University:West Bengal University of Technology
Course: B.Tech Civil Engineering
Subject : BIET transport engineering solve
Year of Question Paper : 2012
BIET _ Transport solve _ 7th sem
Group b
What are the possible causes of creep?
Ans:
Ironing effect of the wheel: the ironing effect of moving wheels on the waves formed in the rail tends to cause the rail to move in the direction of traffic, resulting in creep.
Starting and stopping operations: when a train starts or accelerates the backward thrust of its wheels tends to push the rail backwards. Similarly when the train slows down or comes to a halt, the effect of the applied brakes tends to push the rail forward. This in turn causes creep in one direction or the other.
Changes in temperature: creep can also develop due to variations in temperature resulting in the expansion and contraction of the rail. Creep occurs frequently during hot weather conditions.
Unbalanced traffic: in a double-line section trains move only in one direction. Creep therefore develops in the direction of traffic. In a single line section, even though traffic moves in both directions, the volume of the traffic in each direction is normally variable.
Poor maintenance of track: some minor factors, mostly relating to the poor maintenance of the track, also contribute to the development to the development of creep.
Requirements of a good harbor:
The ship channels which may either be natural or artificial must sufficient depth for the draft of the vessels visiting the harbor.
The bottom should furnish secured anchorage to hold the ships against the force of high winds.
The land masses or breakwaters must be provided to protect against the destructive wave action.
The harbor entrance should be wide enough to permit ready passage for shipping and at the same time it should be narrow enough to restrict the transmission of excessive amounts of wave energy during storm.
Define runway and taxiway. Give neat sketch of a single runway airport.
Ans:
Runway: it is defined rectangular area for the landing; take off of aircraft along its length.
Taxiway: it is defined path on a land aerodrome, selected or prepared for the use of taxing aircraft to and from the runway.
Runway
Sketch: Hanger
Terminal Building
Apron
Taxiway
Taxiway
airport single runway
Merits and demerits of concrete sleepers:
Merits:
The concrete sleepers are quite heavy and thus provide longitudinal, lateral and vertical stability.
The concrete sleepers result in reduced rail bending stresses.
These sleepers have a long useful life of 50 years.
Suitable for track circuiting.
Can be manufactured from local resources.
Demerits:
They are not economical because of high cost of construction.
High standard of maintenance of track is required.
The design and construction are both complicated.
They are more rigid.
Cross section of B.G track in embankment showing the various elements:
Group c
Calculate the maximum permissible train load that can be pulled by a locomotive having four pairs of driving wheels carrying an axle load of 24 tonnes each. The train has to run at a speed of 80km/hr on a straight level track (B.G).
Also calculate the reduction in speed if the train has to climb a gradient of 1 in 200.
If the train climbs the gradient with a curve of 2 degree, what would be reduction in speed?
Ans:
Hauling power of the locomotive = no of pairs of driving wheel*wt on each pair*coefficient of friction=4*24*.2=19.2t
Total resistance negotiated by the train on a straight level at a speed of 80km/hr
Rf+Rwa+Rwi
=.0016W+.00008WV+.0000006WV2
=.01184W
Total resistance=hauling power
W*.01184=19.2t or W=1621.62t
On a rising gradient of 1 in 200, there will be an additional resistance due to gradient= W*gradient
Total resistance=hauling power
19.2=.0016W+.00008WV+.0000006WV2+W(.5/100)
Or, V= 48.128km/hr
On a curve of 2 degree with a rising gradient of 1 in 200 curve resistance for BG will be equal to
R=.004*degree of curve*Wt=.0004*2*W
Hauling power of locomotive=total resistance
19.2=.0016W+.00008WV+.0000006WV2+W (.5/100)+.0008W
Or, .0000006V2+.00008V-.00444=0
Or, V=42.17km/hr
So reduction in speed = 48.128-42.17=5.958km/hr
What do you understand by negative super elevation? Explain with sketch
Ans:
Mainline: B higher than A
Branch line: A higher than B
This two contradictory condition cannot be achieved at a time. On branch line outer rail is kept lower than inner rail. So branch line is experienced a negative super elevation. Therefore speeds on both the track must be restricted particularly on branch line.
Short notes:
Cant deficiency: e
It is the difference between the cant required for equilibrium speed to the cant which is actually provided.
For BG Cant deficiency = 75 mm. (maximum)
For MG Cant deficiency = 65 mm. (maximum)
Grade compensation on curves:
Whenever a train is pulled along a curve, an additional tractive force is required. The ruling gradient is the maximum gradient on a particular section of the track. If a curve lines on a ruling gradient, the total resistance due to the gradient and curvature will exceed the ruling gradient. In order to avoid the total resistance beyond the permissible ruling gradient, the gradients are reduced on curves. This reduction in gradient is known as grade compensation on the curves.
The curve resistances are generally expressed as a percentage per degree of a curve.
B.G.track ….. 0.04% per degree
M.G. track ….. 0.03 5 per degree
N.G track …..0.02% per degree
On a B.G 3 degree curve the equilibrium cant is provided for a speed of 70km/hr. calculate the value of equilibrium cant.
Allowing a maximum cant deficiency what would be the maximum permissible speed on the track?
Ans:
Vmax =70 Kmph > 50
Avg Velocity =52.5 Kmph
4.35
Hence avg, velocity=52.5Kmph
e =
Equilibrium cant =62.36mm
Allowing maximum cant deficiency cant for maximum speed=62.3+76=138.3mm
138.3 =
78.19km/hr
Or,Vmax=
Define breakwater: the protective barrier constructed to enclose harbours and to keep the harbor waters undistributed by the effect of heavy and strong seas are called breakwaters.
Classification:
heap/ mound breakwater
mound with superstructure/ composite breakwater
upright wall breakwater
special breakwaters
Forces acting of break water:
Hydrostatic forces: this force reduces the apparent weight and hence the marine structures suffer these looses to a great extent unless the foundations are absolutely impervious.
External forces: the intensity f external forces especially wind and wave action is enormous. The power of wind produces vibrations in the masonry structures and weakens the different courses of masonry. In a similar way the way the wave when it recedes induces suction action and it results in the erosion of the foundation unless it is made safe and secure.
Solvent action of sea water: this quality of sea water causes damage to the materials of construction.
Sea insects: the concentrated action of sea insects results in the understanding of the hardest and the soundest building material and it is for this reason that the marine structures are made specially bulky and strong.
Force diagram
Controlling factors for selection of type of backwater:
availability of materials of construction
depth of water at site of construction
nature of natural foundations
equipment available for construction
funds and time available for construction
Rubble mound diagram:
Different types of airport:
Personal: airports to handle light aircraft for small communities or urban area
Secondary: airports for large aircraft in non scheduled flying activities
Feeder: airports to serve certified feeder airlines
Trunk lines: airports to serve smaller cities on airline trunk routes
Continental: airports serving aircraft making long nonstop domestic flights
Intercontinental: airports terminating long international flights
Intercontinental express: airports serving the largest transoceanic flights
Name of the basic components of airport:
Runway: it is defined rectangular area for the landing; take off of aircraft along its length.
Taxiway: it is defined path on a land aerodrome, selected or prepared for the use of taxing aircraft to and from the runway.
Airport Apron/ramp: It is usually the area where aircraft are parked, unloaded or loaded, refueled or boarded.
Hanger: A hangar is a closed structure to hold aircraft or spacecraft in protective storage.
Terminal area: it is a control area or portion thereof normally situated at the confluence of air traffic in the vicinity of one or more airfields.
Proximity to other airports:
The nature and volume of business carried at other existing airports in the near vicinity and their plans for further expansion must be studied in detail. The study shall include their history of development, their present financial and operational status; the safety features adopted their planning and design defects which could be improved upon in the planning and construction of the proposed airport or airports.
Neat sketch showing ground side and air side components of an airport
Windrose diagram: graphical procedure used to analyze the wind data for the determination of the best runway orientation.
Types:
Compass type
Free type
Difference: Compass type of windrose plot has either 4,8 or 16 compass direction axis. Directions in input data are limited to one of the compass directions in the plot. The directions are specified as ordinal number of the direction axis. But free type of windrose plot has no pre-defined direction axis. Directions in input data can be arbitrary angles. The 0-angle corresponds to the East direction (3 o'clock).
Problem:
Wind direction Percentage of wind
N 3.6
NNE 2.8
NE 7.8
ENE 5
E 10.3
ESE 2.2
SE 5.6
SSE 2.9
S 8.2
SSW 5.7
SW 7.3
WSW 4.9
W 4.9
WNW 7.6
NW 7.7
NNW 4.1
Calm wind =9.4%
Total =100
Ans: we have to now plot the wind directions and wind percentages in a wind rose diagram.
Course: B.Tech Civil Engineering
Subject : BIET transport engineering solve
Year of Question Paper : 2012
BIET _ Transport solve _ 7th sem
Group b
What are the possible causes of creep?
Ans:
Ironing effect of the wheel: the ironing effect of moving wheels on the waves formed in the rail tends to cause the rail to move in the direction of traffic, resulting in creep.
Starting and stopping operations: when a train starts or accelerates the backward thrust of its wheels tends to push the rail backwards. Similarly when the train slows down or comes to a halt, the effect of the applied brakes tends to push the rail forward. This in turn causes creep in one direction or the other.
Changes in temperature: creep can also develop due to variations in temperature resulting in the expansion and contraction of the rail. Creep occurs frequently during hot weather conditions.
Unbalanced traffic: in a double-line section trains move only in one direction. Creep therefore develops in the direction of traffic. In a single line section, even though traffic moves in both directions, the volume of the traffic in each direction is normally variable.
Poor maintenance of track: some minor factors, mostly relating to the poor maintenance of the track, also contribute to the development to the development of creep.
Requirements of a good harbor:
The ship channels which may either be natural or artificial must sufficient depth for the draft of the vessels visiting the harbor.
The bottom should furnish secured anchorage to hold the ships against the force of high winds.
The land masses or breakwaters must be provided to protect against the destructive wave action.
The harbor entrance should be wide enough to permit ready passage for shipping and at the same time it should be narrow enough to restrict the transmission of excessive amounts of wave energy during storm.
Define runway and taxiway. Give neat sketch of a single runway airport.
Ans:
Runway: it is defined rectangular area for the landing; take off of aircraft along its length.
Taxiway: it is defined path on a land aerodrome, selected or prepared for the use of taxing aircraft to and from the runway.
Runway
Sketch: Hanger
Terminal Building
Apron
Taxiway
Taxiway
airport single runway
Merits and demerits of concrete sleepers:
Merits:
The concrete sleepers are quite heavy and thus provide longitudinal, lateral and vertical stability.
The concrete sleepers result in reduced rail bending stresses.
These sleepers have a long useful life of 50 years.
Suitable for track circuiting.
Can be manufactured from local resources.
Demerits:
They are not economical because of high cost of construction.
High standard of maintenance of track is required.
The design and construction are both complicated.
They are more rigid.
Cross section of B.G track in embankment showing the various elements:
Group c
Calculate the maximum permissible train load that can be pulled by a locomotive having four pairs of driving wheels carrying an axle load of 24 tonnes each. The train has to run at a speed of 80km/hr on a straight level track (B.G).
Also calculate the reduction in speed if the train has to climb a gradient of 1 in 200.
If the train climbs the gradient with a curve of 2 degree, what would be reduction in speed?
Ans:
Hauling power of the locomotive = no of pairs of driving wheel*wt on each pair*coefficient of friction=4*24*.2=19.2t
Total resistance negotiated by the train on a straight level at a speed of 80km/hr
Rf+Rwa+Rwi
=.0016W+.00008WV+.0000006WV2
=.01184W
Total resistance=hauling power
W*.01184=19.2t or W=1621.62t
On a rising gradient of 1 in 200, there will be an additional resistance due to gradient= W*gradient
Total resistance=hauling power
19.2=.0016W+.00008WV+.0000006WV2+W(.5/100)
Or, V= 48.128km/hr
On a curve of 2 degree with a rising gradient of 1 in 200 curve resistance for BG will be equal to
R=.004*degree of curve*Wt=.0004*2*W
Hauling power of locomotive=total resistance
19.2=.0016W+.00008WV+.0000006WV2+W (.5/100)+.0008W
Or, .0000006V2+.00008V-.00444=0
Or, V=42.17km/hr
So reduction in speed = 48.128-42.17=5.958km/hr
What do you understand by negative super elevation? Explain with sketch
Ans:
Mainline: B higher than A
Branch line: A higher than B
This two contradictory condition cannot be achieved at a time. On branch line outer rail is kept lower than inner rail. So branch line is experienced a negative super elevation. Therefore speeds on both the track must be restricted particularly on branch line.
Short notes:
Cant deficiency: e
It is the difference between the cant required for equilibrium speed to the cant which is actually provided.
For BG Cant deficiency = 75 mm. (maximum)
For MG Cant deficiency = 65 mm. (maximum)
Grade compensation on curves:
Whenever a train is pulled along a curve, an additional tractive force is required. The ruling gradient is the maximum gradient on a particular section of the track. If a curve lines on a ruling gradient, the total resistance due to the gradient and curvature will exceed the ruling gradient. In order to avoid the total resistance beyond the permissible ruling gradient, the gradients are reduced on curves. This reduction in gradient is known as grade compensation on the curves.
The curve resistances are generally expressed as a percentage per degree of a curve.
B.G.track ….. 0.04% per degree
M.G. track ….. 0.03 5 per degree
N.G track …..0.02% per degree
On a B.G 3 degree curve the equilibrium cant is provided for a speed of 70km/hr. calculate the value of equilibrium cant.
Allowing a maximum cant deficiency what would be the maximum permissible speed on the track?
Ans:
Vmax =70 Kmph > 50
Avg Velocity =52.5 Kmph
4.35
Hence avg, velocity=52.5Kmph
e =
Equilibrium cant =62.36mm
Allowing maximum cant deficiency cant for maximum speed=62.3+76=138.3mm
138.3 =
78.19km/hr
Or,Vmax=
Define breakwater: the protective barrier constructed to enclose harbours and to keep the harbor waters undistributed by the effect of heavy and strong seas are called breakwaters.
Classification:
heap/ mound breakwater
mound with superstructure/ composite breakwater
upright wall breakwater
special breakwaters
Forces acting of break water:
Hydrostatic forces: this force reduces the apparent weight and hence the marine structures suffer these looses to a great extent unless the foundations are absolutely impervious.
External forces: the intensity f external forces especially wind and wave action is enormous. The power of wind produces vibrations in the masonry structures and weakens the different courses of masonry. In a similar way the way the wave when it recedes induces suction action and it results in the erosion of the foundation unless it is made safe and secure.
Solvent action of sea water: this quality of sea water causes damage to the materials of construction.
Sea insects: the concentrated action of sea insects results in the understanding of the hardest and the soundest building material and it is for this reason that the marine structures are made specially bulky and strong.
Force diagram
Controlling factors for selection of type of backwater:
availability of materials of construction
depth of water at site of construction
nature of natural foundations
equipment available for construction
funds and time available for construction
Rubble mound diagram:
Different types of airport:
Personal: airports to handle light aircraft for small communities or urban area
Secondary: airports for large aircraft in non scheduled flying activities
Feeder: airports to serve certified feeder airlines
Trunk lines: airports to serve smaller cities on airline trunk routes
Continental: airports serving aircraft making long nonstop domestic flights
Intercontinental: airports terminating long international flights
Intercontinental express: airports serving the largest transoceanic flights
Name of the basic components of airport:
Runway: it is defined rectangular area for the landing; take off of aircraft along its length.
Taxiway: it is defined path on a land aerodrome, selected or prepared for the use of taxing aircraft to and from the runway.
Airport Apron/ramp: It is usually the area where aircraft are parked, unloaded or loaded, refueled or boarded.
Hanger: A hangar is a closed structure to hold aircraft or spacecraft in protective storage.
Terminal area: it is a control area or portion thereof normally situated at the confluence of air traffic in the vicinity of one or more airfields.
Proximity to other airports:
The nature and volume of business carried at other existing airports in the near vicinity and their plans for further expansion must be studied in detail. The study shall include their history of development, their present financial and operational status; the safety features adopted their planning and design defects which could be improved upon in the planning and construction of the proposed airport or airports.
Neat sketch showing ground side and air side components of an airport
Windrose diagram: graphical procedure used to analyze the wind data for the determination of the best runway orientation.
Types:
Compass type
Free type
Difference: Compass type of windrose plot has either 4,8 or 16 compass direction axis. Directions in input data are limited to one of the compass directions in the plot. The directions are specified as ordinal number of the direction axis. But free type of windrose plot has no pre-defined direction axis. Directions in input data can be arbitrary angles. The 0-angle corresponds to the East direction (3 o'clock).
Problem:
Wind direction Percentage of wind
N 3.6
NNE 2.8
NE 7.8
ENE 5
E 10.3
ESE 2.2
SE 5.6
SSE 2.9
S 8.2
SSW 5.7
SW 7.3
WSW 4.9
W 4.9
WNW 7.6
NW 7.7
NNW 4.1
Calm wind =9.4%
Total =100
Ans: we have to now plot the wind directions and wind percentages in a wind rose diagram.
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