Field of Invention:
The present invention related to an improved railway track or rail section design to provide
significant impact on the overall performance and sustainability of railway networks. The
invention likely involves innovations or modifications to the rail profile design to enhance its
performance, safety, or efficiency of rail track system.
2. Background of Invention:
Over the years, the creation and modification of rail profiles have been crucial in the growth
and development of railway systems. To improve safety, stability, and efficiency in rail
transportation, alteration have been made to the rail profile, most of modification belongs to
change or increase the rail cross sectional area of the rail profile. In railway systems, the
interaction of steel wheels and rails creates difficult contact conditions that may cause both
the wheels and the rails to degrade. Rail life is reduced by several important degradation
mechanisms, including wear, rolling contact fatigue, corrugation, and plastic deformation.
The generic shape of flat bottom rails for railway networks has remained broadly similar for
well over hundred years, the ever-increasing demands resulting from higher axle loads,
vehicle speeds, and traffic density has necessitated a continuous modification to selected key
dimensions to achieve higher structural strength. Flat bottom rails have historically evolved to
their current shape to satisfy the key functional requirements of structural strength, wheel-rail
profile compatibility, avoidance of stress raising features, and provision of sufficient material
as mitigation against inevitable wear.
However, closer examination of rail section developments in past decades suggests that the
primary aim has been to increase rail height to realise higher values of "Moment of Inertia -
lxx".
.,
.5. 2!
m t: • .5
0
;: • E
0 :;:
3500
3000
2500
2000
'""
Rail Section Weight vs MOIIxx
y = 106.56x -3400.2
• R' = 0.9649 ••
50 " ---.--~---'
Sectional Wt (kg/m)
Fig: 2(a) Relationship between Moment of
inertia and Rail Weight.
~
~500
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~.500
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Rail Section Height vs hoc
:
•
= 55.177X· 6405.8
; R• = 0.9897 .
~· ~----~------------------~
125 145 165 165 205
secUon Height, mm
Fig: 2(b) Relationship between Moment of
inertia and Rail Height
3
The above relationship shown incorporates data for" all rail profiles several older sections This
clearly indicates the development trend in rail profile to satisfy the need for increased stiffness
i. e. through increases in rail height and weight. Furthermore, it is also apparent the different
functional contrib)Jtions of the rail head, web, and foot, their proportional distribution of area
has remained broadly similar in all past development Thus, it can be concluded that the state
of the art for rail section development to date has followed the past trends and rules of flat
bottom rail sections. This invention is about significant modification flat bottom rail section and
aims to produce a rail modified larger section of rails that allows for more wear and increase
the vertical, lateral, and torsional stiffness of the rail to give improved load redistribution across
the track length.
3. O~jective of the Invention:
The objective of invention relates to the inventing a special rail profile to increase service
life of railroad track and the main reason of this invention to designing a rail profile that
minimizes wear and tear, reduces fatigue, and withstands high axle loads.
4. Summary of Invention:
With the development of railway transportation, heavy cross-section steel rails are more and
more widely used in heavy-duty passenger and freight transportation, but with the increase
of transportation volume, the damage of steel rails is more serious concern. Railways
frequently look to employ higher cross-section tracks, but the choice to do so is usually based
on a rigorous analysis of these aspects to assure the security, dependability, and
effectiveness of rail transportation. The primary aim of the research into the invention of the
new rail section was to redistribute the cross sectional of the rail to make a greater proportion
available for the inevitable degradation through wear. The conventional 60kg/m rail section
is shown in Figure 4a while Figure 4b (right half) shows a comparative view of the developed
profile (coloured lines) a proposed modified version of new invented profile which imposed,
on 60kg/m rail (dotted line) for better understanding of difference in invented and existing rail
profile.
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1· Fig:4(a) Existing Rail profile of 60kg/m Fig:4(b) New Proposed invented Rail Profile
4
The novel section is based on the footprint of 60kg rail (Figure 4a) but the design rules are
equally applicable to alternative sections in current use. This work consisted of modifying the
cross-secti.on of the reference profile 60kg/m to improve its mechanical behaviour and
increase its expected life. The rail section comprising a head section, a foot section and a web
section shown in fig (4a & 4b). the invented rail profile having Head & foot width, ·rail height,
crown profile, web thickness, thickness maintained same as 60Kg/m rail profile so there is no
need of major changes in the existing railway infrastructure.
The main aspects of developed design of invented profile -
In a first stage, the cross section of the profile of 60kg/m was modified to improve its
mechanical behaviour and increase the expected life. Section was developed by modifying
head depth, Flange thickness and web thickness. By doing the different trial and experiment,
the profiles with combined 50% increase of head depth, foot thickness and web thickness is
the more appropriate profile to provide better vertical and lateral bending stiffness, Therefore,
this profile was initially considered as the best profile.
In the second stage existing thickness and shape of the foot tips were maintained to permit
the use of existing fastening systems. The height of the central part of the foot was increased
so that the vertical stiffness to be maintained.
Rolling of Heavy Rails: The invention adopts 285mmx390mm bloom cross-section to roll the
invented profile. The blooms go into reheating furnace at higher temperatures. (12so•c ±
30.C). After proper homogenization of bloom stock at higher temperature the blooms
discharged from reheating furnace. In order to clean the excessive scale formed· on blooms
during reheating process removed under the descaling unit that sprayed a water at higher
pressure then it passed through the Breakdown mill-1 where the symmetric rolling is carried
out, and box grooves are used, next through the BD2 unit where the asymmetric rolling is
conducted, and grooves (calibres) of varying geometrical shapes are used, and finally through
the universal rolling unit which comprises of three stands, that is, universal roughing (UR),
Edger and universal finishing (UF). After rolling all rail pass through the straightening and NOT
unit. After that physical surface inspection, dimension with gauges is carried out.
Further thorough analysis of the dimensions and sectional property characteristics showed
that the cross-sectional area distribution was not enough to the invented an optimized profile
or best solution of track problem. This major focus of designing is created the largest portion
of the rail head and foot centre. To make adoption into existing networks easier, the developed
section's essential dimensions, including complete rail height, head width, web thickness, foot
width, and the location of the neutral axis, have all been left intact and same as reference
profile of 60kg/m rail. The key benefits stemming from the use of the developed section are:
A. Increased capacity for wear:
o The developed profile with more head area to allow more permissible wear limit
with reference to profile 60kg/m.
o In curved track where rails experience a combination of vertical and lateral
wear, the wear capacity of the developed rail is increased as compared to
60kg/m rails:
B. Improved mechanical behaviour of track:
o Increased lateral and torsional stiffness of the developed profile provides
significantly better mechanical behaviour in ballasted track even with high
vertical and lateral wear.
o The use of developed profile results an increment in the track stiffness in both
low and high frequency domains.
o The increased capacity for natural or enforced wear of the developed profile
provides greater mitigation potential through use of regular grinding or milling.
5
',
5. Drawings of Invention
A fully dimensioned drawing of the most preferred developed section is shown below
and a summary comparison of the key dimensional attributes with the corresponding
benchmark 60Kg/m section.
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Fig5(a)- Shows the 78kg invented rail profile with dimensions.
6. Brief Description of Accompanying Drawing-
As detailed in Table 1, the key dimensions of full rail height, head width, web thickness, foot
width,-and the location of the neutral axis for the developed section are the same as that for
60kg/m rails. Consequently, the developed section is fully compatible for installation in a track
network employing 60kg/m rails.
In comparison to the reference profile of 60kg/m rails, the height of the rail head section has
been increased from 51mm to 76.5mm while maintaining the same head width, rail height,
web thickness, foot width. This increase in head height corresponds to a-:- 63% increase in
the cross-sectional area of the head compared to the reference section. The second key
modification is the foot cross sectional area has been increased from 2856 mm2 to 3939 mm2
· equating to an increase of -38%. In accordance with the results of the parametric
assessments shown in Table-1, the thickness of the web has been kept the same as the
reference section and since the overall rail height has also been left unaltered, the result has
been to reduce the web cross sectional area of the most preferred design compared to the
reference section by just over 35%. This largely cancels the increase in the cross-sectional
6
area of the foot and restricts the increase in the cross-sectional area of the whole rail to just
over 31 % that is predominantly concentrated in the head section which is the active part
dictating performance and life span.