NCCCO Lattice Boom Crane Configuration and Operations

Question 1

What is the primary function of a boom pendant (back hitch) on a lattice boom crane?

Accepted Answer

It suspends and supports the boom from the mast or A-frame, controlling boom angle

Answer

It connects the load block to the hook at the boom tip

Answer

It secures adjacent boom sections together during assembly

Answer

It provides a secondary load path if the main hoist rope fails

Question 2

What distinguishes a luffing jib from a fixed jib on a lattice boom crane?

Accepted Answer

A luffing jib can be raised or lowered independently while the crane is in service

Answer

A luffing jib uses wire rope construction while a fixed jib uses tubular steel

Answer

A luffing jib is rated for heavier loads than a fixed jib of the same length

Answer

A luffing jib requires a separate operator to control while the main operator handles the crane

Question 3

When assembling boom sections on a lattice boom crane, what must be verified before adding additional sections?

Accepted Answer

All section pins are fully inserted and secured with their retaining devices

Answer

The load block has been reeved through each section before pinning

Answer

The counterweight has been fully installed to match the additional boom weight

Answer

The hydraulic outriggers have extended to maximum spread

Question 4

What is the primary ground-bearing advantage of a crawler crane over a rubber-tired mobile crane?

Accepted Answer

Crawlers distribute the crane's weight over a much larger footprint, reducing ground bearing pressure

Answer

Crawlers allow higher travel speeds on paved surfaces

Answer

Crawlers eliminate the need for outriggers during lifting operations

Answer

Crawlers allow the crane to travel on public roads without oversize permits

Question 5

What hazard results from allowing boom suspension pendants to go slack on a lattice boom crane while a load is being handled?

Accepted Answer

Slack pendants remove the boom's rear support, allowing the boom to kick forward suddenly when load is applied, increasing radius uncontrollably

Answer

Slack pendants cause the hoist rope to jump off the boom tip sheave

Answer

Slack pendants allow the boom to swing laterally beyond the rated radius

Answer

Slack pendants increase wind-induced vibration that fatigues the lattice sections

Question 6

A 'superlift' configuration on a large lattice boom crane is designed to accomplish what?

Accepted Answer

Add counterweight on a trailing arm to allow heavier lifts at greater radii

Answer

Reduce the crane's overall height to allow operation under power lines

Answer

Raise the crane's center of gravity to permit steeper boom elevation angles

Answer

Transfer load directly to the crawlers rather than through the swing bearing