Unlike raw files (which might be .im , .texture.txt , etc.), a CDP file preserves the folder structure and internal ID references required by the Trainz Content Manager.
Instructions for back into Trainz
for %i in (*.cdp) do TrainzExtractor.exe extract "%i" "E:\Extracted\%~ni"
Have a specific extraction problem? Check the Trainz Forums (TrainzKuidIndex or N3V Games community) – thousands of creators share their extraction workflows daily.
Every version of Trainz includes Content Manager.