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

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Similar to grade resistance on the gradients, on the curves, the rolling stock encountercurv.e resistance. The curve resistance is significant and is in the order of 0.4 kg per{annes per degree of curvature and can significantly affect the loco starting capability.Graded sections are generally associated with curves. A loco, which can start and haul 58UOX N un.1 in 200 qracJient, on a straight section, may not start 50 BOX N on 1 in 200~radi0nt with 4 d&[jree r;urv~. ~!enc.e the elemert uf curve resistance Ci:.n play animportant role in the stalling or running through of a load.Normally, the effect of curve resistance in a grade is accounted for by designing the gradeas 'compensated' or ' non - compe::nsated' grade, Le., a grade of 1 in 150 on a straighttrack when compensated for eXisting' curve of 4 degree could offer cumulative rollingresistance equal to a grade of 1 in 121. -Since there could be a large variety of curvesavailable in the field, working out loads for each degree of curve would not be feasible, itis the normal practice to consider the value of 'compensated gradient' in the load tables.But in the field the gradient posts indicate the actual typical gradient level available in thespot and it is this value, which becomes the guiding factor when fixing trailing loads, whichneeds to be corrected.On the BG system of IR, normally a curve of more than 4 deg. is rare. Most curves wouldlie somewhere between 0 to 4
6.3.4.2 Length of the Gradient and Approach Speed:Presently the load charts only specify the maximum loads that a loco can start at differentgradients, on a tangent track, and the loads that it can maintain continuously at specifiedbalancing speed on different gradients. While the first part of the information is useful andessential, the latter part - regarding loads it can maintain at different balancing speeds ona gradient is not of great practical significance in regard to fixing up the trailing load. Theweight of the trailing load is primarily determined by the starting capability of thelocomotive only, but when sec.:tionalcapacity approaches saturatic)n point balancing speedalso assumes importance for generation of extra capacity.Important point which is of practical value in the field is the information as to what is thelength of a particular gradient that a loco can clear with the given .train load alreadydetermined by its starting load capability consideration as mentioned above. This lengthwill be dependent on two factors: firstly, the inherent loco design and its capabilityincluding its Tractive Effort (TE) versus speed characteristics and secondly, the attackspeed, i.e. the speed at which the locomotive approaches the start of the gradient.The motive power requirement for clearance of different gradients as per actual conditionsavailable in the field can be worked out for different train speeds ensuring that the tractionmotor currents do not exceed the maximum permitted rating etc. of the locomotive andstalling are avoided.It is therefore proposed to include this information also in the load charts, in future, forguidance, for smoother train operations.For various approach speeds, feasibility of clearing 58 BOXN loads, maximum stretdl thatcan be cleared and balancing speed are evaluated through computer simulation. lhasehave been worked for four critical gradients, viz., 1in 100, 1in 150, 1 in 200 and 1in 250,both for tangent track and 2.5 degree curve and are shown in Annexure No.VII.It will greatly assist in laying 'down operational guide lines like judicious imposition ofspeed restrictions, location of stop/warning signals, need for run through operation at thespecific locations, provision of bankers etc.6.3.5 Based eJn the above discussion thereforu, taking into account the aforesaidoperating/field conditions, the load tables have Leen also drawn for wet rail conditiom with -2.5 0 curve for the different diesel and electric locos and are shown in Annexure No. VI.The incidences of wheel burnt rails / scabb~d r~i1s take place due to continuous \theelslipping of loco becaw;e of inadequate motive p6wer of the locomotive vis-a-vis 10addemand and efforts on the part of driver to pull the train and clear section in such ad'eiseconditions. The year-wise incidences of wheel burnt rails in Bilaspur Division are encbs edas the Annexure No. VIII. I
Page 5 and 6: . ,sma ~HCPZ:i' ~a--i:tzCl
Page 7 and 8: i) Improvement in enginemanship;ii)
Page 9 and 10: INDEX:S.NG. Desc'ript~oll Page No.1
Page 11 and 12: 1.0·Introduction:Adequate powering
Page 13 and 14: Total of 22 cases of freight stalli
Page 15 and 16: gradient of 1 in 37, two triple hea
Page 17 and 18: VI)' Running of 58 Box 'N' rake sho
Page 19 and 20: The "table above shows a substantia
Page 21 and 22: Similarly starting load for WDM2 mu
Page 23 and 24: GRADE 20 30 40 50 60 70 80 STARTLEV
Page 25: 0.3Coeffecientof Adhesion on Oily R
Page 29 and 30: 7.2.2 The restricfions for double-h
Page 31 and 32: plDced at Annexure No. VI. New sets
Page 33 and 34: q-~1~~JF.y~r, m- ~r~1.[
Page 35 and 36: I HL Y- . Di"jsion Total Period T f
Page 37 and 38: __ .' __ 0"_ 0.0.••• 0- __
Page 39 and 40: HAULAGE CHARTS FOR DIESEL LOCOS FOR
Page 41 and 42: ~ ___ • _0 ••••---_._ 0
Page 43 and 44: --_.- ._ ..._._ •.... .... .. ..
Page 45 and 46: S.NO.- --- -- --- ---_. --.--.-----
Page 47 and 48: APPROACH SPEED VS LENGTH OF MAXIMUM
Page 49 and 50: APPROACH SPEED VS LENGTH OF MAXIMUM
Page 51 and 52: •• • • # • • ."'"!=..
Page 53 and 54: ,110'~. •.;...~::.. "(.-:-:A~~ ,
Page 55 and 56: f:.~"L /\!. ~~~:~'!::}.~:;?,~_Gl~~l
Page 57 and 58: ;,1,tI I ,IiC;:.:'iJ1_-,- ---------

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