What is the CDP file format?
A .cdp file is a Trainz Content Dispatcher Pack, a proprietary binary archive used by the Trainz Railroad Simulator series developed by Auran (now N3V Games). The format packages game content - 3D models, textures, sounds, scripts, and complete route layouts - into a single deliverable file for distribution and installation.
When a user downloads content from the Trainz Download Station or a third-party community site, it typically arrives as a .cdp file. Trainz Content Manager processes and imports the assets into the local Trainz database, then deletes the .cdp file once the import completes. The file therefore acts as a temporary delivery container rather than a persistent library format.
The CDP format has been used across all major Trainz releases from the early 2000s through Trainz Railroad Simulator 2022 (TRS22). In newer releases, N3V Games introduced the .tzarc (Trainz Archive) format as a more modern replacement, though .cdp files remain widely distributed for older community content. The archive ranges from under 1 MB for a single locomotive cab to several gigabytes for a complete route with all supporting assets.
CDP files cannot be opened as ordinary archives; they require Trainz Content Manager or the standalone CDP Browser tool. The internal structure uses a proprietary binary container with little-endian byte ordering, likely employing DEFLATE-based compression internally. Attempting to extract a .cdp with a generic archive utility will not yield usable results.
Security & safety
RISK: LOWGame content archives; no known security concerns. Install only from Trainz community sites (trainzportal.com, DLS - Trainz Download Station).
Format details
in a nutshell- Sony CD Architect Project File - CD Architect (v4/v5) used .cdp for CD mastering project files; software sold to MAGIX in 2016, now discontinued.
- CDP Browser diagnostic dump - Some automotive diagnostic tools use .cdp for data captures; unrelated to game or audio use.
Programs that open CDP files
Windows3 apps
Trainz Classics
Paid Use Content Dispatcher or Content Manager built into Trainz Classics to import .cdp files.
CDP Browser
Free Diagnostic/developer tool for inspecting CDP content packs. Limited to CDP content browsing for Trainz.
Trainz (Content Manager)
Paid Double-click the .cdp or use Content Manager > File > Import Content. The pack is installed and the .cdp deleted automatically. Technical details
deep spec| Container format | Proprietary N3V Games binary archive |
| Byte order | Little-endian |
| Compression | Proprietary internal compression (likely DEFLATE-based) |
| Content types | 3D models, textures, audio, scripts, route layouts |
| Typical file size | 1 MB - several GB |
| Import behavior | Deleted by Trainz Content Manager after successful import |
| Magic bytes | No publicly documented magic bytes |
| Compatibility | Version-dependent; older CDP files may be incompatible with newer Trainz releases |
| Primary import tool | Trainz Content Manager |
| Platform | Windows (primary); macOS supported in select Trainz versions |
| Superseded by | .tzarc (Trainz Archive) format in newer Trainz releases |
| Distribution | Trainz Download Station and third-party community sites |
| Released | early 2000s (Trainz Railroad Simulator series, Auran/N3V Games) |
| Latest version | Used in Trainz-series through Trainz Railroad Simulator 2022 (TRS22) |
| Specification | www.n3vgames.com |
CDP conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about CDP files.
