Mobile Crane Operator 1 Flashcards

According to OSHA 1926.1416, what is the minimum frequency at which wire rope on running rigging must be inspected?

Answer: Before each shift or at the start of each day of use

OSHA 1926.1416(d)(1) requires that wire rope used in hoisting operations be visually inspected before each shift or at the beginning of each day the equipment is used, checking for kinks, broken wires, corrosion, and other defects.

A signal person uses the following signal: arm extended horizontally, forearm vertical, hand open, and fingers pointing up — then moves the hand in small horizontal circles. What does this signal mean?

Answer: Use main hoist

The 'use main hoist' standard hand signal is given with one arm extended horizontally, forearm vertical, hand open with fingers pointing up, and the hand moving in small horizontal circles. This distinguishes which hoist the operator should engage.

When determining whether ground conditions are adequate for crane operations, which factor is MOST critical to evaluate before setting outriggers?

Answer: The bearing capacity of the ground relative to outrigger load

Ground bearing capacity is the most critical factor when setting outriggers. If the soil cannot support the concentrated load transmitted through the outrigger pads, the crane can tip or sink, causing a catastrophic collapse. Load charts assume adequate ground support.

Under OSHA 1926.1407, before any part of a crane can operate closer than 20 feet to a power line rated above 350 kV, what must the employer do?

Answer: De-energize and ground the power line, or confirm a minimum clearance with the utility owner

OSHA 1926.1407 requires that before operating within the Table A minimum clearances for high-voltage lines (20 ft for lines up to 350 kV, more for higher voltages), the employer must either have the utility de-energize and visibly ground the line, or determine the voltage and confirm required clearance distances with the utility owner.

What is the purpose of an anti-two-block (ATB) device on a mobile crane?

Answer: It automatically stops hoist motion before the hook block contacts the boom tip or sheave

An anti-two-block device detects when the hook block is approaching the boom tip or upper sheave and automatically cuts power to the hoist, preventing two-blocking. Two-blocking can cause the load line to part or structural damage to the boom, potentially dropping the load.

When operating a mobile crane, wind speed must be monitored because high winds can affect the rated capacity. According to general industry guidance, at what sustained wind speed should a crane operator typically consult the manufacturer's load chart for wind derating or cease operations?

Answer: 20 mph

Most crane manufacturers and industry standards, including guidance from ASME B30.5, recommend operators consult the manufacturer's guidelines and consider suspending operations when sustained winds reach or exceed 20 mph (approximately 30 ft/sec), as wind significantly increases the effective load and can cause the boom or load to swing unpredictably.