It's good easy to learn to use for MEP Drawings Brics CAD can use Cad & BIM extension file DWG # Philemon _Dubai
SCARM - Simple Computer Aided Railway Modeller
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
TrainCad - Freeware Microsoft Windows program for designing model railroad layouts using standard tracks.
SketchUp - 3D for Everyone
WinTrack - Track planing software
FreeCAD - An open-source parametric 3D modeler