Lock system in Kiel-Holtenau

Communicative signal lights

  • Seawater-resistant signal lamps with energy-saving LED technology
  • Simpler maintenance through support with status and diagnostic information
  • Easy installation with prefabricated cables and connectors

Customer profile

The Kiel Canal connects the mouth of the Elbe to the Kiel Fjord and saves ships a detour of up to 460 kilometers. The roughly 100 kilometer-long waterway runs through Schleswig-Holstein and is one of the busiest man-made waterways in the world.

Mast with signal lights

Safe signals


As part of modernization efforts, the lock system in Kiel's Holtenau district has been fitted with a new signaling system. The lights are installed on masts and use red, green, and white signals to notify approaching vessels of whether or not the lock entrance is unobstructed.

Only components that conform to the industry standard are used for the monitoring functions. The signal lights are exposed to harsh weather conditions and must therefore satisfy special requirements. These include high winds, salt water, and even direct sunlight.

The use of modern industrial communication technology ensures that the control room is always informed of the status of the lights. Easy installation without having to set addresses or device IDs is also desirable for maintenance crews. This is particularly important when lights have to be replaced for maintenance.

Service technicians have mobile access to operating data

Mobile access to LED light operating data


Two new masts in the lock have been fitted with 300 LED signal lights, which support maintenance personnel with status and diagnostic information. This is made possible through the use of industrial communication technology.

The lights are connected using prefabricated cables and M17 hybrid plug-in connectors from Phoenix Contact. The hybrid connector simultaneously connects the power supply and the data cable to the light. There is no risk of mismatching. Easy installation is particularly important when lights have to be replaced for maintenance. This is where the benefits of an electronic rating plate that can be read via the communication link come into play. In this way, the control unit can detect whether the correct light is connected.

The color, size, and beam angle are transmitted, for example. In the event of faulty installation or replacement, the control unit sends an alarm message and prevents the light from turning itself on. The light's operating hours and the those of the individual LEDs are recorded separately and stored cyclically in the light.

LED technology with many benefits
Signal light

Durable due to efficient LED technology

The LED technology in the light helps save energy and increase availability. The latter is a result not only of the extended service life, but also the special wiring of the lights.

When one LED fails, this is detected by means of current and voltage monitoring and reported back to the higher-level system. According to the instructions from the control system, the other LEDs can be readjusted in order to achieve the same light output.

In addition to the LED monitoring, two scattered-light sensors are installed in the signal light, which detect whether the LEDs are emitting light as well as the intensity.

The temperature of the light is also recorded in order to ensure the operational safety of the signal light in all instances. If the temperature of the light exceeds the permissible range, light output is reduced or even switched off. This function is supported by notification and alarm messages. If the temperature drops again, the light resumes operation once the message has been acknowledged.


The locks, which compensate for the difference in level of the North Sea and Baltic Sea, play a central role in the smooth operation of the Kiel Canal. Lock maintenance is simplified by LED signal lights from Phoenix Contact, because their operational data can be read at any time.

Maintenance personnel are supported with status and diagnostic information and are therefore continuously informed of the status of the signal lights. A further advantage of the lights is the LED technology, which helps save energy and increase availability.