Amla me jo PF no. 1,2,3&4 hai wo aur bhi extend ho sakte hai but railway kuch kerta hi nhi kuch train ke coachs to 1/2 pf ke bhar rahete aur passengers ko bhi uterne me problem hoti hai .
And, PF no. 4 ke baju me itni sari jagh khali hai wha aur 2 PF bansakte hai but wo bhi nhi banenge shayed.