1. Working Principals of Tamping
Machines
LINING& LEVELLING
Smoothening &Design Mode
By
HOTAM SINGH
VICE PRINCIPAL
IRTMTC/ALD

2. WORKING PRINCIPALS FOR
TAMPING MACHINES
1. Smoothening Mode-In this mode track is ligned/levelled
by the method of error reduction ratio in 4 point (error
remains 1/6 approximately) and 3 point method (error
remains 1/3 approximately) and track will not reach on
designed specified parameters
2. Design/Precision Mode- In this mode precise track
geometry data must be known before work
commences.The correct track geometry data should be
input at the front tower as even small error will have a
cummulative effect on the slews produced by the
machine.for this 3point method is mainly used.In this
track is to be lined according to specified radius or
versines

3. TAMPING OF TRACK

4. There are two ways only;
• Leave everything to machine.
Sit comfortably and simply
watch.-Easiest thing to do.
• OR
• Order the machine to do the
exact things you want. Some
hard work is required.

5. Tamping Tools
Tamping Arm
(Big)
Squeezing Cylinder Small
Tool Bolt
Main Body
Squeezing Cylinder BigSleeper spacing Block
Tamping Unit

6. Front Input Panel Of CSM

7. Front Input Panel of 09-3X

8. Front Input Circuit
To Lining circuit
Front Input
PCB
Versine potentiometer
Slew Potentiometer
General Lift Potentiometer
Front Pendulum
Laser & Computer
To levelling Circuit

9. .
• Methods of working;
• Auto mode, Compensation/Smoothening mode.
• No measurement of track. Some error is left out after tamping.
• Design/Precision Mode.
• Track is measured beforehand. No error is left out after tamping.
• Working Planes;
• Horizontal Plane- Lining (Single Chord).
• Auto mode, Compensation/Smoothening mode - 4 point (for curves).
• Auto mode, Compensation/Smoothening mode - 3 point (for straight)
• Design/Precision Mode. - 3 point.
• Vertical Plane - Leveling (Double Chord).
• Auto mode, Compensation/Smoothening mode
• Design/Precision Mode.

10. LINING
• LINING is a process of correction of
alignment in horizontal plane
• Methods of lining
– Manual
– Mechanized

11. Lining System
Comparison of 4 point and 3 point Working
3 Point Method 4 Point Method
•Requires Versines to be set in the
machine as Target Versine by the
operator.
•Versine measured at measuring
bogie ( H2 ) is the reference versine
,and H1 (H1=ixH2 ) is automatically
set as the target Versine.
•The Track Parameters are not
essentially to be known prior to work.
•The Track Parameters are to be
known prior to commence the
work.
•Error Reduction ratio is 1 : 3.14 •Error Reduction ratio is 1 : 6.09
•Residual Error is more than 4
Point ( Twice of 4 point )
•Residual Error is less than 3 Point
(Half of 3 point )
•This method is best suited for
smoothening mode of lining for curves.
•Requires precise data. Hence
called as Precision Method. Best
suited for Design mode of lining.

12. SYSTEM OF MECHANIZED
LINING
• 3 POINT LINING
– 3 points are used on the curve and straight
• 4 POINT LINING
– 4 points are used on the curve

13. Why people likes Smoothening
Mode (Four Point)
Because
• PWI becomes free in this mode of tamping, no
need to furnish track profile / geometry data.
• Can be resorted, when geometry is unknown.
• It is easier and faster to use in the field.
• The evaluation of the lining system is not
according to fixed points but according to the
alignment.
• Due to the nature of the errors where large slew
are expected.
• On unstable track

14. INPUTS

15. Versine Potentiometer
• This potentiometer is
used for feeding
versine and Vm value.
• This potentiometer is
provided in front cabin.
• Toggle switch decides
direction of feeding.

16. Slew potentiometer
• This potentiometer is
used for feeding slew
value(offset value).
• This potentiometer is
provided in front
cabin.

17. • R = INFINITE
• HENCE H = ZERO
• WHILE WORKING ON STRAIGHT ZERO
VERSINE IS FEEDED

18. ON TRANSITOIN
• THE THEORITICAL VERSINE ON
TRANSITION IS CALCULATED
FOR EVERY SLEEPER AND FEEDED
B
D

19. Lining System
Versine measuring Arrangement in CSM machines
6 M 4.7 M 10.05 M
A B C D
A = Rear Bogie : B = Measuring Bogie : C= Lining Bogie : D = Front Bogie
Tr = Versine Measuring Transducers
(For other tamping machines Chord length may vary )
Tr
Tr Fork
Hyd Cyl

20. SYSTEM OF LINING
1-Transducer measuring H1
2-Transducer measuring H2
5- Digital Potentio meter (To feed
curvature adapting values
6-Slew Potentiometer
16- Chord Fixing fork
REAR TIGHTENING
TROLLY
MEASURING
TROLLY
LINING TROLLY
FRONT TROLLY
LIFTING CUM LINING UNIT

21. S3 = Chord pos. 3-point-lining
S4 = Chord pos. – 4-point-lining
St = Working range of tamping unit
A = Rear tighteneing trolley
B = Measuring trolley
C = Lining trolley
D = Front tightening trolley
1 = Lining transducer for measuring the lining versine
"H1"
2 = Transducer for measuring the versine "H2"
3 = Zero-point-potentiometer 5 mm
5 = Digital potentiometer for manual input of the
curvature-adapting values (V,F,W, respec. V,HF,HW)
6 = Adjusting potentiometer for man.input of the
slewing values (lining.errors)

22. • 7 = Adjusting potentiometer (TELE-pot.) for remote control input of
the slewing values (TEKE-operation, LASER or remote control with
• sighting device)
• 8 = Selector for 3-point-system
• 9 = Selector for TELE-operation 10 = Lining indicator
• 11 = Total evalution of all input signals
• 12 = Controlsignal for automatic lining (triggered by the signal for
tamping units lowering)
• 13 = Manual control of the lining system
• 14 = Servo control of the hydr lining system
• 15 = Indicator for the adjusting values
• 16 = Chord fixing fork for 3-point-lining
• 17 = GVA (Track geometry adjust. motor
• 18 = TELE-Receiver – adjust. motor
• 19 = Control of the follow up motor
• 20 = Follow up motor
• 21 = Follow up – Compensation transducer

23. Functional sequene of the 4-point-method
• The measuring axles (A, B, C, D) are pneumatically preloaded
to the selected reference rail. The chord which is stretched
between "A" and "D" represents the direction of the alignment.
• Transducers are mounted on the measuring trolley "B" and
lining trolley "C", which are connected to the measuring chord
by means of a chord leap control and a carrier fork.
• Depending on the track alignment at the contact points, the
potentiometers are operated by the chord. In this way, the
versines are measured as analogue electronic signals.
• By means of the analogue control circuit all inputs are fed into a
compound line.
• The versine "H2" is adapted to the versine ratio i = (H1: H2) and
the lining versine

24. • "H1" is added but with the polarity reversed. If "H1" is not in
the right ratio to "H2", a difference signal remains on the
compound line, which represents the lining value "C". This
difference is fed into the indicator "10" and into the total
evaluation "11". If the lining operation commences, the servo
hydraulic "14" is triggered until the track is lined to the right
versine ratio.
• The hydraulic control and oil supply of the lining cylinders is
carried out proportional to the lining value by electrically
controlled valves

25. Lining: Auto, Compensation/Smoothening mode- 4Pt
.
12
Versines H1 &
H2 measured
Versine Ratio,
i = AC x CD
AB x BD
Lining done
till H1 is i x H2
• Machine measures only one rail i.e. Datum rail and rectify it. Other
rail is fixed with the sleeper, hence that is also rectified.
• Four trolleys A, B, C & D provided for alignment measurement.

26. 4 POINT LINING PRINCIPLE
For various distances for CSM, i =10.70x10.050/6.000x14.750
i =1.21508
6.000
4.700
14.750
6.000
4.700
14.750
REAR TIGHTENING
TROLLY
MEASURING TROLLY LINING TROLLY FRONT
TROLLY

27. 4 POINT LINING METHOD
DESIGNED
TRACK
ACTUAL/ EXISTING
TRACK
POST TAMPING
ALLIGNMENT IF FD ≠ 0
For CSM ERROR REDUCTION RATIO,
n = ADxBD/ACxBC= 20.750x14.750/10.700x4.700 =6.0859
Error in H2
Curved slewed to
ideal curve

28. GEOMETRICAL PRINCIPLE OF 3 - POINT
SMOOTHENING LINING SYSTEM
• 1 = Perfect alignment
• 2 = Before lining
• 3 = After lining without FD input
• 4 = Lining Value
• 5 = Actual position of the lining chord
• 6 = Theoretical position of the lining chord
• 7 = After lining with error FD input

29. ERROR REDUCTION ACCORDING TO
THE 4 - POINT LINING SYSTEM
Ideal line = 1 Before lining = 2 After lining = 3

30. 4- POINT LINING

31. Lining System
Versine Ratio
v2 (6 + 4.7) x 10.05 2r
----- = --------------------- x --------------------
v1 2 r 6 x (4.7 + 10.05)
107.535
h = ------------ = 1.21
88.5
Versine ratio h = 1:1.21
4.7 M 10.05 M
1. The lining is done at C.
2. B is always in the Worked
area (i.e) „corrected area‟
3. So V1 is taken as reference
versine.
4. V2 is maintained at V1 x 1.21
5. Predicted slew is V4
4 Point Measurement Method
B C D
6 M
V1
A
Lining
Cylinder
V3
V4
V2

32. FOUR POINT LINING SYSTEM
• GEOMETRICAL PRINCIPLE OF 4 - POINT
LINING SYSTEM:
• In a circular curve, two Versines of a
chord are related in a ratio, depending
on the measuring point distance. This
Versine ratio is independent of the
radius of the circular curve and is
always constant. It is also valid for a
straight, which may be considered as a
curve with infinite radius.

33. In 4 - point lining system, the track is measured at
4 points (A, B, C & D) and Versines at two
points are compared (B & C) to control the
lining. The existing errors are reduced or
eliminated by means of the Hydraulic Lining
System .

34. Existing Versine H1 = AC x CD
2R
Theoretical Versine H2 = AB x BD
2R
Versine Ratio i = H1 = AC x CD
H2 AB x BD
H1 = i x H2
Hence, lining is done at Point C until Versine
H1 is in the correct ratio to H2 (H1 = i x H2)
at Point B.

35. Versine Ratio „i value‟ for different
machines
• Machine i Value
• 08-UNO-DUO = 1.33
• 08-275 UNIMAT = 1.35897
• 08-275-3S = 1.62241
• MP-2000 = 1.395122
• WST = 1.3292
• 09-32 CSM = 1.2157
• 09-3X TAMPING EXPRESS = 1.507

36. The points A & B always remain on the
corrected track and the Versine H2 at
Point B represents the measuring base.
Point D always remains on the
disturbed track. Lining is done at Point
C. H2 and H1 are separately measured
by measuring and lining bogies of the
machine, respectively. H2 is fed in
PCB where it is multiplied with
constant i and becomes “H2 x i”.

37. • Thus H2 x i and H1 are then fed in
difference amplifier and if the
alignment is OK both will be equal and
reading on the dial will indicate zero. If
alignment is not OK, the difference of
the two will be indicated on the dial as
well as the current will flow to lining
solenoids, the alignment will be
corrected till both H2 x i and H1 are
equal or the ratio H1/ H2 = i, is
maintained.

38. • In the above figure, Points A & B are on the
already lined track behind the machine. The
front end of the chord, Point D is on the
disturbed position with lining error FD, resulting
in new Versine H2. Point C is now lined until H1
is in the correct ratio to H2. Depending on the
measuring point distances (Error reduction
ratio „n‟), an error remains at lining Point C,
which is called Left over error or Residual
error „FR‟.

39. n depends on Bogie distances, which is
as under for different machines
• Machine n - value
• 08-UNO/DUO = 6
• 08-275 UNIMAT = 6.42720
• 08-275 UNIMAT = 7.61997
• 08-32 WST = 5.7411
• 9-32 CSM = 6.27692
• 09-3X TAMPING EXPRESS = 6.47

40. SUMMARY
• MACHINE CORRECTS VERSINE ERROR =(THEORATICAL
VERSINE – EXISTING VERSINE)
• IN ABOVE FORMULA H2 IS TREATED AS THEORATICAL
VALUE
• H1 IS TREATED AS EXISTING VERSINE
• H1 AND H2 MAY NOT BE EQUAL BUT BOTH HAVE SOME
RELATION HENCE H1 IS CORRECTED w.r.t. H2 i.e I H2

41. • Toggle switch is given in front cabin to decide
compensation direction as under:
– High radius to low radius = Toggle switch outside
+ve( Entry of the curve)
– Low radius to high radius = Toggle switch inside –
ve(Exit of the curve)
Direction of Compensation
Calculation of Vm
• A readymade chart is given on each machine.
• Vm value may be calculated by following formula:
Vm = Constant Value / Radius x Transition Length
– Constant value depends on Machine length as under:
• 08-UNO/DUO – 83000, CSM – 82485, UNIMAT 2S
- 88333, UNIMAT 3S – 116603, WST - 84000

42. FR= FD/N
 N= REDUTION RATIO WHICH
DEPENDS ON BOGIE DISTANCES
 N= (AD X BD)/(AC X BC)
 FOR 08- MACHINE AD=20M ; BD= 15M
; AC=10M & BC= 5M
 N= (20 X 15)/(10 X 5 ) = 6
 HENCE FR= FD/6

43. VERSINE COMPENSATION VALUE (Vm)
FOR VARIABLE VERSINE
• The constant Versine ratio is only valid for
tracks with the constant curvature e.g.
circular curve, straight. But when there is
change in curvature (variable Versine), the
Versine ratio is adapted to the curvature by
input of correction values called Versine
Compensation (V) values.

44. • Generally, the V values are fed manually to
the Versine Potentiometer in the front tower.
With the provision of GVA/ALC, V values are
calculated automatically and fed in the
Lining system. The cut off zero point of the
Versine H1 is corrected accordingly. As an
example, let us consider a case of the
machine

45. PRINCIPLE OF
ADJUSTMENT ON
TRANSITION
STRAIGHT TRANSITION
DIRECTION OF
WORK

46. ADJUSTMENTS DUE TO
TRANSITION- 4 POINT LINING
BEGINING OF
TRANSITION
TOWARDS
OUTER RAIL
TOWARDS
INNER RAIL
20M 20M
20M 20MVM
VM
VM = 82485 / R * L
Transition
Transition

47. 14.75
14.75 14.75
14.75
CALCULATION OF VERSINES ON
TRANSITION FOR CIRCULAR CURVE
WITH TRANSITION
T2
T1
T1
T2
Machine working Direction
Transition
Transition
CIRCLAR CURVE
STRAIGHT

50. `

52. Lining System
Compensations for the differences in radius.
Compensation is must in both 3 point and 4
point in Smoothening mode and in Design mode
when the Machine Enters or leaves from one
Radius to another Radius.
Failure of Compensations will lead to formation
of “Dog-Leg” effect in the entry and exit points.
P.Way Supervisors should ensure feeding of
compensation by the Front Tower operator.

53. 4 POINT LINING DESIGN
MODE
• Not on straights
• On curves
– Determine slews by ROC
– Enter slews in the slew potentiometer
– Correction in Transition curve in versine
potentiometer

54. NON - SUITABILITY OF 4-POINT LINING
ON STRAIGHT
• On Straight Track H2 is zero, the machine
corrects Versine at C with respect to H2.
• Hence H1= i x H2 = 1.33 x H2 = 0
(i = 1.33 for 08-UNO-DUO)
• If at any Point FD = 12mm
FR = FD / n = 12 / 6 = 2mm
• If Point H2 is at C H1 = 1.33 X 2 = 2.66mm
• As the machine moves forward, H2 will be
2.66mm and H1 becomes 1.33 x 2.66 = 3.5378
• Thus, error is accumulated and the machine
makes a false curve. Hence 4-point is not
suitable for straight.

55. 3 POINT LINING PRINCIPLE
For any circular curve
H1= BC * CD/2R
DIRECTION OF
WORK
REAR TROLLY IS
FOLDED
X
MEASURING TROLLY
IS CLAMPED TO ZERO
LINING TROLLY –ONLY
H1 IS MEASURED

56. • The Versine H2 at Point B is not
measured. The track is measured at
three points. The lining Versine H1 at
point C is specified according to the
curvature. Lining commences until the
Theoretical Versine H1 is achieved.
Using the 3-point system, the chord is
generally fixed at point B, which results
in a reduction of the distance A-B.

57. Functional sequence of the 3-point-system
• The chord is fixed on the measuring trolley "B" by
means of the fork "16". The measuring transducer
"H2" is not in use. Only the lining versine "H1" is
measured which is added to the specified
THEORETICAL versine (HV, HF, HW) as lining
adjusting value.
• The difference between the THEORETICAL- and
ACTUAL versine represents the lining value. The input
of the THEORETICAL versines id carried out by the
digitalpotentiometer "E" of fully automatic GVA.

58. • ERROR = THEORETICAL VERSINE – EXISTING VERSINE
• Error---Calculated by PCB
• Theoretical Versine-----Fed Manually or by
Computer
• Existing Versine--------Measured by Machine
through Transducers

59. 3 - POINT LINING SYSTEM
SMOOTHENING MODE
1= Perfect alignment
2 = Before lining
3 = After lining without FD input

60. 3 POINT DESIGN LINING PRINCIPLE

61. • Point B is on the already lined track behind
the machine. The front end of the chord,
point D is at the lining error FD. Point C is
lined until H1 corresponds with the
specified Theoretical Versine. Specifying the
Theortical Versine, H1 shifts Point C in a
position which corresponds with the
required radius R. The remaining error FR =
FD / n, is a result of the ratio of the
measuring point distances. Proceeding with
the lining, Point B is at the remaining error
and influences therefore the next
measurement.

62. Lining System
23617.5
Target Versine v = ---------- mm
r
Measured Versine = v + Fc
Track will be slewed to Target value v i.e vc
Error left behind is by the value Fc
4.7 M 10.05 M
v
3 Point Error Reduction ratio
B
C
Fc
vc
E.R.Ratio
Fd Fc 4.7xFd
------ = ---- Fc= --------
14.75 4.7 14.75
Fd
Fc = ------
3.14
E.R.Ratio = 1 : 3.14
D Fd
Designed
Existing
After work

63. 23617.5
Target Versine v = ---------- mm E.R.Ratio = 1 : 3.14
r
Error left behind is Fc = Fd  mm
Straight Line is considered to be a curve with infinite versine
For Straight line 0 mm versine is set as target versine
Lining System
B C D
Fd = 10 mm
Fc = Fd  = 3.18 mm
Smoothening mode of working in 3 point

64. 3 POINT LINING
• Straight track - smoothening mode
– H1 = 0
– Error reduces to 1/3
• Straight track in design mode
– H1 = 0
– Feed slews in slew potentiometer
– Error is completely eliminated

65. 3 POINT LINING
Curves in construction
• May be used to lay designed curvature
• Smoothing mode
– H1 fed in VPM (based on calculated value of R)
• Design mode
– Feed the slews
– H1 fed in VPM (based on calculated value of R)

66. 3 POINT LINING
Curves in O / L
• Not recommended
• R based on average versine calculated
after ROC
• H1 = 23617/R & fed
• Slews from ROC in design mode

67. n(3- Pt) - value for different
machines
• Machine n(3- Pt) - value
8-UNO/DUO = 3
08-275 UNIMAT = 3.12
08-275 UNIMAT -3S = 3.297
08-32 WST = 2.91
09-32 CSM = 3.138
9-3X TAMPING EXPRESS = 3.04

68. DETERMINATION OF THEORETICAL
VERSINES
• Versines for circular curves are determined by
the formula, H = (BC x CD) / 2R.
• Versine formula for transitions and track
calculation with curvature variations are more
complicated. Basically all formula and other
calculating aids for permanent way can be
applied. The THEORETICAL Versines can also
be calculated by the electronic onboard
computer GVA / ALC and fed into the lining
control.

69. NON - SUITABILITY OF 3-POINT LINING
ON CURVE IN SMOOTHENING MODE
• On Cueved Track H2 is zero, the machine
corrects Versine at C with respect to theoritical
versine values.
• As per principle of 3 point, error reduced to 1/3
but there is no comparision of curvature
(versines) at two points in the pattern of 4 point
to avoid formation of kinks in the track, hence
track will disturbed due to non achieving the
designed profile or smoothening due to non
comparision of curvature at two points
• Hence 3-point is not suitable for curve in
smoothening mode.

70. LIMITATION OF SMOOTHENING MODE
LINING
• Errors with longer wavelengths can only be
corrected with the help of input of additional
correction values. The front end of the measuring
systems has to be adjusted in such a manner that
it is moved along the design line of the track.
• Another feature of the measuring systems which
has to be taken into consideration is that the
theory behind the automatic correction system is
based on circular curves and straight track.
Correction values have also to be put into the
system, when working in transition curves in
smoothing mode.

71. • To calculate correction values in transitions it is
necessary to know the basic curve data like
radius, length and form of transition, end points
and so on. If those are known the correction can
be derived from tables in the machine handbooks.
Neglecting the correction values in transitions
causes misalignment and false curves resulting
rough running.
• Working in smoothing mode may result in
considerable shifts of the tracks away from the
design or original position. In curve with long
welded track it may create lateral rail tension and
the danger of track buckling. Furthermore, at
higher speeds also long wave faults cause
dynamic vehicle reactions. If those faults are not
corrected, vehicle and track wear and faster
development of geometrical faults are the result.

72. WORKING OF TAMPING MACHINE
IN DESIGN MODE
• Maintenance of track geometry to
desired parameter is very important for
the safe and smooth running of trains.
Track machines have facilities of
measurement and rectification of track
defects for achieving design geometry. 5
initial CSMs & all 3x machines are also
equipped with ALC for track geometry
measurement and LASER Sighting
System (LSS) for lining besides other
features for design tamping.

73. DESIGN LINING
• Modern Track Machine always
corrects Versine during Alignment
correction using single chord. Machine
measures only one rail i.e. Datum rail
and rectify it. Other rail is fixed with the
sleeper, hence that is also rectified. Four
trolleys are provided for alignment
measurement. In design lining, only
three trolleys are used.

74. DESIGN LINING –3 POINT
ON STRAIGHT
• Curve of infinite radius- H1=0
• Find out slews on long chord (80-300 m)
• Correction of kinks at joint &weld
• Distribute slews on every 2nd /3rd sleeper
• Run the CSM/T.EXP & feed the slews

75. Lining System
v = ab/2r
v = (4.7 x 10.05)/2r
23617.5
Versine = ---------- mm
r
4.7 M 10.05 M
v
Lining
Cylinders
v1
3 Point Measurement Method
B C D
V2
A
The Versine (v1) is Referred
with Target Versine (v)
(v) is set in the machine.
v – v1 = v2
The slew is v2

76. • Single chord lining system is used in present
generation tie tamping machines viz UNO, DUO, CSM,
tamping express. Four trolleys are provided for
alignment measurement. In design lining only three
trolleys are used. The trolleys are pneumatically
pressed against reference rail, and transducer
provided on lining trolley measures offset of
alignment at C (distance between lining chord and
center of lining trolley).
DESIGN LINING

77. • After measuring the offset track is slewed so
much that specified versine is achieved at lining
trolley location The specified versine is zero for
straight track and certain value on curved track.
After lining and packing of sleeper machine
moves to next tamping position. Again lining is
done at that position. This process continues till
machine works.
• In the lining process front trolley always remains
on unlined/disturbed track and trolley (M) always
remains on lined track Because of mis-alignment
in track at front trolley front end of the chord will
be out of its correct position equal to alignment
defect at that point

78. • Due to incorrect position of the front end proportional
alignment error will remain after lining. Alignment
error at C = AF * a/(a+b), where AF = Lining offset at
front trolley.
• In design lining this error is eliminated by shifting
front end of the chord equal to alignment defect at
that point. In machine other than UT chord wire is not
physically shifted but proportional electronic signals
are relayed through microprocessor(Lining PCB) to
lining unit and track is lined accordingly.
• Total slew at C = Lining offset measured by
transducer at C + Proportional signals corresponding
to lining offset at front trolley – Versine to be kept at
C.

79. • Functions available in machine:
• Values of slew, versine, unevenness and cant are fed in
machine through potentiometers. Various input potentiometers
of CSM machine provided in front cabin and used in design
lining and leveling are lifted below:
Front Cabin -
• Designed Slew (FD Value)
(Three Feeding options –Manual/LASER/Computer)
• Designed versine value and Vm(versine companatsation
value)- Two feeding options are available-manual through
potentiometer and geometric value assessment (GVA
computer)
• General Lift- selected on the basis of crosslevel difference(+/-
)longitudinal level variation
• Cross level correcting potentiometer– To give extra lift up to
+10 mm to base rail for correcting cross-level in addion to
general lift
• Working Cabin- Cant Value( CSM,CSM-3X)
Cross level correcting potentiometer–extra lift provision up to
+5 mm to base rail for correcting cross-level in addion to

80. Practical problems in Design Tamping:
• Large quantity of graph paper is required for plotting
reduced level of rail top for calculating lifts. Scale used for
plotting is horizontal 1 cm = 10m; vertical 1 mm = 10 mm.
One meter graph paper is required for plotting one kilometer
track. Least count for plotting lift is 10mm. So error less than
10 mm will not be rectified.
• Choosing good point for lining is subjective and requires
experience.
• Measurement of slews by theodilite is on track method and
survey is done in time available between two trains. In off
track method also setting of instrument disturb during
passing of train.
• Two operators are required in front cabin for feeding values
of slew, lift and versine in curves.
• Curves require two three tamping because most of the time
designed slew comes more than maximum limit of machine.
• Some times machine is backed to rectify cross level. In that
case values of feeding in front cabin is required to be
changed.

81. Condition for Design Lining
 Design lining is applicable only for that track where
summation of existing versine is equal to summation
of theoretical versine.
 Else Smoothening mode will be more better.
 FD (offset value) to be written on alternate sleeper
with direction.

82. Lining: Design / Precision Mode 3-Point
• In Design lining, only 3 Measuring trolleys used.
• FD (Slew) values & Versines determined beforehand .
• Track lined until Target/Specified Versine reached.
• FD values also fed.
• Left over error at C eliminated, FR = 0.
FD

83. • 1 = Perfect alignment
• 2 = Before lining
• 3 = After lining without input F D
• 4 = Lining Value
• 5 = Actual position of the lining chord
• 6 = Theoretical position of lining chord
• 7 = After lining with input of F D
Geometrical Principle of 3-Point Design Lining
Correction at C
= Lining Value (4)
= (H 1+FC) - H
H- Measured V
H 1- Theoretical V
FC- Proportional
Lining offset at C

84. Determination of Lining Offset/Slew Values FD
A. By Long Chord (Ann 5.3 to IRTMM):
• By measuring offsets at 5m intervals on 40m chord on
straight and at 10m intervals on 20m chord on curves.
• But, long-wave track geometry faults with longer λ from
about 70m become significant with the increase in speed.
• Assuming typical natural frequency of vehicular oscillation, f as
1Hz, the critical track geometry fault λ even in speed range upto
160km/h is upward of 40 m {λ=v/f=(160x1000)/(3600x1)= 44.44m}.
• On straight, the most preferable chord length for alignment
correction is in the order of 60–80m.
B. Theodolite Method with normal ranging rods:
• For such chord length, if Theodolite with the standard
tripod stand is used, it takes 10-12 minutes for centering,
leveling & measurements and whenever a train
approaches, Theodolite is to be removed and reset.
• It is even difficult to ensure verticality of Ranging rod.

85. Determination of Lining Offset/Slew Values FD
C. By Theodolite using the Specially Designed Gadgets:
• More practicable, fast FD measurement without
repeated centering / leveling of Theodolite. These are:
• Scaled Sliding Table: Made of metal L-1.85m, H-0.45m
on which Theodolite slides laterally at required distance.
• Target: Made of metal and zero point has a fixed
vertical pointer of 0.75 m height.
• Satellite: Made like the Target with a movable vertical
arm of L-30cm and H-45cm in „reverse T shape‟ ┴, with
a 30cm Steel scale (L.C.-1mm) at either ends at 15cm
from centre point on which vertical arm slides laterally.
• This movable vertical arm is sighted and brought in line
with line of collimation of Theodolite and Target.
• Shift of movable vertical arm from centre point is Slew.
• Slew at alternate sleeper by interpolating offsets.

86. • Using the Theodolite and Target, a chord of up to 400 to 500
meter or more as per ranging capacity of instrument (longer
chord will give better results) may be taken between 2 Good
points.
• This is the line of collimation of Theodolite at a fixed lateral
distance from gauge face of Reference rail.
• Slew measurements at every 5m intervals are directly measured
Scaled Sliding Table
Target (Fixed Arm) and
Satellite (Movable Arm)

87. • Initial 5 CSMs (901 to 905) & all 3x machines provided
with a Laser Sighting System to extend measuring system
on straight. LSS is in disuse on the aforesaid 5 CSMs.
• Laser lining is used on straight track in 3-point mode to
remove long misalignment or false curve.
• Laser system consists of a Laser gun mounted on Laser
trolley and a Laser Receiver mounted on Front trolley.
• Laser trolley is placed in front of the machine upto 300m.
• On CSM, Receiver is adjustable. It follows the Laser
beam and the position is detected by a transducer that
provides an input to the lining system equivalent to FD.
• On 3x, 200mm square Receiver is fixed on Front trolley.
Displacement of Laser beam as it impinges on Receiver
from initially set centre i.e. FD, is measured and displayed
on a Micro-controller and entered into Lining system.
D. Determination of FD by Laser Sighting System

88. Lining System
B C D
V2 is maintained at V1 x 1.21
V1 = 0 so, V1 x 1.21 is also 0
Slew = 0 – measured Versine V2 = - 10 mm
Fd = 0 mm
Rc = Fd  = 0 mm
Design mode of working in 4 point
A
V1 V2
Fc
Fb

89. FIELD MEASUREMENT FOR DESIGN
LINING OFFSET BY LONG CHORD
• Surveying and Marking of Slews without any
Infringement to SOD:
• Surveying should be done between two good
points, which may be on well maintained
obligatory points i.e. girder bridges, level
crossings, points & crossings, permanent
structure etc, with the centre line of track on the
design or original theoretical position.
• In case of any shift in alignment of the centre line
at obligatory points from the design or original
position, the centre line must be brought to design
or original theoretical position, manually for a
minimum track length of 50m before surveying.

90. • Lining errors are to be determined by measuring
offsets at every 5 m intervals on 40 m chord on
straight track and at every 10 m intervals on 20 m
chord on curves track and marked on the track.
S1
S2
S3 S4
S5
S6
S7
S8 S9
S10
S11
BRIDGE
Level Xing
0mm
5mm
10mm
10mm
10mm 10mm
5mm
5mm 5mm
0mm 0mm

91. • The required slew at every alternate sleeper is
worked out by interpolating the offsets. The slews
are then marked on alternate sleepers and Design
tamping done by feeding the slew values to Slew
Potentiometer in the Front tower.
BRIDGE Level
Xing
0 1 2 3 4 5 6 7 8 9 10 ------ 10 9 8 7 6 5 4 3 2 1 0
0 1 2 3 4 5 6 7 8 9 10 -------- 10 9 8 7 6 5 4 3 2 1 0

92. Surveying and Marking of Slews in
case of Infringement to SOD
• If the required slew is infringing the SOD viz OHE
Mast etc, the slew has to be worked out taking note
of the obligatory points and ensuring that there are
no infringements to moving dimensions as below.
BRIDGE
LEVEL XING
INFRINGING
EXISTING TRACK
PROPOSED TRACK
OHE MAST
Required Slew Values Infringing SOD

93. BRIDGE
LEVEL XING
EXISTING TRACK
FINAL SLEW
OHE MAST
• The final worked out slews are then marked
on alternate sleepers and Design tamping
done by feeding the slew values to Slew
Potentiometer in the Front tower.
Final Slew Values With No SOD Infringement

94. Surveying Design Lining Offset
By Theodolite
• The long-wave track geometry faults
become significant with the increase in speed
of trains.
• Assuming the typical natural frequency of
vehicular oscillation to be 1 Hz, the critical
track geometry fault wavelength even in
speed range upto 160km/h is upward of 40 m.
• While working on straight track, the most
preferable chord length for alignment
correction is in the order of 60 – 80 m.

95. • For achieving such chord length, if the
Theodolite with the standard tripod
stand is used it takes about 10-12
minutes for centering, leveling and
measurements.
• In the saturated high density routes,
so much time is not available and
whenever a train approaches, the
Theodolite is required to be removed
and reset.
• It is even difficult to ensure verticality
of Ranging rod at target.

96. • For making it more practicable, fast and
efficient, some specially designed gadgets, may
be developed, which makes the direct slew
measurement with Theodolite quite easy. Using
these gadgets, a chord of upto 400-500 metre or
more as per capacity of ranging of instrument
may be taken between 2 good points, which is
the line of collimation of Theodolite at a fixed
lateral distance from gauge face of reference rail
of existing track and the slew measurements at
every 5 m intervals are directly measured on
specially designed Satellite with reference to the
line of collimation.
• The equipments and specially designed
gadgets used are as follows:

97. • Theodolite: Normal Theodolite
• VHP Sets: One each at Theodolite, Satellite
and Target i.e. total 3 Nos.
• Scaled Sliding Table (SST): It may be made
of wood or metal with 1.85 m Length and
0.45 m Height. On upper side, one horizontal
graduated table is fixed in which a plate is
mounted on which Theodolite slides
laterally to keep it at any required lateral
distance from the reference rail. A lug is
provided similar to that provided in gauge-
cum-level. Touching Hook is on left side of
the sliding table stand to bypass the burr on
rail. SST will be perpendicular to rail, when
both lugs are touching reference rail.

98. Scaled Sliding Table (SST)

99. Satellite
• It may be made like the Target described
ahead with a movable vertical arm of length
30 cm and height 45 cm in „reverse T shape‟
┴, painted white with a black vertical central
line pointer towards Theodolite and a
Satellite scale (30 cm Steel scale with Least
Count – 1mm) on the upper side at either
ends starting at 15 cm distance from the
centre point on which the vertical arm slides
laterally. During survey, this movable
vertical arm is sighted and brought in line
with the alignment of line of collimation of
Theodolite and Target.

100. • The shifting of movable vertical arm from
centre point is read from Satellite scale and
deviation is directly recorded as slew at
that point. Alternatively, the Satellite may
be prepared from existing gauge-cum-level.
In middle portion of the vertical face
towards Theodolite, a teethed scale made
of luminous red strip is pasted for a length
20 cm either side of zero (centre) point. The
height of triangular teeth is 10 mm and
distance between the two apexes of teeth
is 10mm. This is further divided into 5
equal parts by 4 nos. of black horizontal
lines to give a least count of 1 mm.

101. Target
• It may be made of wood. One end of its
horizontal board ensures reference rail
contact and zero point has a fixed
vertical pointer of 0.75 m height
painted white and has got a red vertical
central line passing through zero point
towards Theodolite.

102. Method of Working
• Preliminary Works:
–Marking of stations at 5 m apart at
the centre of track.
–Selecting good point at about 300-
400 metre apart or more as per
instrument capacity. These good
points should have their position in
the mean alignment of the existing
track.

103. Slew Recording
Step 1 – Check squaring of SST with
reference rail by touching it‟s both the
notches on gauge face.
Step 2 – Set the Sliding table at zero point,
place Theodolite and level it.
Step 3 – Sight the Target and fix the line of
collimation.
Step 4 – With the alignment of line of
collimation, read deviation at Satellite scale
by seeing through telescope of Theodolite.

104. Step 5 – Take and record deviations of
subsequent stations till the readings are
visible with the telescope of Theodolite.
Step 6 – Leaving satellite on last recorded
station, SST is shifted on second last
recorded station.
Step 7 – Slide SST as per slew reading of the
station on which it is shifted, place
Theodolite, level it at site the target again so
that initial line of collimation is maintained for
further measurement of slews. Repeat the
steps till Slews of each stations at 5 m apart
are recorded for full length.
• An example on Field measurement by
Theodolite is as follows.

105. FIELD MEASUREMENT FOR DESIGN
LINING OFFSET BY THEODOLITE
• Surveying and Marking of Slews
without any Infringement to SOD:
• Preliminary Works and Slew Recording
Steps are already given in the presentation.
However, the following procedure may be
followed for Permanent (Girder Bridges,
Fixed Structure etc.) and Temporary
Obligatory points (Level crossings etc):

106. • In case of any shift in alignment of the
centre line at Permanent obligatory points
(Girder Bridges, Fixed Structure etc.) from
the design or original theoretical position, the
centre line must be brought to design or
original theoretical position, manually for a
minimum track length of 50m before
selection of good points.
• Either the Permanent obligatory points or
any other points at about 400-500m apart
having their position in the mean alignment
of the existing track are taken as good points.
Thereafter, the Working Method as already

107. • Temporary Obligatory points (Level crossings
etc) should be opened out and may be shifted to the
extent possible after ensuring that there are no
infringements to moving dimensions.
• Any shifting of Temporary Obligatory points
should be approved by the ADEN.
BRIDGE
TEMPORARY
OBLIGATORTY
POINT
PERMANENT
OBLIGATORY
POINT / GOOD POINT
PERMANENT
OBLIGATORY
POINT / GOOD POINT
LEVEL CROSSING

108. BRIDGE
LEVEL
CROSSING
0 1 2 3 4 5 6 7 8 9 10 ------ 10 9 8 7 6 5 4 3 2 1 0
0 1 2 3 4 5 6 7 8 9 10 -------- 10 9 8 7 6 5 4 3 2 1 0
ST0
ST1
ST2
1 2 1

109. 3x Express
3x can record the Track Parameters in “Record Run” at
8 to 10 KMPH.
The recorded parameters can be analysed with the “On-
Board Computer” (ALC). Longitudinal surface correction
values, Vertical curve values can be calculated. These
values can be fed to the machine automatically while
working.
Curve slewing values can be calculated with this computer
duly taking care of transitions on either side. These values
can also be fed to machine automatically. The lift values of
Datum rail and Cant rail including the Super Elevations are
also fed.
Design lining can also be done without “Record Runs” by
calculating the slews and lift values and feeding them to
the “ On- Board Computer (ALC)” manually.

110. LASER SIGHTING SYSTEM
• Initial 5 CSMs (from 901 to 905) and all 3x
machines are provided with a LASER Sighting
System (LSS) that can be used to extend the
measuring system on straight track.
• LASER lining is used on straight track in 3-
point mode to remove long misalignment or
false curve.
• The LASER system consists of LASER gun
(transmitter) and LASER receiver. The LASER
trolley which consists of laser gun is placed
in front of the machine up to 300 m away.

111. • The receiver mounted on the front
tightening trolley is adjustable so that it
follows the LASER beam and the position is
detected by a transducer that provides an
input to the lining system equivalent to the
offset of the front of the chord. As the
machine is working it moves up to the LASER
trolley until the distance is a minimum of 20 m
away. LASER system operates fully
automatically and is able to cope with
distances of up to 300 m. But LASER lining is
only applicable for straight track. Important
details are as follows:

112. • By means of a special device, the LASER
beam is fanned vertically in such a way that,
the eventual change in track height has no
influence on the system.
• By means of an automatic follow up
control, the LASER receiver is always
positioned at the centre of the LASER beam
and therefore determines the input of the
slewing values.
• The distance of the LASER gun from the
machine is also dependent on the ambient
conditions (rain, snow, fog, high ambient
temperature). In good ambient conditions
(clear, dry air) the lining distance can be
extended considerably.

113. Working Sequence of Design Lining
with the Laser Sighting System
• Phase 1: When the design lining
commences the front end of the chord
with the LASER receiver is shifted by
the amount of the error FD in the
direction of the THEORETICAL
alignment, whereby the follow up
control is switched off. If the lining
errors exceed certain amount, a
transition is necessary for the new
alignment.

114. • LASER transmitter is positioned as far
as possible from the machine, adjusted
laterally over the amount of the lining
error F, aimed at the LASER receiver
and fixed in this position.

115. • Phase 2 and 3: The design is set; the
follow-up control is switched on. The track
is lined at point C and matches exactly with
the line of sight.

116. • Phase 4 and 5: The machine drives
forward and the front end of the chord is
matched up again with the line of sight. The
machine is ready for the next lining
operation.

118. PROPORTIONAL LEVELLING SYSTEM
• The tamping machines with non-displaceable
front end of the leveling chords are equipped with a
proportional levelling and lifting system for
measuring and correcting the track geometry.
• Measuring of the Longitudinal Profile: The track is
measured at three locations per rail:
- At the front of the machine (location “F”) for
determination of the actual level and the front
measuring reference point.
- In the area of the tamping units (location “M”)
for the proportional control of the hydraulic track
lifting system.
- At the rear of the tamping units (location “R”)
on the already corrected track for determination of
the rear measuring reference point.

119. • A chord is stretched above each rail
between the reference points “F” and “R”
which forms two, independent from each
other, measuring references for the
longitudinal level.
• Measuring transducers are mounted on the
feeler rod of the centre measuring device. The
control arms of the transducer are connected
with the leveling chord. Proportional to the
level of the track at point “M”, the measuring
transducers send electronic signals for the
automatic control of the track lifting Servo
hydraulic system.

120. • Measuring of the Cross Level:
• At the measuring points “F” and “M” the
cross level is measured by means of
pendulums.
• The difference between the THEORETICAL
and the measured ACTUAL cross level at the
front measuring point “F” is automatically
transmitted to the lifting adjustment,
corresponding to the side.
• During the lifting and tamping operation,
the cross level is checked at the centre
measuring point “M” (in the area of the
tamping units).

121. • The measuring of the cross level at the rear
measuring point “R” (optional) serves several
functions:
–Checking the cross level of the track
which has been lifted and tamped
immediately beforehand.
–Recording of the cross level by means of
an electronic recorder.
• Input of the Lifting Values: The
adjustment of the track lifting takes place at
the front reference point “F” and is
automatically and in the right proportion
transmitted to the cut off points of the
measuring transducer mounted on the centre
measuring device “M”.

122. • The leveling system may be used for the
following methods:
–Compensating method: Without having
the track surveyed, a required lifting
value is selected. Existing longitudinal
errors are reduced and the cross level
errors are eliminated.
–Precision method: The track has to be
surveyed beforehand and the lifting
values of Base rail are marked on the
sleepers. During work the lifting values
are set manually.

123. • Base Rail: For carrying out attention to
longitudinal profile, one rail is kept as Base or
Datum Rail. Machine corrects Cross-level w.r.t. Base
Rail, which should be selected as under:
– On straight track in single line and middle track
in multiple lines, higher/less disturbed rail is kept
as Base Rail.
– On straight track in double line, non-cess rail is
kept as Base Rail.
– On curves, inner-rail is kept as Base Rail.
In Plasser Tampers, direction of Cant Selector
Switch is to be always kept opposite to the Base
Rail. In Russian Tamper, Base Selector Switch is
provided for selecting Base Rail.

124. • General Lift: The amount of lift, which is given to
track while tamping to cover all undulations over the
Base Rail, is called General Lift. It is decided on the
magnitude of the dips/peaks generally available in the
track. General Lift should always be more than the
largest of dips which shall be ascertained by P.Way
supervisor in advance. It is given to the Base Rail.
General Lift is the algebraic difference of higher and
lower point of Base rail + 5mm. At one time, General
Lift value should not exceed 50 mm. If more than 50
mm lift is required it can be achieved by lifting twice.
To be Lifted
Existing Track
5 mm

125. Importance of General Lift
Errors that are more than the General Lifts
will not be lifted and the peaks will be left
over.
Hence the track to be tamped is to be
prior surveyed to find out the maximum
dip in the section and the general lift is to
be finalised accordingly. P. Way
Supervisors shall ensure that the track is
surveyed prior to TTM work and the

126. Cross Level
 So far we dealt with lift values on one
rail. The lift values of the other
rail is transferred to other rail
through a pendulum circuit, taking
into account of the cross level
difference at that point.
 The rail on which survey is made and
general lift is given is called reference
rail or “Datum Rail”.
 The other Rail is called “Cant Rail”.

127. Lifting of the Track
Important Points to be noted
1. The Track can not be Lowered with
Tamping Machines !
2. The Tamping Machines are equipped with a
proportional leveling System for measuring
and correcting the Track Geometry !!

128. Leveling System (1)
R M F

129. Leveling System (2)
R M F

130. Leveling System (3)
R M F

131. Leveling System (4)
R M F
Say
Error „E‟ = 15 mm
14.75 M
4.7 M
e = Error measured at
Middle Feeler Rod
(Error Portion )

132. Error at Front Feeler Rod is 15 mm low i.e –15 mm
E e
-------- = ------
14.75 4.7
E x 4.7
e = ------------ = 0.318 x E
14.75
E -15
e = -------- = -------- = -4.79 mm
3.138 3.128
That means 4.79 mm is to be lowered at Middle feeler rod
Remember that the Track Can‟t be lowered !!!
Providing a General Lift is the
solution.
Lift Value Calculation

133. Leveling System (5)
R M F
Provide a
RAMP of
1 in 1000
15 x .318 = 4.79 mm
15
mm
G.lift
in
chord
wire

134. Leveling System (6)
R M F
Theoretical
Extension of
existing Track
Theoretical
Extension of Lifted
Track
General Lift of
15 mm
15 mm
G.lift in
chord
wire

135. Leveling System (7)
R M
F(Error Portion )
15mm
G.lift in
chord
wire
15mm
error in
Track
15 x 0.138 = 4.79 mm

136. Leveling System (8)
R M
F(Error Portion )
15mm
G.lift in
chord
wire15mm
error in
Track
Already low (Say 4.79 mm)
Error read = 15- 4.79 = 10.22 mm

137. Leveling System (9)
R M
F(Error Portion )

138. Leveling System (10)
(Error Portion - longer than machine length)
Track After Work
( 15 mm Max Dip)
Theoretical extension of lifted track (15
mm General Lift)
Existing Track with Error
(15 mm max dip)
10.05 M

139. Cross Level (2)
Zero Cross level Error
Datum Rail Cant Rail
General Lift on
Datum Rail = 15
mm
Lift Value on
Cant Rail =
Datum Rail Lift
value + Cross
level Difference
i.e 15 + 0 = 15
mm
15 mm lift 15 mm lift

140. Cross Level (3)
Cross Level Error
= 20 mm Cant side Low
Datum Rail Cant Rail
General Lift on
Datum Rail = 15
mm
Lift Value on
Cant Rail =
Datum Rail Lift
value + Cross
level Difference
i.e 15 + 20 = 35
mm
15 mm lift 35 mm lift

141. Cross Level (4)
Cross level Error
= 20 mm Datum Rail Low
Datum Rail Cant Rail
General Lift on
Datum Rail = 15
mm
Lift Value on
Cant Rail =
Datum Rail Lift
value + Cross
level Difference
i.e 15 -20 = -5
mm
15 mm lift
-5 mm lift
Datum Rail will still be
low by 5 mm after
tamping.
i.e 5 mm Cross Level
Error will remain in the
Track.

142. • While giving the General Lift, ramp in of
1:1000 and also while closing the work ramp
out of 1:1000 should be given to the track for
smooth transition.
1
1000
1000
1
To be lifted
Existing Track

143. • For Curves, when the existing Super-
elevation (SE) is less than equilibrium
SE, General Lift will be equal to track
irregularities over the Base Rail (Inner
Rail + 5mm) and when the existing SE is
more than equilibrium SE, General Lift
will be the track irregularities in the Base
Rail + max difference between existing
and equilibrium SE.

144. Feeding of Cant Value in Curve

145. • In all tamping machines, generally there are two
digital potentiometers for feeding the Cant value,
one at front tower and another at working cabin
except CSM in which there is only one potentiometer
in working cabin.
• Cant value is written by JE/P.way on the sleeper
near inside rail seat of outer rail.
• Total cant value should be distributed through
out the transition length in such a way that it is Zero
at TTP and Max. at CTP.
• There is incorrect practice of feeding of Cant
value wrongly in the field i.e. when tamping machine
enters into the transition portion, the operator in the
front cabin starts feeding cant value according to
the value written on the sleeper.

146. • As soon as cant value is fed in front cabin when it
is at TTP, the lifting starts and cant rail is also lifted.
Since, lifting is not required till measuring trolley
reaches over TTP, it creates hump. So the operator
of front cabin should not feed any cant value till the
working cabin reaches over TTP. Thereafter,
whatever value is written on the sleeper in front of
the front cabin should be fed by the operator.
• When front cabin reaches at CTP1, the working
cabin is still in transition portion i.e. it has not
reached at full cant value. The operator in the front
cabin should keep on feeding the Cant value at the
same rate till the working cabin reaches at CTP1.
Thereafter, the operator in the front cabin should
instantaneously reduce the Cant value to Max. Cant

147. • Similarly when the front cabin reaches at
CTP2, the cant value should be kept as Max.
Cant till the working cabin reaches at CTP2,
when suddenly the cant value is reduced to
the value as written on the sleeper in front of
the front cabin.
• When the front cabin reaches at TTP2,
although the cant value becomes zero at
TTP2, but the cant value should be fed at the
same rate by changing the direction of the
toggle switch i.e. negative cant value is fed,
till working cabin reaches at TTP2, when
suddenly the cant value is brought to zero.

148. • After leveling and packing of sleepers machine moves to
next tamping position. Again leveling is done at that
position. This process continues till machine works. In
this leveling process front tower always remains on
unleveled track and rear measuring post always remains
on leveled track. Because of level defects (unevenness)
in track at front trolley, front end of the chord will be out of
its correct position equal to level offset at that point. Due
to incorrect position of the front end of chord proportional
level error will remain after leveling. Track leveled at C
will have level error equal to LF* a‟/(a‟+b‟). Where LF =
Level offset at front tower.
• In design leveling, this error is eliminated by raising or
lowering front end of the chord equal wire is not
physically shifted but electronic signals are relayed
through microprocessor to leveling unit and track is lifted
accordingly.

150. FUNCTIONAL DIAGRAM

151. • LEVELLING SYSTEM
• 1 = Pendulum for measuring and automatic transmission of the
cross level errors on the front levelling feeler rod “F”.
• 2 = Pendulum for measuring the cross level on the centre
levelling feeler rod (tamping area) “M”.
• 3 = Pendulum for measuring the already tamped track at the
rear levelling feeler rod “R” and for controlling the theoretical
level automatically.
• 4 = Digital-potentiometer for manual in put of the theoretical
cross level for the pendulum, at the centre measuring point “M”.
• 5 = Win ALC for automatic input of the theoretical cross levels
and adjusting values of transition, inclinations, changes in lifting
values, etc. (additional).
• 6 = Digital-potentiometer for manual input of the theoretical
cross level for the pendulum, at the front measuring point “F”.

152. • 7 = Regulator for the settlement compensation.
• 8 = Distance measuring transmitter for the Win ALC control.
• 9 = Manual input of the track lifting
• 10 = Remote control input of the track lifting values by means of
radio control or laser (additional).
• 11 = Proportional transmitter on the centre levelling feeler rod
(left and right) for measuring and automatically cut off of the
track lifting.
• 12 = Cross level recorder (optional). obslete
• 13 = Indication of the cross level after tamping (optional).
• 14 = Indication of the cross level after tamping (optional).
• 15 = Indication of the lift (left or right).
• 16 = Servo control of the hydraulic lifting (left and right).

153. PROPORTIONAL – LEVELLING SYSTEM
• The lifting, lining and tamping machines are equipped
with a proportional levelling and lifting system for
measuring and correcting the track geometry.
• MEASURING OF THE LONGITUDINAL PROFILE
• The track is measured at three locations per rail:
• - At the front of the machine (location “F”) for determination of
the actual level and
• the front measuring reference point.
• - In the area of the tamping units (location “M”) for scanning and
proportional
• control of the hydraulic track lifting system.
• - At the rear of the tamping units (location "R") on the already
corrected track for
• determination of the rear measuring reference point.

154. • A steel chord is stretched above each rail between the
reference points “F” and “R”
• which forms two, independent from each other, measuring
references for the
• longitudinal level.
• 1.3 Measuring transducers are mounted on the feeler rod of the
centre measuring
• device. The control arms of the transducers are connected with
the levelling chords.
• The measuring transducers change their position in proportion
to the level of the
• track at point “M” and transmit electronic signals for the
automatic control of the
• track lifting hydraulic system.

155. CROSS LEVEL MEASUREMENT
Electronic precision pendulums measure cross level at the
measuring points “F” and “M”.
• The difference between THEORETICAL and measured
ACTUAL cross level at the front measuring point “F” is
automatically and for the required side transmitted to
the lifting adjustment system.
• During the lifting and tamping operation the cross level is
checked at the centre measuring point “M” (in the area of the
tamping units).
• The measuring of the cross level at the rear measuring “R”
(optional) serves several functions:
• a) Checking the cross level of the track which has been lifted
and tamped immediately beforehand.
• b) Recording of the cross level by means of an electronic recorder.
• c) Output of the difference between theoretical and actual
superelevation values

156. • On the standard version the values for the theoretical
cross level are set manually.
• If the machine is additionally equipped with “WinALC”,
the values of theoretical
• cross level are transmitted fully automatically
INPUT OF THE LIFTING VALUES
• Track lifting is set at the front reference point “F” and is
automatically transmitted in the required proportion to
the cut off points of the measuring transducers, mounted
on the central scanning rod “M”.
• The lifting values are entered only for one rail. The
values for the other rail are added automatically,
considering the cross level error

157. Proportional Leveling System
Suitable for both Compensation Method & Precision Method
Steel chord between A-C over each rail forms LL Ref line.
Point B lifted physically/electronically until it reaches A-C.

158. • When exact/design Longitudinal Level not known.
• Fixed GL over Base rail and faults compensated.
• Left over Lifting error f due to F, as Front Point
on uncorrected track & Rear on corrected track.
• Only short wave defects up to 20m are removed.
Leveling: Auto, Compensation/Smoothening mode
Direction of Work
Level error f = F*a/b = F/r,
F = Level offset and
r = Reduction Ratio = b/a

160. DESIGN LEVELLING
• Tamping Machine corrects the leveling error
in the following two modes:
– Proportional or Compensation mode- In this
mode, General lift over the Base rail is generally
fixed and smoothening action takes place.
Longitudinal level and Cross-level are not
completely corrected and the Machine leaves
some error. Only short wave defects are
removed. Details are given in Annexure-I.
– Design or Precision mode- In this mode instead
of General lift, the target heights are fed over
the Base Rail to rectify 100% error. All long
wave and short wave defects are fully removed.
This presentation is to enrich knowledge of
Design Levelling.

161. • Levelling and Lifting System consists of
two chord wires one for each rail, stretched
tightly from Front tower (F) to Rear tower
(R). Tamping machines rectify level
defects in track by lifting it with
reference to these levelling chords.
Height Transducers are mounted on Middle
feeler rods (M), which rest on track at the
place where tamping is actually done and
these are also lifted when the track is lifted.
Both rails are controlled separately. For
Cross-level / Super-elevation correction,
Pendulums (P) are provided. Only CSM &
3x are designed for twist correction also.

162. Schematic Diagram
FMR
P
Chord Wire
Chord Wire

163. • Height transducers provided on Middle
feeler rod measures the gap between its zero
level and chord wire. Base rail is lifted to
eliminate this gap and other rail is lifted to
bring specified cant between two rails, which
is kept zero in straight track and a certain
value on curved track. Values of unevenness
and cant are fed through potentiometers.

164. • In levelling process, front tower always
remains on disturbed (unlevelled) track and
rear tower on levelled track. Because of
level defects in track at front trolley,
front end of the chord goes out of its
correct position equal to level offset at
that point. Due to incorrect position of
the front end of chord proportional level
error remains after levelling.
• Thus, the leveled track at M is having
Level error = LF*a/(a+b) = LF/r
where LF = Level offset at front tower and
r = Reduction Ratio = (a+b)/a

165. Bogie Distances and Reduction Ratio for
different Track machines
Bogie
Distance
(m)
UNO/
DUO
UNI2S UNI3S O9CSM MP2000 09-3X
RM (a) 4.04 3.32 4.85 3.90 5.10 4.56
MF (b) 9.64 8.89 10.73 8.90 9.05 10.67
RF (a+b) 13.68 12.21 15.58 12.80 14.15 15.23
Lifting
Ratio (r)
3.326 3.678 3.212 3.232 2.775 3.333

166. • In Design levelling, this Level error is
eliminated by raising or lowering front
end of the chord equal to level offset at
that point.
• In CSM, UNIMAT and 3x, chord wire is
not physically shifted but electronic
signals are relayed through
microprocessor to leveling unit and
track is lifted accordingly.

167. DETERMINATION AND ADJUSTMENT OF
LEVELLING ERRORS
• Detailed guidelines on „Survey for Vertical
Profile Correction, Plotting of Vertical Profile and
Surfacing Operations‟ as contained in Ann 5.3 to
IRTMM at stations marked at 10m interval using
conventional level and staff are very time
consuming because of repeated setting up
(centering & leveling) of dumpy level, change
in height of instrument, difficulty in taking
precise reading on conventional staff and a
lot of calculation work involved for
interpolating the data. Hence, it cannot be used
at the site immediately after taking data.

168. • In view of the voluminous survey work
involved, some specially designed gadgets may
be developed, which not only makes the direct
measurement of „Design Level Offset‟ quite
easy with Theodolite kept on rail but it is also
more practicable, fast, efficient and accurate.
• Theodolite Stand: It is modified for easy
fixing over rail head with the Theodolite at
specified height (line of sight at 1.2m) to have
a fixed height of instrument. No centering and
levelling of the Theodolite is required for
surfacing work in straight horizontal and
inclined track as no turning of Theodolite is
required. Only correct sighting of Target staff
and parallax removal at Intermediate staff
needs to be done.

169. Design Lifting (1)
What is to be done to Eliminate the Track
Surface errors Completely ?

170. Design Lifting (2)
R M
F(Error Portion )
15mm
G.lift in
chord
wire
15mm
error in
Track
15 x 0.138 = 4.79 mm

171. Design Lifting (3)
R M
F(Error Portion )
15mm
G.lift in
chord
wire
+
Lift
Value
15mm error in
Track
compensated
0 x 0.138 = 0 mm
We must know the exact
value of the dip here to get
perfect 15 mm G.lift at
Middle feeler rod.

172. Design Lifting (4)
R M
F(Error Portion )
15mm
G.lift in
chord
wire
15mm error in
Track
compensated

173. Design Lifting (5)
R
M
F
(Error Portion )
15mm
G.lift in
chord
wire

174. 1- Diopter focusing eye-piece 2- Rough Pointer
3- Tilting Screw 4- Telescope 5- Focusing screw
6- mm graduation for height adjustment 7- Tripod
8- Air level 9- Clamping device

175. • Target Staff: Height of target point on target staff
is to be kept equal to the height of instrument (1.2m)
from the bottom of staff. It is designed using
luminous strips for clear visibility and also to ensure
verticality without much effort.
• Graduated Intermediate Staff: It is designed to
take direct readings of lift required to be given to
track, which can be transferred instantaneously.
Graduation on Intermediate staff starts from height
equal to height of instrument (1.2m) from the bottom
of staff. It is designed using luminous strips for clear
visibility and Air level is also provided to ensure
verticality. No negative reading is indicated on staff,
however, reading up to -25 mm can be incorporated
in the staff which may some times be used to reduce
general lift at isolated points.

176. 1- Staff 2- Air Level 3- Graduated scale
4- Application-angle 5- Supporting Tube

177. Mono-rail Clamping Arrangement for
Theodolite and Levelling Staff

178. Method of Working
• Generally the rail, which is higher and has
minimum undulation, is chosen as the Base
or Datum rail for leveling. Guidelines for
selection of Datum rail is contained in Para
1.0 of Ann 5.3 to IRTMM.
• Survey is started from obligatory points like
bridges, level crossing, points & crossings.
When survey is started from other point, a
level track of 15 m is prepared and rail top
level is transferred on traction mast or rail
post as Bench Mark (BM) for record. Survey of
dips is done at Stations marked at 5 m interval
on Base rail.

179. • Two high point are chosen on Datum rail at
required base length (80 to 300m interval
within visual range). Care should be taken
while choosing higher points that no
intermediate point is higher than the chosen
points. In case negative value appears during
leveling, this indicates that the High Point has
been badly chosen.

180. • Height of instrument (line of sight) is fixed
with respect to datum rail level. For this fixed
height of instrument, the Target is sighted
from Theodolite and intersection point of
Target staff is fixed with respect to rail level,
which is equal to height of line of sight with
respect to rail level. Similarly height of zero
point is fixed on Intermediate staff equal to
height of line of sight with respect to rail level.
• Once the line of sight is fixed as above, the
intermediate staff will read zero value on each
point which is on straight line joining base of
target staff and base of Theodolite stand.

181. • This is true for straight horizontal as well as
inclined track.
• In this way height of instrument is
automatically deducted on each reading and
readings of sags are achieved without any
calculations on site instantly.
• The required design level offset (lift) at
every alternate sleeper is worked out by
interpolating the level offsets taken at
Stations marked at 5 m interval on Base rail.
• In this method neither plotting nor
computer calculations are required.

182. STRAIGHT HORIZONTAL

183. STRAIGHT INCLINED

184. PRECISION METHOD WITH SIGHTING DEVICE
• Instead of surveying the track beforehand for the precision
method, the following systems may be used (optional
equipment)
COMBINED SYSTEM WITH REMOTE CONTROL AND
SIGHTING DEVICE
• By means of a special levelling device which is fixed to the
track in front of the machine, a target board is aimed at, which
is on the front levelling feeler. During work, the target board is
adjusted to correct height by means of the remote control.
These adjustments are added automatically to the lift setting.
LASER-SYSTEM
• A laser beam which is aimed at a receiver on the front end of
the levelling feeler produces a parallel base for the required
level of the track. During work, the receiver is automatically
adjusted to the height of the laser beam and controls therefore
the lifting adjustment

186. Place the levelling
instrument
vertically to the
chosen begin of
the ramp "RA" and
set the
sight to the zero
mark on the height
adjusting
graduation.

187. Place the levelling
staff vertically on the
end of the ramp "RE"
and inscribe the
required lift
on the sleeper or on
the rail base. The
inscriptions should be
clearly in view of the
machine
operator

189. One rail is determined as datum or reference rail. In a tangent
the datum rail is normally
the one which is higher, in curves it is always the inner rail (the
lower one).

190. Levelling is usually carried out form high point to high
point, which are to be found within a maximal distance of
70 – 80 m (within visual range).

191. In case negative values appear during levelling this means
that the high point in question has been badly chosen. In
order to obtain a good track geometry, the highest point within
the track section must be again levelled out.

192. Place the staff on every 5th sleeper, from "RE" to one
machine length before "RA". Read
the lifting value for each measuring point and inscribe it on
the rail base or on the sleeper.
Be careful not to change the axis of measurement during
levelling.

193. Leveling: Design / Precision Mode
• To eliminate Longitudinal faults completely.
• Front chord must be placed physically or electronically in
correct Lifting Offset Value (F) measured beforehand.
• Instead of General Lift, Target height fed over Base rail.
• Other rail is laid in the correct XL/SE.
• Precise LL produced.
• Rectify 100% error. No left over error.
• All long wave and short wave defects are fully removed.
Direction of Work

194. Determination of Leveling Offset F
A. Using conventional Dumpy level & staff:
–Very time consuming because of;
• Repeated setting up (centering/leveling) of dumpy
level.
• Change in height of instrument.
• Difficulty in precise reading on conventional staff .
• A lot of calculation involved for data interpolation.
• Cannot be used at site immediately after taking data.
B. Theodolite with Specially designed gadgets:
– Easy direct measurement of „Design Level Offset‟ with
Theodolite kept on base rail.
– More practicable, fast, efficient & accurate.

195. • Theodolite Stand:
• Modified for easy fixing over rail head with Theodolite at specified
height (1.2m) to have a fixed height of instrument.
• No centering and leveling of the Theodolite on straight horizontal
and inclined track as no turning of Theodolite.
• Only correct sighting of Target staff and parallax removal at
Intermediate staff is done.
• Target Staff:
• Height of target point on target staff is to be kept equal to height of
instrument (1.2m) from the bottom of staff.
• Designed using luminous strips for clear visibility and also to
ensure verticality without much effort.
• Graduated Intermediate Staff:
• Designed to take direct readings of lift.
• Graduation on Intermediate staff starts from height equal to
height of instrument (1.2m) from the bottom of staff.
• Designed using luminous strips for clear visibility and Air level is
also provided to ensure verticality.
Determination of Leveling Offset F

196. • Generally the rail, which is higher and has minimum undulation,
is chosen as the Base rail for leveling.
• Survey is started from obligatory points like bridges, level
crossing, points & crossings.
• When survey is started from other point, a level track of 15 m is
prepared and rail top level is transferred on traction mast or rail
post as Bench Mark (BM) for record.
• Survey of dips is done at Stations at 5 m interval on Base rail.
• Two high point are chosen on Datum rail at required base length
(80 to 300m interval within visual range).
• Care should be taken while choosing higher points that no
intermediate point is higher than the chosen points.
• In case negative value appears during leveling, this indicates that
the High Point has been badly chosen.
Method of Working

197. • Height of instrument (HOI) fixed w.r.t. Datum rail level.
• For this fixed HOI, the Target is sighted from Theodolite and
intersection point of Target staff is fixed w.r.t. rail level, which is
equal to height of line of sight w.r.t. rail level.
• Similarly height of zero point is fixed on Intermediate staff equal
to height of line of sight w.r.t. rail level.
• Once the line of sight is fixed, the Intermediate staff will read
zero on each point which is on straight line joining base of target
staff and base of Theodolite stand.
• This is true for straight horizontal as well as inclined track.
• In this way height of instrument is automatically deducted on
each reading and readings of sags are achieved on site instantly.
• The required design level offset (lift) at every alternate sleeper is
worked out by interpolating the level offsets taken at Stations
marked at 5 m interval on Base rail.
Method of Working