DOCK AND TUNNEL 03/06/2025

DOCK AND TUNNEL

By WINCENTRE CLASSES

Multiple Choice

What is the main purpose of a wet dock?

• To repair ships below waterline
• To load/unload cargo at varying tidal levels
• To maintain constant water level for safe berthing
• To allow vessels to enter at high tides only

Explanation Slide...

Wet docks maintain a constant water level using lock gates, ensuring safe and efficient cargo handling.

Multiple Choice

Which dock type is most affected by high tidal range and results in rubbing of ships against the berth?

• Enclosed wet dock
• Dry dock
• Tidal basin dock
• Floating dock

Explanation Slide...

Tidal basin docks are open to sea tides, causing fluctuating water levels which affect loading/unloading and ship berthing.

Multiple Choice

Assertion (A): In enclosed wet docks, water level is maintained constant. Reason (R): Lock gates help control the water level for easy cargo handling.

• Both A and R are true, and R is the correct explanation of A
• Both A and R are true, but R is not the correct explanation of A
• A is true but R is false
• A is false but R is true

Explanation Slide...

Lock gates regulate water inside enclosed wet docks, making loading and unloading easier despite external tide changes.

Multiple Choice

Which type of dry dock consists of a hollow structure with two side walls and open ends?

• Ship lift
• Graving dock
• Marine slipway
• Floating dock

Explanation Slide...

Floating dry docks are hollow steel or RCC structures that can submerge and float to lift ships using buoyancy.

Multiple Choice

What is the function of the intermediate pair of gates in a wet dock lock system?

• Used for storing fresh water
• Reduce water wastage while handling small vessels
• Allow large ships only
• Balance water pressure on both sides

Explanation Slide...

Intermediate gates in locks save water when dealing with small vessels, allowing partial chamber use.

Multiple Choice

Which part of the tunnel is responsible for providing flat surface for laying track or roadway?

• Arch
• Bench
• Invert
• Key stone

Explanation Slide...

The invert forms the bottom curved surface of the tunnel and provides a base to transfer loads uniformly.

Multiple Choice

Which method of tunnelling is best suited for soft and unstable soils?

• Cut and cover
• Heading and bench
• Drill and blast
• Central drift

Explanation Slide...

Cut and cover method is suitable for soft ground as it involves excavation from the surface and structural support.

Multiple Choice

In the heading and bench method, what is the primary advantage?

• No drilling required
• Excavation in full cross section
• Simultaneous drilling and mucking possible
• No blasting needed

Explanation Slide...

Heading and bench allows mucking of bench while drilling continues at the heading, improving productivity.

Multiple Choice

In TBM, what is the function of the shield?

• Drilling rock surface
• Providing support to excavated tunnel
• Placing tunnel linings
• Removing muck

Explanation Slide...

The shield acts as a protective support during tunnel excavation through unstable soils.

Multiple Choice

Assertion (A): In central drift method, drift is excavated at center. Reason (R): This provides better ventilation and ease of expansion.

• Both A and R are true, and R is the correct explanation of A
• Both A and R are true, but R is not the correct explanation of A
• A is true but R is false
• A is false but R is true

Explanation Slide...

Central drift provides better ventilation and allows easier widening of tunnel from center outwards.

Multiple Choice

Which is NOT an operation involved in bored tunnelling?

• Supporting
• Piling
• Draining
• Grouting

Explanation Slide...

Piling is used in foundation works, not a direct operation in tunnel boring.

Multiple Choice

Statement 1: Immersed tunnels are used under water. Statement 2: They require open excavation from top.

• Both statements are true
• Only Statement 1 is true
• Only Statement 2 is true
• Both statements are false

Explanation Slide...

Immersed tunnels are submerged under water but do not need top open excavation like cut and cover method.