Track structure on Bridges Provisions of IRPWM PartF

Track structure on Bridges Provisions of IRPWM (Part-F of Chapter-2) Prakash Upadhyaya (IRSE-1999) PTM

INTRODUCTION- Track Structure on Bridges Ballasted deck bridge – Rails, fittings and sleeper are similar to the track structure on approach except guard rails are provided to prevent over turning of derailed rolling stock. These type of deck is used over masonry arch bridge, RCC/PSC I girder/slab and box, composite girder, PSC I girder/PSC box girder. Open deck bridge – • Space between two sleepers is open hence called open deck. • Plate Girder • Open web Girder

Open deck bridge

Ballasted deck bridge GIRDER

Ballasted deck bridge

Open deck bridge

Open deck bridge

Open deck bridge GIRDER PIER

Major Components of Track Structure on Bridges (Open Deck Bridge) • • • Pad Plate / Bearing Plate/Packing plate Sleepers Rubber pad Cleat Angle Hook Bolt Guard Rail

Major Components of Track Structure on Bridges Sleeper Guard Rail Main Rail Pathway Guard Rail Main Rail

Track structure on Bridges Running Rails GUARD RAIL RUNNER PATHWAY CLEAT

Major Components of Track Structure on Bridges RAIL CLEAT ANGLE & BOLT RUBBER PAD CHANNEL SLEEPER HOOK BOLT Pad Plate / Bearing Plate/ Packing plate PLATE GIRDER

Rail and Rail Joints on Bridges • Longitudinal profile of track – on standard plate girder - No camber. – on open web girders having span 30. 5 m & more - with Camber • Track on these bridges are laid correctly following the camber of the girder

Rail and Rail Joints on Bridges- Free Joints • Rail joints over the Bridge– – small bridge having openings < 6. 1 m » rail joints should be avoided. – For other higher spans, » the preferred position of the rail joint is at 1/3 the span from either end. • Rail Cant– Yes – On Bridges the rail should be laid with an inward cant of 1 in 20 by continuing the same cant as on the approaches.

Rail and Rail Joints on Bridges- SWR • SWR on Bridges– • SWR may be continued over girder bridges with un ballasted decks – upto 13. 3 m opening if SWR is symmetrical to the centre line of bridge – and upto 6. 1 m opening if SWR is unsymmetrical to the centre line of the bridge. L/2 Symmetrical to the centre line of bridge

Rail and Rail Joints on Bridges- SWR • SWR on Bridges– • No fish-plated joint should be located on the girder or within six meters from either abutment. • In all such cases rail free fastenings, such as rail screws, dog spikes or rail free clips shall be used, so that relative movement between rail and sleepers may take place. • 26 m long rolled rail may be laid on bridges with 1. 0 m long fish plate and 06 bolts. LWR/CWR on Bridges • For laying LWR/CWR, provisions contained in Para 329, 330 & 331 of New IRPWM-2020 should be followed.

LWR/CWR on Bridges - Ballasted deck • Para 329 - Bridges with ballasted deck (without bearing): • LWR /CWR can be continued over bridges with ballasted deck without bearings like slabs, box culverts and arches. • Para 330 - Bridges with ballasted deck (with bearing): • Detailed calculations shall be done by the Design office of Chief Bridge Engineer / CAO(C) to ascertain the effect of LWR of such bridges and its effect on the Sub-structure of the bridge as per Para 2. 8. 1. 2 of “Bridge Rules”. • The LWR/CWR may be permitted on a case-to-case basis based on the above calculations. • In case detailed calculations are not done, LWR may be permitted as per Para 331 of new IRPWM-2020 for bridges with un-ballasted deck.

LWR/CWR on Bridges : Un-ballasted deck • Para 331 - Bridges with Un-ballasted deck: LWR/CWR shall be continued over such bridges with overall length as specified in sub-Para (1) to (3) below: • Sub-Para (1) of para 331 of new IRPWM-2020: Bridges provided with rail-free fastenings (single span not exceeding 30. 5 metre and having sliding bearings on both ends), Overall length of the bridge should not exceed the maximum as bellow with some stipulations: Rail Section Maximum overall Length of bridge (with Rail-free fastenings on bridges and PRC sleepers on approaches) Temperature Zone-I Temperature Zone -II Temperature Zone-IV 60 Kg 30 11 11 11 52 Kg 45 27 27 27

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (1) of para 331 of new IRPWM-2020: Bridges provided with rail-free fastenings…. Contd… • Stipulations: a) Rail-free fastenings shall be provided throughout the length of the bridge between abutments. b) SEJ of the LWR should be located such that bridge does not fall in the breathing length of the LWR. The approach track upto 50 m on both sides shall be well anchored by providing PRC sleepers with elastic rail clips with adequate toe load so as to arrest creep. c) The ballast section of approach track upto 50 metre shall be heaped upto the foot of the rail on the shoulders and kept in well-compacted and consolidated condition during the months of extreme summer and winter

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (2) of para 331 of new IRPWM-2020: Bridges provided with rail-free fastenings and partly box-anchored (with single span not exceeding 30. 5 metre and having sliding bearings on both ends), Overall length of the bridge should not exceed the maximum as bellow with some stipulations: Rail Section Maximum overall Length of bridge (with Rail-free fastenings on bridges and partly box-anchored along-with PRC sleepers on approaches) Temperature Zone-I Temperature Zone -II Temperature Zone-IV 60 Kg 77 42 23 23 52 Kg 90 58 43 43

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (2) of para 331 of new IRPWM-2020: Bridges provided with rail-free fastenings and partly box-anchored…. Contd…. • Stipulations: a) Central sleepers shall be anchored with anchoring arrangement (two each in end spans and one each in the middle spans) as per RDSO Drg. No. M-10920(1) (Fig 3. 26, page-150 of new IRPWM 2020) and the remaining sleepers shall be provided with rail-free fastenings. b) The track structure in the approaches shall be laid and maintained to the standards as stated in subpara-1 (b) & (c) c) The girders shall be centralized with reference to the location strips on the bearing, before laying LWR/CWR. d) The sliding bearings shall be inspected during the months of March and October each year and cleared of all foreign materials. Lubrication of the bearings shall be done once in two years.

LWR/CWR on Bridges : Un-ballasted deck Fig 3. 26, page-150 of new IRPWM 2020

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (3) of para 331 of new IRPWM-2020: • LWR/CWR may also be continued over a bridge with the provision of SEJ at the far end approach of the bridge using rail-free fastenings over the girder bridge. (Fig. 3. 5(b)). • The length of the bridge in this case, however, will be restricted by the capacity of the SEJ to absorb expansion, contraction and creep, if any, of the rails. • The length of the bridges with the above arrangement that can be permitted in various rail temperature zones for LWR/CWR with SEJs having maximum movement of 120 mm and 190 mm are as specified in table:

LWR/CWR on Bridges : Un-ballasted deck Sub-Para (3) of para 331 of new IRPWM-2020… Temperat Maximum ure Zone movement of SEJ used (mm) IV Initial gap to be provided Maximum at td With PRC approach permitted length of sleepers bridge 7. 0 cm 55 III 7. 0 cm 70 II 6. 5 cm 110 I 6. 5 cm 160 4. 0 cm 20 4. 0 cm 50 II I 190 contd…. 120 Note: i. SEJ is to be installed 15 m away from the abutments. ii. Improved SEJ with 2 gaps of 65 mm (max. ) each (Drawing no. RDSO/T 6922 and RDSO/T-6930) may also be used for laying at far end approach of bridges in lieu of IRS design SEJ with 120 mm max gap.

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (4) of para 331 of new IRPWM-2020: • Welded rails may be provided from pier to pier with rail-free fastenings and with SEJ on each pier. • The rail shall be box-anchored on four sleepers at the fixed end of the girder is supported on rollers on one side and rockers on other side. • In case of girder supported on sliding bearings on both sides, the central portion of the welded rails over each span shall be box-anchored on four sleepers. See Fig. 3. 5 (a).

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (5) of para 331 of new IRPWM-2020: • Welded rails may be provided over a single span bridge with rail free fastenings and SEJs with 190 mm gap at 30 m away from both abutments. • The rail shall be box anchored on four sleepers at the fixed end of the bridge if bridge is supported on rollers on one side and rockers on other side. • In case of bridge supported on sliding bearings on both sides, the central portion of the welded rails shall be box anchored on four sleepers. • The approach track upto 50 m on both sides shall be well anchored by PRC sleepers with elastic rail clips with minimum toe load as specified. • The installation temperature of such welded panels shall be equal to tm. The length of single span bridge permitted temperature zone-wise shall be as under: Maximum length of single span girder bridge Temperature Zone I II IV 146 110 87 75

LWR/CWR on Bridges : Un-ballasted deck • Sub-Para (6) of para 331 of new IRPWM-2020: Bridges on which LWR/CWR is not permitted/provided as per above shall be isolated by a minimum length of 30 metre of well anchored PSC sleeper track on either side. • Sub-Para (7) of para 331 of new IRPWM-2020: In case of LWR is continued over bridges as per Sub Para (3), the measurement of gaps of stock rail / tongue rail tip of SEJ provided at bridge approach from the reference post shall be compared with theoretical gaps as prescribed in Annexure - 3/9 A. • Sub-Para (8) of para 331 of new IRPWM-2020: In case welded rails are provided as per Sub Para (4) or (5), these shall not be entered in TMS as LWR and accordingly, measurement of gaps of at such SEJs of welded panels is not warranted.

Rail and rail joints on Bridges Precautions for arresting Creep– • Track on girder bridges with un-ballasted deck is always laid with rail free fastenings in all cases. • Track on girder bridges laid with standard single rails and fishplated joints should be isolated from the SWR, if existing, on approaches on either side by providing at least two wellanchored Standard rail lengths or one rail of 26 m. • Similarly, the track on the girder bridges not laid with LWR/CWR shall be isolated from LWR/CWR by a minimum length of 30 metre of well anchored SWR on either side

Track Structure- Bridge Approaches • Rail joints should be away from abutment by 3 m in case of single rail & 6 m in case of SWR. • Minimum 26 m (2 rail length) in case of single rail & 36 m (3 rail length) in case of SWR should be well anchored. • Spacing of sleepers not more than 60 cm. • 100 m approach length should have LWR ballast profile. • Ballast retainers should be provided in one rail length. • If a curvature of 3 degree & more on BG or 5 degree & more on MG exists, check rail should be provided.

SLEEPERS Type of bridge sleepers in IR • Wooden Sleepers (Bridge Timber): • Para 273 of old IRPWM. Now deleted in new IRPWM-2020. • Steel Sleepers • Channel Sleepers • H Beam sleepers

SLEEPERS • Wooden Sleepers (Bridge Timber) E S N W O O N U N I T

STEEL SLEEPERS ON BRIDGES

STEEL SLEEPERS ON BRIDGES Steel sleepers refer to steel channel sleepers & H-beam sleepers both. H – Beam Sleeper Steel Channel Sleeper

STEEL SLEEPERS ON BRIDGES • Steel sleepers refer to steel channel sleepers & H-beam sleepers both. • Steel sleepers to be used on Girder bridges should be fabricated as per approved drawings. • For girder bridges on curved track, and track on skewed alignments, steel sleepers should be designed to suit the specific locations. • This may require special arrangement such as special bearing plates, special hook bolts and other arrangements as necessary to provide required cant on curve.

STEEL SLEEPERS ON BRIDGES • Steel channel sleepers, including its fittings, may be provided on girder bridges as per applicable RDSO drawings. • H-Beam steel sleeper, including its fittings, for Girder Bridges may be provided as per applicable RDSO drawings. • All standard drawings should be followed as per Latest alterations.

STEEL SLEEPERS ON BRIDGES Sleeper spacing : • Maximum centre to centre spacing should be 600 mm at all locations on the bridge except at the cross girder in open web girders. • At the cross girder in open web girders the spacing may be suitably increased depending upon the top flange width of the cross girder. • However, in case of width of top flange of cross girder exceeds 450 mm. then special channel sleeper to be provided as per applicable RDSO drawing for such situations. • The clear distance between joint sleepers should not be more than 200 mm.

Steel Channel Sleepers

H-Beam Sleepers

H-Beam Sleepers

STEEL SLEEPERS ON BRIDGES Fabrication of steel sleepers & other components: • Fabrication of steel sleepers & its protective coating should be in conformity with BS-45 issued by RDSO. • For girder, location of steel sleepers should be marked & numbered after detailed survey of the girder. • The fabrication of steel sleeper should be location specific considering the girder centre, top flange cover plates, rivets etc.

STEEL SLEEPERS ON BRIDGES Fabrication of steel sleepers & other components: • In case of bridge on curves, the location of steel sleepers should be marked after taking into account the realigned curve. • In case transition curve lies on bridge fully or partially, the thickness of steel pad plate should take care of cant gradient.

Laying of steel sleepers on bridges • Minimum level of supervision while laying of steel sleepers shall be JE/P. Way. • Before laying steel sleepers, creep if any, should be pulled back and rail joints should be so located that after laying sleepers, joints should not become supported joints. • The top flange of girder should be cleaned of paint & repainted as specified. • Existing cross level & misalignment of girder/track should be corrected in advance before steel sleeper laying. • Single pad plate below Steel sleeper is preferable. • Packing plates can be used along with pad plate to adjust Parameters, wherever required. • The pad plates are not required where neoprene pad is provided to cover the rivet head.

Guard Rails

Guard Rails (Para-228 of new IRPWM) Location– • on all girder bridges (including pre-stressed Concrete girder bridges without deck slab) whether major or minor. • on all major and important ballasted bridges and also on such other minor bridges where derailment may cause serious damages. • On all flat top, arch and prestressed concrete girder bridges with deck slab, where guard rails are not provided - the whole width of the bridge between the parapet walls shall be filled with ballast upto the top of sleeper level.

Dispensation with Guard Rails Location– • The provision of guard rails along the inner rails can be dispensed with, in case of ballasted deck bridges located on sharp curves where the maximum permitted speed is not more than 30 kmph and track is laid with PSC sleepers having arrangement for provision of check rail due to which guard rail can not be provided. • In case of ROB/FOBs, the guard rail shall be provided on the track adjacent to a column/pier/abutment which is located within a distance of 8 m from centre of track.

Guard Rails - Design Guard Rails length • BG - L 1=1825 mm, L 2=4875 mm, a =250+_50 • L 1 - Length of straight Guard Rail Outside Ballast Wall L 2 - Length of Guard Rails to be bent a - Clearance between Guard rail and Running Rail • Top table of guard rail should not be lower than 25 mm from main line. Same section as far as possible. • In the case of bridges on curves with canted track the difference should be measured with reference to a straight line connecting the running tables of inner and outer rails.

Guard Rail – Typical Arrangement

Fixing of Guard Rails - Splaying • • • In the case of through girder bridges on double lines, the guard rails should be splayed on both ends on both lines. In the case of bridges other than through bridges on double lines, the splaying need be done only on the facing direction of the particular line. The ends of guardrails should be bent vertically and buried and a block of timber fixed at the end to prevent entanglement of hanging loose couplings However, the non-splayed end should be bent downwards after it is stopped at the end of the abutment and wooden block provided. The fixing of guardrail on concrete sleepers on ballasted deck bridges and approaches shall be done as per approved RDSO drawings by proper tightening of rail screws

Guard Rails - Fixing • Sleepers should be tied at both ends by MS Flats/tie bars fixed through holding down bolts to avoid bunching • Guard rail should form a joint at free end of girder with elongated holes to permit movement of girder. • The fixing of guard rail on concrete sleepers shall be done as shown in drawing No. RDSO/T-4088 to 4097 or RDSO/T-8672 to 8680 (wider sleeper) by proper tightening of rail screws. • Provision of MS flats/tie bars for tying PRC sleepers together at ends is not required.

Fittings for Guard rail

Provision of Side Pathways and Walkways Side Pathways

Provision of Side Pathways and Walkways Walkway Over all girder bridges, footways (walkways) should be provided in the centre of track over sleepers to help the Engineering staff for inspection. The footways (walkways) should be made of chequered plates with holes.

Provision of Side Pathways and Walkways • Side Pathways shall be provided on all new girder bridges as per applicable RDSO drawings to ensure safety of maintenance staff. • Possibility should be explored to provide Side Pathways on existing girder bridges also. • Properly secured walkways (or inspection gangways), made of chequered plates with hole, should be provided inside the track to cover the width available between the Guard Rails, and at other suitable locations to ensure safety of maintenance staff and to facilitate inspections. • For the guidance of field officials, some of the commonly used RDSO drawings for commonly used steel Channel sleepers, H Beam sleepers and fixing of Guard Rails is as per Annexure - 2/4 (A). For detailed information, respective RDSO drawings with their latest alterations and / or Track Manual may be referred

Provision of Trolley refuse • Maximum distance apart of trolley refuges on bridges will be: i. On bridges with main spans of less than 100 metres : 100 metres. i. On bridges with main spans of 100 metres or more – : A refuge over each pier. – On ballasted deck Bridges : 50 metres.

Inspection and maintenance of Track on Approaches of Bridges For all Bridges 1) On the bridge approaches, sleepers with arrangement for fixing guard rails should be provided for provision of guard rails as per Para-228 of new IRPWM. 2) Full complement of track fittings at bridge approaches up to 100 metres should be provided to maintain required track geometry and effort should be made to immediately recoup deficiency noticed, if any. 3) Rail level of track at approaches of bridges should be maintained as per designed L-section and dips in rail level immediately after the abutments should be avoided. The alignment and super elevation in case of curved track should also be maintained as per provisions of new IRPWM.

Inspection and maintenance of Track on Approaches of Bridges For all Bridges 4. Rail joints should be avoided within three metres of a bridge abutment. 5. In case of LWR track, full ballast section as specified in LWR Manual should be provided up to 100 metres from the abutment. 6. Switch expansion joints should be provided at the bridge approaches in LWR/CWR track as per provisions of LWR manual. 7. Joggled fish plate with clamps or two far end bolts on good AT welds shall be provided on bridges having length of water way as 100 m or more and on approaches upto 100 m length.

H-Beam Steel Sleeper

H - BEAM STEEL SLEEPERS • ISHB – 200 is used as H-Beam, suitable for Welded Plate Girders / Stringers of standard spans. • Cross section of sleeper is 200 mm x 200 mm, Size and Length as per Drawing No. RDSO / B-1636 / 8. • For riveted plate girders same type of H-Beam with same fixing arrangement is used. • H-Beam steel sleeper consists of: • Stiffener plates • Rail fastening assembly • Packing plates for fixing Guard Rails • Gangway Plate

Length of H - Beam sleeper • Length of H - Beam sleeper varies as per the type of girder bridges. Drg. No. RDSO/ B-1636/ 5.

H - Beam sleeper Drawing

Inspection schedule (only for channel sleepers) • By ADEN and SSE/SE(Pway) Incharge Once in a year by rotation. • Condition of channel sleeper shall be thoroughly inspected. During intensive inspection, the condition of Rivets, distortion or crack in sleepers or any sign of crack in girder flange and tightness of fittings should be looked for. • All loose fittings should be tightened after inspection, if required. • Watch must be kept for few days in the beginning as per need. • SSE/SE/Pway and SSE/SE/S&T should jointly inspect insulated steel sleepers, every six month for checking the effectiveness of insulation in track circuited areas. SSE/SE/S&T should coordinate this.

Maintenance Aspects • Maintaining steel channel sleepers • Painting • Loose rivets • Damage due to hanging parts • Maintaining track alignment and cross levels • Initial laying • In service maintenance

Maintenance Aspects • Steel channel sleepers require no painting up to 20 years if it is galvanized • If not galvanized, problems may come as early as 5 years of laying • To prolong the life of galvanizing, one coat of red oxide zinc chrome paint to IS: 2074 followed by one coat of aluminium paint to IS: 2339 shall be applied • If corrosion is there, full painting as per IRBM to be done.

Problems in track due to improper Laying • Problem of misalignment due to hook bolt holes – Oblong hole of 30 x 24 mm for 22 mm dia hook bolt as per RDSO drg. • Causing of 4 mm extra clearance • In adverse condition, 8 mm misalignment – May lead to 11 to 14 mm misalignment • Care to be Taken: Eccentricity of the track on girders is not permitted - Can lead to cracks and failure in girders Solution • • C/L of the bridge/girder to be marked Stretch nylon cord, take left & right measurements Fabricate sleepers for individual measurements Special precautions to be taken on curved track.

Problems in track due to improper Laying Special precautions to be taken on curved track. • If track on bridge is curved, the channel sleeper has to be specially fabricated for each location • If girders are not in proper alignment, the track cannot be laid in proper geometry • Variables – Curvature of track: versines – Superelevation: whether in girder or in sleepers – Whether track is in transition portion or circular portion • Then the offsets for each sleeper location shall be found out.

Problems in track due to improper Laying Special precautions to be taken on curved track. • Sleepers shall be fabricated accordingly and numbered for easy identification • Lay sleeper at its proper location only • For ease of fabrication of types of sleepers • Ideally girders shall lie on chord stretched on the curve, tangential to the curve • Curve shall be symmetrical about the girder • Sleepers in middle 1/6 th are mirror reflection of those in end 2/3 rd. • If curve is mild or above cannot be met, the hook bolt plates shall be welded at site itself

Channel sleepers in track circuited area- Problem • Problem- Old RDSO drawing – GFN liner provided between the sleeper and cleats – Problems due to breakage of liners after some time Solution • M/S Rawatson drawing Approved by RDSO • Insulating material provided between the rail and fittings

Frequent Problems in track on steel sleepers Loose Hook bolt Missing Hook bolt

Case study- Frequent breakage of hook bolts

Steel Channel Sleepers RUNNER PATHWAY Hole for Hook bolt CLEAT

Location of Hook bolt hole Steel Sleeper Packing / Elastomeric pad Steel Sleeper Contact/ Grip Area GIRDER Contact/ Grip Area Utmost Care is required to ensure proper location of Hole in Steel sleeper for fixing of Hook Bolt

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