What schwebefähre.info offers
The Rendsburg transporter bridge connects Rendsburg and Osterrönfeld across the Kiel Canal and is one of only eight still operating worldwide. On schwebefähre.info we gather all information about its operation in one place. Passengers see the current schedule, the operational status in real time and whether the ferry is running or paused.
- Schedule with the current departure times
- Operational status, refreshed every one to four minutes
- Journey history for the last 24 hours
- Push notifications and emails when service is disrupted
Finding the right data source
At the start of the project, the biggest challenge was where to get reliable data on the ferry's location and operational status in the first place. One idea was to analyse the publicly available webcams with AI. That failed on the quality and reliability of the stream. Especially in the morning and evening hours, even the human eye cannot always tell clearly which side of the canal the ferry is currently on.
The solution turned out to be AIS, the Automatic Identification System, a monitoring system used in shipping for collision avoidance and traffic control. Getting to this data reliably and without an expensive subscription is not easy, though. So we consolidate the signals of several free AIS providers to obtain data that is as regular and accurate as possible. On top of that we analyse the information and notices from the German Waterways and Shipping Office (WSA) and, for greater resilience, have built our own AIS infrastructure. Even so, a crossing may not be captured immediately if the AIS signal temporarily does not transmit a current position.
How we determine the operational status
For the operational status we check whether, within operating hours, the ferry has moved from one side of the canal to the other within a fixed time interval, currently one hour. This lets us tell whether the ferry is actually running, independently of official disruption notices. The approach has a downside. Right at the start of operating hours we cannot yet say for certain whether the ferry is already underway. We keep refining this method, but cannot fully rule out errors given the methodology.
It is best to also look at the update time next to the operational status, which we show right below it in the box on the right. It indicates when AIS data was last received. A quick glance at the journey history helps to judge the current situation as well.
How the platform is built
The application is built with Next.js and React and runs on our servers in Germany. Operational data is updated continuously and delivered to the frontend and the notifications through a lean interface. This keeps the site fast, even under many simultaneous visitors.
Why we do this
The service is free and ad-free. We build and operate it out of ties to the region and because it shows well what reliable information systems look like in everyday use. The same standard for availability and data quality goes into the projects we deliver for clients.
