New name, new sign:


The tower was built in 1970-1972 by the GDR architect Henselmann. Today, at 144.5 m high (159.60 m with antenna tip), it is the tallest office building in the new federal states. Originally planned as a research building for the Zeiss Group, it was later used as a university tower before the headquarters of the software company INTERSHOP moved in.

Today, the 29 floors are shopping centres and offices, with a hotel on the 27th floor.

For a long time, the tower was nameless. The former INTERSHOP lettering was removed when the software company of the same name moved out at the end of 2020. The lettering was made of red neon letters in a double contour on the tower at a height of 125 metres. The double contour was chosen to compensate for the possible loss of individual letters.

The project

In July 2021, the company NEL GmbH from Leipzig was commissioned by PASSAT Grundstücksgesellschaft mbH to design a new lettering for the tower. NEL GmbH was well acquainted with the conditions there, having installed the old INTERSHOP lettering in 2001 and dismantled it in 2021.

The new lettering will be JENTOWER and it should be sustainable and energy-efficient. It didn't take long for NEL GmbH to decide that LED technology from HANSEN was the first choice here, according to André Bellstedt, specialist consultant for illuminated advertising at NEL.

The two companies, HANSEN and NEL, have had good business relations for a long time and have already set up several lighting projects together, and this should also be the case with the JENTOWER. You can rely on HANSEN and the quality of the products is right. Moreover, HANSEN responds to individual wishes, you always get support and not only products, but also solutions.

The task

The look of the INTERSHOP lettering of the time was to be kept.
A building permit was required for the new lighting system. So as far as possible, the colour and design were kept to the old design, only in LED technology. And this made the approval process a lot easier.

HANSEN's swing~light was chosen as the product, with a neon look that was made for this project. Moreover, the fitters at NEL are well acquainted with it, because the lettering for the GLOBANA Hotel in Leipzig was also made with it.

Now a long planning phase began, because there were a few hurdles to overcome. First, a pattern was built on a Dibond panel. This sample was mounted at the top of the tower to test the effect from below and from a distance. It also helped to find a solution for mounting the letters on the façade. Everything has to be brought up with a lift car, it takes 20 minutes for one way!

Since the light should shine nicely to the front and not drift away to the side, the edges of the letters were again specially bevelled to "catch" the light.

Another hurdle was the shape of the letters. For the tower appears round, but it is not. The windows are lined up at an angle of about 6%. And so each letter also had to be bent accordingly - that was precision work!

The planning was a technical challenge that NEL was happy to take on. And through the prototype construction, they had gained essential knowledge to be able to plan further with it.

The lengths of the swing~light profiles were then worked out at NEL. And in October 2022, André Bellstedt from NEL was able to place the order with HANSEN.

Each individual letter is 3.10 m high, the lettering is 25.6 m long in total. Each letter consists of two lower and two upper parts, only the "W" consists of three lower and three upper parts. For the transport up to a height of 125 metres, only the lift car was available. This was allowed to carry a maximum load of 240 kg. With two fitters with tools, a maximum of 50 kg remained for one letter part, all of which had to be meticulously calculated and then taken into account again and again.

The letters were fitted with the swing~light profiles in the workshop at NEL. Again, double contours were provided, just as with the previous neon lettering. The converters were installed in the lower part of each letter. On site, the old distribution system was to be used for the power supply, which facilitated the installation.

The lettering is 25.60 m long in total.

Each individual letter is 3.10 m high.

Each letter consists of two lower and two upper parts,
only the "W" consists of three lower and three upper parts.

For the transport up to a height of 125 metres, only the lift car was available. This was allowed to carry a maximum load of 240 kg. With two fitters and their tools, the maximum load for a letter part was 50 kg.

Implementation and execution

For the installation on the façade, help was obtained from industrial climbers. First, 150 pieces of M16 bolts were glued into the façade to place the letters on top.

Then all the individual parts were brought up to the terrace of the 3rd floor with a crane. From there, the lift car could be loaded and then travel up to the installation site with the parts and two fitters in 20 minutes.

The first thing to be installed was an "E", which was in mid-June 2023. The local press took notice and the people of Jena were eager to see what was coming. They had to be patient, because only one letter could be installed per day, provided the weather was good and there was little wind.

At the beginning of July 2023, the new JENTOWER lettering could be admired in its entirety and the installation could be put into operation.

A total of 245 metres of swing~light profiles were used, plus 34 converters and a light-sensitive controller.

The system has a total output of 2.2 kW - sustainable and energy-efficient, as required.

Project manager André Bellstedt from NEL praises above all the cooperation with the sales representative Steffen Tschernich and the HANSEN production department: "All requests for improvements were dealt with ad hoc, even during installation. This was extremely helpful.

The support from TONI MARONI regarding the light-sensitive controller was also excellent. They were quick and uncomplicated in providing help and advice.

The result is impressive and Jena has a ray of hope in the sky again!


Hansen GmbH

Norderstraße 1
D 25855 Haselund
T +49 4843-2009-0

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