Transportation Engineering

Course Code –CE-422

Contact Hours -3+3

Dr Hassan Mujtaba
 Railway Track

Sleeper

Ballast
Rails

2
Cross Section of a Railway Track

Formation
Ballast

Natural Subgrade

3
 History of Railway
• Goods are carried by head load or carts drawn
by men or animals in the past.

• Efforts were made to replace manual or animal

labour with mechanical labour

• Modern railways are refined form of tramways

and plateways of eighteenth century.
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 Development of Railways
• The original tramways consisted of two lines
of slabs of stones or beams made of timber laid
flush with an existing road surface to facilitate
the haulage of heavy loads by horses.

• The timber beams were subsequently covered

with iron straps or plates to reduce wear.

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 Development of Railways (cont’d)

• These plates were later replaced by angle irons

with one edge vertical to keep the wheels on
the track. These were known as plateways.

• In 1789, cast iron beams with supports at the

ends were used by William Joseph in England
and the present permanent way or track
gradually evolved.

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 Development of Railways (cont’d)
• The steam engine was developed after the
introduction of tramways.
• Nicolas Cugnot in France and William
Murdock in Britian carried out experiments
with steam carriages since 1771.
• The first steam locomotive was developed by
Richard Trevithick and was used for traction on
roads.
• George Stephenson in 1814 produced first
locomotive to be used for traction in railways.
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 Development of Railways (cont’d)

• The first railways in England was

– the Stockton and Darlington in 1825.
• In America
– the Mohawk and Hudson in 1833
• In subcontinent (Indo- Pak) in 1853

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 History of Pakistan Railways
• The idea of first rail network was though in 1847 with
Karachi being the sea port.
• Sir Henry Edward Frere sought permission from Lord
Dalhousie to begin survey for Karachi seaport and a
railway line in 1858.
– The proposed railway line was to connect Karachi
(city) to Kotri.
– Stream boat service on the Indus and Chenab river
to connect Kotri to Multan
– From Multan another railway line would be laid to
Lahore and beyond.
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 History of Pakistan Railways
• In 1886, North Western State Railways later on
named as (NWR) was formed which eventually
became Pakistan Railway in 1947 by merging four
companies.
• The company names are
– Scinde (Sindh) Railway
– Indian Flotilla Company
– Punjab Railway
– Delhi Railway
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 History of Pakistan Railways
• 1861 first railway line was opened to public between
Karachi city and kotri (105 miles long/ 169 km)
• 1889 railway line between Karachi city and Kemari
was opened
• 1897, line from Kemari to Kotri was doubled.
• 1898, Peshawar to Karachi railway line was
proposed.
• During early 20 century, railway line was laid
between Peshawar and Rawalpindi and Rawalpindi
and Lahore.
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 History of Pakistan Railways
• In 1947,3133 km of North Westren Railway
were transferred to India leaving 8122 km to
Pakistan.
• In 1961, Pakistani portion of NWR was
renamed as Pakistan Railways

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 History of Pakistan Railways

• In 1954, railway line was extended to Mardan

and Charshadda

• In 1956, Jacobabad- Kashmore 2 ft 6 in (762

mm) was converted into Broad Gauge (5.5 ft).

• Kot Addu- Kashmore line was constructed

between 1969 to 1973.
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 Pakistan Railways
• Total length of the rail track in Pakistan is
about 11881 km.
• Major Routes (Domestic)
– Peshawar-Karachi
– Peshawar-Quetta
– Lahore- Sialkot
– Lahore- Faisalabad
– Faisalabad- Khanewal
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 Pakistan Railways
• Proposed Routes are
– Karachi – Gawadar
– Quetta – Gwadar
– Bostan – Zhob
– Rawalpindi - Sost

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Railway
Network of
Pakistan

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 International Routes

• Iran
– A broad gauge (BG) railway track runs from
Zahedan to Quetta.
– There is a break -of- gauge between Islamic
Republic of Iran Railways (SG) and Pakistan
Railways (BG).

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 International Routes
• India
– Thar Express to Karachi
– Samjhauta Express (Lahore to Amritsar
(Attari) and Delhi, India
• China
– There is no rail link with China
– Feasibility study for rail line between Havelian
via Khunjerab Pass to Kashgar has been
awarded.
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 International Routes
• Afghanistan
– No rail link exist
• However, Pakistan has extended his help to
built Afghan Rail network in three phases
– Chaman to Spain Boldak
– Extend this line to Khandar
– Finally, to Herat

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 International Routes
• Turkey
– Istanbul – Tehran – Islamabad rail service
was proposed recently.
• Turkmenistan via Afghanistan is also proposed

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 Track Doubling
• Lodhran – Multan – Khanewal line (121 km )
was dual tracked. (2003 – 2007)

• Khanewal – Raiwind line has been doubled

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 Track Doubling Proposed
• Shahdrabagh – Lalamusa (126 km)

• Shahdrabagh – Faisalabad (135 km)

• Lalamusa – Chaklala (152 km)

• Golra Sharif – Peshawar Cantt (160 km )

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 Track or Permanent Way
• The combination of rails, sleepers, fittings, ballast
etc is known as a track or permanent way.

• In other words, railway locomotives, coaches or

wagon need a path to run over it

• The name of permanent way is given to the track

to distinguish the final track constructed for the
movement of trains from the temporary track laid
for the conveyance of earth material for
constructing formation of a railway track. 23
 Track

RAILS

Ballast
Sleepers

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 Formation
Ballast

Natural Subgrade

Cross Section of a Railway Track

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 Track Components
• Rails
• Sleepers
• Fittings and fastening
• Ballast
• Formation

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 Functions of Track Components

• Rails
– Rails are the steel girders over which the train
moves and transmit the wheel loads of the
trains to the sleepers below.
• Sleepers
– The sleepers hold the rails at exact distance
or gauge throughout with the help of fittings
and fastening and transfer the load from the
rails to the ballast below.
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Functions of Track Components
• Ballast
– Ballast holds the sleeper in position and
provides a uniform level surface.
– Ballast act as an elastic bed to absorb the
blows and shocks of the moving train.
– They also provide drainage to the track and
transfer the load to larger area of the
formation below.
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 Functions of Track Components
• Fittings and Fastening
– They provide a grip between the rails and the
sleepers.
– The rails are fastened with the sleepers by
fittings and fastening.
• Formation
– Formation is the foundation of the railway
track made up of locally available earthen
material.
– It distribute the load over wider area of the
natural ground. 29
 Requirement for an ideal track
• Gauge of the track should be uniform and
correct.
• Alignment of the track should be correct.
• In straight reaches the rail level should be the
same while on curves proper transition curves
should be provided between straight and the
curves.
• The rails should have perfect cross level. On
the curves the outer rail should have proper
super elevations to take into account the
centrifugal forces.
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 Requirement for an ideal track
• Gradient should be uniform and as gentle as
possible. Too steep gradient should be
avoided.
• Drainage system of the track should be perfect.
• Friction between the wheels of the rolling
stock and the rail should be minimum.
• Track should be designed in such a way that
the load of the train should be uniformly
distributed over it.
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 Requirement for an ideal track
• Adequate provision of repair , replacement and
renewal of the damaged portion should be
provided.
• Track should possess high resistance to the
damage at the time of derailment.
• Joints, points and crossing should be designed and
maintained properly.
• The track should possess antitheft qualities.
• The structure of the track is less so that not only
its initial cost as well as the maintenance cost
should be low.
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 Capacity of railway Track
• Maximum number of trains that can run safely
on any given length of the track per hour.

• In actual practice, it is somewhat less due to

safety considerations as speed of train,
signaling and control system etc.

• Maximum number of the trains which can be

handled in a yard per day is known as terminal
capacity. 33
 Measures to Increase Track Capacity

• The track speed of all the trains should be kept

same. This can be achieved by providing
uniform gauge and traction. The speed of
trains can be achieved using diesel or electric
traction.

• To alert the driver regarding the position of the

section ahead, multi aspect signaling may be
adopted.
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 Measures to Increase Track Capacity

• Speed of the trains can be increased by making

suitable modification in the existing tracks and
removing the speed restrictions.
• Reduction in stoppage time of the trains will
increase the track capacity.
• To meet the present requirements, existing
yard facilities should be improved.
• For quick shunting operations, additional
operating facilities should be provided.
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 Comparison of Roads and Railways
• Nature of Track
– Flexible or rigid pavement
– Track is considered as a beam on elastic
foundation
• Service to user
– Door delivery is possible
– Delivery is at the railway station

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Comparison of Roads and Railways (cont’d)

• Transportation cost
– Economical for short distances because of saving
time and money in transit to and from station
– Economical for long distances because of reduced
operating expanses
• Nature of traffic
– traffic ranging from pedestrian to heavy trucks
– Track is reserved for scheduled trains

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Comparison of Roads and Railways (cont’d)

• Stresses
– transmitted to subgrade through pavement and
formation
– Heavy concentrated loads of locomotives, wagons
and coaches come on the track
• Speeds
– Speed is restricted due to variety of traffic
– Comparatively higher speed can be achieved
because there is no obstruction on the track
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Comparison of Roads and Railways (cont’d)

• Frictional Resistance
– between the tyres and the road surface is high
– Between the steel rails and the steel wheel.
Frictional resistance is about 20% of the road
resistance.
• Cost of construction
– Comparatively less
– The rails has to be carefully laid and rigidly fixed
at fixed distances hence heavy cost
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Comparison of Roads and Railways (cont’d)

• Cost of maintenance
– Comparatively less
– Even slight change is distance would result in
derailment.
• Change of track
– Change from one highway to another is done by
junctions and crossings
– The lateral movement of trains wheels is restricted
because of wheel flange fixed to the rails.
Moreover to move from one track to another is
done through points and crossings. 40