Usually Special trains are alloted Freight locos because the "Special Trains" only run for a limited time, and thus there is no requirement of having a LSA (loco sharing allotment? I think) meanwhile regular trains have some sort of LSA. but im not too educated on this matter so take what i said with a grain of salt.
please wait...Translate to HindiBhaade ke trainon ko normally Freight locos se chalaya jaata hai kyunki "Special Trains" sirf limited time tak chalti hai aur isliye LSA (loco sharing allotment? I think) ki zaroorat nahi hoti hai jabki regular trains me LSA hoti hai. Lekin main is mamle me bahut educated nahi hoon, isliye jo kuch maine bola hai usko ek pinch of salt ke saath lena.