handbook on installation & maintenance practices of
TRANSCRIPT
GOVERNMENT OF INDIA
MINISTRY OF RAILWAYS
Handbook on
Installation & Maintenance practices of
Electric Point Machine 220 mm throw
With Clamp type lock for Thick Web Switch
End Users : SSE/JE (Signal) & Signal Maintainers
CAMTECH/S/PROJ/2020-21/SP8/3.0
December 2020
Maharajpur, Gwalior (M.P.) – 474005
i
ii
Handbook on
Installation & Maintenance practices of
Electric Point Machine 220 mm throw With Clamp type lock for Thick Web Switch
CAMTECH/S/PROJ/2020-21/SP8/3.0
December 2020
iii
Foreword
The traffic density has increased tremendously over the years on Indian
Railways and along with it high speed trains have also been introduced. For safe
and efficient operation of high speed rolling stock various means such as higher
section of rail, high power locomotives and high speed turnouts have been
inducted. High speed train projects on some identified routes are also in the
pipeline. To meet the requirements of point operation on such high speed turnouts
Electric Point Machines 220 mm throw with additional safety feature of clamp
type lock are being installed. CAMTECH has prepared this handbook for Signal personnel to get them
acquainted with installation and maintenance practices of Electric Point Machine
220 mm throw. I am confident that this handbook will help them in installation and
maintenance of this machine under their jurisdiction.
CAMTECH Gwalior Jitendra Singh
Date: Principal Executive Director
iv
Preface
On Indian Railways, high speed trains such as Rajdhani Express, Shatabdi
Express and Gatiman Express are in operation and new high speed corridors are
proposed to cater for demand of increasing traffic density. In projects like
dedicated freight corridor, high speed turnouts with thick web switch are being
installed for which Electric Point Machine of 220 mm throw with clamp type
locking is provided.
CAMTECH has prepared this handbook for the guidance of Signal
personnel regarding correct installation and efficient maintenance of Electric Point
Machine for Thick web Switch installed in their section. Installation as per
modified RDSO drawing has also been covered in the handbook.
We are sincerely thankful to Signal Directorate RDSO Lucknow, West
Central Railway, M/s Vossloh Cogifer Signalling India Pvt. Ltd., Bhilai and S&T
personnel of Indian Railways who helped us in preparing this handbook by
providing valuable information.
Since technological upgradation and learning is a continuous process, you
may feel the need for some addition/modification in this handbook. If so, please
give your comments on email address [email protected] or write to us at
Indian Railways Centre for Advanced Maintenance Technology, In front of
Adityaz Hotel, Airport Road, Maharajpur, Gwalior (M.P.) 474005.
CAMTECH Gwalior Dinesh Kumar Kalame
Date: Jt. Director (S&T)
v
Table of Contents
Foreword ...................................................................................................................................................... iii
Preface ......................................................................................................................................................... iv
Table of Contents .......................................................................................................................................... v
Issue of Correction Slip ............................................................................................................................... vii
Disclaimer................................................................................................................................................... viii
Our objective ................................................................................................................................................ ix
CAMTECH Publications.................................................................................................................................. x
1 Introduction ........................................................................................................................................... 1
Salient features of TWS ............................................................................................................................. 1
2 Clamp type lock and its advantages ...................................................................................................... 1
3 Spring setting device (SSD) .................................................................................................................. 2
4 Modification in design of Spring Setting Device to prevent track circuit failures ................................ 4
5 Main Parts ............................................................................................................................................. 6
6 Main parts of Clamp Lock and Functions ............................................................................................. 6
Working of Clamp Lock ....................................................................................................................... 7
7 Installation guidelines ........................................................................................................................... 7
7.1 Installation as per RDSO drawing no. RDSO/S3454 .................................................................... 7
7.2 Installation as per RDSO drawing no. RDSO/S3454 ALT –A Ver.1.0 ...................................... 16
8 Adjustment.......................................................................................................................................... 17
9 Testing................................................................................................................................................. 18
9.1 Obstruction Test.......................................................................................................................... 18
9.2 Insulation Test ............................................................................................................................. 18
10 Maintenance ................................................................................................................................... 19
11 Troubleshooting .............................................................................................................................. 20
12 Do’s & Don’ts ................................................................................................................................. 22
13 Tools & Spares ................................................................................................................................ 22
vi
14 Summary ......................................................................................................................................... 24
15 References ....................................................................................................................................... 27
16 Annexure I : Modified RDSO design for Spring Setting Device (SSD) of Thick Web Switch (Drg.
No. RDSO/T 6216 ALT-4) ......................................................................................................................... 28
17 Annexure II : RDSO Drawings for Ground connections of Electric Point Machine 220 mm stroke
with Clamp Lock for Thick Web Switch (TWS) (Drg. No. RDSO/S-3454) ................................................... 28
18 Annexure III : Modified RDSO Drawings for Ground connections of Electric Point Machine 220
mm stroke with Clamp Lock for Thick Web Switch (TWS) (Drg. No. RDSO/S-3454 ALT–A Ver. 1) ............. 28
vii
Issue of Correction Slip
The correction slips to be issued in future for this handbook will be numbered as follows:
CAMTECH/S/PROJ/2020-21/SP8/3.0# XX date .......
Where “XX” is the serial number of the concerned correction slip (starting from 01 onwards).
CORRECTION SLIPS ISSUED
Sr. No. of
Correction
Slip
Date of
issue
Page no. and Item
No. modified
Remarks
viii
Disclaimer
It is clarified that the information given in this handbook does not
supersede any existing provisions laid down in the Signal Engineering
Manual, Railway Board and RDSO publications. This document is not
statuary and instructions given are for the purpose of guidance only. If
at any point contradiction is observed, then Signal Engineering Manual,
Railway Board/RDSO guidelines may be referred or prevalent Zonal
Railways instructions may be followed.
ix
Our objective
To upgrade Maintenance Technologies and Methodologies and achieve
improvement in Productivity and Performance of all Railway assets and manpower
which inter-alia would cover Reliability, Availability and Utilisation.
If you have any suggestion & any specific comments, please write to us:
Contact person : Director (Signal & Telecommunication)
Postal Address : Centre for Advanced Maintenance Technology,
Maharajpur, Gwalior (M.P.) Pin Code – 474 005
Phone : 0751 - 2470185
Fax : 0751 – 2470841
Email : [email protected]
x
CAMTECH Publications
CAMTECH is continuing its efforts in the documentation and up-gradation of information on
maintenance practices of Signalling & Telecom assets. Over the years a large number of
publications on Signalling & Telecom subjects have been prepared in the form of handbooks,
pocket books, pamphlets and video films. These publications have been uploaded on the internet
as well as railnet.
For downloading these publications
On Internet:
Visit www.rdso.indianrailways.gov.in
Go to Directorates → CAMTECH → Publications for download → S&T Engineering
Or http://www.rdso.indianrailways.gov.in/view_section.jsp?lang=0&id=0,2,17,5025
On Railnet:
Visit RDSO website at 10.100.2.19
Go to Directorates → CAMTECH → Publications → S&T Engineering
Or
http://10.100.2.19/camtech/Publications/CAMTECH%20Publications%20Online/CAMTECHMai
n.htm
A limited number of publications in hard copy are also available in CAMTECH library which can
be got issued by deputing staff with official letter from controllong officer. The letter should be
addressed to Director (S&T), CAMTECH, Gwalior. For any further information regarding
publications please contact:
Director (S&T) – 0751-2470185 (O)(BSNL)
SSE/Signal - 7024141046 (CUG)
Or
Email at [email protected]
Or
FAX to 0751-2470841 (BSNL)
Or
Write at
Director (S&T)
Indian Railways Centre for Advanced Maintenance Technology,
In front of Hotel Adityaz, Airport Road, Maharajpur,
Gwalior (M.P.) 474005
xi
CAMTECH/S/PROJ/2020-21/SP8/3.0 1
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Electric Point Machine 220 mm throw
With Clamp type Lock for Thick Web Switch
1 Introduction
The traffic density is increasing day by day on Indian Railways and to increase the section
capacity higher speeds of trains are always aimed at. To meet this demand higher power
locomotives were developed and high speed turnouts i.e. more than the existing 1 in 12
turnouts are being laid. In most of the new works such as the work of freight corridor (third
line) high speed turnouts with higher section of rails i.e. Thick web switch (TWS) with 60
Kg rails are being installed. For operating TWS, the existing design of Electric Point
Machine was modified with the incorporation of clamp type lock for additional safety.
Salient features of TWS
The crossing angle has been broadened so that the train negotiating at higher speeds does
not pose any danger.
The switch opening is of 160 mm as against of 115 mm of ordinary cross over.
The web of the switches is made thicker to make than them strong enough to withstand load
of train at high speeds.
2 Clamp type lock and its advantages
A CLAMP LOCK clamps together the closed switch against the stock rail and achieves the
locking of the switch. For the working of clamp lock, the throw bar of point machine is
provided with a total of 220 mm stroke the distribution of which is as given below:
60 mm for the unlocking,
100 mm for the throwing of points and
60 mm for the locking of closed switch.
Advantages:
(a) It ensures and proves the proper setting of switch rail against stock rail.
(b) Due to the 160 mm opening of thick web switch (TWS) at toe the clearance at junction
of rail head (JOH) is 60 mm. This prevents the repeated striking of the open switch at
junction of rail head (JOH) by inner side of the wheel, which in conventional switches
leads to chances of under wheel flashing.
(c) It prevents vibration caused in the switch due to train movement which in turn prevents
disturbance to detection and control contacts assembly unit directly. In conventional
switches this leads to reduction in efficiency of the unit.
(d) Due to complementary tapers in switch and stock rail, the switch rail toe fits underside
the stock and therefore the wheel of the train engages the switch rail well after 6" from
toe. Therefore, damage and wear and tear of the switch is prevented.
(e) Provides direct locking between tongue rail and stock rail in closed position.
(f) Firmly holds the tongue rail in the open position. Checks any relative movements
between tongue and stock rail
(g) It ensures and proves the proper setting of switch and stock rail.
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
3 Spring setting device (SSD)
(a) In a TWS turnout, no stretcher bar is used and hence switches are able to move
independently.
(b) A spring setting device (SSD) is provided at junction of Rail head (JOH), in lieu of
stretcher bars, to assist in proper setting of switch upto JOH, which is placed between
sleeper number 13 and 14.
(c) Adjustment of locking is done by means of packing shims between switch rail and stock
rail bracket. Three each of 1 mm and one of 0.5 mm shims are provided for each switch.
Need for SSD
(Reference: www.binametalway.com of M/s Bina Metal Way Pvt. Jamshedpur)
Railways are increasingly using curved switches in turnouts, since they enable smoother
passage and also permit higher speeds. In curved switches, the distance from Actual Toe
(AT) up to Junction of Rail Heads (JOH), where the machining of tongue rail head ends, is
much longer as compared to the corresponding distance in straight switches which were
used earlier. As a consequence, the tongue rail in curved switches is comparatively much
slender in the stretch from AT to JOH.
When a throw is given to the tongue rail of curved switches at AT, the flange way
clearance between the open tongue rail and the corresponding stock rail near JOH is of the
order of 35 to 50 mm only. This is much lesser than the minimum clearance of 60 mm
(approx) needed for smooth passage of the wheel-flange through open switches. As such,
back-face of wheels graze the back-face of tongue rails when vehicles negotiate open
switches, thus causing rattling of tongue rail as also wear on its back-face. While wear on
the gauge-face of tongue rail is quite usual, the wear caused on the back-face of tongue
rails distorts the geometry of switch when such a worn tongue rail is closed against its
stock rail.
Another consequence of the slenderness of tongue rails of curved switches is non-butting
of the closed tongue rail against its corresponding stock rail at JOH, where a gap of 10 to
25 is observed between the two rails. This gap causes gauge variation in switch portion and
vibration of tongue rail when wheel-flange presses against the gauge-face of tongue rail.
Curved switches are used in preference to straight switches basically for enabling smoother
and faster travel. Therefore, there is a greater need to ensure proper alignment, gauge,
fitment etc in curved switches. The problems noticed in curved switches as discussed
above, defeat the very purpose of their introduction.
SSD have been designed to address this particular problem. When this device is located
near and connected to the Last following Stretcher Bar of the switches, it ensures the
following:
A minimum flange way clearance of 60 mm (approx) at JOH between the open tongue
rail and its stock rail.
The butting of closed tongue rail against its stock rail from AT to JOH.
CAMTECH/S/PROJ/2020-21/SP8/3.0 3
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Figure 1 : IRS-Clamp type Point Machine Layout with TWS
Function of SSD
(Reference : IRICEN Pune's publication on Turnout - Laying, Inspection,
Maintenance, September 2014)
For best performance, tongue rail should bear against the stock rail from Actual Toe of
Switch (ATS) to Junction of Rail Head (JOH). However achieving setting of tongue rail up
to JOH may be difficult in the field. Since the stretcher bar is fixed to the tongue rail while
the tongue rails are at half throw, it sets a force in tongue rail, when it is pressed against any
stock rail. Point machine presses the tongue rail against one of the stock rails at the ATS but
in the absence of any force near JOH, tongue rail opens out at this location.
Since on Indian Railways there is no
means to provide force on tongue rail at
JOH, Spring Setting Device has been
developed which provides thrust on the
tongue rail, near JOH so that the tongue
rail bears well against stock rail. As per
present orders, only RDSO approved
design of SSD are to be used.
Figure 2: Spring Setting Device (SSD) with
cover open
CAMTECH/S/PROJ/2020-21/SP8/3.0 4
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Spring setting device is provided with springs which initially opposes the movement of
tongue rail at the time of beginning of change of direction till the time tongue rail crosses
half throw. After passing a particular position, direction of force provided by spring changes
and it provides a force to press the tongue rail which is to be set for train movement. Thus it
presses tongue rail against the stock rail at JOH. Provision of Spring Setting Device may
take care of the problems such as tongue rail not fully bearing against stock rail up to JOH.
It will also take care of inadequate clearance of open tongue rail and stock rail at JOH,
which is particularly more pronounced in case of 1 in 12 turnouts. SSD is able to provide
opening of 60 + 2mm of tongue rail at JOH. It also takes care of rattling of tongue rail under
passage of wheels.
4 Modification in design of Spring Setting Device to prevent track
circuit failures It has been observed that present design of SSD is prone to track circuit failures due to
existing insulation arrangement in SSD arm (connecting arm). These failure are mainly due
to iron dust falling over insulation and frequent crushing of very thin layer of insulation. To
prevent track circuit failures, insulation has been provided at a new location in Agra and
Prayagraj Division of North Central Railway on trial basis. This trial has drastically reduced
the track circuit failures. RDSO Track Directorate in consultation with Signal Directorate
has also issued revised drawing for SSD {Refer Annexure I - Drawing No. RDSO/T-6216
Figure 3: Sketch showing Spring Setting Device (SSD)
CAMTECH/S/PROJ/2020-21/SP8/3.0 5
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
(ALT-4) dated 04.10.2019}. Meanwhile the following arrangement can be done locally till
SSDs with new design are supplied:
A 50 mm piece is cut in the SSD Arm (connecting rod) and links are welded at both ends
similar to that provided in roding joints as shown in the figure below:
Insulation plate is provided between the two links and fixed through nuts and bolts with
nylon washers.
Figure 4: 50 mm piece cut from SSD arm and links welded
Figure 5 : Provision of insulation in SSD arm
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
5 Main Parts
Main parts of point machine are:
(a) DC series split field Motor with- in built reduction gear unit.
(b) Transmission assembly.
(c) Throw rod, lock slides and detection slides.
(d) Detection and control contact switch Assembly.
(e) Cast iron Case with cover.
(f) Crank handle.
Operating data as per IRS: S 24/2002 - Amendment No. 1
Motor- DC series split field
Throw of point machine - 220 mm + 4 / -1
Time of operation (Max.) - 5.0 sec.
Current consumption - < 5.5 Amp.
Rated voltage - 110 VDC
Max. Throw – 450 Kg.
Slipping load - < 580 Kg.
Stalling load (Min.) - 1000 Kg.
6 Main parts of Clamp Lock and Functions (a) Locking bar (L.H.)
(b) Locking bar (R.H)
(c) Insulating plates
(d) Locking washers
(e) Locking arms
(f) Stopper
(g) Drive lug
Locking bar (L.H) and locking bar (R.H) are joined with insulating plate and locking washer
at both ends are inside of both switch rail and stock rail brackets. Its movement depends on
the stroke of drive rod, which is attached to one end of locking bar by drive rod.
Locking arm assembly: it consists of L.H. and R.H. Arms. Its main function is to lock and
unlock the clamp. It is attached with the stock rail with the help of bracket and to the lock
bars with guide.
CAMTECH/S/PROJ/2020-21/SP8/3.0 7
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Working of Clamp Lock
Initially the point is lying in normal and right hand switch is locked whereas left hand
switch is open with an opening of 160 mm.
When the lockbar is pulled by the electric point machine the open switch starts moving
towards the stock rail.
The lock bar’s initial stroke of 60 mm is used to unlock the clamp lock at closed switch.
After unlocking of the clamp lock the closed switch starts opening.
When the lockbar travels 160 mm, open switch completes the stroke and closes fully with
stock rail.
However, the closed switch which had started opening, opens up to about 100 mm only.
When the lock bar further travels and completes the total stroke of 220 mm, the open
switch completely closes with the stock rail and gets locked.
The earlier closed switch which has opened upto 100 mm now further completes the
opening to 160 mm.
To summarize the above operation, 220 mm throw of Point machine is distributed as
follows:-
(a) First 60 mm throw of Point machine
(i) Unlocking of Closed switch and
(ii) Open switch moves 60 mm towards its stock rail.
(b) Next 100 mm throw, both switches move
(i) Closed switch opens by 100 mm and
(ii) Open switch completes (60 mm+100 mm) =160 mm and it is now closed.
(c) Last 60 mm throw
(i) 100 mm Opened switch further movers to 60 mm = (100 mm+60 mm)=160 mm.
(ii) Locking of Closed switch by 60 mm.
7 Installation guidelines The installation of IRS Point machine 220 mm throw was earlier done as per RDSO
drawing no. RDSO/S3454. RDSO has now issued a new drawing no. RDSO/3454 ALT-A
Ver. 1 vide letter no.STS/E/PM/220 mm Vol-I dated 07.11.2019. Details of installation as
per both drawings are given in following sections.
7.1 Installation as per RDSO drawing no. RDSO/S3454
The procedure for IRS Point Machine with Clamp Lock and Ground Connection
arrangement 60 Kg (with Thick Web Switch) for B.G as per RDSO as per RDSO DRG.
No. RDSO/S3454 is as follows (Refer Annexure II) :
(A) Preparatory steps
(a) Bring the toe of switch at 32 mm in advance of centre line of sleeper No.3 and distance
between sleeper No.3 and 4 to 685 mm. (centre-line to centre-line). (As per RDSO
CAMTECH/S/PROJ/2020-21/SP8/3.0 8
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
drawing no. RDSO/S 3454 Sleeper spacing has been modified as 685 mm instead of
745 mm vide ALT 4 dated 28.12.2001).
(b) Ensure that insulated gauge tie plate is provided on sleeper No. 3.
(c) Remove all leading and following stretcher bars.
(d) Provide spring setting device of approved design at junction of rail head (JOH).
(e) Maintain gap at junction of rail head (JOH) not less than 57 mm for every flange way
clearance.
(B) Marking & drilling holes for Clamp Lock Assembly
(a) Stock rail
(i) For marking holes in stock rails mark centre-line on the web of stock rail at the height of
76 mm from bottom of stock rail up to the length of 550 mm from toe.
(ii) Mark centre punch to the length of 450 mm for 1st hole and 530 mm for 2
nd hole from the
edge of the tongue rail toe.
(iii) Ensure that there is a gap of 80 mm between both the holes (Centre-line to Centre-line of
the holes) as shown in figure given below.
(iv) Drill two holes of 22mm dia in the web of both stock rails for fixing stock rail brackets.
Figure 6: Marking & drilling of holes in stock rail for Clamp Lock Asembly
CAMTECH/S/PROJ/2020-21/SP8/3.0 9
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Figure 7: Cross-section showing position of holes in stock rail for Clamp lock assembly
(b) Tongue rail (i) For marking in tongue rails, mark centre-line on web of the tongue rail at the height of
55 mm from bottom of tongue rail up to the length of 500 mm.
(ii) Mark centre punch to the length of 428 mm for first hole and 498 mm for second hole
from toe.
(iii) Ensure that there is a gap of 70 mm between both holes (Centre-line to centre-line of the
holes).
(iv) Drill two holes of 22 mm dia in the web of the tongue rail for fixing switch rail bracket.
Figure 8: Sketch showing view of holes in stock rail for Clamp Lock Assembly
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Figure 9: Marking & drilling of holes in tongue rail for Clamp Lock Assembly
Figure 10: Cross-section showing height of the holes in tongue rail
Figure 11: Sketch showing holes in tongue rails for Clamp Lock Assembly
CAMTECH/S/PROJ/2020-21/SP8/3.0 11
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
(C) Marking & drilling holes for ground connections (Lock and detector rods)
(a) If point machine is connected to Left hand- side.
(i) First make the centre-line in the foot of both tongue rails up to 350 mm length from toe.
(ii) Mark centre punch up to the length of 148 mm for first hole and 328 mm for second hole
from the toe in the LH tongue rail.
(iii) Mark punch up to the length of 200 mm for first hole and 272 mm for second hole from
toe in RH tongue rail.
(iv) Drill two holes of 24 mm dia in the foot of the switch rail at the markings for connecting
lock rod and detector rods.
Figure 12 : Marking & drilling of holes in LH Tongue rail for ground connections (Point
machine on
LHS)
Figure 13: Marking & drilling of holes in RH Tongue rail for ground connections (Point
machine on LHS)
CAMTECH/S/PROJ/2020-21/SP8/3.0 12
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
(b) If point machine is connected to Right hand- side.
(i) First make the centre-line in the foot of both tongue rails up to 350 mm length from toe.
(ii) Mark punch up to the length of 148 mm for first hole and 328 mm for second hole
from toe in RH tongue rail.
(iii) Mark centre punch up to the length of 200 mm for first hole and 272 mm for second
hole from the toe in the LH tongue rail.
(iv) Drill two holes of 24 mm dia in the foot of the switch rail at the markings for
connecting lock rod and detector rods.
Figure 15: Marking & drilling of holes in LH Tongue rail for ground connections (Point
machine on RHS)
Figure 14: Sketch showing holes for ground connections in tongue rails (Point
machine on LHS)
CAMTECH/S/PROJ/2020-21/SP8/3.0 13
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Figure 16: Marking & drilling of holes in RH Tongue rail for ground connections (Point
machine on RHS)
Figure 18: Ground connections for RH Tongue rail and holes for ground connections
in LH Tongue rail
Figure 17: Sketch showing holes for ground connections in tongue rails (Point
machine on RHS)
CAMTECH/S/PROJ/2020-21/SP8/3.0 14
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
(D) Connection for Clamp Point locks
(i) Connect the stock rail bracket to the stock rail as in Fig. below.
Figure 19: Connecting Stock rail bracket
(ii) Assemble the LH and RH Lock Arm assemblies
(iii) Now fix tongue rail bracket with the lock arm assembly
(iv) Remove both the stoppers from locking bar assembly.
(v) Lock slides of the locking bar assembly are then inserted in to the groove of the stock
rail bracket (under the rail) through the guide of the lock arm. Fish tailed end of the
lock arm should be housed in the notch of the lock slide while inserting the lock slide
in the stock rail bracket.
(vi) The tongue rail brackets are then bolted to the web of the switch rail.
(vii) Fix the stopper of both locking bar assembly. Bend longer end of the lock washer on
the side of the stopper end on to the nut.
Figure 21: Inserting Lock slides into the groove
of the stock rail bracket (under the rail)
Figure 20: Fixing of Tongue rail brackets
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
(E) Connection of drive rod
(i) Connect drive rod lug to the
throw slide (Driving rack) of
point machine.
(ii) Connect the drive rod between
the drive rod lug and end of
locking bar assembly.
(iii)Adjusting screw of the drive rod
should be adjusted for 160 mm
opening of the switch.
(iv) Keeping the drive rod
perpendicular to track; fix the
point machine on the extended
sleepers on gauge tie plate.
Note: It is advisable to install the
point machine at the side where
the tongue is normally closed.
This shall be advantageous for
maintaining bars, which are then
inside the machine as much as possible.
(F) Connection of the Lock rods and Detector rods. (i) Lock and detector rods are to be
assembled at site by inserting drop lug
in the threaded portion of the rods. The
drop lugs can be suitably turned to suit
LH/RH mounting.
(ii) Put tapered washer on the foot
of the switch rail such that the thicker
portion of the washer is towards the
edge of the rail.
(iii) Now connect jaw of the
detector/lock rods with the foot of the
tongue rail and drop lug with the
detector/lock slide of the point
machine.
Figure 22: Connection of Drive rod
Figure 23: Connection of Lock & Detector rods
CAMTECH/S/PROJ/2020-21/SP8/3.0 16
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
7.2 Installation as per RDSO drawing no. RDSO/S3454 ALT –A Ver.1.0
The procedure for IRS Point Machine with Clamp Lock and Ground Connection
arrangement 60 Kg (with Thick Web Switch) for B.G as per RDSO as per RDSO DRG. No.
RDSO/S3454 ALT-A Ver.1.0 is similar to that of RDSO DRG. No. RDSO/S3454, except
following (Refer Annexure III) :
(i). Provision of switch extension brackets (P brackets) for connecting Normal and Reverse
lock and detection rods with tongue rails, instead of direct connection to the foot of the
tongue rail.
(ii). Increase in Sleeper spacing 745 mm instead of 685 mm.
(A) Preparatory steps
Same as that given in Section 7.1 (A)
(B) Marking & drilling holes for Clamp Lock Assembly
Same as that given in Section 7.1 (B)
(C) Holes for Switch extension brackets (P brackets) to connect ground connections (Lock
and detector rods)
(i). For fixing of Switch extension brackets (P brackets) to tongue rails, two holes of 22 mm
dia at a height of 58 mm from the bottom of the tongue rail come prefabricated in the
tongue rail irrespective of LH or RH Tongue rail.
(ii) The first hole is at a distance of 40 mm from the edge of the tongue rail toe and second
hole is 295 mm from the edge of the tongue rail toe.
(iii) There is a gap of 245 mm between both holes (Centre-line to centre-line of the holes).
Figure 24: Holes on tongue rails for fixing of Switch extension brackets for ground
connections
CAMTECH/S/PROJ/2020-21/SP8/3.0 17
Electric Point Machine 220 mm throw for Thick Web Switch December 2020
8 Adjustment (a) Lubricate all the moving parts of the clamp lock assembly.
(b) Put grease on the bronze brush in the lock arm assembly.
(c) Put grease on the notches of the lock slide and fishtail portion of the lock arm.
(d) Loosen the nuts of stock rail bracket so that it can move freely in its oblong holes and
take its own portion.
(e) Operate the machine with crank handle and adjust the lock and detector slides (usually
Near end first)
(f) If clamp lock is not locking the point then do the following:
For proper locking on both sides additional numbers of packing shims have been
provided between switch rail and tongue rail bracket.
Required no of shims will be put outside the tongue rail bracket to facilitate locking on
either side.
Six numbers of packing shims are provided with each clamp point assembly.
(j) Now tighten the nuts of the stock rail bracket.
Figure 25: Position of notches on fish tail portion of lock arm for closed switch
Figure 26: Position of notches on fish tail portion of lock arm for closed switch
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
9 Testing
After installation the following test should be carried out.
9.1 Obstruction Test The detector slides, lock slides and drive rod must be so adjusted that with 5 mm thick test
piece placed between the switch and gauge face of stock rail at 150 mm from the toe of the
point:
(a) Friction clutch de-clutches the motor from mechanism.
(b) The point cannot get locked either by clamp lock or by locking segment inside the point
machine.
(c) Lock segment does not enter into the notches of locking slides.
(d) Switch detection contacts do not make.
(e) The slipping current is not exceeding twice the normal working current
9.2 Insulation Test Check the insulation for the following.
(a) Point machine Check that point machine is insulated from ground connection.
(b) Spring setting device Insulated from both the rails.
(c) Clamp lock assembly. Check that it is insulated from both the rails.
(d) Leading and following stretcher bar (If point is operated without clamp point
locking arrangement). They are insulated from both the rails.
Fig.1.16: Ground connections of point machine
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
10 Maintenance
Points
(a) Ensure graphiting or lubricating of slide chairs at every week.
(b) Ensure that all nuts and bolts are tight and split pins are opened properly.
(c) Lubricate at the following moving parts of the clamp lock fortnightly.
(d) Stock rail bracket groove.
(e) Moving part of tongue rail and lock arm assembly.
(f) Between machine of lock bar and lock arm assembly.
(g) Ensure that the rodding and other connections are tight.
(h) Check that the point area is well ballast, packed and free from vegetation.
(i) Check that water does not stagnate in the vicinity of points.
(j) Ensure information to engineering department regarding to avoid any emergency failure.
Point Machine
(a) Ensure that wire connections of the machine are tight and laced properly.
(b) Ensure that the locking segment enters freely into the notches on the lock slides and with
a little pressure in the notch of drive rod.
(c) Ensure the point machine fittings are tight.
(d) Check all parts for any crack or breakage etc. and replace immediately if any defect is
found.
(e) Ensure smooth working of the gears without any cracking noise.
(f) The slipping of friction clutch during obstruction shall be ensured and slipping current
shall not exceed twice the normal working current.
(g) Ensure that the carbon brushes are exerting sufficient pressure on commutator. Clean the
commutator properly by using chamoise leather.
(h) Ensure that all moving parts are free from dust and are well lubricated.
(i) Ensure that gauge tie plate is properly insulated.
(j) Ensure that the roller rolls freely on the periphery of the control and lift out disc.
(k) Check that the contact pressure of control and detection contact is adequate.
(l) Apply non-corrosive all temperature grease (IS-507/508) through the entire grease nipple
by a grease gun, after 8,000 operations or six months whichever is earlier or as per
instructions issued by the railway.
(m) After every six months or as per instructions issued by the railway pour lubricating oil,
SAE-30/SHELL 100, through inlet in to the oil reservoir for lubricating gearbox of the
motor.
(n) Check the overload current.
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Track Locking schedule
Check track locking once in six months or as per instructions issued by the railway.
Workshop overhauling schedule
After 4,00,000 operations or five years for bigger yard or seven years whichever is earlier.
The point machine should be taken out and should receive a general overhaul and thorough
cleaning in an authorized workshop.
Insulation Testing schedule
Check insulation once in six months or as per instructions issued by the railway.
11 Troubleshooting Sr.
No
Nature of Failure Cause Remedy
1 Tongue rail not housing up
to 13 sleepers or tongue rail
housing one side properly
but not housing another side
at adequate distance.
Spring setting device not
adjusted properly
Arrange P-Way staff for
proper adjustment of
spring setting device.
2 Clamp lock not locking point
on either side.
Packing shims between stock
rail and tongue rail bracket or
outside the tongue rail are to
be adjusted.
Adjust the numbers of
packing shims of tongue
rail bracket.
3 Point machine does not start. Fuse blown Off. Replace the same.
Feed is not coming out from
relay room.
Check the circuit and
rectified
Cable conductor becomes
faulty
Megger the conductor,
replace if faulty.
Motor winding got low
insulation.
Replace the motor
While starting control
contacts are not making.
Adjust the control
contact.
4 Point is showing gap and
motor rotates continuously
Obstruction in between stock
and tongue rail.
Remove the obstruction.
In friction due to improper
cleaning and oiling of points.
Clean and check oiling of
point.
Wrong adjustment of point
throw rod.
Adjust point throw rod.
Defects with P.Way fitting. Attend with P.Way
staff.
5 Point is properly set, but
motor continuously rotates.
Respective detection
contacts are not making (Point
may lock)
Adjust detection
contact.
Adjustment required in lock Adjust lock rod for proper
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Sr.
No
Nature of Failure Cause Remedy
rod, if point is not locked. locking
The respective detection
terminal loose or broken in
point machine.
Attend respective
detection contact.
6 1st point is correctly set,
locked and detection contacts
are making, but feed not
extended to 2nd
point
machine.
Feed not coming to 2nd
point
machine due to
cable between the machine
defective.
Check cable
conductor between
point machine,
replace if defective
or low insulation.
Crank handle contact of 2nd
point machine not making.
Adjust crank handle
contact.
Respective terminal loose or
broken in 2nd
point machine.
Tighten terminal or
replace broken terminal.
7 While operating the points
the motor rotates in just
reverse direction.
Any wire interchanged. Check wiring and
Rectify.
In point junction box cable
interchanged.
Check wiring at
junction box and
rectified.
8 First point is correctly set,
locked and detection made
but the motor do not stop
even after starting of 2nd
point machine.
Short circuit faults in the
terminals in point junction
box.
Check wiring at junction
box and rectified the short
circuit faults.
9 Out of correspondence
between point and relay
group.
Cables interchanged in point
junction box.
Check and rectify
Wiring interchanged in crank
handle box terminal.
Check and rectify
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
12 Do’s & Don’ts
Do’s.
Get disconnection of point, before carrying out any work.
Always ensure schedule maintenance.
Test the working of friction clutch.
Do ensure that track locking, route locking, crank handle release locking are
effective.
Do test the correspondence of the points with indication at panel or cabin.
Always use proper lubricant. Wipe away excessive oil or grease.
Always use proper rating of fuse.
Dont’s.
Do not operate the point manually except through specific crank handle.
Forget to exercise safety checks initially, during and after disconnection.
Forget to carry necessary tools while attending the failure.
Leave any discrepancies noticed in the point machine.
Use too much lubricant.
Allow unsquared notches on slides.
13 Tools & Spares
Recommended Tools and measuring instruments
Following tools and measuring instruments should be kept in the duty room for installation
and maintenance of Electric point machine:
Spanner set
32 mm (11/4”) single end spanner
Adjustable pipe wrench
Screw driver
Hammer
Tommy bar
Measuring tape
Test gauge
Cutting pliers
Wire cutter
Insulation peeler
DC Ammeter with centre ‘0’ incase of Analog (0-30 Amp)
DC Voltmeter (0-250V)
Track shunt resistance. Grease Gun
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
Spares and Consumables
Following spares and consumables are necessary for maintenance and inspection.
SAE 30/SHELL 100 oil
Grease IS 507/508
Chamois leather
Cotton waste grade A
Carbon brush
Contact assembly
MS-pins and split pins
D-bracket and stretcher bar insulation material sets
Tools and accessories to be supplied with new point machines
The following set of tools in a suitable box shall be supplied along with every set of eight
point machines or less:
1. Hand operated square drive socket wrenches of 12.5 mm driving square (short type) as
per IS: 7381 for M8, M10, M12 & M18 threads. (One 250 mm long 12.5 mm square
extension bar as per IS: 7991 alongwith compatible Tee handle Square drive as per IS:
7975 suitable for above socket wrenches.
2. Open jaw wrenches (spanners) for M10, M12, M20, M24 & M33 threads as per IS:
2028.
3. Adjustable wrench.
4. Screw driver 300 mm long
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
14 Summary
(1) Throw of point machine
Throw of the point machine throw bar – 220 mm, which is distributed as follows:
(a) First 60 mm throw of Point machine
(i) Unlocking of Closed switch and
(ii) Open switch moves 60 mm towards its stock rail.
(b) Next 100 mm throw, both switches move
(i) Closed switch opens by 100 mm and
(ii) Open switch completes (60 mm+100 mm) =160 mm and it is now closed.
(c) Last 60 mm throw
(i) 100 mm Opened switch further movers to 60 mm = (100 mm+60 mm) =160 mm.
(ii) Locking of Closed switch by 60 mm.
(2) Main Parts of point machine (a) DC series split field Motor with- in built reduction gear unit.
(b) Transmission assembly.
(c) Throw rod, lock slides and detection slides.
(d) Detection and control contact switch Assembly.
(e) Cast iron Case with cover.
(f) Crank handle.
(3) Components of Clamp Lock (a) Locking bar (L.H.)
(b) Locking bar (R.H)
(c) Insulating plates
(d) Locking washers
(e) Locking arms
(f) Stopper
(g) Drive lug
(4) Operating data as per IRS: S 24/2002 - Amendment No. 1
Motor- DC series split field
Throw of point machine - 220 mm + 4 / -1
Time of operation (Max.) - 5.0 sec.
Current consumption - < 5.5 Amp.
Rated voltage - 110 VDC
Max. Throw – 450 Kg.
Slipping load - < 580 Kg.
Stalling load (Min.) - 1000 Kg.
.
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
5) Installation
(i) General
Toe of switch at 32 mm in advance of centre line of sleeper No.3.
Distance between sleeper No.3 and 4 to 745 mm. (From centre-line to centre-line)
Insulated gauge tie plate on sleeper No. 3.
Removal of all leading and following stretcher bars.
Provision of spring setting device at junction of rail head (JOH).
Gap of not less than 57 mm at junction of rail head (JOH) for every flange way
clearance
(ii) Holes for Clamp Lock Assembly
(a) Stock rail
Two holes of 22 mm dia on the web of both stock rails at the height of 76 mm from
bottom for fixing stock rail brackets.
1st hole at 450 mm from the edge of the tongue rail toe.
2nd
hole at 530 mm from the edge of the tongue rail toe.
Gap of 80 mm between both the holes.
(b) Tongue rail
Two holes of 22 mm dia on the web of both tongue rails at the height of 55 mm from
bottom for fixing switch rail brackets.
1st hole at 428 mm from the edge of the tongue rail toe.
2nd
hole at 498 mm from the edge of the tongue rail toe.
Gap of 70 mm between both the holes.
(iii) Holes for ground connection
As per RDSO Drawing. No. RDSO/S-3454
(a) Point machine on LHS.
Two holes of 24 mm dia on the foot of both tongue rails for connecting lock rod and
detector rod.
LH Tongue rail - 1st hole at 148 mm from the edge of the tongue rail toe.
2nd
hole at 328 mm from the edge of the tongue rail toe.
RH Tongue rail - 1st hole at 200 mm from the edge of the tongue rail toe.
2nd
hole at 272 mm from the edge of the tongue rail toe.
(c) Point machine on RHS
Two holes of 24 mm dia on the foot of both tounge rails for connecting lock rod and
detector rod.
LH Tongue rail - 1st hole at 200 mm from the edge of the tongue rail toe.
2nd
hole at 272 mm from the edge of the tongue rail toe.
RH Tongue rail - 1st hole at 148 mm from the edge of the tongue rail toe.
2nd
hole at 328 mm from the edge of the tongue rail toe.
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
As per RDSO Drawing No. RDSO/S-3454 ALT–A Ver. 1
Two prefabricated holes of 24 mm dia on the web of both tongue rails at the height of 58 mm
from bottom for connecting lock rod and detector rod.
. 1st hole at 40 mm from the edge of the tongue rail toe.
2nd
hole at 285 mm from the edge of the tongue rail toe
Irrespective of RH or LH tongue rail
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
15 References
IRS Specification no. IRS: S 24/2002 - Amendment No. 1 for Electric Point Machine
Non-Trailable type
RDSO Drawings for Ground connections of Electric Point Machine 220 mm stroke with
Clamp Lock for Thick Web Switch (TWS) (Drg. No. RDSO/S-3454).
Modified RDSO Drawings for Ground connections of Electric Point Machine 220 mm
stroke with Clamp Lock for Thick Web Switch (TWS) (Drg. No. RDSO/S-3454 ALT–A
Ver. 1) (RDSO Signal Directorate Letter no. STS/E/PM 220 mm Vol-I, dated
07.11.2019).
Modified RDSO design for Spring Setting Device (SSD) of Thick Web Switch (Drg. No.
RDSO/T 6216 ALT-4) (HQ Office S&T NCR Letter
no.NCR/S&T/1031/Signal/RDSO(Misc)/Pt -5 dated 01.06.2020.
IRICEN Pune's publication on Turnout - Laying, Inspection. Maintenance September
2014.
Manual on IRS Electric Point Machine Non-Trailable 220 mm throw -M/s Vossloh
Cogifer Signalling India Pvt. Ltd., Bhilai (C.G.)
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Electric Point Machine 220 mm throw for Thick Web Switch December 2020
16 Annexure I : Modified RDSO design for Spring Setting Device (SSD) of
Thick Web Switch (Drg. No. RDSO/T 6216 ALT-4)
17 Annexure II : RDSO Drawings for Ground connections of Electric
Point Machine 220 mm stroke with Clamp Lock for Thick Web Switch
(TWS) (Drg. No. RDSO/S-3454)
18 Annexure III : Modified RDSO Drawings for Ground connections of
Electric Point Machine 220 mm stroke with Clamp Lock for Thick
Web Switch (TWS) (Drg. No. RDSO/S-3454 ALT–A Ver. 1)
ANNEXURE I
Modified RDSO design for Spring Setting Device (SSD)
of
Thick Web Switch
(Drg. No. RDSO/T-6216 ALT-4)
ANNEXURE II
RDSO Drawings for Ground connections of
Electric Point Machine 220 mm stroke with Clamp Lock
for Thick Web Switch (TWS)
(Drg. No. RDSO/S-3454)
ANNEXURE III
Modified RDSO Drawings for Ground connections of
Electric Point Machine 220 mm stroke with Clamp Lock
for Thick Web Switch (TWS)
(Drg. No. RDSO/S-3454 ALT–A Ver. 1)
Quality Policy
“We at RDSO Lucknow are committed to maintain and update transparent
standards of services to develop safe, modern and cost effective railway
technology complying with statutory and regulatory requirements, through
excellence in research, designs and standards by setting quality objectives,
commitment to satisfy applicable requirements and continual improvements of
the quality management system to cater to growing needs, demand and
expectations of passenger and freight traffic on the railways through periodic
review of quality management systems to achieve continual improvement and
customer appreciation. It is communicated and applied within the organization
and making it available to all the relevant interested parties.”
INDIAN RAILWAYS
Centre for Advanced Maintenance Technology Maharajpur, Gwalior (M.P.) Pin Code – 474 005