Air SuspensionAir SuspensionInIn

Coaching Stock Coaching Stock ofof

Indian RailwaysIndian Railways

Presentation By Presentation By Bhaskar SrivastavaBhaskar Srivastava

To take advantage of superior technological standard of LHB coaches and keeping the cost low, stainless steel body coach on ICF bogie with Air Spring as secondary suspension (Stainless steel SG coaches) have been introduced.

Cost effective compared to LHB/FIAT Cost effective compared to LHB/FIAT coaches coaches

Stainless Steel ShellStainless Steel Shell› LHB design shell – longer and LHB design shell – longer and

corrosion resistant corrosion resistant ICF Design Furnishing in initial rakesICF Design Furnishing in initial rakes

› Future rakes will be with LHB type Future rakes will be with LHB type furnishingfurnishing

ICF BogieICF Bogie› Air springs in Secondary Suspension Air springs in Secondary Suspension

LHB FeaturesLHB Features Stainless steel shell of LHB typeStainless steel shell of LHB type CDTSCDTS CouplerCoupler Sound insulation paintSound insulation paint LHB design windowsLHB design windows LHB type main doorLHB type main door Auto closing vestibule doorsAuto closing vestibule doors Sound insulating floorboardSound insulating floorboard SS plumbing and air brake pipesSS plumbing and air brake pipes SS main & aux. water tanks for AC coachesSS main & aux. water tanks for AC coaches

ICF FeaturesICF Features ICF Bogie with Air suspensionICF Bogie with Air suspension Single flap lavatory doorSingle flap lavatory door Bogie mounted Brake cylinderBogie mounted Brake cylinder Conventional AC unitConventional AC unit Conventional electricsConventional electrics Powder coated aluminum ceiling. Powder coated aluminum ceiling.

(instead of FRP ceiling)(instead of FRP ceiling) LP sheet sidewall panels with FRP window LP sheet sidewall panels with FRP window

cowl. (instead of full FRP panels) cowl. (instead of full FRP panels)

Powder coated conventional ducting.Powder coated conventional ducting. SS square tube partition frames with LP SS square tube partition frames with LP

panels. (instead of honeycomb panels. (instead of honeycomb partition frames)partition frames)

FRP doorway ceiling (instead of hard FRP doorway ceiling (instead of hard PVC)PVC)

Fabricated lavatory (instead of FRP Fabricated lavatory (instead of FRP module)module)

Glass wool insulation (instead of Glass wool insulation (instead of resonaflex)resonaflex)

ICF type furnishingICF type furnishing SG versionSG version

Roof sheet and trough floor –Austenitic (304)

Other members -Ferritic (409M)

Under-frame –Corten steel

Cabin

Arrangement

Lavatory

Arrangement

CoachCoach No. of Seats/Berths No. of Seats/Berths in SS coachesin SS coaches

No. of Seats/Berths in No. of Seats/Berths in ConventionalConventional

AC 2 TIERAC 2 TIER 5454 4848

AC 3 TIERAC 3 TIER 7272 6464

SCNSCN 8080 7272

GSGS 9999 9090

DSLRDSLR 30 + 430 + 4 20+420+4

AC 2T + AC 3TAC 2T + AC 3T 24 + 4824 + 48 24+3624+36

Minimum tare load = 50KNMax. Full load = 140 KN

AC and non-AC coaches are in service as AC and non-AC coaches are in service as Duranto express.Duranto express.

Bogie general arrgt. to drg. No. CA00001 Bogie general arrgt. to drg. No. CA00001 and CA00002 are applicable for AC and and CA00002 are applicable for AC and non-AC coaches respectively. non-AC coaches respectively.

RDSO Spec. No. C-K509 rev-2 for air RDSO Spec. No. C-K509 rev-2 for air spring and C-K407 for control equipments. spring and C-K407 for control equipments.

Guidelines for maintenance of air springs Guidelines for maintenance of air springs have been circulated by RDSO . (CMI- have been circulated by RDSO . (CMI- RDSO/2009/ CG/CMI-01)RDSO/2009/ CG/CMI-01)

Common secondary suspension for all Common secondary suspension for all hybrid coaches for different loads.hybrid coaches for different loads.

No compensating rings are required for No compensating rings are required for buffer hight. adjustment.buffer hight. adjustment.

Easy buffer height adjustment by Easy buffer height adjustment by installation lever.installation lever.

Low maintenance.Low maintenance. Wheel life increased due to improvement in Wheel life increased due to improvement in

lateral riding index.lateral riding index. Capable to sustain Super Dense Crush Capable to sustain Super Dense Crush

Loads typical of suburban traffic. Loads typical of suburban traffic.

Maintain constant floor height of coach. Maintain constant floor height of coach. Provide superior ride comfort. Provide superior ride comfort. Virtually Constant natural frequency from Virtually Constant natural frequency from

tare to full loads, reducing passenger tare to full loads, reducing passenger fatigue. fatigue.

Isolation of structure borne noise, thus Isolation of structure borne noise, thus improving comfort. improving comfort.

Improved reliability, reduced maintenance Improved reliability, reduced maintenance effort. effort.

Flexibility to chose characteristics as per Flexibility to chose characteristics as per requirement at design stage requirement at design stage

› Coaches with deflated springs not to Coaches with deflated springs not to be run beyond 60kmphbe run beyond 60kmph

› Feed pipe feeds the air for springs Feed pipe feeds the air for springs and must be activeand must be active

› Air spring height/coach clearances to Air spring height/coach clearances to be maintained as per drg no. be maintained as per drg no. CA90001. Tighten the lock nut of CA90001. Tighten the lock nut of installation lever after adjustment of installation lever after adjustment of spring height/ clearances. spring height/ clearances. 

› Provide a safety plate for leveling Provide a safety plate for leveling valve to avoid stone hitting etc. valve to avoid stone hitting etc. 

› Ensure that all the fasteners are Ensure that all the fasteners are properly tightened.  properly tightened.  

› Check the leakage of all air joints and Check the leakage of all air joints and rectify, if required. rectify, if required. 

› Ensure that installation lever is in Ensure that installation lever is in position and tightened properly.position and tightened properly.

Soft flexible characteristics in vertical Soft flexible characteristics in vertical direction direction

- Achieved by compression of air.- Achieved by compression of air. Excellent lateral spring characteristics, as Excellent lateral spring characteristics, as

desired. desired. - Achieved by variation in effective area - Achieved by variation in effective area

in lateral direction. in lateral direction. Avoids excess air consumption due to Avoids excess air consumption due to

instantaneous modes of vehicle oscillation instantaneous modes of vehicle oscillation or change in air pressure. or change in air pressure. - Achieved by designing delayed reaction - Achieved by designing delayed reaction levelling valve . levelling valve .

Air spring is a suspension where properties of Air spring is a suspension where properties of air are used for cushioning effect air are used for cushioning effect (springiness).(springiness).

Enclosed pressurized air in a pre-defined Enclosed pressurized air in a pre-defined chamber called air spring, made up of rubber chamber called air spring, made up of rubber bellow & emergency rubber spring, provides bellow & emergency rubber spring, provides various suspension characteristics including various suspension characteristics including damping.damping.

Air springs are height-controlled load leveling Air springs are height-controlled load leveling suspension devices. With changing loads, air suspension devices. With changing loads, air spring reacts initially by changing the spring reacts initially by changing the distance between air spring support and distance between air spring support and vehicle body.vehicle body.

The levelling valve is in turn actuated, The levelling valve is in turn actuated, either taking the compressed air pressure to either taking the compressed air pressure to the air spring or releasing air pressure from the air spring or releasing air pressure from it to the atmosphere.it to the atmosphere.

This process continues until the original This process continues until the original height is restored. This mechanism ensures height is restored. This mechanism ensures a constant floor height on coaches provided a constant floor height on coaches provided with air springs, irrespective of the load.with air springs, irrespective of the load.

This greatly reduce problems associated This greatly reduce problems associated with low buffer / coupler heights.with low buffer / coupler heights.

Bogie Frame & Suspension:Bogie Frame & Suspension: Air spring has been installed at secondary stage Air spring has been installed at secondary stage

replacing steel coil springs. replacing steel coil springs. A fixed lower spring beam (as cradle) to A fixed lower spring beam (as cradle) to

accommodate the air spring has been provided on accommodate the air spring has been provided on bogie bolster. bogie bolster.

A lateral hydraulic damper and lateral bump stop A lateral hydraulic damper and lateral bump stop have been provided at secondary stage. have been provided at secondary stage.

Primary springs have been retained as steel Primary springs have been retained as steel spring. spring.

Details are shown in Fig.Details are shown in Fig. Leveling valve provided between bogie frame and Leveling valve provided between bogie frame and

bogie bolster. bogie bolster.

Figure: 4

BOGIE GENERAL BOGIE GENERAL ARRANGEMENTARRANGEMENT

Bogie bolsterBogie bolster Provision made for air inlet to air spring. Provision made for air inlet to air spring. 40 lit addl. Reservoir connected to each air 40 lit addl. Reservoir connected to each air

spring. spring. Duplex check valve is provided.Duplex check valve is provided. Under frameUnder frame A pipeline is drawn from M.R pipe (feed pipe) A pipeline is drawn from M.R pipe (feed pipe)

for pneumatic suspension for pneumatic suspension One isolating cock, one non return valve, one One isolating cock, one non return valve, one

150 lit air reservoir (auxiliary reservoir) one 150 lit air reservoir (auxiliary reservoir) one air filter and two separate isolating cocks to air filter and two separate isolating cocks to isolate each bogie have been providedisolate each bogie have been provided

BASE PLATEBASE PLATE Base plate to be used should be as per drawing No. RDSO Base plate to be used should be as per drawing No. RDSO sketch- K4018 alt ‘1’ is enclosed as fig.5.sketch- K4018 alt ‘1’ is enclosed as fig.5.

OPERATING INSTRUCTIONSOPERATING INSTRUCTIONS Train Driver to maintain 7 bar pressure in Train Driver to maintain 7 bar pressure in

compressor. compressor. In case of heavy leakage of air from air spring In case of heavy leakage of air from air spring

system, Isolate the affected bogie and observe system, Isolate the affected bogie and observe speed restriction at 60 km/h up to the terminal speed restriction at 60 km/h up to the terminal point for maintenance. point for maintenance.

Inspect for any water collection in Inspect for any water collection in rubber bellow of air spring rubber bellow of air spring

Inspect the air spring for any Inspect the air spring for any damage or leakage. damage or leakage.

Inspect air spring seat and top Inspect air spring seat and top plates for corrosion, if corrosion plates for corrosion, if corrosion noticed is paint with primer & noticed is paint with primer & black paint.black paint.

Inspect all welding joints of the lower spring Inspect all welding joints of the lower spring beam (cradle) and repair if required. beam (cradle) and repair if required.

Inspect air spring fixing holes of lower Inspect air spring fixing holes of lower spring beam for elongation, if elongated spring beam for elongation, if elongated build them to dia.17 mm or dia. 26 mm. build them to dia.17 mm or dia. 26 mm.

Inspect the corrosion on top surface of Inspect the corrosion on top surface of lower spring beam, Remove the corrosion lower spring beam, Remove the corrosion paint with primer and black paint.paint with primer and black paint.

The air spring piping may be checked The air spring piping may be checked for any leakage/damage by soap test for any leakage/damage by soap test and repair if requiredand repair if required..

"O" rings provided on air spring spigot "O" rings provided on air spring spigot must be changed. must be changed.

Mount air spring on lower spring beam Mount air spring on lower spring beam and match the holes of bottom plate of and match the holes of bottom plate of air spring and holes of lower spring beam. air spring and holes of lower spring beam.

Tight all 4 nut-bolts with the help of M16 Tight all 4 nut-bolts with the help of M16 Allen key and suitable spanner. Allen key and suitable spanner.

Place the bolster on air spring ensuring Place the bolster on air spring ensuring no damage to spigot of air spring. no damage to spigot of air spring.

Connect levelling valve arm with installation Connect levelling valve arm with installation lever. lever.

Mount vertical and lateral shock absorber. Mount vertical and lateral shock absorber. Connect all flexible/fixed pipe connections of Connect all flexible/fixed pipe connections of

bogie bogie All the threaded joints of air spring be All the threaded joints of air spring be

sealed with thread sealing tape to avoid air sealed with thread sealing tape to avoid air leakage. leakage.

The filter of levelling valve must be cleaned. The filter of levelling valve must be cleaned.

Connect the hosepipes on the under frame Connect the hosepipes on the under frame piping with the leveling valves of the bogies. piping with the leveling valves of the bogies.

Connect pressure gauges to the drain plug Connect pressure gauges to the drain plug locations of 150-litre reservoir. locations of 150-litre reservoir.

Provide packing in the gap between bolster & Provide packing in the gap between bolster & bogie frame. bogie frame.

Connect the 150-litre reservoir on the under Connect the 150-litre reservoir on the under frame to the compressed air source of frame to the compressed air source of pressure 9.0 kgf/cm2 . Allow air into the air pressure 9.0 kgf/cm2 . Allow air into the air springs to a value of 9.0 kgf/cm2in the springs to a value of 9.0 kgf/cm2in the pressure gauge by adjusting pressure gauge by adjusting horizontal lever of horizontal lever of the leveling valve and keep it in the same the leveling valve and keep it in the same position. position.

Close the isolating cock connecting MR pipe Close the isolating cock connecting MR pipe with 150-litre reservoir. with 150-litre reservoir.

Test all pipe joints for leakages. Test all pipe joints for leakages. Check the pressure gauge readings after one Check the pressure gauge readings after one

hour. The pressure drop should be within 1% of hour. The pressure drop should be within 1% of the test pressure 9.0 kgf/cm2 . the test pressure 9.0 kgf/cm2 .

Release the air completely by dropping the Release the air completely by dropping the horizontal lever. horizontal lever.

Remove the packing. Remove the packing.

TYPE OF COACH ICF DRAWING No. RCF DRAWING No.

AC EOG(16 T) WTAC5-0-0-501 (ANNEXURE.-C)

AC SG(16 T) LWGSCWAC-0-0-001 (ANNEXURE.-D)

CA00001(ANNEXURE.-F)

NON AC (13 T) LGS-0-0-001 (ANNEXURE.-E)

CA00002(ANNEXURE.-G)

Firstly find out the type of bogie as AC EOG (16 T), AC SG (16T), or NON AC (13 T) coaches and make RCF or ICF. List of relevant drawings are as under:

Than the coach should be placed at leveled track. The primary springs should be grouped as per ICF drawing no. ICF/STD-9-0-

003 placed at Annexure-H, in which the different type of primary springs is grouped for air

spring bogie and other type of bogie.

The primary springs used for the air spring The primary springs used for the air spring bogies as follows:bogies as follows:

TYPE OF COACHTYPE OF COACH ICF DRAWING No. ICF DRAWING No. RCF DRAWING No.RCF DRAWING No.

AC EOG(16 T)AC EOG(16 T) WTAC-0-1-202WTAC-0-1-202 WTAC-0-1-202WTAC-0-1-202

AC SG(16 T)AC SG(16 T) WTAC-0-1-202WTAC-0-1-202 AW01101AW01101

NON AC (13 T)NON AC (13 T) WTAC-0-1-202WTAC-0-1-202 CC01129CC01129

POWER CARPOWER CAR WLRRM8-0-1-801 WLRRM8-0-1-801

Place the proper primary springs and compensating rings in AC Place the proper primary springs and compensating rings in AC EOG,AC SG and NON AC coaches with air spring bogie as per EOG,AC SG and NON AC coaches with air spring bogie as per following suspension diagram: following suspension diagram:

TYPE OF COACHTYPE OF COACH ICF DRAWING No.ICF DRAWING No. RCF DRAWING NoRCF DRAWING No

AC EOG(16 T)AC EOG(16 T) WTAC5-9-0-501(ANNEXURE.-I)WTAC5-9-0-501(ANNEXURE.-I) --

AC SG(16 T)AC SG(16 T) -- CA90001(ANNEXURE.-J) CA90001(ANNEXURE.-J)

NON AC (13 T)NON AC (13 T) -- CA90001CA90001

Than maintain the bogie corner heights as per relevant suspension diagram.

After the bogie corner height is maintained, adjust the air spring height as per relevant suspension diagram with the help of installation lever.

After POH and before assembling the bogie, measure the wheel After POH and before assembling the bogie, measure the wheel diameter. diameter.

Depending upon the wheel diameter, place wooden packing of Depending upon the wheel diameter, place wooden packing of required thickness under the flange of lower spring seat as required thickness under the flange of lower spring seat as indicated in the following table: indicated in the following table:

Average wheel dia. between Average wheel dia. between the two wheels on the same the two wheels on the same bogiebogie

Thickness of hard packing ring Thickness of hard packing ring (mm)(mm)

889 mm to 864 mm889 mm to 864 mm 1313

863 mm to 840 mm863 mm to 840 mm 2626

840 mm to 820 mm840 mm to 820 mm 3838

819 mm819 mm 4848

Load in KN Load in KN (Static)(Static)

Vertical stiffness Cz IN N/mmVertical stiffness Cz IN N/mmAdditional Volume Additional Volume 20dm320dm3

Additional volume Additional volume 40dm340dm3

5050 550±50 N/mm550±50 N/mm 400±50N/mm400±50N/mm

115115 875±75N/mm875±75N/mm 625±75N/mm 625±75N/mm

140 140 1000±100N/mm1000±100N/mm 700±100N/mm700±100N/mm

STATIC VERTICAL LOADS ON AIR SPRINGSTATIC VERTICAL LOADS ON AIR SPRINGTare load -------------------------- -- 50.0 KN Tare load -------------------------- -- 50.0 KN Full load --------------------------- -- 140.0 KNFull load --------------------------- -- 140.0 KN

VERTICAL STIFFNESSVERTICAL STIFFNESS At dz + 20 mm and constant speed of 5mm/sec, the vertical stiffness (Cz) shall be:At dz + 20 mm and constant speed of 5mm/sec, the vertical stiffness (Cz) shall be:

HORIZONTAL STIFFNESSHORIZONTAL STIFFNESSAt dy +20 mm at constant speed of 5 mm/sec, At dy +20 mm at constant speed of 5 mm/sec, the lateral stiffness (Cy) shall be:the lateral stiffness (Cy) shall be:

Load in KN (Static) Lateral stiffness Cy IN N/mm

50 50 150 ±25 N/mm 150 ±25 N/mm

115115 175±25 N/mm 175±25 N/mm

140 140 200±25 N/mm 200±25 N/mm

Min. height of air spring under full load with no air and without spigot - 210 mm Installed height without spigot - 255+0 -5mm.

Dimensional check:ITEM REFERENCE DOCUMENTS

Air spring As per Firm’s assembly drawing approved by RDSO & technical requirements of clause 6 of STR No.C-K509, Rev.-2

Top Plate with spigot

“O” Ring

Base plate

Leak test of air spring bellow: Leak test of air spring assembly shall be carried out as follows-

Install the air spring assembly at design height. Gradually raise the air pressure to 9 kg/cm2 and

disconnect the air supply. Air spring assembly shall be checked for pressure drop at

the following pressure and time intervals. a) After one hour at internal pressure 9.0 kg/cm2.

b) After 15 minutes at internal pressure 6.0 kg/cm2. The above tests shall be conducted with the air supply and drain system of test device turned off.Drop of pressure at the completion of test shall be measured. The pressure drop is required to be within 1% of the test pressure i.e. 9.0 kg/cm2 or 6.0 kg/cm2 as applicable.

END of SLIDESEND of SLIDES