The following specification particularly describes the invention and the manner in which
it is to be performed.
Detailed description of the invention:
1. Introduction:
Due to the non-availability of adequate number of bridge timber for renewal and
subsequent ban of procurement and use of wooden sleeper by Hon'ble Supreme court
in Indian Railways (IR) in 1999, IR started renewal of bridge timbers with steel channel
sleeper on girder bridges. Almost all the bridges have been provided with st.eel channel
sleepers on Indian Railways. Steel Channel sleepers are provided with rail fastening
arrangement which comprise of clips with T-head bolts and nuts to hold rail over steel
channel sleepers through canted bearing plate. Such fastening arrangements do not
allow longitudinal movement of rail required for providing welded rails and continuing
Long Welded Rail (LWR) on girder bridges as per the stipulations contained in "Manual
of Instruction on Long Welded Rails 1996".
For providing welded rail and continuation of long welded rail (LWR) on girder bridges,
provision of a fastening system which renders the rail free to expand and contract due
to thermal forces, yet keeping the rail in safe position, may be a pre-requisite.
This requirement is achieved by having a fastening system which has its components
assembled in such a manner that the toe load exerted by the Elastic Rail Clip is not
transferred to the rail permitting the longitudinal expansion and contraction of the rail but
simultaneously position of the rail at desired line and level is maintained. RDSO has
developed a design of rail free fastening system (RFFS) for use on sleeper on girder
bridges. At present, RDSO has developed design for RFFS for use on H-Beam Sleeper
·on girder bridges. With minor modification, this design may also be used for sleepers
such as steel channel sleeper and wooden/composite sleeper on girder bridges. The
design of rail free fastening system basically consists of:
a. SGCI Canted bearing plate
b. SGCI liner,
c. Rubber pad
d. Elastic Rail Clip (ERC)
e. HOPE pad
f. Bolts with lock nuts
The first two components given above are specifically developed for rail free fastening
system and have novelty while rest of the components are of known art and are
presently in use in main line/ other different locations on Indian Railway.
In this rail free fastening system, the SGGI canted bearing plate is fixed on the sleeper
with the help of a thorough arrangement of bolts and nuts along with spring washer, lock
nuts, etc. which also provides the ease of replacing the base plate quickly in case of
damage to the fastening system due to derailments, etc. After placing bearing plate, a
rubber pad is fixed on the canted portion of the bearing plate which gets interlocked due
to horn in the space between shoulders. An HOPE pad is placed over rubber pad to
provide smooth surface for longitudinal movement of rail. The rail is then placed over
the HOPE pad and ERG driven through the shoulder on the bearing plate and SGGI
liner.
The SGGI bearing plate has raised portion, herein after called as shoulder, on either
side having horizontal hole and a recess in the shoulder. The SGCI liner is so designed
that it has extended portion having a horizontal hole. The liner is placed in the recess in
the shoulder on the bearing plate. The liner is placed in such a way that the hole
provided in the shoulder of bearing plate and hole of extended portion of liner falls in
same line and level (i.e. holes coincide with each other). After putting liner in the recess
of shoulder on bearing plate, the central leg of Elastic Rail Clip (ERC) is driven into the
hole provided in the shoulder of the bearing plate as well in the liner. With this type of
arrangement, interlocking of the liner with the bearing plate is ensured. Rail free
fastening system is designed such that in driven condition, heel portion of the tension
clamp i.e. ERG rests on space provided on the shoulder of the bearing plate while toe
portion of the clamp rests on the liner. In this arrangement, the full toe load of ERC is
exerted on the liner but not on the rail foot and by doing so, possibility of working out of
clip due to track vibration etc. during passage of train is avoided. Also, due to toe load of
the clip, rest of the fastening components remains in their position. A layer of plastic
sheet (HOPE) is provided in between bearing plate and the sleeper to counter
undulation on both surfaces and also providing a sacrificing layer in between.
The liner of the assembly is so designed that a gap of the order of 2.5 mm is available
between rail and the liner, hence, longitudinal movement of the rail remains
· unrestricted, which is the basic requirement of the provision of welded rails and long
welded rail (LWR) on girder bridges.
The assembly is so designed that different rail sections presently in use in Indian
Railway i.e. 60 Kg & 52 Kg rail can be used on the same sleeper with the change of
liner only.
Schematic Picture of SGCI Bearing Plate
Schematic picture of SGCI Liners for 52 Kg and 60 Kg
List of sketches used in Rail Free Fastening Syatem
S. No. Description of Sketch Sketch No.
1. Rail Seat Assembly using Rail Free Fastening System 1
2. SGCI Bearing Plate for Rail Free Fastening System 2
3. SGCI Liner for Rail Free Fastening 3

Claims:

1. A Rail Free Fastening System (RFFS) for sleepers on Girder Bridges comprising

a) a bearing plate made of SGCI material with raised portion on either side (called shoulder) having horizontal hole and a recess in the middle of raised portion to accommodate extended portion of SGCI liner. A through cant is provided between shoulders of bearing plate.

b) a pair of SGCI liners with extended portion having horizontal hole has been used. The liner is placed in such a way that the hole provided in the shoulder of bearing plate and hole of extended portion of liner falls in same line and level (i.e. holes coincide with each other). After putting liner in the recess of shoulder on bearing plate, the central leg of Elastic Rail Clip (ERC) is driven into the hole provided in the shoulder of the bearing plate as well in the liner. With this type of arrangement, interlocking of the liner with the bearing plate is ensured.

c) a pair of Elastic Rail Clip(ERC) of existing design placed in such a manner that in driven condition, heel portion of ERC rests on space provided on the shoulder of the bearing plate while toe portion of ERC rests on the liner with a gap between bottom of liner and top of rail foot.

d) a rubber pad of existing design over bearing plate

e) an HDPE pad in below rail and another below bearing plate

f) a thorough arrangement of bolts and nuts to fasten bearing plate over sleeper

2. A Rail Free Fastening System (RFFS) as claimed in claim 1 wherein liner may be made of SGCI material by casting or MS material by forging.
, Description:COMPLETE SPECIFICATION

The following specification particularly describes the invention and the manner in which it is to be performed.

Detailed description of the invention:

1. Introduction:

Due to the non-availability of adequate number of bridge timber for renewal and subsequent ban of procurement and use of wooden sleeper by Hon’ble Supreme court in Indian Railways (IR) in 1999, IR started renewal of bridge timbers with steel channel sleeper on girder bridges. Almost all the bridges have been provided with steel channel sleepers on Indian Railways. Steel Channel sleepers are provided with rail fastening arrangement which comprise of clips with T-head bolts and nuts to hold rail over steel channel sleepers through canted bearing plate. Such fastening arrangements do not allow longitudinal movement of rail required for providing welded rails and continuing Long Welded Rail (LWR) on girder bridges as per the stipulations contained in “Manual of Instruction on Long Welded Rails 1996”.

For providing welded rail and continuation of long welded rail (LWR) on girder bridges, provision of a fastening system which renders the rail free to expand and contract due to thermal forces, yet keeping the rail in safe position, may be a pre-requisite.

This requirement is achieved by having a fastening system which has its components assembled in such a manner that the toe load exerted by the Elastic Rail Clip is not transferred to the rail permitting the longitudinal expansion and contraction of the rail but simultaneously position of the rail at desired line and level is maintained. RDSO has developed a design of rail free fastening system (RFFS) for use on sleeper on girder bridges. At present, RDSO has developed design for RFFS for use on H-Beam Sleeper on girder bridges. With minor modification, this design may also be used for sleepers such as steel channel sleeper and wooden/composite sleeper on girder bridges. The design of rail free fastening system basically consists of:

a. SGCI Canted bearing plate
b. SGCI liner,
c. Rubber pad
d. Elastic Rail Clip (ERC)
e. HDPE pad
f. Bolts with lock nuts

The first two components given above are specifically developed for rail free fastening system and have novelty while rest of the components are of known art and are presently in use in main line/ other different locations on Indian Railway.

In this rail free fastening system, the SGCI canted bearing plate is fixed on the sleeper with the help of a thorough arrangement of bolts and nuts along with spring washer, lock nuts, etc. which also provides the ease of replacing the base plate quickly in case of damage to the fastening system due to derailments, etc. After placing bearing plate, a rubber pad is fixed on the canted portion of the bearing plate which gets interlocked due to horn in the space between shoulders. An HDPE pad is placed over rubber pad to provide smooth surface for longitudinal movement of rail. The rail is then placed over the HDPE pad and ERC driven through the shoulder on the bearing plate and SGCI liner.

The SGCI bearing plate has raised portion, herein after called as shoulder, on either side having horizontal hole and a recess in the shoulder. The SGCI liner is so designed that it has extended portion having a horizontal hole. The liner is placed in the recess in the shoulder on the bearing plate. The liner is placed in such a way that the hole provided in the shoulder of bearing plate and hole of extended portion of liner falls in same line and level (i.e. holes coincide with each other). After putting liner in the recess of shoulder on bearing plate, the central leg of Elastic Rail Clip (ERC) is driven into the hole provided in the shoulder of the bearing plate as well in the liner. With this type of arrangement, interlocking of the liner with the bearing plate is ensured. Rail free fastening system is designed such that in driven condition, heel portion of the tension clamp i.e. ERC rests on space provided on the shoulder of the bearing plate while toe portion of the clamp rests on the liner. In this arrangement, the full toe load of ERC is exerted on the liner but not on the rail foot and by doing so, possibility of working out of clip due to track vibration etc. during passage of train is avoided. Also, due to toe load of the clip, rest of the fastening components remains in their position. A layer of plastic sheet (HDPE) is provided in between bearing plate and the sleeper to counter undulation on both surfaces and also providing a sacrificing layer in between.

The liner of the assembly is so designed that a gap of the order of 2.5 mm is available between rail and the liner, hence, longitudinal movement of the rail remains unrestricted, which is the basic requirement of the provision of welded rails and long welded rail (LWR) on girder bridges.

The assembly is so designed that different rail sections presently in use in Indian Railway i.e. 60 Kg & 52 Kg rail can be used on the same sleeper with the change of liner only.