Implementing the SSI solid-state interlocking S1 North

All services from one provider

The S-Bahn line 1 connects the north of Berlin to Brandenburg. Thousands of commuters use the S1 every day to reach their workplaces. The Berlin S-Bahn network and long-distance railway will be equipped with modern electronic interlocking technology with the construction of the new solid-state interlocking S1 North. SPITZKE’s Equipment/​Electrical Engineering and Large-Scale Projects/​Civil Engineering Departments, together with their branches in Großbeeren and Leer, are responsible for the following tasks: Overhead lines, electrical power equipment, traction current, telecommunications, control and safety technology, cable civil engineering work, engineering structures as well as specialized civil engineering, foundations and the tracks. Follow all the work on this major project in this ticker.


Update #6 – New elevator for the station at Lehnitz

August 22nd, 2022 // During the long-closure break in summer (see update #3), our engineering contractors started another construction project: The construction of a new elevator should be completed by September, 2023.

Starting with the long closure of the S-Bahn, the stairway was cut in half and the dismantling of the stairs began. Then, colleagues from the Major Projects / Engineering Department built a support structure as a working level for the subsequent HDI work. The support structure was made of wood and also served as a base for the approx. 40 core holes to be drilled. Now, the special civil engineers can continue.

Drilling by jet grouting at the closed Lehnitz station

The parking lot at the Lehnitz train station had to be utilized as an area for creating the excavation pit as well as for the HDI method (high-pressure injection). HDI is a jet grouting method used in special civil engineering processes to improve the subsoil.

The HDI work, which took place during the station’s closure, was completed ahead of schedule. This gave the SPITZZKE team more time to put up the temporary partition wall in the stairway. Simultaneously, the complex steel construction work began, To be able to excavate the pit for the elevator, the outer walls of the staircase had to be braced against each other using steel beams.

Breaking off and reinforcing by hand – difficult work in the summer heat

The first walers were especially difficult because they were located approx. 5 meters high and the steel beams were not exactly easy to maneuver at just under 5 meters in length. The roof of the platform made the use of a lifting device impossible. After the first beam had been installed, the step-by-step demolition and caulking work began. Our engineers were cautious not to exceed the individual working levels until the next beam had been installed. For them and the technology they used, it was hard work considering the high summer temperatures.

Following the preparatory measures in July, the relocation for the lighting is currently being planned. Work will begin on the reinforced concrete walls of the shaft frame in September.  Once again, our specialists will have to resort to manual labor. Large equipment will not be allowed into the construction area because the S-Bahn will be running on the neighboring tracks. Precautions will have to be taken in order to place the concrete. Two empty pipes have been laid under the tracks, which the concrete will be pumped through.

Update #5 – Building Bridges for the ESTW S1 North

July 28th, 2022 // Not only our track specialists have achieved a lot in the last few weeks. The projects from the company’s Large-Scale-Projects/​Structural-Engineering Department are currently focusing on bridges for the ESTW S1 North.

In July, a cable support bridge was built in the Birkenwerder cemetery. To accomplish this, the SPITZKE team installed pile-driving girders as supports for the 26.5 m wide bridge during a night-time closure. So they didn’t have to request a shutdown of the feeder conduits for this job, they brought in 26 t excavators including vibration units for the girders. The bridge, which is essential for the next group of upgrades on the Berlin-Rostock main line, was installed two weeks later using two loading cranes. The advantage in comparison to installation using large truck-mounted cranes – analogous to the night-closure for the piling work – was that it wasn’t necessary to switch off or dismantle the feed conduit. The auxiliary cable bridge should remain for 10 years.

Cable bridges for the new electronic interlocking ESTW S1 North

The next project was, once again, a bridge – this time a permanent cable bridge. Using a truck-mounted crane and a separate vibration unit, two ramming pipes were installed on the right and left of the pedestrian underpass, which was closed at the time.

At the end of July, the SPITZKE engineers were once again expecting an intensive work day. This time, it was about lifting the cable bridge, which is essential for the electrification of the urban railroad, but cannot be built on site due to space restrictions. The bridge, which is 13 m long and 1.7 m wide, was transported to Lehnitz station using heavy-duty transport. Public traffic was regulated alternately with a traffic light system. ESTW S1 North’s SPITZKE team placed the steel bridge on the support girders and fastened it using a 70 t truck-mounted crane. Moreover, it placed two precast-concrete elements manufactured in-house, which serve as foundations for two connected staircases on the cable bridge.

Road closure for the 30-meter bridge

A bridge similar to the one in Lehnitz is being built in Birkenwerder – only this one is three times larger. Excavation work is currently being done – which will be followed at the end of August by the special civil engineering work for the 6.3 m long pile-driven girders and the 8.5 m long pile-driven pipes with a diameter of 76 cm. Starting September 19th, Brieseallee in Birkenwerder will be completely closed. The cable bridge, which will be delivered in three segments, will then be pre-assembled at the specially set-up BE area. On September 22nd, a 160 t truck-mounted crane will lift the 28.5 m long and 1.8 m wide cable bridge. Shortly beforehand, the SPITZKE team from the overhead line department will dismantle the railway’s feeder conduits, which are suspended 20 m above ground.

Update #4 – Installation of several switches in Lehnitz

July 6th , 2022 // Our track professionals have installed several switches since Thursday, June 9th in the area of Lehnitz, a district of Oranienburg. At the beginning of the closure period, the control and safety technology unit (LST) set up the construction tracks and then disconnected them at the completion of the work in the night from July 6th to July 7th. This also included corresponding adjustments in the Birkenwerder signal box. LST’s main task was to equip the two points.

Before these were installed, our track team renewed the formation protection layer and replaced the ballasts, which were accordingly compressed. For further work steps, SPITZKE’s team mounted the sleepers into the first rails, which were placed in the correct position and then measured. While measuring, the W179 and W171 points were repeatedly aligned. Finally, the ESTW S1 North team installed all the small components and connections for the conductor rail.

New points, conductor rails and work at the station

Around 300 m of conductor rails were dismantled and re-installed for the installation of the points at the Lehnitz S-Bahn station. In addition, our traction current experts laid 500 m of new contact line cable, installed the switch cabling and connected the existing return line system. The conductor rail system was successfully accepted on July 5th.

The cable civil engineers from the Equipment/​Electrical Engineering Department laid 29 track crossing with KSE bricks (cable protection elements) with two to twelve pipes using the cut-and-cover method, including cable installation shaft sizes V to VII and as well as mini shafts. They also laid around 950 m of cable support sized I to IIIA.

The major projects/​engineering construction team was also required: In addition to explosive ordnance detection and site installation, they performed demolition work and dismantled part of the staircase and roof at Lehnitz station. They also undertook core drilling and improved the subsoil using the HDI (high-pressure injection) jet grouting method. Additional services at Lehnitz station included ground work for the foundation levels and special civil engineering for the pile-driving foundation. At the forest cemetery in Birkenwerder, they installed a cable support bridge on which they carried out a pile-driving foundation. Finally, the brackets including integrated cable duct were dismantled at the Andre´-Pican street bridge.

Update #3 – Closures on the S1 are pending

 June 3rd, 2022 // The major ESTW S1 North project has really gotten underway – nearly all of the experts and trades involved from SPITZKE’s side have started their work. A major closure period on the urban railroad line will start on June 9th, 2022. The main focus of the construction will be the installation of several points/​switches in the area around the Lehnitz station.

In preparation for the closure, the track was dismantled and the old ballasts removed. SPITZKE’s ESTW S1 North team has planned and prepared everything. The closure is scheduled from June 9th to July 7th. We will report what our track, current, cable civil engineering and LST experts are doing as well as our large projects/​engineering division.

Update #2 – The cable civil engineering work begins

March 30th, 2022 // At the end of February, our cable-civil engineers took advantage of the short closures to construct track crossings, cable ducts and various troughs. The installation of track crossings and cable ducts on all lines is a prerequisite for the subsequent laying of the new SSI cables as well as cables for point heaters, 50 Hz lighting and telecommunications. Without these cable ducts, neither signals nor track lights, point heating or announcements on the platforms will work properly.

The first track closures on the adjacent lines 6091 and 6089 were carried out. An open-design track crossing was constructed with cable protection element stones and two cable troughs (size VII) on line 6089. A concrete cable trough, including diversion constructions at the draining shafts, (size I, internal support mortice) was constructed as well. Temporary plastic cable troughs were laid on both sections, cables were moved to them, and the existing elevated GRP cable troughs were dismantled.

During a short shut down of section 6091, SPITZKE’s cable civil engineers transported the material needed for laying cable troughs (size IV, internal support mortice), which will be laid in the next steps along the section safely using fixed barriers and mini-excavators. Furthermore, they carried out countless search shafts as a result of the building permission measures and the execution planning.

Update #1 – Project start and the first closures

February 20th, 2022 // SPITZKE’s major project in Berlin and Brandenburg, the “solid-state interlocking S1 North” has begun. Planning has been in full swing ever since. The first closures were scheduled not even three months after the commissioning by DB AG. The time challenge was successfully mastered. On February 12th and 13th, SPITZKE carried out the vegetation work, explosive ordnance detection and subsoil investigation.

In the meantime, the planning was moving along smoothly for summitting the plan packets in the other departments, such as major projects/​engineering, track, telecommunications, control and safety technology. In addition to the construction work, SPITZKE is also responsible for preparing the detailed design.

Currently, a few details are being clarified: working together with people responsible at DB AG, our planners and project managers are reviewing the specifications from the construction description and site plans and comparing them to the conditions on site. For instance, the necessary construction clearances are being determined which are essential for our execution planning.

Our cable civil engineers will get involved in the construction work for the next step. You can read all about it in the next ticker.

Welcome to the capital

In November 2021, SPITZKE was awarded the contract for the Solid-state interlocking S1 North. DB AG’s extensive construction project stretches from Frohnau station (Berlin) to Oranienburg station (Brandenburg). Within this major project, the railroad infrastructure company SPITZKE is implanting everything required for the subsequent commissioning of the new Solid-state interlocking S1 North. All services from civil engineering to the tracks, foundations and the overhead lines are being carried out by SPITZKE as the single provider.

We’ll report regularly on the work on the CBI S1 North project and include you on our journey during the construction project in Berlin-Brandenburg. Take a look behind the scenes of this major project!

We hope you enjoy learning about it and thank you for your interest.

You can get an overview of all projects here.