Reinforced concrete design to BS 8110:1997. Python port of Oyenuga's RCD2000 FORTRAN programs with a professional desktop GUI.

RCD2000 is a structural engineering tool that designs beams, columns, slabs, stairs, and foundations in accordance with British Standard BS 8110. It uses the Clapeyron three-moment equation for continuous analysis and strain compatibility for column interaction curves.

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Downloads

Platform	File	How to use
Windows	RCD2000-windows.exe	Installer — run it, follow the setup wizard, launch from Start Menu.
macOS	RCD2000-macos.dmg	Open the DMG, drag the app to your Applications folder. See HOW_TO_OPEN.txt for first-launch steps.
Linux	RCD2000-linux.AppImage	chmod +x RCD2000-linux.AppImage && ./RCD2000-linux.AppImage
Terminal UI (any OS)	pip install "rcd2000[tui]"	No binary needed — the TUI runs in any terminal on Windows, macOS, or Linux. See TUI install below.

How downloads work: the Windows/macOS/Linux files above are GUI app bundles built automatically by the GitHub Actions workflow on every v* tag and attached to the Releases page. The TUI is the same Python package — there is nothing extra to download; install it with pip and run rcd2000-tui.

Or install via pip (CLI only or with GUI):

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Installing Python

Before you can use RCD2000 (either the TUI or the GUI), you need Python 3.11 or newer installed on your computer. Follow the instructions for your operating system below. Even if you have never used a terminal before, these steps will get you running.

Windows

1. Go to https://www.python.org/downloads/
2. Click the big yellow button "Download Python 3.x.x" (the latest version)
3. Run the downloaded .exe file
4. Important: On the first screen of the installer, check the box that says "Add python.exe to PATH" at the bottom — this is the most common mistake beginners make
5. Click "Install Now" and wait for it to finish
6. Open Terminal (press Win key, type Terminal, hit Enter)
7. Type this command and press Enter:

   python --version

   You should see something like Python 3.12.x. If you do, Python is installed correctly.

If python opens the Microsoft Store instead: Search "Manage app execution aliases" in the Windows Start menu, turn off the Python aliases, and restart your terminal.

macOS

1. Open Terminal (press Cmd + Space, type Terminal, hit Enter)
2. Check if Python is already installed:

   python3 --version

   If you see a version number (3.11 or newer), you're good — skip to step 5.
3. If Python is not installed or is too old, download the installer from https://www.python.org/downloads/
4. Run the downloaded .pkg file and follow the installation wizard
5. Verify in Terminal:

   python3 --version

Note: On macOS, always use python3 (not python) and pip3 (not pip) to make sure you're using Python 3.

Linux

Most Linux distributions come with Python pre-installed. Open a terminal and check:

python3 --version

If Python 3 is already installed, you're ready to go. If not, install it with your distribution's package manager:

# Ubuntu / Debian
sudo apt update
sudo apt install python3 python3-pip

# Fedora / RHEL
sudo dnf install python3 python3-pip

# Arch Linux
sudo pacman -S python python-pip

Online (no install needed)

If you just want to try Python in your browser without installing anything, you can use a free online Python interpreter:

• Python Playground — runs Python 3 in your browser, supports pip packages
• Playcode — full Python IDE in the browser, supports NumPy, Matplotlib, and more
• PyRun — lightweight, fast, runs entirely in your browser via WebAssembly

Note: Online interpreters are great for testing Python code, but the RCD2000 TUI needs a real terminal to run. For the full TUI experience, install Python locally using the instructions above.

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Installation

Quick install (CLI only)

pip install rcd2000

With GUI (recommended)

pip install "rcd2000[gui]"
rcd2000-gui

Terminal UI (TUI)

pip install "rcd2000[tui]"
rcd2000-tui

A DOSBox‑style retro Terminal UI with full keyboard navigation (Tab, F‑keys), retro amber-on‑dark‑blue styling, and support for all 6 design modules. Uses Textual framework.

From source (development)

git clone https://github.com/Al-hussein31/rcd2000.git
cd rcd2000
pip install -e ".[gui,dev]"

With development tools

pip install "rcd2000[dev]"       # pytest, coverage
pip install "rcd2000[gui,dev]"   # GUI + everything (add tui)

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Quick start

GUI (desktop application)

rcd2000-gui

Terminal UI (TUI)

rcd2000-tui

Run it in any terminal — no window server needed, works over SSH too.

CLI

# Design a beam from a JSON input file
rcd2000 beam input.json

# Show formatted report
rcd2000 beam input.json -o results.txt

# Export as JSON
rcd2000 beam input.json --json

# List available modules
rcd2000 info

Python API

from rcd2000.beam import BeamDesigner, BeamInput

designer = BeamDesigner(fcu=25, fy=460)
beam_input = BeamInput(
    beam_id="B1", n_supports=2, n_members=1,
    b=225, h=450, hf=0, bf=225,
    member_lengths=[6.0], member_udl=[25.0],
)
results = designer.design([beam_input])

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Modules

Command	Design type	Methods
beam	Simply supported and continuous beams	Clapeyron three-moment, moment redistribution, shear link design, deflection check
column	Axial, uniaxial, and biaxial columns	Strain compatibility, Nu/Mu interaction curves, biaxial ratio check (BS 8110)
slab	Cantilever, simply supported, continuous one-way, two-way	Moment coefficients, span-depth ratios, two-way table coefficients
stair	Straight-flight stairs	Waist slab design, effective span, imposed load distribution
base	Square isolated, rectangular isolated, combined footings	Bearing pressure, punching shear, local bond, combined footing centroid method
continuous-beam	Continuous beam analysis (no design)	Clapeyron three-moment equation, support moment distribution

Interface	Command	Description
Terminal UI	rcd2000-tui	Retro DOS-style TUI with keyboard navigation for all 6 modules

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Input format

Each module accepts a JSON file with material properties and geometric parameters:

{
  "fcu": 25,
  "fy": 460,
  "beams": [
    {
      "beam_id": "B1",
      "n_supports": 2,
      "b": 225,
      "h": 450,
      "member_lengths": [6.0],
      "member_udl": [25.0]
    }
  ]
}

Full input schemas with all parameters are available in the module documentation. See tests/test_validation.py for working examples.

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Validation

Every design module is verified against the original FORTRAN 77 source output. The test suite confirms:

• 64 automated tests all passing (35 design validation + 29 state/persistence)
• Numerical agreement within 1% of FORTRAN reference values
• Edge cases discovered and corrected (including a latent array bug in the original FORTRAN)
• Punching shear unit mismatch identified and fixed (N/m² vs N/mm²)

Run the tests:

python3 -m pytest tests/ -v

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Reference

The original RCD2000 was authored by V.O. Oyenuga and published in Reinforced Concrete Design to BS 8110 -- Simply Explained (1999). The 13 FORTRAN 77 source files are preserved in references/ for audit and verification.

File	Program
beam_main.f77, beam_subs.f77	Beam analysis and design
bmdsgn.f77	Beam moment redistribution
column.f77	Column design
slab_main.f77, slab_subs.f77	Slab design
stair.f77	Stair design
base.f77	Foundation design
continuous_beam.f77	Continuous beam analysis
utility_subs.f77, disctf.f77, ploss.f77	Utility routines
sample.f77	Sample problem data

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Contributing

Contributions are welcome. Open an issue or pull request on GitHub.

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License

MIT