RDSO's report no. TFC-77 (January 2002) of the ... - eLocoS

7.2.2 The restricfions for double-headed 'operation of WDG2 as per speed certificate No.H SD.WDG2.11 dated 27.12.95 are as under:~ 2.2.3 - Double headed operation is permitted on MBG and RBG spans except for12.2 m RBG span where dispersion of longitudinal forces should be ensured interms of clause 2.8.2.3 of Bridge Rules. BGML bridges may be checked for theirsuitability for MBG loading in terms of guidelines issued for same by ROSa andsubsequent letter No. CBS/DOW dated 31.8.94:Based on revised values of TE & BF of WOG2 advised as 40.5t and 11.7t (MP Dte's NoteNo. SD.POL.12.8 dated 02.&:2000) double:'headed operation of WDG2 is constrained asIunder: .."8GML spans of 31.9m and 47.3m (effective) are prollibited."The clearance with regard to' bridges refers to standard design of girders, slabs. pipes.culverts, piers and abutments etc. issued by ROSa for BGML, RBG and MBG-1987standard loadings. The constrains specified in 7.2.1 & 7.2.2 above do not include thenon-standard bridges including those to GC loading.7.2.3 The above restriction is necessary to limit the longitudinal track forces to 60 t of TE ,on such bridges.Additional Member/Electrical's suggestion received vide D.O. No. 2001/Elect (TRS)/440/6dated 17.9.2001 to overcome bridge constraints for multiple operation of locos byproviding switch to limit TE on bridges is not considered acceptable for safety ofpermanent vital assets like bridges. Therefore bridge strengtf-tening will be necessary.All those bridges, which do not conform to ROSa. design. the superstructure. bearingsand substructure including foundations, are to be checked by Railways on condition basis(case by case) befo,~eevolving the cost of strengthening/modification for such bridges asit may vary considerably. However. tne appruximate cost per span of 45.7m span i3GMLgirder bridge. requiring modifications, has been worked out as Rs. 12.50 lacs.8.0 Summary of Discussions & Recommendations:The issues dealt primarily in this report are:1. Whether under powering has really affected the Line Capacity of crticalsections?2. Whether there has been substantial damage to the track due to wheel burns?3. Can ROSa give any techniGsl Ll.oluU~HJ to overcome the problem Of stalling? .4. Cost implications of the techniCal solutions. .The data collected from the field shows that there are about 3.6 cases of stallirg offreight trains every day on the Indian Railways. Each stalling takes an' average 011.519