle multiplier

For a two-leg bridle, leg tension equals half the load divided by the sine of the angle from horizontal; lower angles increase tension sharply.

Choker hitch capacity

A sling configuration where the sling passes around the load and through its own eye; capacity is reduced relative to vertical rating, often to about 80 percent.

Center of gravity

The point where the load's weight is concentrated; the hook must be directly above it so sling legs share load evenly and the load stays level.

Shift inspection

A pre-use inspection performed before each shift covering controls, brakes, hooks, wire rope, safety devices, and fluids, with safety-affecting defects corrected before operation.

Monthly inspection

A documented inspection by a qualified person covering the crane's structural and mechanical components, performed at intervals not exceeding one month.

Annual inspection

A comprehensive documented inspection that may require disassembly of components, performed at least annually and after certain repairs or modifications.

Ground bearing pressure

Outrigger load divided by the area of the supporting mat; it must not exceed the soil's capacity or the crane may settle and tip.

Standard hand signals

A defined set of arm and hand motions used to direct crane operators; the signal person must be qualified and clearly visible to the operator.

STOP signal

A universal signal any person may give; the operator must halt immediately and not resume until directed by the signal person.

Dedicated spotter

A person whose sole duty is to observe the crane's approach to a power line and warn the operator before the minimum approach distance is reached.

Minimum approach distance

The required clearance from energized power lines: 20 feet for lines up to 350 kV and 50 feet for lines over 350 kV up to 1000 kV.

Power line contact response

If the crane contacts a line, the operator stays in the cab, warns others away, and avoids simultaneous contact with the machine and ground.

Two-leg bridle tension

Leg tension equals (load divided by two) divided by the sine of the angle each leg makes with horizontal; steeper legs carry less tension.

Rigging deduction

The weight of hook block, slings, shackles, spreader beams, and other below-the-hook gear subtracted from rated capacity to determine allowable load weight.

Boom angle and radius

For a fixed boom length, raising the boom angle reduces radius and increases capacity; lowering the angle increases radius and reduces capacity.

Leveling tolerance

The manufacturer's limit on crane out-of-level condition, commonly about one percent grade, which must be met before lifting to keep charts valid.

Pre-lift meeting

A briefing before personnel platform lifts covering procedures, signals, and emergency actions, required by the standard before the trial lift.

Trial lift

A test raising of the loaded platform a short distance to verify stability and rigging before personnel are lifted, required for platform operations.

Signal person qualification

Employer verification that a signal person knows standard signals, crane dynamics, and can give clear directions, documented and kept on file.

Operator certification

Documented proof of crane operator qualification by an accredited testing organization, licensing, or employer audit, with records retained by the employer.

Subpart CC scope

OSHA 29 CFR 1926 Subpart CC covers power-operated equipment that hoists, lowers, and horizontally moves a suspended load in construction, with listed exclusions.

Lockout/tagout

A procedure isolating energy sources during crane maintenance so the machine cannot be started or moved unexpectedly, protecting service personnel.

Near-miss reporting

Recording events that could have caused injury or damage but did not, allowing corrective action before a serious accident occurs.

Wire rope design factor

The ratio of wire rope breaking strength to the load it carries; running lines for most crane applications use a design factor of about five.

Tag line use

A rope used to control load rotation and swing; it is not rated to support the load and must not be used to arrest a fall.

Suspended load rule

The operator must not leave the controls while a load is suspended; if leaving the cab, the load is lowered and the machine secured.

Wind limit

The maximum wind speed set by the manufacturer's manual or chart; load sail area increases wind force and can exceed capacity or stability limits.

Proof load test

A test applying a specified load greater than rated capacity to verify structural integrity, required after certain repairs or modifications per the manufacturer.