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TRANSPORTATION ENGINEERING – 2

UNIT – 1

1. What is meant by zonal railways?

The entire railway station has been divided into nine zonal railways
having different territorial Jurisdictions which are responsible for all
management and planning of works.

2. What are the advantages of railways?

 Railways have helped in the mass migration of the population.
 The role of railways during emergencies in mobilizing troops and war
equipment has been very significant.
 Railway has made it easier to reach places of religious importance.
 Railways provide a convenient and safe mode of transport for the
country.
 Land values have increased due to industrial development which
ultimately results in the increase of national wealth.
 Speedy distribution of finished product is achieved through railways.
 Environment friendliness
 Higher safety and energy efficiency.

3. What are the different types of gauges?

 Broad gauge
 Metre gauge
 Narrow gauge
 Feeder track-gauge (or light gauge)

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4. Define gauge of track.

The gauge of a track in India is measured as the minimum distance
between the inner or running faces of the two track rails.

5. Enumerate the various factors that govern the selection of various types
of gauges.
 Cost of construction
 Volume and nature of traffic
 Development of the areas
 Physical features of the country
 Speed of movement

6. Define formation.
Formation is the prepared sub – grade ready to receive the ballast.

7. Define ash pits.

These are long masonry pits built longitudinally under the track for
discharging of ash from locomotives.

8. Define drop pits.

They are rectangular deep pits in which wheels of the locomotives are
taken out for repairs.

9. Define examination pits.

These are rectangular masonry lined pits, larger than ash pits in size,
and are provided in locomotive yards to examine the engine from
underneath.
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10.Define inspection pits.

These are the pits, similar to ash pits, but of larger dimensions
provided in loco yard for inspection of the engine from underneath.

11.What is meant by cutting?

When the ground has to be cut, it is called cutting. Cutting is termed
as shallow cutting when the depth is 3m or less and is called deep cutting
when the depth is more than 3m.

12.What is meant by embankment?

The raised structure above the ground level for carrying the railway
track is called embankment. When the height of the embankment is more,
the side slopes are steepened for better stability of slopes.

13.What are the two types of continuous automatic brakes?

 Compressed air brakes
 Vacuum brakes

14.What are the objectives of “Reconnaissance Survey”?

 To acquire the knowledge of physical features of the country like the
rivers, valleys, cultivated lands, forests, hills, existing roads, canals,
etc., for selecting the proper position of alignment
 To collect geological information regarding the following points are
nature of soil, surface formation of the ground, dip of the existing
rocks and hill slopes

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 To collect the information regarding availability of constructional

materials, labour and sources of water as permanent facilities for the
proposed alternative alignments
 To have an idea about possible alternative alignments
 To have an idea of rivers and streams which may cross the proposed
alignments for determining suitable bridge sites and their bridging
requirements
 To locate various control points or obligatory points for getting an
idea from where the alignment should pass and from where the
alignment should not pass
 To decide the maximum gradient and curvature for proposed
alignment
 To prepare rough estimates for different proposed alignments to know
most economical, safe and efficient alignment

15.What are the various resisting forces which a locomotive has to

encounter before starting a train and to keep it in motion?
 Train resistances
 Resistances due to track profile
 Resistances due to starting and acceleration
 Wind resistance

16.What engineering surveys are to be conducted for choice of route for a

new railway line?
 Traffic survey
 Reconnaissance survey
 Preliminary survey
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 Detailed survey

17.What are the details to be taken on reconnaissance survey?

 Accurate topography of the country.
 Towns, railways, river crossings, tunnel sites, etc.
 Geological characteristics of the soil of the area affecting foundations
for bridges and stability of the project line.
 Width of waterway required for rivers and drainages.
 Maximum flood levels of the intercepting natural drainages.
 Availability of building materials and labor.
 Probable radii of the horizontal curves.
 The total length of the route.
 Amount of expected earth work.
 The approximate cost of construction of each probable line.

18.What are the factors to be kept in view during reconnaissance survey?

 The reconnaissance survey should be done for the whole area
influencing the railway project, particularly for wide belt on either
side of the general direction of alignment rather than for a line only
 All the possible alignments marked on the map, during map study,
should be examined and improvements made if necessary
 All the intermediate points should be very carefully fixed so as to
attract maximum traffic and hence more revenue; less construction
problems and hence economy in construction, to achieve this, the
following points should be considered:
 Rivers should be crossed at right angles and those places where
approaches are sound and approach banks are not very high
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 Mountain passes should be so located that they could be

reached without steep gradients or deep cuttings
 A tunnel may also be proposed if very economical
 The station site should be located within 2km from the existing
town or village and at level stretch of land.

19.What are the instruments used in preliminary survey?

 Theodolite – for traversing
 Tacheometer – for plotting main features
 Dumpy level – for drawing the longitudinal sections and cross
sections
 Plane table – for plotting interior details
 Prismatic compass – for magnetic bearings of routes and main points

20.Write a brief note on Indian railways.

In the nineteenth century before the introduction of railways, India
was a country with extremely poor means of communications and without a
well-developed system of transport. Early efforts for the introduction of
railways may be traced back to the year 1832 when construction of a railway
line between madras and Bangalore was contemplated, though it did not
materialize then.

21.What is a dynamometer car and what is its purpose in railways?

This car gives information regarding the condition of track. It is
placed between the locomotive and train. It plots automatic graphic record
called ‘Hallade Chart’ of the track profile. The recording equipment is

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called ‘Hallade recorder’. This test on the track condition with

Dynamometer car is usually conducted every six months.

22.What is EDM?
Electro-magnetic Distance measurement is a general term used
collectively in the Measurement of distances applying electronic methods.

23.List the uses of Remote sensing data.

 Gives a bird’s eye view of large areas
 Ground condition can be defined with a combination of satellite
images and Topographic maps

24.Write the advantages of flat footed rails.

 Initial cost is less
 Higher strength, stiffness and rigidity
 No chairs required
 Simple arrangements at points and crossings
 Less liable to form kinks
 Load distribution is high

25.What are the merits and demerits of bull headed rails?

MERITS:
 They keep better alignment and give more solid and smoother track
 The rails are easily disconnected from sleepers as they have no direct
connection with the latter
 The heavy chairs with larger bearing on sleepers give longer life to
wooden sleepers and greater stability to the track
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DEMERITS:
 They require additional cost of iron chairs
 They have less strength and stiffness
 They require heavy maintenance cost

26.What do you understand by the term “Buckling of rails”?

Buckling means the track has gone out of its original position or
alignment due to prevention of expansion of rails in hot weather on account
of temperature variations. This buckling may take place on tangent lengths
and at curves.

27.What is the importance of railways?

The railways have their greatest utilization in the transport of large
volumes of heavy and bulk commodities over long distances and in very
long distance journeys of passengers with safety, comfort and convenience.

28.What are the advantages of “Coning of wheels”?

 To reduce the wear and tear of the wheel flanges and rails, which is
due to rubbing action of flanges with inside faces of the rail head
 To provide a possibility of lateral movement of the axle with its
wheels
 To prevent the wheels from slipping to some extent

29.Define kinks of rails and write its causes and effects.

When, the ends of adjoining rails move slightly out of position,
“shoulders” or “kinks” are formed.

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CAUSES:
 Loose packing at joints
 Defect in gauge and alignment
 Defect in cross level at joints
 Uneven wear of rail head, where kinks are formed at joints.

EFFECTS:
 These kinks cause unpleasant jerks in vehicles passing over them
 Due to uneven wear of rail heads, these kinks appear at places other
than the joints and obstruct the smooth running of trains
 A series of kinks are seen at curves due to which defect in gauge,
alignment and camber may occur. This involves, sometimes, a
serious risk in turning operations of trains.

30.Define sleepers.
Sleepers are members generally laid transverse to the rails on which
the rails are supported and fixed, to transfer the loads from rails to the ballast
and sub-grade below.

31.What are the functions of sleepers in the track?

 To hold the rails to correct gauge.
 To hold the rails in proper level or transverse tilt.
 To act as an elastic medium in between the ballast and rails to absorb
the blows and vibrations of moving loads.
 To distribute the load from the rails to the index area of ballast
underlying it or to the girders in case of bridges.

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 To support the rails at a proper level in straight tracks and at proper

super elevation on curves.

32.What are the requirements of sleepers?

 The sleepers to be used should be economical
 The fittings of the sleepers should be such that they can be easily
adjusted during maintenance operations such as easy lifting, packing,
removal and replacement
 The weight of sleepers should not be too heavy or excessively light
 The design of sleepers should be such that the gauge, alignment of
track and levels of the rails can be easily adjusted and maintained
 The sleeper design and spacing should be such as to facilitate easy
removal and replacement of ballast
 The sleepers should be capable of resisting shocks and vibrations due
to passage of heavy loads of high speed trains

33.Define sleeper density.

Sleeper density is the number of sleepers per rail length and it is
specified as (M + x or N + x), where M is the length of the rail in metres (N
is the length of rail in yards) and x is a number, varying according to the
following factors and is fixed by the railway board for various axle loads.
The factors governing the sleeper density are,
 Axle load and speed
 Type and section of the rails
 Type of ballast and ballast cushion
 Type and strength of sleepers
 Nature of foundation
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34.Write a small note on the need of construction of a new railway line.

 Strategic reasons
 Connecting trade centers
 Developing a backward area
 Shortening the existing route

35.Define track alignment.

The direction and position given to the centre line of the railway track
on the ground is called the track alignment.

36.What is meant by track circuit?

The length of the track, which is connected by electric circuit to signal
cabin, block telegraph apparatus, etc. required for indication of light or bell,
is called track circuit.

37.List the factors influencing the selection of a good railway track

alignment.
 Obligatory or controlling points
 Position, amount and type of traffic
 Gauge selection
 Geometric standards
 Topography of the country
 Economic considerations
 Other considerations

38.What are the three stages of construction of new railway track?

 First stage: Earth work – formation and consolidation
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 Second stage: Plate laying – laying of a railway track

 Third stage: Laying of ballast on the track

39.Write the requirements of a good rail alignment.

 Purpose of the track
 Feasibility
 Economy
 Safety
 Aesthetic aspects

UNIT – 2

1. Define permanent way.

The combination of rails fitted on sleepers and resting on ballast and
sub-grade is called the railway track or permanent way.

2. What are the requirements of ideal permanent way?

 The gauge should be correct and uniform
 The rails should be in proper level
 The alignment should be correct
 The gradient should be uniform and as gentle as possible
 The radii and super elevation on curves should be properly designed
and maintained
 Drainage system must be perfect for enhancing safety and durability
of track

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3. What is meant by capacity of a railway track?

Capacity of the track is the number of trains that can run safely on a
track per hour.

4. What is meant by hauling capacity?

Hauling capacity of locomotive is the total load which can be hauled
by it. It indicates the power of the locomotive.

5. What are the three types of rails?

 Double headed rail
 Bull headed rail
 Flat footed rail

6. What do you understand by the term “Ballast”?

Ballast is the granular material usually broken stone or brick, shingle
or kankar, gravel or sand placed and packed below and around the sleepers
to transmit load (due to the wheels of the train) from sleepers, to formation
and at the same time allowing drainage of the track.

7. What are the functions of ballast?

 It transfers the load from the sleeper to the sub-grade and distributes it
uniformly over a larger area of the formation
 It holds the sleepers in position and prevents the lateral and
longitudinal movement, due to dynamic loads and vibrations of
moving trains
 It imparts some degree of elasticity to the track
 Provides effective drainage to track
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 Act as a medium for provision of super elevation in curves of railway

tracks

8. What are the requirements of good ballast?

 It should be able to withstand hard packing without disintegrating
 It should not make the track dusty or muddy due to powder under
dynamic wheel loads
 It should allow for easy drainage with minimum soakage and the
voids should be large enough to prevent capillary action
 It should offer resistance to abrasion and weathering
 It should retain its position laterally and longitudinally under all
conditions of traffic, particularly on curves, where it should be able to
prevent transverse displacement of sleepers
 It should not produce any chemical action with rail and metal sleepers
 The size of stone ballast should be 5cm for wooden sleepers, 4cm for
metal sleepers and 2.5cm for turnouts and crossovers
 The materials should be easily workable by means of the implements
in use

9. What are the different types of “Ballast”?

 Broken stone
 Gravel or river pebbles or shingle
 Ashes or cinders
 Sand
 Moorum
 Kankar
 Brick ballast
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 Blast furnace slag

 Selected earth

10.What are the components of a permanent way?

 Rails
 Sleepers
 Ballast
 Formation

11.What is creep of rails?

Creep is defined as the longitudinal movement of rails with respect to
sleepers in a track.

12.What are the causes of creep?

 Ironing out effect of moving wheels on waves formed in rails
 Tendency of wheels to push rails forward and backward during
braking, acceleration, deceleration and running
 Impact when wheels run on ends of rails

13.What are the effects of creep?

 Sleepers get out of square and consequently gauge and alignment get
distorted
 Rail joints get opened out, resulting in failure of fishplates and bolts
 The joints are continuously jammed
 Points and signals fails

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 If any rails is removed from the track for any purpose, it becomes
difficult to fix it again at proper position because by the time gap
becomes too short or too long due to creep

14.What is meant by coning of wheels?

The distance between the inside edges of wheel flanges is generally
kept less than the gauge of the track. So there is a gap between the wheel
flanges and running edges of the rails, nearly equal to 1cm on either side.
Normally, the thread of wheels is absolutely dead centre of the head of the
rail, as the wheel is coned to keep it in this central position automatically.
These wheels are coned at a slope of 1 in 20.

15.What are the various types of sleepers used in Indian railways?

 Wooden sleepers
 Metal sleepers
 Cast iron sleepers
 Steel sleepers
 Concrete sleepers
 Reinforced concrete sleepers
 Pre-stressed concrete sleepers

16.What are the different types of rail joints?

 Supported rail joint
 Suspended rail joint
 Bridge joint
 Base joint
 Welded rail joint
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 Staggered or broken joint

 Square or even joint
 Compromise joint
 Insulated joint
 Expansion joint

17.Write short notes on rail section.

The rails on the track can be considered as the steel girders for the
purpose of carrying axle loads. They are made of high carbon steel to
withstand wear and tear. Flat footed rails are mostly used in railway track.

18.What are the functions of rails?

 Rails provide a hard, smooth and unchanging surface for passage of
heavy moving loads with a minimum friction between the steel rails
and steel wheels
 Rails bear the stresses developed due to heavy vertical loads, lateral
and braking forces and thermal stresses
 The rail material used is such that it gives minimum wear to avoid
replacement charges and failures of rails due to wear
 Rails transmit the loads to sleepers and consequently reduce pressure
on ballast and formation below

19.What are the requirements of rails?

 They should be of proper composition of steel as given above and
should be manufactured by open hearth or duplex process

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 The vertical stiffness should be high enough to transmit the load to

several sleepers underneath. The height of rail should, therefore, be
adequate
 Rails should be capable of withstanding lateral forces. Large width of
head and foot endows the rails with high lateral stiffness
 The head must be sufficiently deep to allow for an adequate margin of
vertical wear. The wearing surface should be hard
 Web of rails should be sufficiently thick to bear the load coming on it
and should provide adequate flexural rigidity in horizontal plane
 Foot should be wide enough so that rails are stable against
overturning, especially on curves

20.What is meant by hogged rails?

Due to battering action of wheels over the end of the rails, the rails get
bent down and get deflected at the ends. These rails are called hogged rails.

21.What is meant by corrugated or roaring rails?

In some locations, heads of the rails are found to be corrugated.
Vehicles passing over such rails produce a roaring sound. Such rails are,
therefore, called roaring rails.

22.What are the different forms of rail failure?

 Crushed heads
 Square or angular break
 Split heads
 Split web
 Horizontal fissures
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 Transverse fissures
 Flowing metal in heads
 Horizontal cracks

23.What is meant by wear of rails?

Due to movement of very heavy loads at high speeds, the concentrated
stresses often exceed the elastic limit of metal, resulting in the metal flow.
This flowed material of rails is chipped off by the striking of wheels. The
rail is then called worn out and this happening is called wear of rails.

24.What are the types of fittings and fastenings available in railway?

 Fish plates
 Spikes
 Bolts
 Chairs
 Blocks
 Keys
 Plates

25.What do you understand by the term “Fish Plates” and what are its
uses?
Fish plates are used in rail joints to maintain the continuity of the rails
and to allow for any expansion or contraction of the rail caused by
temperature variations. They maintain the correct alignment of the line both
horizontally and vertically.

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26.What is meant by spikes?

Spikes are used for fixing rails to the wooden sleepers. There are
various types of spikes commonly used for holding flat footed rails. These
can be used with or without bearing plates below the rails.

27.What are the uses of spikes?

 For holding the rails to the wooden sleepers
 Spikes should be strong enough to hold the rail in position
 Spike should be as deep as possible, easy in fixing, removal, cheap in
cost.

28.What is meant by chairs?

C.I chairs are used to hold the bull headed and double headed rails.
These chairs are fixed to sleepers by round spikes.

29.What is meant be blocks?

To provide the required gap between the two rails, steel pieces called
blocks or heel blocks are used. Such blocks are used between main rails and
check or guard rails.

30.What is meant by bearing plates?

Bearing plates are rectangular plates of mild steel or cast iron and are
used below flat footed rails to distribute the load on a larger area of timber
sleepers particularly of soften variety.

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31.What are the uses of keys?

Keys are tapered pieces of timber or steel to fix the rails to the chairs
on metal sleepers.

32.Define elastic fastening.

These are the special types of fastenings used for holding rails to the
sleepers firmly at a constant pressure without affecting the track structure for
sufficient time. These fastenings are suitable for high speed tracks as they
can withstand high frequency vibrations and shocks.

33.Define “Track modulus”.

Track modulus (µ) is an index for stiffness of track (i.e. resistance to
deformation) and is defined as load per unit length of the rail required to
produce a unit depression in the track.

34.List down the various causes of “Track stresses”.

 The wheel loads
 The dynamic effect of wheel loads
 The hammer blow – due to overbalance of driving wheels of
locomotive
 The horizontal thrust
 The horizontal thrust – due to nosing action of the locomotive
 Pressure exerted by flanges of wheels on sides of the rail
 Stresses due to irregularities in the track
 Additional stresses on curves

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UNIT – 3

1. Enumerate the necessities of “Curves”.

 To bypass the natural or artificial obstacles
 To provide easier gradients by diversions from the straight route
 To route the line through areas having traffic potentialities
 To balance the earth work in excavation and cutting thereby
minimizing the cost of construction

2. Write the types of horizontal curves.

 Simple curve
 Compound curve
 Reverse curve
 Transition curve

3. Define Simple curves.

The horizontal curve which consists of a single arc of a circle is called
a simple curve or simple Circular curve. Simple circular curves are
designated either by their degree of radius. They are inserted between two
straights or between two transition curves.

4. Define Compound curves.

The horizontal curve which consists of two or more arcs of different
circles with different radii, having different centers on the same side of the
common tangent and bending in the same Direction, is called a compound
curve.

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5. Define Reverse curves.

The horizontal curve, which consists of two arcs of different circles of
same or different radii, bending in opposite directions with a common
tangent at the junction, is called a reverse curve.

6. What is transition curve? Where is it provided?

Transition curve is defined as a curve of parabolic nature which is
introduced between a straight and a circular curve or between two branches
of a compound curve. Its radius rises from infinity to a selected minimum in
order to attain full super elevation and curvature gradually. This is also
known as spiral or easement curve. The transition curves are, therefore,
necessary to provide an easy change from a tangent to the radius selected for
a particular curve.

7. Define valley or sag curve.

Valley or sag curves are formed when a descending gradient meets
with an ascending gradient. When a train passes over sag, front portions of
the train ascend while rear portion may traverse on the descending gradient.
This compresses the couplings and buffers. Once the train passes on the sag,
again the couplings and buffers are under tension causing a jerk. In order to
avoid inconvenience, sag curves are introduced at the meeting points.

8. Define summit curve.

Summit curves are formed when an ascending gradient meets a
descending gradient. Deviation angle between two intersecting gradients is
equal to algebraic difference between them. When a trains climbs at a

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uniform speed and passes over them summit of a curve, acceleration begins
to act up on it and makes the train to move faster.

9. What is cant deficiency?

Cant deficiency occurs when a train travels on a curve at a speed
higher than equilibrium speed. It is the difference between theoretical cant
required for such higher speed and actual cant provided.

10.Define cant excess.

Cant excess occurs when a train travels on a curve at a speed lower
than equilibrium speed. It is the difference between actual cant and
theoretical cant required for such a lower speed.

11.List few objectives of signaling.

 To provide facilities for the efficient movement of trains.
 To ensure safety between two or more trains which cross or approach
each other’s path
 To provide facilities for the maximum utility of the track.
 To provide facilities for safe and efficient shunting operations
 To guide the trains movement during maintenance and the repairs of
the track.
 To safeguard the trains at converging junctions and give directional
indications at diverging junctions.

12.What are the types of signals based on the various categories?

 Operating characteristics
 Detonating signal (also called fog or audible signal)
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 Hand signal (visual indication signal)

 Fixed signal (visual indication signal)
 Functional characteristics
 Stop or semaphore type signal
 Warner signal
 Shunting signal (disc or ground signal)
 Coloured – light signal
 Locational characteristics
 Reception signal
o Quoter signal
o Home signal
 Departure signal
o Starter
o Advance starter
 Special characteristics
 Repeater or co – acting signal
 Routing signal
 Calling on signal
 Point indicators
 Modified lower quadrant semaphore signal
 Miscellaneous signal

13.Write the types of transition curves and draw it.

 Spiral curve
 Cubic parabola
 Bernoulli’s lemniscate

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14.Define shift and write its formulae.

For the main circular curve to fit in the transition curve, which is laid
in the shape of a cubic parabola, it is required be moved inward by a
measure known as the shift. The value of shift can be calculated using the
formula is given by,
𝐿2
𝑆=
24 𝑅

15.What are the requirements of a transition curve?

 It should be perfectly tangential to the straight
 The length of the transition curve should be such that curvature may
increase at the same rate as the super elevation. This is necessary to
attain the full super elevation at the junction of transition and circular
curve.
 This curve should join the circular arc tangentially (i.e.) curvature of
transition curve should conform to that of circular curve.

16.What is meant by Widening of gauge on Curves?

Due to impounding action of the wheels on curves, the gauge of the
track gets widened and the Rails get tilted outward. To prevent the tendency
of tilting the rail outward the gauge of the track on curves is suitably
widened. The amount of widening of gauge depends on the radius of the
Curve, gauge and rigid wheel base of the vehicles.

17.Write the formulae for widening of gauges.

13 ( 𝐵 + 𝐿 )2
𝑑=
𝑅

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Where,
B = rigid wheel base in metres
For B.G track, B = 6m
For M.G track, B = 4.88m
R = radius of the curve in metres
L = lap of flange in metres
𝑑 = 0.02 √ℎ2 + 𝐷. ℎ Metres
Where,
h = depth of wheel flange below rail top level in cm
D = diameter of wheel in cm.

18.Define switch angle.

This is the angle formed between the running faces (gauge face) of
stock rail and tongue rail.

19.Define Angle of deflection.

The angle through which forward tangent deflected is called angle of
deflection of the curve. It May be either to the left or to the right.

20.What is meant by flange way clearance?

This is the distance between the adjacent faces of the stock rails or
running rails and the check or guard rails. It is provided for free movement
of the wheel flanges.

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21.What is flange way depth?

It is the vertical distance between the top surface to the running rails
or stock rails top to the surface of the heel block which is used between
stock rail and the check rail.

22.Define gradient.
Any departure of the track from the level is known as grade or
gradient, an up or rising gradient is one when the track rises in the direction
of movement, and a down or falling gradient is one when the track fails in
the direction of movement.

23.What are the Various Types of Gradients?

 Ruling gradient
 Momentum gradient
 Pusher or helper gradient
 Gradients at station yards

24.What do you understand by the term “Grade compensation”?

In order to avoid resistances beyond the allowable limits, the gradients
are reduced on curves and this reduction in gradients is known as grade
compensation for curves.

25.Define cant or super elevation.

When a vehicle negotiates a curve, it is subjected to a constant radial
acceleration which produces Centrifugal force acting horizontally at the
center of gravity of the vehicle, radially away from the center of the curve.
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To counteract the effect of centrifugal force, the level of the outer rail is
raised above the inner rail by a certain amount to introduce the centripetal
force. This raised elevation of outer rail above the inner rail at a horizontal
curve is called super elevation.

26.Differentiate between equilibrium cant and negative cant.

When the lateral forces and wheel loads are almost equal, the cant is
said to be in equilibrium. This equilibrium cant is provided on the basis of
average speed of the trains.
Elevation of outer rail below inner rail of turnout or branch track at
the place it meets main track on a curve is known as negative super
elevation/cant.

27.Define crossing.
A crossing is a device, inserted at a location, where two rails cross
each other. Purpose of the introduction is to enable the wheel flanges of rail
vehicles to pass from one track to another. Flanged wheels jump over the
gap provided from the throat to the nose of a crossing. Checkrails guide
wheels on the other side of the train vehicles in order to ensure that wheels
negotiate the gap properly and do not strike the nose.

28.What you mean by Diamond crossing?

When straight tracks or curved tracks of the same or different gauges
cross each other at an angle less than 90 degree, a diamond shape is formed.
So this crossing is called as diamond crossing.

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29.What are the various types of crossings?

 On the basis of shape of crossing
 Acute angle crossing or “V” crossing or frog
 Obtuse angle crossing or diamond crossing
 Square crossing
 On the basis of assembly of crossing
 Spring or movable wing crossing
 Ramped crossing

30.What are the component parts of crossing?

 A crossing or Vee piece
 Point and splice rails
 Wing rails
 Check rails
 Chairs at crossing, at toe and at heel
 Blocks at throat, at nose, at heel and distance block
 In some cases, packing below the wing rails at toe and throat

31.List down the characteristics of Crossing.

 The assembly of crossing has to be rigid to stand against severe
vibrations
 The wear on parts of wing rails opposite the nose and also of nose
itself must be protected

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32.What is meant by crossing number?

The number of crossing is defined as the ratio of spread (i.e. distance
between the point and splice rails at the leg of crossing, generally 30cm) to
the length of crossings are designated by this number and is denoted by the
symbol ‘N’.

33.What is meant by nosing action?

The wheels of the locomotive, wagons and compartments follow a zig
– zag path moving from one rail to another within the limits of wheel gauge
tolerance. This happening is called as nosing action.

34.List out the special types of signals.

 Repeater or co-acting signals
 Routing signals
 Calling on signals
 Point indicators
 Modified lower quadrant semaphore signal
 Miscellaneous signals

35.What is meant by turnouts and write its functions?

Turnout is the simplest combination of points and crossings which
enables one track either a branch line or a siding, to take off from another
track. So the object of turnout is to provide facilities for safe movement of
trains in either direction on both the tracks.

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36.Define tongue rail.

It is a tapered movable rail, made of high-carbon or -manganese steel
to withstand wear. At its thicker end, it is attached to a running rail. A
tongue rail is also called a switch rail.

37.What is termed as points and crossing?

Points and crossings are arrangements by which different routes are
connected. The connection facilitates movement of trains from one route to
another safely. It is also useful for marshalling and shunting operations in
station yards. Combination of points and crossings are termed as turnouts.

38.What is the necessity of points and crossings?

 Points and Crossings provide flexibility of movement by connecting
one line to another.
 They help in Imposing restrictions over turn outs which necessarily
retard the movements.
 In regard of safety aspects, points and crossings are weak kinks or
points in the track which are susceptible to derailments.

39.List down the different types of track junctions.

 Turnouts
 Symmetrical split (or equivalent turnout)
 Three throw switch (contrary and similar flextures)
 Double turnout or tandem
 Diamond crossing
 Cross over’s (between parallel tracks and diverging tracks)
 Single slip and double slip
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 Gauntlet track and fixed point system

 Scissor cross – over
 Gathering lines or ladder tracks
 Temporary diversion
 Triangle
 Double junctions

40.Define cross-over in track junction?

When two adjacent parallel or diverging tracks, which may be straight
or curved, are connected by two sets of turnouts, with or without a straight
length between them, the connecting line is known as cross-over.

41.Define Ladder tracks?

When a number of parallel tracks are branched off from the straight
track in Continuation of a turnout, it is called a gathering line or ladder track.

42.What is meant by flare?

It is the gradual or tapered widening to the flange way which is
formed by bending and splaying the end of check rail or wing rail away from
the gauge line.

43.Define buffer stop.

The dead end of a railway line is provided with a barrier erected
across the track to prevent the vehicles running off the track is called buffer
stop.

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44.Define switch.
A switch consists of a stock rail and a tongue rail. Switches are
tapered rails with the thicker end known as the heels, fixed to the main track
while thinner end known as the toe is kept movable.

45.What are the two types of switches?

 Stub switch
 Split switch
 Loose heel type or articulated type
 Fixed heel type or spring type or flexible type
 Under cut switches
 Overriding switches
 Straight cut switches

46.What is meant by throw of switch?

It is the distance through which the toe of the tongue rail rotates
sideways, with heel of tongue rail as the centre of rotation.

47.Define Platform.
A raised level surface from where passengers board and alight from
trains at the station is called platform.

48.Write short notes on Drainage of Platforms.

 All end platforms shall normally be sloped away from the track.
 All drains from platform shelters, tea stalls toilets, water taps or other
sullage generation points shall be in pipes and normally discharge on

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the non-track slide of the end platform. If necessary longitudinal

covered drains may be provided on the platform.

49.What are the various sources of moisture in a railway track?

 Surface water due to rain, dew or snow.
 Hydroscopic water or Held water.
 Seepage water
 Moisture by capillary action In sub grade

50.What is meant by mechanical tamping or mechanized maintenance?

This is a mechanized method of maintaining the track by use of Tie
Tamping Machines. This method is more effective, economical and
efficient for maintaining high speed and super high speed tracks. This
method is widely used on Indian railways these days.

51.What is directed track maintenance?

Directed track maintenance is a method of track maintenance. This is
based on the directions that are given for maintenance given every day rather
than the routine maintenance. It is need based maintenance.

52.What is calendar system of maintenance?

Calendar system of maintenance is conventional method. Track
maintenance work to be performed by gangs on the course of a year.

53.Write any two necessity of Track Maintenance.

 The strength of track structure goes on deteriorating or reducing due
to movement of high speed trains, heavy axle loads and repetition of
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loads. The elastic structure of railway track thus get disturbed in

alignment, gauge and surface level of rails.
 The track structure is also subjected to other deteriorating effects like
rain water, action of sun and wind. The wear and tear of rails and of
rolling stock is then bound to take place due to their adverse effects.
 The track structure has to bear too many other effects due to
curvature, speed and load, particularly on curves, points and
crossings, bridge approaches and at level – crossings.

54.Write the essentials of Good Track Maintenance.

 The correct gauge is within specified limits.
 Longitudinal levels are uniform.
 The cross levels are same except on curves where difference in cross
levels is equal to the desired super-elevation.
 Along straights, the alignment is perfectly linear.
 There is a sufficient quantity of ballast bed.
 The sleepers are well packed.
 The formation is well maintained with good track drainage for
disposal of rain water.

55.Write any two advantages of Proper Track Maintenance.

 A well maintained track provides safe and comfortable journey to
passengers. If the track is not maintained properly, there will e
discomfort to the passengers and sometimes, there may be a
derailment of vehicles, causing accidents and consequently loss of
lives and property.

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 Proper maintenance of track increases the life of track as well as that

of the Rolling stock.

56.What is Rolling stock?

Rolling stock consists of locomotives, passenger coaches and goods
wagons. The term is used because they roll on the rails.

57.What are the advantages of good maintenance of railway track?

 The life of both track as well as of rolling stock increases by proper
maintenance
 A well maintained track imparts smooth riding quality surface for
vehicles which results in comfort to passengers and safety to goods.
 There is also saving in operating costs as fuel consumptions is less by
locomotives due to reduced friction between wheels and rail surface.
 Safety to passengers and goods encourages the use of railways and
better earnings.

58.What are the requirements of a track drainage system?

 The track alignment should be made to rest on pervious naturally
drained soils.
 The highest level of water table should be much below the level of
sub grade.
 Sub surface water should be efficiently drained off by the sub surface
drainage system.
 The surface water from adjoining Land could be prevented from
entering the track formation.

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59.List the methods of sub-surface drainage methods adopted in railways.

 Drainage of capillary water
 Drainage of seepage water

60.Define railway station.

Railway stations are selected locations along railway tracks where
trains stop for boarding and alighting of passengers, loading and unloading
of goods, detachment or attachment of wagons and compartments, crossing
of trains and for fuelling or watering of locomotives.

61.What are the data’s to be collected for the site selection of railway
station?
 Acquisition of land
 Proximity to town or village
 Nature of land area
 Approach roads to station site
 Station site alignment
 Site drainage
 Station amenities
 Type of station and yard
 Role of authorities

62.What are the requirements of a railway station?

 Public requirements
 Traffic staff and police requirements
 Train requirements
 Requirements of locomotives
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 Requirements for development of railways

63.What are the different classifications of railway stations?

 Classification based on operational characteristics
 Halt station
 Flag station
 Crossing station
 Junctions
 Terminals
 Classification based on minimum signal requirement
 ‘A’ class station
 ‘B’ class station
 ‘C’ class station
 ‘D’ class station or Non – block stations

64.What do you mean by halt station?

This is the lower most in the hierarchy. In its simplest form, the halt
stations have rail level platform with name boards at either ends. Sometimes
a small waiting shed, which may also serve as booking office is also
provided.

65.What do you mean by flag station?

A flag station stands next to halting station, in ranking. The flag
station has a waiting hall, booking office, platforms with benches and
drinking water facilities. Importantly, the flag stations may have a control

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phone connected to one of the stations on either side for easy

communication.

66.What do you mean by crossing station?

The crossing stations have in addition to basic facilities, arrangements
and equipments to control movement of trains. This facilitates trains going
in opposite direction. In case of double line section, there are separate up
and down lines. This enables trains from either direction to pass
independently.

67.What do you mean by double line station?

Layout of a double line station, with separate up and down line is
different to certain extent.

68.What do you mean by junction station?

Railway stations, where two or more lines from different directions
meet are termed as railway junctions. The meeting may be between main
lines and branch lines or between main lines. Different lines are linked by
foot over bridges or other arrangements.

69.What do you mean by terminal station?

A station at which, a railway line or one of its branches terminates is
known as terminal station. Such terminal facilities require higher order
facilities such as servicing, repairing, reversing, sidings, changing of
carriages and such other allied facilities.

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70.What do you understand by the term Stations yards?

A yard is defined as a system of tracks laid usually on a level within
defined limits, for receiving, storing, sorting, making up new trains, dispatch
of vehicles and for other purposes over which movements are not authorized
by a time table. The various movements on a system of tracks are governed
by prescribed rules, regulations and signals.

71.Write the types of yards.

 Coaching or Passenger bogie yard
 Goods yard
 Marshalling yard
 Flat yard
 Gravitational yard
 Hump yard
 Locomotive yard

72.Define marshalling yard.

A goods yard which deals with the sorting of goods wagons to form
new goods trains is called a marshalling yard.

73.What are the functions of marshalling yards and explain any one.
 Reception
 Sorting
 Departure

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74.Define coaching or passenger bogie yard.

The main function of a coaching yard is to deal with the reception and
dispatch of passenger trains. Depending upon the volume of traffic, this yard
provides facilities such as watering and fuelling of engines, washing of
rakes, examination of coaches, charging of batteries, and trans-shipment of
passengers.

75.Define goods yard.

A goods yard provides facilities for the reception, stabling, loading,
unloading, and dispatch of goods wagons. Most goods yards deal with a full
train load of wagons. No sorting, marshalling, and reforming is done at
goods yards except in the case of ‘sick’ wagons or a few wagons booked for
that particular station. Separate goods sidings are provided with the
platforms for the loading and unloading of the goods being handled at that
station.

76.Define locomotive yard.

These yards provide services to locomotives and serve as stables. The
services include coaling, watering, repairing, oiling and cleaning. Normally,
junction stations have locomotive yards. Usually, they are constructed on
the same side as that of the marshalling yard. The loco yards have engine
sheds, inspection pits, repair pits and coaling site.

77.Define flat yard.

In this type of yard, the entire space of the yard is almost level and all
the sorting works or movements of wagons are carried out by means of
engines running to and from this arrangement is costly due to more
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consumption of power in the use of engines. But this type of yard is

justified where the available space is limited for the layout of marshalling
yards. The other two types of yards require more area for their layouts.

78.Define gravitational yard.

In this yard, the level of the natural ground is such that it is possible to
lay some tracks at a gradient. The tracks are so laid that the wagons move to
the siding assigned for the purpose of sorting by the action of gravity.
Sometimes, shunting is done with the help of gravity assisted by engine
power. However, it is very seldom that natural ground levels are so well
suited for gravitation yards.

79.Define hump yard.

In this type of yard, an artificial hump or summit is made through
proper earth work. Wagons are pushed upto summit or hump with the help
of engines. Then wagons move down the hump and go to sidings under the
action of gravity.

UNIT – 4

1. What are the classifications of airport?

 Terminal airport
 Defense
 Commercial
o Ownership
 Public

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 Joint
 Private venture
o Size
 Smaller
 Medium
 Larger
o Area of operation
 Domestic
 International
 ICAO classification
o Letter code : A , B, C, D, E
o Number code : 1, 2, 3, 4, 5
 Intermediate landing port

2. What are the types of surveys conducted on airport?

 Approach zone survey
 Drainage survey
 Meteorological survey
 Natural resources survey
 Soil survey
 Topographical survey
 Traffic survey

3. What is meant by clearway?

It is defined as a rectangular area at the end of a strip or channel in the
direction of takeoff over which the aircraft may make its initial climb.

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4. List out the merits and demerits of air transport.

MERITS:
 Accessibility
 Continuous journey
 Demand for technical skill
 Emergency use
 Engineering use
 Saving in time

DEMERITS:
 Flight rules
 Operating expenses
 Safety
 Weather conditions

5. What are the drawings should be prepared for construction of new

airport?
Drainage plan, grading plan, Lighting plan, Master plan, Obstruction
plan, paving plan and Topographic plan

6. What is the necessity of surveying in construction of new airport?

 To ascertain the characteristics of soil.
 To workout the detailed estimate of the project.
 To prepare suitable drawings
 To make provision for future extension of the airport
 To give an idea of the meteorological conditions prevailing at the
proposed site
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7. What are the three aspects considered for the airport planning?
 Adequate access to the metropolitan area
 Securing sufficient airspace for access to the air
 Sufficient land for carrying out ground operations

8. Write the objectives of airport planning.

 Justify the need for an airport
 Formulate a layout plan for the airport and design of runways,
taxiways and airport buildings
 Prepare cost estimation
 Propose institutional arrangement

9. What are the factors affecting the size of an airport?

 Elevation of the airport site
 Meteorological conditions
 Performance characteristics of aircrafts
 Volume of traffic

10.What are the environmental factors considered in the development of a

new airport or the expansion of an existing one?
 Environmental Impact Assessment (EIA)
 Environmental Impact Statement (EIS)
 Environmental Management Plan (EMP)

11.Define Turning zone.

Area of airports used for turning operations of aircrafts is termed as
turning zones. In the event of any emergency like engine failure, if pilots
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opt for landing immediately after taking over, aircrafts have to come in line
with runways before landing. Normally, area of an airport other than an
approach zone is used for turning.

12.Comment on clear zone.

Clear zone is the innermost portion of an approach zone. It is the
most critical part of an approach zone from obstructions point of view. As
name itself indicates, the portion should be clear and no developments of
any type are permitted.

13.Define apron.
It indicates a defined area of the airport to accommodate aircrafts for
loading and Unloading of cargo and passengers, parking, refueling, etc. It is
usually paved and is located in front of the building or adjacent to hangers.

14.What are the three factors which affect the size of an apron?
 Gate position
 Number of gates
 Systems of aircraft parking

15.Define gate position.

The space allotted to an aircraft parking at a loading apron is known
as gate position.

16.Define holding apron.

The portion of paved area which is provided adjacent to the ends of
runway in case of busy airports is known as the holding apron.
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17.Define orientation of the runway.

The orientation of a runway is defined by the direction, relative to
magnetic north, of the operations performed by aircraft on the runway.
Typically, but not always, runways are oriented in such a manner that they
may be used in either direction. It is less preferred to orient a runway in such
a way that operating in one direction is precluded, normally due to nearby
obstacles.

18.Define runway.
A defined rectangular area prepared for landing and take-off of
aircrafts and over which aircrafts runs on ground.

19.What are the four basic patterns of runway?

 Single runway
 Parallel runways
 Intersecting runways
 Divergent or open – V runways

20.Write the design elements of a runway.

 Runway orientation
 Length of runway – basic and corrected runway lengths
 Runway width
 Width and length of safety area
 Transverse gradient
 Longitudinal and effective gradient
 Rate of change of longitudinal gradient
 Sight distance
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 Design of runway pavement

21.Write the elements of geometric design of runways.

 Runway length
 Runway width
 Width and length of safety area
 Transverse gradient
 Longitudinal and effective gradient
 Rate of change of longitudinal gradient
 Sight distance

22.What are the markings made on the runways?

 Runway centre – line marking
 Runway edge stripes
 Runway numbering
 Touchdown or landing zone
 Threshold marking
 Two or more parallel runways

23.What are the types of runway lightings?

 Emergency lighting
 Aeronautical beacons
 Approach lighting system
 Runway lead – in lighting systems
 Runway threshold identification lights
 Runway edge lights
 Runway threshold and wing bar lights
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 Runway end lights

 Runway centre line lights
 Runway touchdown zone lights
 Stop way lights

24.What are the corrections required for runway length?

 Correction for elevation
 Correction for gradient
 Correction for temperature

25.What do you understand by the term basic runway length?

The length of the runway based on the following assumed conditions
is known as the basic runway length.
 No wind is blowing on the runway
 The aircraft is loaded to its full loading capacity
 The airport is situated at sea level
 There is no wind blowing on the way to the destination
 The runway is leveled in the longitudinal direction or in other words,
it has zero effective gradient
 The standard temperature is maintained along the way
 The standard temperature of 15oc exists at the airport

26.Define taxiway.
A defined path on a land aerodrome selected or paved for the use of
taxiing aircraft to and from the runway and loading apron is known as
taxiway.

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27.Mention the different types of aircraft propulsion.

According to the method of propulsion, the aircrafts can be classified
in the following three categories
 Piston engine
 Jet engine
 Turbo jet
 Turbo propulsion
 Ram jet
 Rocket engine

28.Differentiate between approach zone and approach surface.

APPROACH ZONE APPROACH SURFACE
An approach zone is an area A line rising at a particular slope
through which aircrafts approach or from the runway – end represents
leaves airports. It is the climb out the obstruction clearance line and
and landing path. In this zone, the imaginary inclined plane
aircrafts loose or gain altitude at a containing this line and directly
very slow pace as compared to above the approach area is known
forward speed. In view of this, as approach surface.
wider clearance on both sides of the
runways is required in the approach
zones of the airport.

29.What is meant by wind rose diagram?

The diagram showing direction, duration and intensity of wind over a
certain period in a specified region is known as wind rose diagram.

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30.What are the parameters represented in a wind rose diagram?

 Direction of wind
 Duration of wind
 Intensity of wind

31.Name the different characteristics of aircrafts?

 Aircraft capacity
 Aircraft speed
 Aircraft weight and wheel arrangement
 Fuel spilling
 Jet blast
 Minimum circling radius
 Minimum turning radius
 Noise
 Range
 Size of aircraft
 Takeoff and landing distances
 Type of propulsion
 Tyre pressure and contact area

32.What are the data’s to be collected for airport site selection?

 Regional plan
 Types of airport
 Ground accessibility
 Topography
 Soil characteristics
 Meteorological factors
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 Wind
 Frost and fog
 Temperature
 Noise nuisance
 On – site and off – site infrastructures
 Shape and dimensions of site
 Future development
 Comprehensive evaluation

33.Define airport obstructions and zones.

Restrictions and removal of obstructions in airspace around airports
are essential to conduct safe aircraft operations. Obstructions may be
broadly divided into two categories. They are,
 Imaginary surfaces
 Objects with actual heights

The different types of zones are,

 Approach zone
 Clear zone
 Turning zone

34.What is meant by zoning?

It pertains to the enactment of legislation for a restricted development
of the area surrounding the airport so that no structure protrudes above the
obstruction clearance line and thus cause hazard to safe air navigation,
especially in the approach and turning areas.

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35.What are the two types of zoning?

 Height zoning
 Land use zoning

36.What are the phases of Master plan by FAA recommendation?

 Phase І: Airport Requirements
 Phase ІІ: Site selection
 Phase ІІІ: Airport plans
 Phase ІV: Financial plans

37.What do you mean by airport capacity?

The number of aircraft movements which an airport can process or
handle within a specified period of time, usually an hour, is called the airport
capacity. A landing or take off operation is taken as one movement.

38.Define wind coverage.

The percentage of time in a year during which the cross wind
component remains within the limit of 25kmph is called the wind coverage
of the runway.

39.Define Hangar.
The large shed erected at the airport for the purpose of housing,
servicing, and repairing of aircrafts is known as hangar.

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40.Define terminal area.

The portion of the airport other than the landing area is known as
terminal area and it includes terminal building, aircraft apron, cargo storage
building, hangars, automobile parking area, etc.

41.Define terminal building.

The building or buildings which are meant for providing facilities to
all Passengers, for serving as office for airport management and for carrying
out other non- aeronautical functions are known as terminal buildings. They
act as the focal points of the terminal area.

42.What is the main function of hangar?

The main function of a hangar is to provide an enclosure for housing
and repairing of the aircraft. They are constructed of steel framework
covered with the galvanized iron sheets.

UNIT – 5

1. Specify the functions of taxiway.

The main function of taxiways is to provide access from the runways
to the terminal area and service hangars. It is evident that the speed of
aircraft on the taxiway will be much less than that on the runway at the time
of landing or take off. The standards for the taxiway design and
construction will therefore not be as rigorous as for the runway.

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2. Differentiate cross wind and head wind components.

CROSS WIND COMPONENT HEAD WIND COMPONENT
It is not possible to get the direction The runway is usually oriented in
of opposite wind parallel to the the direction of the prevailing
centre – line of the runway length winds. The head wind indicates the
everyday of throughout the year. wind from the opposite direction of
For some period of the year at least, the head or nose of the aircraft
the wind may blow making some while it is landing or taking off.
angle θ with the direction of the
centre – line of the runway length.
If ‘V’ kmph is the velocity of the
inclined opposing wind, its
component 𝑉 sin 𝜃 which is normal
to the centre – line of the runway
length is called cross wind
component.

3. What are the advantages of head wind?

 During landing, it provides a breaking effect and the aircraft comes to
a stop in a short length of the runway
 During takeoff, it provides greater lift on the wings of the aircraft

4. What are the elements of geometric design of taxiway?

 Length of taxiway
 Width of taxiway
 Longitudinal gradient
 Rate of change of longitudinal gradient
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 Sight distance
 Transverse gradient
 Turning radius
 Width of safety area

5. What are the markings made on taxiways?

 Taxiway centre line marking
 Taxiway holding position marking
 Taxiway intersection marking

6. What are the types of taxiway lightings?

 Taxiway centre line lights
 Taxiway centre line lights on rapid exist taxiways
 Taxiway centre line lights on other exit taxiways
 Taxiway guard lights

7. What are the factors should be consider for layout of taxiway?

 Arrangement
 Busy airports
 Crossing
 Higher turn – off speeds
 Route

8. What are the factors considered for the location of exit taxiways?
 Air traffic control
 Exit speed
 Location of runways
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 Number of exists
 Pilot variability
 Topographical features
 Types of aircraft
 Weather conditions

9. Enumerate the necessity of aircraft classification.

The necessity of aircraft classification is the method of propulsion and
method of engine is provided. The main purpose of providing an engine to
the aircraft is to make available the force for propelling the aircraft through
the air.

10.Define “turning radius of taxiway”.

A horizontal curve is to be provided whenever there is a change in the
direction of the taxiway. It is necessary to design the curve in such a way
that the aircraft can negotiate it without significantly reducing the speed.
For this purpose, the circular curve of large radius is most suitable and its
radius can be obtained from the following formula
𝑉2
𝑅=
125 𝑓

Where,

R = radius of curve in m

V = speed of aircraft in kmph

f = coefficient of friction between the tyre and pavement surface usually

assumed as 0.13

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11.Mention the purpose of installing visual aids at the airport?

 To avoid accidents during landing of the aircraft
 To convey to the pilot the ground to air visual information required
during landing
 To direct the pilot to make the landing of the aircraft in the landing
area only
 To enable the pilot to locate and identify the particular feature
specified by the marking
 To grant safety to the persons and properties
 To maintain an orderly flow of aircraft without any congestion
 To satisfy the visual requirements for takeoff and taxiing

12.What are the airport markings?

 Apron marking
 Landing direction indicator
 Runway marking
 Shoulder marking
 Taxiway marking
 Wind direction indicator

13.What are the guidance and information required by the pilots during
landing operation?
 Alignment guidance
 Height information
 Visual parameters

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14.What are the factors, which affect the type and intensity of airport
lighting?
 Airport classification
 Amount of traffic
 Availability of power
 Nature of aircraft using the airport
 Type of night operations planned
 Type of the landing surfaces provided
 Weather conditions

15.Give the elements of airport lightings.

 Airport beacon
 Approach lighting
 Apron and hangar lighting
 Boundary lighting
 Lighting of landing direction indicator
 Lighting of wind direction indicator
 Runway lighting
 Taxiway lighting
 Threshold lighting

16.Define heliport.
The area for landing and taking off of helicopter is known as heliport.

17.What are the two arrangements adopted for approach lighting?

 Calvert system
 ICAO system
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18.Define the term visibility.

The greatest distance, to which a prominent object of certain specified
dimension is perceivable to the eye, the object being observed in the day
light during day and properly lit during night under the existing atmospheric
conditions is known as visibility.

19.Define ceiling.
The meteorological visibility is also generally associated with the
height of the underside of a dense cloud above the airport surface. The
height is referred to as the ceiling.

20.What are the broad principles that are to be observed in the design of a
terminal building?
 Arrival and departure areas
 Baggage delivery
 Information
 Movement

21.What are the basic requirements to be kept in mind while deciding the
site for a terminal building?
 It should be centrally located with respect to the runways
 It should have convenient and easy access to the highway
 It should have enough provision for future expansion
 It should have favorable orientation with respect to wind,
topographical features of the area, etc.
 There should be adequate space available for the parking of the
vehicles
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 The site should have easy facility of natural drainage

 The utilities like water, sewage and telephone should be easily
available

22.What is the importance of air traffic control?

 It avoids the possibility of occurrence of the accidents in the air
 It grants the economic and efficient utilization of the aircraft and the
airports
 It guides the aircraft to their destinations safely and speedily
 It increases the confidence of the passengers using the facility of air
travel
 It separates the aircraft to a safe distance during their flight both
vertically as well as horizontally

23.What are the three components of an air traffic control network?

 Control centres
 Control towers
 Flight service stations

24.What are the types of air traffic control aids?

 En route aids or airway aids
 Landing aids or terminal aids

25.Define passenger flow.

The design of the terminal building should be such that an
uninterrupted flow route is formed for the passengers to follow on or off an
aircraft without offending or disturbing each other.
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26.Define calm period.

The absence of appreciable wind, generally considered as 6kmph or
less is called the calm period. The knowledge of calm periods of a particular
place throughout the year plays an important role in designing an airport.

27.What are the systems of aircraft parking?

 Frontal or linear system
 Open – apron or transporter system
 Pier or finger system
 Satellite system

28.What are the different types of parking of aircraft?

 Nose – in parking
 Angled nose – in parking
 Nose – out parking
 Angled nose – out parking
 Parallel parking

29.Define time of concentration.

The total time required by the flow to reach to the maximum limit is
known as the time of concentration and it consists of two parts are time of
entry and time of flow.

30.What are the functions of airport drainage?

 To intercept and divert the surface and groundwater flow originating
from lands adjacent to the airport

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 To lower the sub – surface water level in the airport so as to be within

permissible limit
 To remove the surface runoff from the airport

31.What are the characteristics of airport drainage?

 Absence of side surface ditches or drains
 Combined drainage pipe for surface and sub – surface drainage
 Comparatively flat longitudinal and transverse grades
 Concentration of the outfall flow
 Extensive area under consideration
 Heavy concentrated wheel loads of the modern aircraft
 Large percentage of paved areas in the form of the aprons, taxiways
and runways
 Proper provision of future runway extension
 Requirement of rapid drainage for the safety of the aircraft operations
 Shallow water courses
 Varying soil conditions

32.What are the basic requirements of airport drainage system?

 Capacity
 Future expansion
 Rapid drainage
 Strength

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33.What are the aims of Airport drainage?

 If the sub – surface drainage system is improper, it may moisten and
weaken the sub – grade and thus, reduce its load bearing capacity,
resulting in the failure of pavements of runways, taxiways, etc.
 If the surface drainage system is improper, it may result in the
ponding on the pavements of runways, taxiways and aprons which
might prove hazardous to the takeoff and landing operations of the
aircraft
 It grants longevity to the pavements
 It increases the efficiency of the airport
 It is essential for proper and safe functioning of the aircraft
 It reduces the maintenance cost of an airport
 It shortens the periods during which the airport might have to be kept
out of use due to inundation, etc. The closing down of the airport
results in great loss in addition to the inconvenience of the passengers

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