UNIT-I

RAILWAY ENGINEERING
{BALLAST & FISHPLATES}

LECTURE BY
VENKATESH KANNEKANTI
jusvenki@yahoo.in // 14-11-2012
AGENDA OF LECTURE

BALLAST
 Functions
 Requirements
 Types
 Renewal of ballast
FISH PLATES
 Introduction on fish plates
 Failures of fish plates.
BALLAST
 WHAT IS BALLAST
 Ballast is a granular material usually broken
stone or brick, shingle or kankar, gravel or sand
placed and packed below and around the
sleepers to transmit load.

 Ballast also provides suitable drainage to the

railway track.
FUNCTIONS OF BALLAST

Some of the important functions of ballast are:

 To provide firm and level bed for the sleepers to
rest on
 To allow for maintaining correct track level
without disturbing the rail road bed
 To drain off the water quickly and to keep the
sleepers in dry conditions
FUNCTIONS OF BALLAST
To discourage the growth of vegetation.
 To protect the surface of formation and to form
an elastic bed.
 To hold the sleepers in position during the
passage of trains.
 To transmit and distribute the loads from the
sleepers to the formation.
 To provide lateral stability to the track as a
whole.
REQUIREMENTS OF BALLAST

The ideal material for ballast should fulfill the

following requirements.
 Ballast should not produce any chemical action
with rails and metal sleepers.
 It should be possible to maintain the required
depth of the material in order to distribute the
load of passing train on the formation ground.
 The material to be used for ballast should not
be too rigid but it should be elastic in nature.
REQUIREMENTS OF BALLAST
 The material for ballast should be of such
nature that it grips the sleepers in position and
prevent their horizontal movement during
passage of train.
 It should not allow the rain water to accumulate
but should be able to drain off the water
immediately without percolating.
 It should be strong enough a resistance to
abrasion.
REQUIREMENTS OF BALLAST
 The size of ballast is 5cm for wooden sleepers,
4cm for metal sleepers & 2.5cm for turnouts
and crossovers.
 The ballast material should be easily workable.
TYPES OF BALLAST
 The different materials used for the ballast in India are :
1) Broken Stone
2) Gravel
3) Cinders / Ashes
4) Sand
5) Kankar
6) Moorum
7) Brick Ballast
8) Blast Furnace slag
9) Selected Earth.
TYPES OF BALLAST
1. Broken Stone
 Broken stone is one of the best materials for
railway ballast to be used on the railway tracks.
 Almost all the important railway tracks are
provided with broken stone.
TYPES OF BALLAST
Broken Stone
 The stone to be used as railway ballast should
be hard, tough, nonporous and should not
decompose when exposed to air and light.
 Igneous rocks like quartzite and granite forms
the excellent ballast materials. When these are
not available then lime stone and sand stone
can also be used as good ballast material.
TYPES OF BALLAST
Advantages of Broken Stone
 It holds the track in position
 It is good for heavy traffic
 It can serve high speeds equally well.
Disadvantages of Broken Stone
 The main disadvantage is that it is expensive in its
initial cost.
TYPES OF BALLAST

2. Gravel
 Gravel ranks next in its suitability for use as
materials for ballast and is used in many
countries of the world in very large quantities.

TYPES OF BALLAST

2. Gravel

 Gravel consists of worn fragments of rocks

occurring in natural deposits. Gravel or shingle
may be obtained from river bed or it may be
dug out from gravel pits.
TYPES OF BALLAST
Advantages of Gravel
 It is cheaper in its cost as it has not to be broken as like
stone ballast.
 It has got excellent drainage properties, if properly
cleaned.
Disadvantages of Gravel
 It easily rolls down under the vibrations and packing
under the sleepers get tense
 The variation in size is considerable and hence requires
screening before use
 It is obtained from gravel pits, is full of earth and hence
requires proper cleaning if proper drainage of the track
is to be done.
TYPES OF BALLAST
 3. Cinders Or Ashes
 The residue from the coal in locomotives or
other furnaces is called cinder or ashes.
 It is one of the universal forms of ballast as it is
a byproduct of all the railway which uses coal
as a fuel.
TYPES OF BALLAST
Advantages of Cinders or Ashes
 Handling of the material is not cumbersome this
material can be handle easily
 Cost is very low and hence can also be used for sidings
 It has got fairly good drainage properties
 Large quantities of this material can be made available
at short notice.
 In case of emergence such as caused by the destruction
of portion of railway track during floods.
 This material proves to be very useful and is used in the
formation repairing as well as for packing of track.
TYPES OF BALLAST
Disadvantages of Cinders or Ashes
 It is highly corrosive and cannot be used where steel
sleepers are fixed
 The foot of the rails get affected due to use of this type
of material as ballast
 It is very soft and can easily be reduced to powder under
vibrations and hence the track becomes very dusty.
 This is objectionable particularly in dry weather.
TYPES OF BALLAST
4. Sand
 Sand is another good materials for railway
ballast , coarser sand is to be preferred to finer
sand.
 The best sand is that which contains a good
quantity of fine gravel and sand which is used
on narrow gauge tracks.
TYPES OF BALLAST
Advantages of Sand
 If the sand is free from earth and vegetation then it has
good excellent properties to drain off water immediately
 It is cheaper if available in nearby locality

 It produces very silent track and hence are suitable for

packing cast iron pot sleepers.
Disadvantages of Sand
 It gets easily disturbed under vibrations and hence its
maintenance is very difficult.
 The sand can be easily washed off or blown away and
hence requires frequent renewal.
TYPES OF BALLAST
 The sand particles may get into the moving
parts of the vehicles and produces friction.
 This leads to heavy wear of vehicles
TYPES OF BALLAST
 5. Kankar
 Kankar a lime agglomerate is found in many
places in the form of nodules of varying sizes.
TYPES OF BALLAST
Advantages of Kankar
 Kankar is suitable Materials for ballast when other good
material for ballast is not available or if available
uneconomically.
 Kankar is good for light traffic on meter and narrow gauges
Disadvantages of Kankar
 It is very soft and can be reduced to powder form easily, hence,
making the track dusty.
 The maintenance of track is very difficult.
TYPES OF BALLAST
6. Moorum
 The decomposition of laterite results into the
formation of moorum.
 It has red and sometimes yellow color.

 The best moorum is that which contains large

quantities of small laterite stones.
TYPES OF BALLAST
Advantages of Moorum
 Moorum is good materials for ballast when other
material for ballast is not available.
 Moorum can be safely used on newly laid track
and acts as a soling when broken stones are laid
afterwards.
 Moorum has got good drainage properties.
Disadvantages of Moorum
 Moorum is very soft and reduces to powder and
hence to dust form in short time.
 Maintenance of tracks laid with this material is
difficult.
TYPES OF BALLAST
7. Brick Ballast Or Brick Bats
 Sometimes the broken pieces of over burnt
bricks, called brickbats, are used as materials
for ballast.
TYPES OF BALLAST
Advantages of Brick Ballast
 It has got excellent drainage properties

 They can be used as good ballast material where suitable

material for ballast is either unavailable or uneconomical.

Disadvantages of Brick Ballast

 Brickbats turn down into powder form easily and hence the
track becomes dusty
 Maintenance of the track laid with this material as ballast is
very difficult.
 Rails are often corrugated on the tracks laid with this material
as ballast.
TYPES OF BALLAST
 8. Selected Earth
 Selected earth may be used as material for
railway ballast for sidings and also for newly
laid tracks.
 Indurated (hardened) clay and decomposed
rock are suitable materials.
RENEWAL OF BALLAST

 Due to the prolonged and repeated movement

of wheel loads over the railway track, the
ballast material gets crushed.
RENEWAL OF BALLAST

 The fine crushed particles gets filled in the

voids and form an impervious layer, which
prevents the rapid flow of rain water.
 To makeup the loss, the ballast is renewed time
to time.
 In the process of renewal, the crushed fine
material is removed by screened and new
material of desired size is added.
DETAILS OF BALLAST SECTIONS
SL.NO DIMENSIONS B.G M.G N.G

1 WIDTH OF BALLAST 3.35 m 2.5 m 1.83 m

2 DEPTH OF BALLAST 20 TO 25 cm 15 TO 20 cm 15 cm

3 QUANTITY OF 1.036 m3 0.71 m3 0.53 m3

BALLAST
PER METER LENGTH
 Chapter- 4
FISH PLATES
 TRACK FITTINGS
 Track fittings and rail fastenings are used to keep
the rails in the proper position.
 The important fittings commonly used in a
permanent-way are the following.
 Fish plates
 Spikes
 Bolts
 Chairs
 Blocks
 Keys & plates
FISH PLATES
FISH PLATES

 Fish plates are used in rail joints to continuity

of the rails and to allow for any expansion or
contraction of the rail.
FISH PLATES

 They maintain the correct alignment of the line

both horizontally and vertically.
FAILURE OF FISH PLATES

The following are the failures of fish plates.

 Abrasion on the top of the fish plate.

 Reversal of stresses due to large length of

fishplates resulting into cracking along the section.

 Cracking developed along the section may even

extend up-to top or bottom of fish plate.