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A ship is berthed in a chamber and lifted by principles of budyancy. Such a chamber is called
Docks or wet docks or tidal basins are enclosed and are shut off by entrances or locks to maintain a uniform level of water and basins are partially enclosed areas of water. Dry docks are repair docks. These are long, excavated chamber, having side walls, a semi circular end wall and a floor, A floating dry clock is a floating vessel which can lift a ship out of water and retain it above water by means of its own buoyancy.
Match List-I (Description) with List-II (Structure) and select the correct answer using the codes given below the 1 lists:
Groynes are structures built to protect beach or retard erosion of an existing or resorted beach by trapping of littoral drift. They are usually made perpendicular to shoreline.
Sea-walls, bulkheads and revetment are the structures constructed parallel to shoreline to develop a demarcating line between land area and water area.
Jetties are piled projection and they are built out from the shore to deep water. They are provided at places where harbour entrance is affected by littoral drift or the sea is shallow for a long distance.
How many hectares of anchorage area will be required by a 181 m long ship anchored by a single anchor in a harbour of 15 m depth?
Anchorage area is a place where ships may be held for quarantine inspection, await docking space or await favourable weather condition. The water area required for an anchorage depends upon number, type and size of vessels.
The anchorage area is calculated as the area of the circle having radius,
R = 4 x depth of water + length of ship + safe clearance to adjacent ship
= 4 x 15 + 181 + 12 = 253 m
So area = πR2 ≌ 20 ha
On which of the following factors will the selection of the type of Groyne depend?
1. Availability of material
2. Foundation condition
3. Presence or absence of marine borers
4. Topography of the beach
5. The height, period and angle of attack of approaching waves
Select the correct answer using the codes given below:
Matdh list - l (Shape of tunnel) with List-II (Attribute for preference) and select the correct answer using the codes given below the lists:
Consider the following factors:
1. Size and type of ship served
2. Availability of materials
3. Wharf configuration
4. Mooring procedures
The spaces required alongside a what for berthing would depend upon factors
Berth is a facility where one vessel may be safely moored and load/unload cargo or let passengers or vehicles embark or disembark.
Which one of the following is a component of a shield for tunnelling?
Components of a shield are hood, tail, cutting edges, propelling jacks.
Match List-l (Structure) with List-Il (Purpose) and select the correct answer using the codes given below the lists:
Which of the following type of sea walls results in greatest protection of shore structures?
Which of the foliowing are repair docks?
Which of the following conditions of loading imposes the greatest load on the foundation is case of dry docks?
For designing the dock, the proportion of ship load assumed to be borne by keel blocks is
If W is the weight of the ship and V is the velocity at right angle to the berth, then the berthing energy of the ship, when it first strikes the fenders, while coming alongside at a quarter point contact is
The lowest tide which occurs in half lunar month is called
Spring tides occur usually at new and full moon or rather a day or two after (or twice in each lunar month). At new moon, the sun and moon have the same celestial longitude and cross a meridian of the earth at the same instant. The sun and moon are on same side of the earth. The high water level of the resulting tide is above the average, whereas the low water level is below the average.
During neap tide, the moon falls behind the sun. High water level is below the average, whereas the low water level is above the average.
If 'D’ is the diameter of tunnel is metres, then the thickness of lining in mm, as per the empirical formula is given by
Which one of the following tunnelling method is used for laying under ground sewers?
Ribs are used for strengthening and stiffening the liner plate for tunnels of diameter greater then
The needle beam method of tunnelling
1. is suitable for soils in which roof can stand for few minutes without support
2. is suitable for brick lining
3. is suitable for concrete lining
4. requires large number of trench jacks
Which of these statements is/are correct?
With reference to tunnelling, which of the following factors are to be considered for deciding the size of the shaft?
1. System used for hoisting
2. Size of the muck car
3. Quantity of muck to be lifted
4. Eventual use of the shaft
Select the correct answer using the codes given below:
Size of shaft depends upon the following factors:
(i) Quantity of muck to be handled
(ii) Nature of hoisting system
(iii) Nature of equipment used in tunnelling
(iv) Number of labourers needed for tunnelling
(v) Space required to carry pipes and wires
(vi) Eventual use of the shaft.
In deep water waves, individual particles
The deep water waves are those which occur in water having a depth greater than one half of the wave length (d > L/2), at which depth the bottom does not have any significant influence on the motion of water particles.
For shallow water waves (d < L/2), they influence the bottom such that particles moves in orbital motion.
An unbroken wave is wave of oscillation, and even after breaking in deep water it will usually reform into an oscillatory wave of reduced height. When it reaches to shallow water, it becomes a wave of translation.