Construction Equipment MCQ with answer and solution

Concept

Underwater excavation equipment

Formula

NONE

Step-by-step solution

1. The question asks for the most suitable excavator to carry out excavation in water. 2. Self-propelled, truck-mounted, and crawler-mounted excavators operate on land and become submerged or unstable in deep water. 3. Excavators mounted on a floating barge (dipper dredge or backhoe on pontoon) are equipped with spuds/anchors to perform steady underwater dredging. 4. Therefore, option C (Excavators on barge) is correct. Answer: C

Explanation

Excavators mounted on a barge or pontoon are specifically designed for marine, river, and harbour dredging/excavation works where equipment cannot be supported by ground. The barge provides buoyancy and stability to position the excavator directly above the submerged excavation site.

Why the other options are wrong

A) Self-propelled excavators cannot operate floating in deep water. B) Truck-mounted excavators require solid road/ground platforms. D) Crawler-mounted excavators can work in shallow muck but cannot perform open water excavation.

Shortcut

Excavation in water = Excavators on barge / floating pontoon.

Common mistake

Selecting crawler-mounted excavator, which is meant for soft terrestrial ground and cannot operate floating in deep water.