Delphi controls an entire world
Markus Greschat, 04.08.2017
Here's the English translation:
In Hamburg, right on the Elbe River, the number one tourist attraction draws well over 1 million visitors annually to the halls of the Miniatur Wunderland. On an area of about 7,000 square meters, an incomparable miniature world has been created over approximately 760,000 working hours.
The idea to build the world’s largest model railway was conceived in July 2000 in the Alpine metropolis of Zurich, in a model railway shop by Frederik Braun.
The implementation of the project by twin brothers Gerrit and Frederik Braun along with Stephan Hertz began in December 2000.
Challenges of the Project
Apart from the requirement for 100% system availability, a major challenge lies in controlling the various parts of the layout and their subsystems simultaneously. Another requirement is, for example, synchronizing the movement of cars with the traffic light signals. Not only the approximately 1,040 trains are controlled but also over 385,000 lights, and around 9,250 cars, airplanes, and ships.
Just like in a real megacity, it’s the software that keeps operations running in the miniature Hamburg counterpart. Within Wunderland, there exists a broad software landscape, which has been developed with Delphi by the founders since the beginning and now comprises nearly three-quarters of a million lines of code. The reason for this is quite simple: During his studies in Business Informatics in the 1990s, Gerrit Braun learned to program in C/C++ and Pascal, with the latter becoming his favorite. He naturally gravitated towards Delphi, which dominated the Pascal world then and continues to do so today.
Systems Developed with Delphi
Vehicle Control System
Controls all vehicles, including cars, airplanes, and ships, and plans and monitors their routes.
Designed so it doesn’t just follow a simple sequential movement but provides each vehicle with a “brain”.
Approximately 25,000 parameters are needed for smooth operation. These include:
Routes with millimeter-precise measurements, slopes, curve radii, right-of-way rules, traffic lights, complex signal control systems, intersections, radar traps, speed measurements, vehicle type permissions, etc.
The car system also handles events like firefighting missions, directing vehicles to the incident site with priority over other vehicles. Controlled randomness ensures varied routes, contributing to a lively scene, yet rules like right-hand driving are maintained.
Each vehicle has its own process, recalculating the overall situation 20 times per second.
The system is designed to control 65,000 vehicles, though only about 8,000 are currently active.
Rail Control – Railware
Not developed at Wunderland but is also a Delphi program.
Controls train traffic across all layout sections, ensuring zero delays.
Relies heavily on feedback from the trains to determine their location in the layout.
Lighting Control
Houses, streets, vehicles, runways, etc., are illuminated by LEDs—approximately 300,000 miniature light sources.
About 20,000 separately addressable LED groups are controlled.
The software also controls the lighting in the hall, following a day-night cycle every 15 minutes.
Development Process
Unlike large-scale projects usually developed by large teams with well-defined processes, the Miniatur Wunderland software was largely written by Gerrit Braun himself. Documentation was mostly handled with inline comments—an approach unsuitable for larger teams.
Gerrit Braun focused heavily on code reusability. Over the years, he built a large collection of functions and procedures that could be adapted through parameterization. New routines and expansions are written on a separate development computer and tested in a special simulator. The Delphi tools for debugging are used extensively.
For version control, he relies on the built-in tools of the Delphi IDE.
Gerrit makes use of only a small selection of tools offered by the Delphi community. Any issues with the development environment or algorithm implementations were resolved through the well-established Delphi forums.
Why Delphi?
The main reasons Gerrit has remained loyal to Delphi over the years are its versatility and consistency. He has always found the necessary support for all technical functions he developed in Delphi's function libraries. Equally important is the reliable support for older versions and self-developed function libraries. Early software versions developed with Turbo Pascal were seamlessly migrated to newer Delphi versions.
Large-scale software projects require high-quality, productivity-enhancing tools. Delphi provides the necessary tools to not only write large programs but also programs with complex functions. This applies to the entire development process, from designing to code generation, testing, and debugging.
The development processes at Wunderland are certainly somewhat unconventional and may not be directly applicable to larger development teams. But the daily, smooth functioning of everything speaks unmistakably for the reliability of the software and the development environment used.
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