IRS POINT MACHINE FOR THICK WEB SWITCH - Indian …rdso.indianrailways.gov.in/works/uploads/File/Handbook on IRS Point... · CAMTECH/S/2002/TWS/1.0 3 IRS Point Machine December ’2002

CAMTECH/S/2002/TWS/1.0 1

IRS Point Machine December ’2002for Thick Web Switch

IRS POINT MACHINE FOR THICK WEB SWITCH

1. Introduction

Increased speed limits on the Indian rails havelead to use of heavier 60 Kg and 52 Kg railssection with thick web.The conventional point machine with the throwof 143 mm proves inept for the operation ofthese thick web switches so IRS point machinethrow of 220 mm has been developed.The present hand book covers the IRS pointmachine for operation on thick web switch(TWS) along with clamp point lockarrangement.

2. Working of Point Machine

The machine is involved in doing thefollowing:

Throwing the points. Independent switch locking with clamp point

lock. Retaining the tongues in end positions. Providing possible protection against trailing

point. Detection of end position of the tongues.



3. Technical specifications of the pointmachine.

Motor - 110V DC, 0.44 KW Throw - 220 mm Max. Thrust - 450 kg Max. operating current - 5.5 Amps. Weight of machine - 210 kg Slipping load - 700 Kg

The machine is similar in construction to theconventional machine. The addition being thatthe clamp locking is also achieved by theoperating rod itself.

4. Clamp locking with thick web switch

4.1 Clamp point locking

(RDSO Drawing No. RDSO/S-3454 for 60 kgrail and RDSO/S-3455 for 52 Kg rail)

Provides direct locking between tongue railand stock rail in closed position.

Firmly holds the tongue rail in the openposition.

Checks any relative movements betweentongue and stock rail.



It ensures and proves the proper setting ofswitch and stock rail.

No stretcher bar is used and hence switchesare able to move independently.

A spring setting device (SSD) is provided atJOH, in lieu of stretcher bars, to assist inproper setting of switch upto junction ofRail head (JOH).

The outer side of the switch and the insideof the stock has complementary slighttapers. Therefore, the toe of switch fitsinside and under the stock rail so that theflange of wheel engages the switch railmuch after 6" beyond the toe.

Adjustment of locking is done by means ofpacking shims between switch rail and stockrail bracket. Three each of 1 mm and one of0.5 mm shims are provided for each switch.

4.2 Salient features of point machine

The point machine has a throw of 220 mmwith independent lock and deduction slides.

The switch opening is 160 mm.

There are two levels of locking provided:

• Indirect method as use in conventionalmachines.



• Clamp locking which is direct locking ofswitch.

220 mm throw of point machine is used forthe following.SR Throw Use 1. 1st 60mm

throw forpointmachine.

i) Use of unlockingof lock switch

ii) Open switchmoves 60 mmtowards its stockrail

2. Next 100mm throw

Both tongue railmoves together by100 mm • The tongue rail

of open switchhas completed its160mmmovement and isnow closed.

3. Next 60 mmthrow

• Closed switch getslocked.

• Open switchcompletes itsmovementremaining 60-mmand open by 160mm.



4.3 Advantage.

It ensures and proves the proper setting ofboth stock and switch rails.

Due to the 160mm opening of thick webswitch (TWS ) at toe the clearance atjunction of rail head (JOH) is 60mm. Thisprevents the repeated striking of the openswitch at junction of rail head (JOH) byinner side of the wheel, which inconventional switches leads to chances ofunder wheel flashing.

Clamp locking of the switch preventsvibration caused in the switch due to trainmovement affecting the friction clutchdirectly. In conventional switches this leadsto reduction in efficacy of the frictionclutch.

In a TWS in case of obstructions like stonepieces coming between switch and stockrail, the chances of obstruction clearing byfalling down are more as compared toconventional points in which theobstruction can get lodged in because ofsmall space between switch and stock rail.

Due to complementary tapers in switch andstock rail, the switch rail toe fits undersidethe stock and therefore the wheel of thetrain engages the switch rail well after 6"from toe. Therefore, damage and wear andtear of the switch is prevented.



5 Installation.

Bring the toe 32mm in advance of centerline of sleeper No.3 and the distancebetween sleeper No.3 and 4 to745mm(From center line to center line)

Ensure that insulated gauge tie plate isprovided on sleeper No.-3

Remove all leading and following stretcherbars.

Provide spring setting device of “approveddesign” at junction of rail head (JOH).

Maintain gap at junction of rail head (JOH)not less than 57mm for every flange wayclearance

5.1 Sequence of connection for ClampPoint locks

For connecting the clamp lock sequence ofaction shall be as below.

A. Marking holes for clamp lock assembly.

Stock rail

For marking holes in stock rails markcenterline on the web of stock rail at theheight of 76 mm from bottom of stock railup to the length of 550 mm from toe.



Mark center punch to the length of 450 mmfor Ist hole and 530 mm for IInd hole fromthe edge of the tongue rail toe.

Ensure that there is a gap of 80 mmbetween both the holes (Centerline toCenterline of the holes) as shown in figuregiven below.



Drill two holes of 22mm dia in the web ofboth stock rails for fixing stock railbrackets.

Tongue rail

For marking in tongue rails, markcenterline on web of the tongue rail at theheight of 55 mm from bottom of tongue railup to the length of 500 mm.

Mark center punch to the length of 428 mmfor first hole and 498 mm for second holefrom toe.



Ensure that there is a gap of 70 mmbetween both holes (Centerline tocenterline of the holes) as shown in figurebelow.



Drill two holes of 22mm dia in the web ofthe tongue rail for fixing switch railbracket.

B Marking holes for ground connection.

i) If point machine is connected to lefthand- side.

First make the centerline in the flange ofboth tongue rails up to 350mm length fromtoe.

Mark punch up to the length of 148mm forfirst hole and 328mm for second hole fromtoe in LH tongue rail.



Mark center punch up to the length of200mm for first hole and 272mm forsecond hole from the toe in the RH tonguerail as shwon in fihgure below.



ii) If point machine is connected to righthand- side.

First make the centerline in the flange ofboth tongue rails up to 350mm length fromtoe.

Mark punch up to the length of 200mm forfirst hole and 272mm for second hole fromtoe in LH tongue rail.

Mark center punch up to the length of148mm for first hole and 328mm forsecond hole from the toe in the RH tonguerail as shown in figure.



Connection for Clamp Point locks

Drill two holes of 24mm dia in the foot ofthe switch rail for connecting lock rod anddetector rods.

Connect the stock rail bracket to the stockrail as in Fig.

Assemble the RH and LH lock armassemblies.

Now fix tongue rail bracket with the lockarm assembly as in Fig.



Remove both the stoppers from the locking.bar assembly.

Lock slides of the locking bar assembly arethen inserted in to the groove of the stockrail bracket (under the rail) through theguide of the lock arm. Fish tailed end of thelock arm should be housed in the notch ofthe lock slide while inserting the lock slidein the stock rail bracket, as shown in theFig.



The tongue rail brackets are then bolted tothe web of the switch rail.

Fix the stopper of both locking barassembly. Bend longer end of the lockwasher on the side of the stopper end on tothe nut as shown in Fig.

The two lock bar assemblies are then boltedtogether with lug as in Fig.



5.2 Connection of drive rod Connect drive rod lug to the throw slide

(Driving rack) of point machine.



Connect the drive rod between the drive rodlug and end of locking bar assembly.

Adjusting screw of the drive rod should beadjusted for 160 mm opening of the switch.

Keeping the drive rod vertical to track; fixthe point machine on the extended sleeperson gauge tie plate.





5.3 Connection of the Lock rods andDetector rods.

Lock and detector rods are to be assembledat site by inserting drop lug in the threadedportion of the rods. The drop lugs can besuitably turned to suit LH/RH mounting.

Put tapered washer on the foot of the switchrail such that the thicker portion of thewasher is towards the edge of the rail.

Now connect jaw of the detector/lockrods with the foot of the tongue rail anddrop lug with the detector/lock slide ofthe point machine.



6 Adjustment.

♦ Lubricate all the moving parts the clamplock assembly.

♦ Put grease on the bronze brush in the lockarm assembly.

♦ Put grease on the notches of the lock slideand fishtail portion of the lock arm.

♦ Loosen the nuts of stock rail bracket so thatit can be move freely in its oblong holesand takes its own portion.

♦ Operate the machine with crank handle andadjust the lock and detector slides usually(Near end first)

♦ If clamp lock is not locking point then dothe following.• For proper locking on both sides

additional numbers of packing shimshave been provided between switch railand tongue rail bracket.

• Required no of shims will be put outside the tongue rail bracket to facilitatelocking on either side .

• Six numbers of packing shims areprovided with each clamp pointassembly.

♦ Now tighten the nuts of the stock railbracket.



7 Testing

After installation the following test should becarried out.

7.1 Obstruction test.

The detector slides lock slides and drive rodmust be so adjusted that with 5mm thick testpiece placed between the switch and gaugeface of stock rail at 150mm from the toe of thepoint.

♦ Friction clutch de-clutches the motor frommechanism.

♦ The point can not get locked either byclamp lock or in the point machine.

♦ Lock segment does not enter into thenotches of locking slides.

♦ Switch detection contacts do not make.

♦ The slipping current is not exceedingtwice of the normal working current.

7.2 Insulation test.

Check the insulation between the following.

Point machineCheck that point machine is insulated fromground connection.



Spring setting device

Insulated from both the rails.

Clamp lock assembly.

Check that it is insulated from both therails.

Leading and following stretcher bar.

(If point is operated without clamp pointlocking arrangement).

They are insulated from both the rails.

8. Maintenance

8.1 Points

♦ Ensure graphiting or lubricating of slidechairs at every week.

♦ Ensure that all nuts and bolts are tight andsplit pins are opened properly.

♦ Lubricate at the following moving parts ofthe clamp lock fortnightly.

i) Stock rail bracket groove.

ii) Moving part of tongue rail and lockarm assembly.

iii) Between machine of lock bar andlock arm assembly.



♦ Ensure that the rodding and otherconnections are tight.

♦ Check that the point area is well ballast,packed and free from vegetation.

♦ Check that water does not stagnate in thevicinity of points.

♦ Ensure information to engineeringdepartment regarding to avoid anyemergency failure.

8.2 Point Machine ♦ Ensure that wire connections of the

machine are tight and laced properly.

♦ Ensure that the locking segment entersfreely into the notches on the lock slidesand with a little pressure in the notch ofdrive rod.

♦ Ensure the point machine fittings are tight.

♦ Check all parts for any crack or breakageetc. and replace immediately if any defectis found.

♦ Ensure smooth working of the gearswithout any cracking noise.

♦ The slipping of friction clutch duringobstruction shall be ensured and slippingcurrent shall not exceed twice the normalworking current.



♦ Ensure that the carbon brushes are exertingsufficient pressure on commutator. Cleanthe commutator properly by using chamoiseleather.

♦ Ensure that all moving parts are free fromdust and are well lubricated.

♦ Ensure that gauge tie plate is properlyinsulated.

♦ Ensure that the roller rolls freely on theperiphery of the control and lift out disc.

♦ Check that the contact pressure of controland detection contact is adequate.

♦ Apply non-corrosive all temperature grease(IS-507/508) through the entire greasenipple by a grease gun, after 8,000operations or six months which is earlier oras per instructions issued by the railway.

♦ After every six months or as perinstructions issued by the railway pourlubricating oil, SAE-30/SHELL 100,through inlet in to the oil reservoir forlubricating gearbox of the motor.

♦ Pour lubricating oil, SAE-30 on theperiphery of control and lift out disk andfelt pad provided over the driver rod andthe lock slides.

♦ Check the overload current.



8.3 Track Locking

♦ Check track locking once in six months oras per instructions issued by the railway.

8.4 Workshop Overhaul

♦ After 4,00,000 operations or five years forbigger yard or seven years whichever isearlier. The point machine should be takenout and should receive a general overhauland thorough cleaning in an authorizedworkshop.

8.5 Insulation Testing

♦ Check insulation once in six months or asper instructions issued by the railway.



9.0 Troubleshooting

Sr.No

Nature ofFailure

Cause Remedy

Tongue railnot housingup to 13th

sleepers or tonguerail housingone sideproperly butnot housinganother sideat adequatedistance.

Spring settingdevice notadjusted properly

Arrange P-Waystaff for properadjustment ofspring settingdevice.

1

2 Clamp locknot lockingpoint oneither side.

Packing shimsbetween stockrail and tonguerail bracket orout side thetongue rail are tobe adjusted.

Adjust thenumbers ofpacking shims oftongue railbracket.



Sr.No

Nature ofFailure

Cause Remedy

Fuse blown Off. Replace withsame.

Feed is notcoming out fromrelay room.

Check the circuitand rectified

Cable conductorbecomes faulty

Megger theconductor, replaceif faulty.

Motor windinggot lowinsulation.

Replace the motor.

3. Pointmachinedoes notstart.

While startingcontrol contactsare not making.

Adjust the controlcontact.

Obstruction inbetween stockand tongue rail.

Remove theobstruction.

In friction due toimpropercleaning andoiling of points.

Clean and checkoiling of point.

Wrongadjustment ofpoint throws rod.

Adjust pointthrough rod.

4 Point isshowing gapand motorrotatescontinuously

Defects with P-.Way fitting.

Attend with P.Waystaff.



Sr.No

Nature ofFailure

Cause Remedy

Respectivedetectioncontacts are notmaking (Pointmay lock)

Adjust detectioncontact.

Adjustmentrequired in lockrod, if point isnot locked.

Adjust lock rod forproper locking.

5 Point isproperly set,but motorcontinuouslyrotates.

The respectivedetectionterminal loose orbroken in pointmachine.

Attend respectivedetection contact.

Feed not comingto IInd pointmachine due tocable betweenthe machinedefective.

Check cableconductor betweenpoint machine,replace if defectiveor low insulation.

Crank handlecontact of IIndpoint machinenot making.

Adjust crankhandle contact.

6 First point iscorrectly set,locked anddetectioncontacts aremaking, butfeed notextended toIInd pointmachine.

Respectiveterminal loose orbroken in IIndpoint machine.

Tighten terminalor replace brokenterminal.



Sr.No

Nature ofFailure

Cause Remedy

Any wireinterchanged.

Check wiring andrectified.

7 Whileoperatingthe pointsthe motorrotates injust reversedirection.

In point junctionbox cableinterchanged.

Check wiring atjunction box andrectified.

8 First point iscorrectly set,locked anddetectionmade but themotor do notstop evenafter startingof IIndpointmachine.

Short circuitfaults in theterminals inpoint junctionbox.

Check wiring atjunction box andrectified the shortcircuit faults.

Cable interschanged in pointjunction box.

Check andrectified.

9 Out ofcorrespondence betweenpoint andrelay group.

Wiring interschanged in crankhandle boxterminal.

Check andrectified.



10. Do’s and Dont’s.

10.1 Do’s.

♦ Get disconnection of point, before carryingout 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.

10.2 Dont’s.

♦ Do not operate the point manuallyexcept through specific crank handle.

♦ Forget to exercise safety checks initially,during and after disconnection.

♦ Forget to carry necessary tools whileattending the failure.

♦ Leave any discrepancies noticed in thepoint machine.

♦ Use too much lubricant.♦ Allow unsquared notches on slides.

Documents

IRS POINT MACHINE FOR THICK WEB SWITCH - Indian …rdso.indianrailways.gov.in/works/uploads/File/Handbook on IRS Point... · CAMTECH/S/2002/TWS/1.0 3 IRS Point Machine December ’2002