2. 2
S. K. GARG Sr. Prof. (WORKS)
IRSE 1987 EXAM BATCH
Worked in Central Railways 1989 to 2008
Asst. Engineer at Wardha in Nagpur Division
Divisional Engr(N) in Solapur Division
Senior Divional Engineer(Co) in Mumbai Div
Dy Chief Engr in MTP and at Panvel in
Mumbai area
In Head quarters of Central Railways at CSTM
3. 5
Important Functions of Ballast
Resist vertical, lateral and longitudinal forces
Provide resilience and absorb energy
Reduce formation pressure
Facilitate track geometry correction
Facilitate track drainage
Provide voids
5. 8
Requirements of Track Ballast
Tough and wear resistant
Hard without getting crushed under moving loads
Generally cubical having sharp edge
Non-porous and non-absorbent of water
6. 9
Requirements of Track Ballast
Resist Attrition
Durable and should not get pulverized under
weather condition
Good drainage of water
Economical in cost
7. 10
Ballast may be subdivided into following
zones:
1. Crib
2. Shoulder
3. Top Ballast
4. Bottom Ballast
Track Ballast
10. 13
Flakiness Index
The flakiness index of an aggregate is
the percentage by weight of particles in
it whose least dimension (thickness) is
less than three-fifths(60%) of their mean
dimension
11. 14
Elongation Index
The elongation index of an aggregate is the
percentage by weight of particles in it whose
greatest dimension (length) is greater than
one and four-fifth times (1.8 times) their mean
dimension
15. 18
Remedial measures - fouling
Shoulder screening : Preventive maintenance –
Once in 3 yrs.
Deep Screening : Breakdown maintenance –
Once in 10 yrs.
Deep Screening of track shall be done after
500GMT or 10 years, whichever is earlier, or if
clean cushion is less than 150mm.(ACS132)
16. Physical
parameters
General
Requirement
Functional Requirement
i) Specific
Gravity
More mass More mass helps in resisting
lateral forces.
ii) Structure Cubical shape i. For compaction & internal
friction
ii. Round ballast cannot be
compacted
iii. Helps enhanced retentivity
a) Shape
b) Grading Uniformly graded i) Optimum voids for resilience and
drainage
ii) Longevity is controlled by the
voids available to accommodate
fines.
Parameters for determination of
Standard of Ballast
CONTD..
17. 21
Mechanical parameters
i) Hardness Resistance to abrasion/attrition, required
for least damage / breakage during
maintenance. This is measured by Los
Angels Abrasion value.
ii) Toughness Resistance to fracture under impact
loads. This is measured by Impact Value.
iii) Water
absorption
This should be checked to ensure higher
resistance to weathering during adverse
weather conditions.
Parameters for determination of
Standard of Ballast
CONTD..
18. 22
Chemical parameters:
i) Inertness This should be checked to ensure that
ballast is chemically inert and inactive
from decomposition.
Parameters for determination of
Standard of Ballast
19. 23
DETAILED SPECIFICATIONS
IRS GE – 1 JUNE 2004
Basic Quality: Ballast should be hard, durable
and as far as possible angular along
edges/corners, free from weathered portions of
parent rock, organic impurities and inorganic
residues.
Particle Shape: Ballast should be cubical in
shape as far as possible. Individual pieces
should not be flaky and should have generally
flat faces with not more than two rounded/sub
rounded faces.
20. 24
Mode of Manufacture:
1. All BG main lines and running lines, except on ‘E’
routes but including ‘E’ special routes: machine
crushed
2. Other BG lines and MG/NG routes
planned/sanctioned for conversion: preferably
machine crushed. Hand broken ballast can be
used in exceptional cases with prior approval of
Chief Track Engineer/CAO/C.
3. Other MG & NG routes not planned/sanctioned for
conversion: hand broken ballast, no approval shall
be required.
DETAILED SPECIFICATIONS
21. 25
Physical Properties
Ballast sample should satisfy the following physical
properties in accordance with IS:2386 Pt.IV-1963 when
tested as per the procedure given in Annexure 1&2
BG, MG & NG
(Planned/sanctioned
for conversion)
NG&MG(Other than
those planned for
conversion)
Aggregate
abrasion value
30% Max* 35% Max
Aggregate
Impact Value
20% Max* 30% Max
DETAILED SPECIFICATIONS
CONTD..
22. 26
* In exceptional cases, on technical and/or
economic grounds relaxable upto 35% & 25%
respectively by CTE in open line and CAO/C
for construction projects. The relaxation in
Abrasion and Impact Values shall be given
prior to invitation of tender and should be
incorporated in the tender document.
DETAILED SPECIFICATIONS
23. 27
The “Water Absorption” tested as per IS:2386
Pt-III – 1963 following the procedure given in
Annexure 3 should not be more than 1%. This
test however, to be prescribed at the
discretion of CE/CTE in open line and
CAO/Con for construction projects.
As per correction slip No 3 a new para 2.2.2.1
is added. Now CAO/CTE can permit relaxation
upto 2.5% in water absorption for specified
areas
DETAILED SPECIFICATIONS
24. 28
•SIZE AND GRADATION: FULL RATE
PAYMENT
Retained on 65mm sq. mesh sieve - 5% Maximum
Retained 40mm sq.mesh sieve
For machine crushed ballast : 40% to 60%
For hand broken ballast : Not required, but the
executive must ensure that the ballast is well graded
between 65 mm and 20 mm sieve.
Retained on 20mm sq.mesh sieve
Not less than 98% for machine crushed
Not less than 95% for hand broken
DETAILED SPECIFICATIONS
25. 29
OVERSIZE BALLAST - Reduced Rate
Payments
i) Retention on 65mm square mesh
sieve
A Maximum of 5% ballast retained on 65mm
sieve shall be allowed without deduction in
payment.
In case ballast retained on 65mm sieve
exceeds 5% but does not exceed 10%,
payment at 5% reduction in contracted rate
shall be made for the full stack.
DETAILED SPECIFICATIONS
26. 30
• If ballast retained on 40mm square mesh sieve
(machine crushed case only) > 60%, payment at the
reduced rates shall be made for the full stack in
addition to the reduction worked out above.
• 5% reduction in contracted rates if retention
on 40mm sq. mesh sieve is between 60%
(excluding) and 65% (including)
• 10% reduction in contracted rates if retention
on 40mm sq. mesh sieve is between 65%
(excluding) and 70% (including).
DETAILED SPECIFICATIONS
OVERSIZE BALLAST- Reduced Rate
Payments
27. 31
OVERSIZE:
When the ballast retained on 65 mm sieve > 10 %.
When the ballast retained on 40 mm sieve > 70 %.
UNDERSIZE:
When the ballast retained on 40 mm sieve < 40 %.
Machine Crushed Ballast: When the ballast retained on 20
mm sieve < 98%.
Hand Broken Ballast: When the ballast retained on 20 mm
sieve < 95%.
DETAILED SPECIFICATIONS
REJECTION OF BALLAST ON GRADATION
ACCOUNT
28. 32
METHOD OF SIEVE ANALYSIS
• Sieve sizes are nominal sizes.
• The following tolerances shall be permitted:
65mm square mesh sieve plus minus 1.5mm
40mm Square Mesh Sieve Plus Minus 1.5mm
20mm Square Mesh Sieve Plus Minus 1.0mm
• Mesh size of the sieves should be checked before actual
measurement.
• The screen shall not be less than 100cm in length, 70cm in
breadth and 10cm in height on sides.
DETAILED SPECIFICATIONS
29. 33
METHOD OF SIEVE ANALYSIS
• While carrying out sieve analysis, the screen shall not be
kept inclined, but held horizontally and shaken vigorously.
• The pieces of ballast retained on the screen can be turned
with hand to see if they pass through but should not be
pushed through the sieve.
• The percentage passing through or retained on the sieve
shall be determined by weight.
DETAILED SPECIFICATIONS
30. 34
CONDITIONS FOR SUBMISSION OF
TENDER
Each tenderer at the time of tendering shall submit
the test report of Impact Value, “Abrasion Value,
Water Absorption Value from approved
laboratories and the list of these Laboratories shall
be mentioned in the tender documents.
The tenderer shall also furnish an undertaking as
incorporated in the tender document that the ballast
supply at all times will conform to Specifications for
Track Ballast as specified by Railway.
DETAILED SPECIFICATIONS
31. 35
STACK MEASUREMENT
Stacking on a neat, plain, firm and well drained ground
The height of stack shall not be less than 1 m (hilly areas -
0.5 m ) but not more than 2.0 m.
Top width shall not be less than 1 m.
Top of stack shall be kept parallel to the ground plane.
The side slopes should not be flatter than 1.5:1 (H : V).
Cubical content of each stack shall normally be not less
than 30 cum in plain areas and 15 cum in hilly areas.
DETAILED SPECIFICATIONS
32. 36
WAGON MEASUREMENT
A continuous white line should be painted inside the
wagon
The cubical content in cubic meter corresponding to
white line should also be painted on both sides
outside the wagon.
In addition, short pieces of flats with cubical
contents punched shall be welded at the centre of
all the four sides as permanent reference.
In case the supply is taken in general service
wagons, actual measurements will be taken.
DETAILED SPECIFICATIONS
33. 37
SHRINKAGE ALLOWANCE
Payment shall be made for the gross
measurements either in stacks or in wagons
without any deduction for shrinkage/voids.
When ballast supply is taken in wagons,
shrinkage upto 8% shall be permitted at
destination while verifying the booked
quantities by the consignee.
DETAILED SPECIFICATIONS
34. 38
SAMPLING AND TESTING
A minimum of 3 samples of ballast for sieve
analysis shall be taken for measurement done on
any particular date even if the numbers of stacks to be
measured are less than three.
The test viz., determination of Abrasion Value, Impact
Value and Water Absorption should be got done
through approved laboratories or Railway’s own
laboratories (List of these laboratories shall be
mentioned in the tender document).
DETAILED SPECIFICATIONS
35. 39
Norms to be followed in respect of sampling, testing and
acceptance:
On supply of the first 100 cum, the tests for size gradation,
Abrasion value, Impact value and water absorption (if
prescribed) shall be carried out by Railways.
Further supply shall be accepted only after this ballast satisfies the
specifications for these tests.
Railway reserves the right to terminate the contract as per GCC at
this stage itself in case the ballast supply fails to conform with any
of these specifications.
DETAILED SPECIFICATIONS
CONTD..
SAMPLING AND TESTING
36. 40
Subsequent tests :
Supply in stack
Supply in
wagons
For stack of
volume less than
100cum
For stack volume
more than
100cum
a) Size and
Gradation Tests
- No of Tests One for each stack One for each
stack
One for each
wagon
- Size of one sample ** 0.027 cum
** 0.027 cum for
every 100cum or
part thereof
** 0.027 cum
b) Abrasion Value
Impact Value &
Water
Absorption test @
One test for every 2000 cum
DETAILED SPECIFICATIONS
CONTD..
37. 41
** Sample should be collected using a wooden box
0.3mx0.3mx0.3m from different parts of the
stack/wagon.
@ These tests shall be done for the purpose of monitoring
quality during supply – further supply can be suspended in
case of non-conformation.
• The above tests may be carried out more frequently, if
warranted at the discretion of Railway
All tests for abrasion value Impact value and water
absorption conducted subsequently to award of contract
shall be done at Railways’ cost.
DETAILED SPECIFICATIONS
38. 42
IRPWM PROVISIONS REGARDING
BALLAST
PARAS 261 TO 271 IN IRPWM
PARA 263: PROFILE OF BALLAST
PARA 270 OF IRPWM: SURPLUS BALLAST IN
TRACK SHALL BE COLLECTED AND STACKED
IN REGULAR HEAPS.
PARA 264-267 MODIFIED VIDE RAILWAY
BOARD’S LETTER No. 2006/CE – II/MB/2 Dt.
25.05.07
