Center Buffer Coupler for Coaching StockPresentation by Design on 26.04.12 at RCF

RCF KAPURTHALA

Adaptation of H-Type CBC Existing IR coaches haveScrew Coupling with side buffersSeparate elements for draft and buff actionLHB uses Electro-pneumatic couplers for high speed trainsIR Adopted AAR `H Type Tight lock couplerCouple-ability with E Type Coupler fitted on IR Locomotives Anti-climbing Feature-in builtStrength Suitable for Operation of 26-coach TrainLow CostSame element to take the draw and buff load

CBC vs Screw Coupling

CBC vs Screw Coupling

CBCScrew Coupling- Shunting at Higher Speeds Possible - Shunting Time ReducedQuick detachment due to automatic Coupling and uncouplingShunting Staff at Risk

Lesser Maintenance due to less no. of ComponentsHigher maintenance due to more no. of Components and AssembliesHigher Energy absorptionLess Energy absorption

Slack between coupler heads:Between E type of loco and H type of coachBetween H Type Coupler Heads of adjacent coaches Slack in the coupler and draft gear connection Slack generation due to draft gear action High response time of the draft gear phenomenonLongitudinal Jerks occur due to slack

Total Possible SlackS1- Between coupler knuckles ( E to H -13mm, H to H -3.5mm)S2- Slack in the coupler and draft gear connection (10mm between coupler shank and yoke of draft gear- M/s Faiveley)S-3 - Slack generation due to draft gear action (Depends on quantum of force) High response time of the draft gear phenomenonS1S2S3

S-3S-1S-2 S-1 Between knuckles S-2 Between coupler and draft gear connection S-3 Slack due to draft gear actionS-1Total Possible Slack:

Slack between coupler heads Between E type of Loco and H type tight lock couplers of coach upto 13 mmBetween H type tight lock couplers heads of adjacent coaches -3.5mm

( E type does not have Horn, thus have free vertical movement. Also parts are not machined, thus have uncontrolled slack)

H-typeE-type

Problems with existing couplersM/s Faiveley / M/s Escort coupler Single pack draft gear Connection between Draft gear and coupler head through pinM/s ASF coupler Twin pack draft gear Connection between draft gear and coupler head through pin

Soft Side BuffersTrials carried out with soft side buffers in S.Rly. on ICF type coaches Not recommended by RDSO Soft side buffers also tried on BBS Rajdhani with LHB coaches in Dec- 2008 not recommended by RDSOReduced Pre-Load Preload reduced to 30KN from 77 KN initiallyTrials conducted on 24 coach Kashi Vishvanath Exp. during 27th Aug to 5th Sept 2008, using both E(standard) & H type loco couplerConsiderable reduction in jerks when hauled by loco fitted with H-type coupler with special designed draft gear.All CBCs being fitted with for low pre-load (30KN)Railways also replacing draft gear with low pre-load to 30KN Endeavors made so far

Endeavors made so farRCF has fitted 30 coach sets of CBCs with floating type draft gear in Feb-10- 24 Hybrid coaches and 06 LHB coaches. In this draft gear has floating plate between pads. As per RDSO this is also not to be pursued further.

Floating draft gear

Endeavors made so far New Design Coupler from M/s Dellner, SwedenSingle piece coupler -No connection between draft gear and coupler shank. No transversal and horizontal pivoting movement.No slack generation due to draft gear actionTight tolerances- minimum slack 2mm between headsRCF has fitted Dellner couplers on 30 coaches in Feb-11 - 22 to SCR and 08 on WR. Initial trials conducted by RDSO have indicated that performance of these coaches is similar to screw coupling coaches w.r.t. Longitudinal jerks.

Endeavours made so far

Present Status: Henceforth, all CBCs are to be procured as per RDSO "RDSO/2011/CG-03 with balanced draft gear".

RCF KAPURTHALA

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