CDP files are essentially compressed archives—similar to ZIP or RAR files—but formatted specifically for the Trainz engine. An extractor reads the binary data of the CDP to:
If you are downloading a lot of custom content, follow this workflow to keep your game stable: trainz cdp extractor work
If you double-click a CDP file, Windows will not know how to open it. If you force it to open with WinRAR or 7-Zip, you will see gibberish or a single unreadable binary file. Standard archive tools do not work on CDP files because the internal indexing and compression algorithm (zlib with a custom header) is unique to Trainz. trainz cdp extractor work
Here are the general steps to extract content from Trainz CDP files: trainz cdp extractor work