What is the primary difference between a telescopic mobile crane and a lattice boom mobile crane in terms of boom extension and speed?

• A. Telescopic cranes use hydraulic extension of tubular sections for varying reach and generally offer quicker, smoother extension with moderate lifting capacity; lattice boom cranes use a truss-like boom for higher lifting capacity at greater heights but extends more slowly and requires longer setup.
• B. Telescopic cranes have slower extension and higher capacity than lattice boom cranes.
• C. Lattice boom cranes extend by hydraulic cylinders and are faster than telescopic cranes.
• D. Lattice boom cranes are limited to short reaches and cannot reach tall heights.

Answer: (A)

The main idea being tested is how the boom design affects how it extends and how fast that extension happens. Telescopic mobile cranes use a single main boom made of tubular sections that slide in and out under hydraulic control. This setup lets the boom reach varying lengths quickly and smoothly, giving a moderate lifting capacity and good flexibility for changing reach on the jobsite. Lattice boom mobile cranes, on the other hand, use a rigid, truss-like boom built from interconnected members. That design provides much higher lifting capacity and the ability to reach greater heights, but extending and setting up the lattice structure takes more time because segments must be aligned, pinned, and tensioned, and more extensive setup is required. So, the key difference in terms of boom extension and speed is that telescopic booms extend rapidly and smoothly with hydraulic tubular sections, while lattice booms extend more slowly due to their segmented lattice construction but offer higher lifting capability and taller reaches.