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4th Tube for River Elbe tunnel


1. General

Especially since the beginning of industrialization, the Elbe has been an important lifeline for Hamburg; however, it has also been an "annoying" obstacle for north-south traffic, which developed with a large-scale inland market in Germany. It was not until the end of the last century that the railroad bridges over the Süderelbe and the road bridge over the Norderelbe were built. For many years, this remained Hamburg's only efficient connection to the south. The old Elbe Tunnel at Hamburg's Landungsbrücken, opened in 1911, with its elevators at both ends of the tunnel, served only to provide a direct link to the port and industrial areas south of the Elbe. Another road connection was built in 1963 in the course of the new construction of the A1 freeway to the east of Hamburg's urban area.

However, a noticeable relief of the inner-city road network of Hamburg was not created until the western bypass BAB/A 7 was opened in 1975, the centerpiece of which is the new Elbe Tunnel with its three tubes and six lanes between Othmarschen and Waltershof. The tunnel was designed for a traffic load of 70,000 vehicles/day; at peak times, a traffic load of up to 140,000 vehicles/day was reached in the three tunnel tubes, which made an extension of the tunnel imperative.

The construction of the 4th tube Elbtunnel, which began in the fall of 1995, will significantly increase the capacity of the Elbtunnel and further improve safety for tunnel users.

Due to the difficult construction task, an international ideas competition was held in 1986 with eleven experienced construction companies. This was intended to ensure, on the one hand, that the specifications in the subsequent plan approval procedure would not have to be corrected by the subsequent invitation to tender and any resulting redesign and, on the other hand, that the latest civil engineering techniques and innovative details of the construction methods could be incorporated into the plan approval procedure. The procedure was carried out between 1988 and 1990 with more than 7,500 objections.

In the course of the proceedings at the OVG, however, numerous safety measures had to be promised in detail by the construction authority. These included, among other things, the use of a special tunnel boring machine, extensive suitability tests for the segments, the development and use of equipment for preliminary ground investigation, also from the tunnel boring machine, prior testing of ground injection measures for building undercuts to be carried out in and from a test shaft, and extensive quality and evidence preservation.

Due to a lack of financing options, project work was suspended for the time being in 1990 and was not resumed until 1992, when the construction project was included by the German government in the list of pilot projects for private pre-financing to be carried out via banks.

Under this financing model, construction was initially prefinanced through private financing, which was put out to tender along with the construction work, and then reimbursed by the client in 15 equal annual installments from the road construction budget after completion and acceptance of the construction work.

2. Structure design

2.1 Location and cross-section

The 4th tube of the Elbe Tunnel is located west of the existing tunnel, which passes under the Elbe at an angle of 45°. It is about 50 m away from it in the middle section. The S-shaped alignment connects to the A 7 freeway in the north at the Othmarschen exit in a cut and to the south to the elevated freeway there. In its final, operational state, the 4th tube will be used exclusively from north to south with a very high proportion of trucks. For this reason, the tube will have two 3.75 m wide lanes, a 2 m wide hard shoulder and two 0.50 m wide sidewalks.

The 4th tube will pass under the Elbe at a fairway depth of more than 15 m; it will be connected to the existing tunnel by three cross tunnels between 15 and 70 m long with an inside diameter of 3.50 m. The total length of the project is 4,402 meters. The length of the closed tunnel section is 3,100 m, of which 2,561 m were driven using shield tunneling.

In the northern section, the shield tunnel was followed by a 430 m long tunnel constructed using the diaphragm wall method. In parallel, the three existing tubes were extended by 160 m to the north. A new operations control center for joint traffic control of the four tubes was installed on the superstructure. The extension of the tunnel ceiling above the three tubes was carried out using the incremental launching method in order to keep traffic disruptions in the three tubes to a minimum.

In the southern section of the shield tunnel, the 4th tube was threaded into the existing elevated road ramp via an approx. 100m long cut-and-cover tunnel, an approx. 290m long trough section and an approx. 175m long widening of the existing elevated road. Above the tunnel section, another service building was erected to supply the southern section.

2.2 Geology

The geology to be dealt with during the construction of the 4th Elbe Tunnel tube is very heterogeneous (sands, gravels, clays and boulder clay), plus organic soil (silt, peat) and deposits, e.g. in boulder clay, sand lenses that may be under excess water pressure, as well as boulder fields and large boulders.

The penetration of this geology in connection with settlement-sensitive building material as well as extremely low cover heights in the area of the Elbe river bottom (minimum approx. 7 m) represents a challenge even for modern tunnel construction. It is only possible if the tunnel builder has extensive information on site about the structure and type of ground in front of the tunnel boring machine with a working face of approx. 150 m².

At the time the construction project was commissioned, no standard procedures for permanent preliminary soil investigations were available for the individual case described here. Nevertheless, some different geophysical methods are still in the development phase and methods from neighboring fields of application can be modified or transferred.

According to the construction contract, it was therefore the task of the 4th Elbe Tunnel tube consortium to apply the latest developments and the state of the art in science and technology in order to achieve the best possible preliminary investigation of the ground.

In an extensive investigation program, the suitability of available geophysical methods was therefore examined on their behalf and these were calibrated with regard to the geological insitu conditions in the area of the route.

In the context of the construction project 4th tube Elbtunnel, a procedure for the investigation of tunnel routes was thus adopted that went beyond what had been usual up to then, and it was found that the seismic methods achieved the best results under water. A corresponding technique was installed in the cutting wheel of the shield tunneling machine.

2.3 The single-shell lining in tubbings

The 4th tube of the Elbe Tunnel, which was constructed by shield tunneling, received a single-shell lining of reinforced concrete tubbings. For the total length of 2,560 m of the tunnel to be constructed by shield tunneling, 1,280 tunnel rings with a total of 11,520 lining segments were required. With an inside tunnel diameter of 12.35 m and a shield tunnel diameter of 14.25 m, the static requirements resulted in a segment thickness of 0.70 m. The 45° ring spacing selected leads to a reduction of the tunnel lining thickness by 0.5 %.

The selected 45° ring pitch results in 8+ 1 =9 segments, i.e. 6 standard segments, 2 counter segments and 1 key segment. The segments have an average width of 2.00 m and a maximum length of approx. 5.30 m and their individual masses amount to approx. 18 t. They are thus the largest segments ever produced. This makes them the largest segments ever produced.

The reinforcement of the segment consists of a grid reinforcement on all outer surfaces, connected by stirrup cages. The longitudinal joints receive full coverage of the splitting tensile forces. To cover the shear forces, the longitudinal joints are underlaid with so-called ladder mats. In total, this results in a reinforcement of approx. 130 kg of steel per m3 of concrete; the concrete quality is B 45. The entire manufacturing process of the segments is designed to specifically achieve this high concrete quality. For example, the maximum permissible deviation from the nominal dimensions of the segments to be produced in robust steel molds was only 0.6 mm in width.

2.4 The sealing elements

The ring joint is a tongue-and-groove construction with a screw-dowel connection running at 45° on one side. The longitudinal joint is smooth on both sides with a crosswise bolted connection. To transmit the pressing forces of the tunnel boring machine to the tunnel rings, hardboard panels are inserted in the contact surfaces of the ring joints. Furthermore, so-called kaubit strips are glued in place to absorb the coupling forces between the rings and the offset individual bricks. A special feature was the joint sealing. Due to the large segment thickness and possible joint movements caused by the influence of the high water pressures of over 50 m water column at the highest flood water levels and the extremely difficult soil conditions, a double sealing strip construction was chosen. Inner and outer strips, located approx. 8 cm from the edge on the upland side and approx. 10 cm from the edge on the tunnel inner side, are connected by webs so that 4 chambers are created around a segment, which make it possible to localize any leakage that may occur and to inject water in a targeted manner in the event of leakage.

The two profile strands are made of EPDM rubber, each 56 mm wide and 32 mm thick. During assembly, the strips of two adjacent segments are compressed to 60% of their thickness. This enables them to absorb even larger opening movements without leakage. The material has been tested for a service life of over 100 years.

2.5 The escape tunnels and emergency exits

The three escape tunnels between the 4th tube Elbtunnel and the west tube of the existing Elbtunnel are an essential part of the safety installations and the escape route concept. They are each located at a distance of around 1000 m from each other, or around 500 m from the tunnel portals. This division means that the 1 5 m long north escape tunnel is located close to the surface in the area of the north ramp and can be built as a reinforced concrete frame structure using the cut-and-cover method. The 70 m long central escape tunnel and the 30 m long southern escape tunnel are located at a depth of approx. 30 m to 25 m in the northern and southern bank areas of the Elbe riverbed. They each connect the shield drive section of the 4th tube with the South and Central fan structures of the existing Elbe Tunnel. Due to the great depth and the associated water pressures, these two escape tunnels will be driven from the 4th tube as pipe jacking tunnels with a hood shield as a roadheading machine.

In order to obtain a clear space of 2.50 m width and 2.50 m height for the escape route, reinforced concrete jacking pipes with an inside diameter of 3.50 m and a statically required outside diameter of 4.40 m are used. All three escape tunnels are separated from the travel spaces of the adjacent tunnel tubes by fire doors. Thanks to their own ventilation, the escape tunnels are always supplied with fresh air from outside and a small excess air pressure is generated, which prevents these escape routes from being filled with smoke in the event of a fire.

2.6 The ramp structures

Due to the geometric constraints in the gradient of the 4th tube Elbtunnel, there are areas at the northern and southern ends where the cover above the tunnel tube is too low for shield driving. In these two areas, the so-called north ramp and south ramp, the tunnel will be built up to the portals using the cut-and-cover method. Here, the 4th tube of the Elbtunnel will also be structurally merged with the existing three tubes of the Elbtunnel, so that the tunnel user will have the impression of a uniform tunnel structure for all four tubes.

A grid section is located in front of the north portal of the existing Elbe Tunnel. This is an open ramp in a cut in the terrain, bounded by angled retaining walls on the east and west sides, as well as guide walls between the individual tubes. Above the guide walls is a grid ceiling, which is intended to make it easier for drivers to adapt to the change in brightness between the 4th tube of the Elbe Tunnel Hamburg daylight and the artificial tunnel lighting. According to today's technology, however, this adaptation no longer requires any structural precautions; instead, it is achieved by means of specially switched lighting, known as adaptation lighting, in the portal area of the tunnel. The resulting elimination of the grid ceiling in front of the former north portal makes it possible to convert the area of the former ramp with its walls into a tunnel by covering it.

3. Tunnel safety and tunnel operation

In addition to the three escape tunnels into the adjacent west tube described in Section 2.1, a high level of safety in the Elbe Tunnel is basically ensured by the fact that the four tubes are monitored around the clock by video from the tunnel operations center. In the event of an emergency, people in the tunnel can be informed and guided by loudspeaker announcements and, if necessary, also addressed via their car radios.

3.1 Ventilation

The 4th tube will be equipped with a state-of-the-art ventilation system. Since the new tube will only be used for directional traffic, pure longitudinal ventilation by means of 68 jet fans arranged in groups in the south and north of the tunnel will suffice as operational ventilation here. As a special feature, ventilation throughout the Elbe Tunnel will in future be controlled not only as a function of measurements of CO and visual haze concentrations, but also by continuous monitoring of NO^ levels on all four sides of the tunnel portals.

In the event of a fire, a separate smoke extraction duct is located in the tunnel roof. Here, the system of punctual smoke extraction is implemented. In the event of a fire, smoke extraction flaps are opened automatically by line detectors or manually from the operations control center; four flaps each form an extraction slot across the width of the tunnel. The distance from one row of dampers to the next is 60 meters. In principle, at least two rows of dampers are opened, namely the row of dampers directly assigned to the fire location and the row of dampers following in the direction of travel. In normal operation, however, all dampers are closed.

Axial fans at both ends of the tunnel, arranged in exhaust stacks, create a negative pressure in the smoke extraction duct and convey the fire gases to the ends of the tunnel.

The ceiling duct structure consists of a stainless steel ceiling clad with fire protection panels attached to the segment lining. Together with the fire protection cladding of the segment lining, this forms a highly temperature-resistant smoke extraction duct. Despite design-related air leakage, the extraction system can still deliver around 240 m3/s directly in the area of the fire event - even in the case of so-called "cold fires" with large smoke development - depending on the location of the fire event.

3.2 Tunnel operations center

The organizational center and thus the heart of safety at the Elbe Tunnel is the Tunnel Operations Center. It is manned around the clock. On the one hand, a police officer performs all the tasks required for monitoring and controlling traffic, and on the other hand, a tunnel operations technician performs all operational tasks. These personnel are reinforced by the permanent presence of the fire department, which can initiate and coordinate rescue measures from its own workstation at the control console.

The most important aid here is the uninterrupted television monitoring by means of cameras in the tunnel and in the tunnel switch sections, the images of which are transmitted to a monitor wall. These monitors are integrated into a mosaic wall on which the functions of all traffic equipment are also displayed and malfunctions or failures are immediately indicated. The operations center is thus the heart and control center of the entire Elbe Tunnel and an indispensable safety element.

In addition to the monitoring and control functions mentioned above, the fire department keeps emergency vehicles with corresponding crews on standby at both ends of the tunnel. This constant readiness has so far ensured that, in the event of stranded persons, accidents and, in particular, fires, trained personnel with appropriate equipment are on site within a short time and can take appropriate action. In the event of a fire, it means that initial extinguishing measures are taken immediately, if possible to prevent large fires from developing.

3.3 Traffic control

Traffic control in the Elbe Tunnel was already of particular importance when the first 3 tubes were planned. Two reasons were decisive for this:

  • The A 7 motorway has two three-lane carriageways, whereas the tunnel has three tubes, each with two lanes.
  • When one tube is closed, directional traffic must be carried out in the remaining two tubes.

As a result, today, when three tubes are open, traffic in the center tube is two-way. When one outer tube is closed, on the other hand, the center tube is used by directional traffic, either from north to south or from south to north. Therefore, 4 main operating conditions (MOS) are distinguished today for traffic handling.

This traffic handling requires a special roadway geometry on the approaches. It must allow traffic to enter/exit either 3 lanes in front of/behind the tunnel or 2 lanes, then either in the outer or middle tube. These conditions required the construction of so-called switch sections, where the 3-lane directional carriageway is first widened to four lanes, then with two lanes each into the outer and middle tubes.

Traffic handling will improve considerably after completion of the overall construction measure. The following three reasons speak for this:

  • With eight lanes, the traffic capacity of the tunnel is adapted to the capacity of the 6-lane freeway.
  • Congestion in the tunnel area will occur less frequently.
  • As a rule, the tunnel will only be used by directional traffic.
  • Structural measures will ease the height control; full closures of one direction of travel, as in the past, will then be the exception.

4. construction execution

For the international invitation to tender carried out in 1993 for the execution of the major construction project in four construction lots, a performance specification with a performance program - a so-called functional performance specification - was selected in order to be able to use the know-how of the bidders for an economical execution design of the complex construction task. The invitation to tender was issued in a restricted procedure following a public invitation to tender in order to restrict the group to competent bidders. Four bidding consortia with companies from five countries participated in the tender. On October 13, 1995, the main contract was awarded to the "Arbeitsgemeinschaft 4. Röhre Elbtunnel" (Elbe Tunnel 4th Tube Consortium), which was made up of seven major German construction companies and which, as a total contractor (TU), had to subcontract the ramp structures (lots 1 and 3) and also the operating technology (lot 4) to subcontractors consisting of medium-sized companies.

The client took out a client-controlled combined liability and construction performance insurance policy for the construction project, covering all parties involved in the construction, i.e. the total contractor, all subcontractors and the client, in this case the Federal Republic of Germany and its contracting authority, the Ministry of Construction and Transport of the Free and Hanseatic City of Hamburg with all its employees and the engineering offices and special experts commissioned by it, including the client risk. The advantage of including the builder's risk in the overall insurance concept is that the builder's liability risk, which is independent of fault, is also insured.

This meant that, in the event of a claim, there was no longer any dispute between the client and the contractor over who was responsible for the damage. This in turn led to a speedy settlement of claims, which was ultimately also important in order to maintain the "goodwill" of the citizen toward the construction project.

4.1 Shield machine

With an outer diameter of 14.20 m, the largest shield ever used worldwide for driving in unconsolidated rock had been built for the shield driving section.

The tunnel boring machine was operated as a hydroshield with a fluid-assisted face. The cutting wheel consisted of five main arms and five secondary arms and was equipped with 111 peeling blades and 31 disc bits. The mining tools could be changed under atmospheric pressure via the accessible main arms. The stone crusher located behind the cutting wheel was capable of crushing boulders up to 1.20 m in diameter into sizes suitable for mining. The entire jacking machine, including the trailing wheel, was 60 m long. Its total weight was 2,600 tons. Of this, 2,000 tons were accounted for by the 12m long shield alone.

4.2 The shield tunneling

The construction work began with the construction of the start shaft using the diaphragm wall method (20 m x 40 m in plan, 20 m deep, diaphragm wall length 38 m). In addition, extensive ground improvement measures had to be carried out in the area of the south bank and the Elbe. In order to achieve the medium-density bedding of the soils required for the structural verification of the stability of the face and thus to ensure the safety of shield travel at the partly very low overburdens, the loosely bedded sands present here had to be compacted to a depth of 12 m using the vibro-pressure method. In the Elbe area, a total of 46,000 t of metal slag with a grain size of 16/32 mm was additionally vibrated over a width of 25 m. The entire Elbe river bottom area was compacted using the vibro-pressure method. In addition, the entire Elbe bottom area was covered with a 1.50 m thick layer of 0-250 mm copper slag stones (80,000 t) to protect against scouring and loosening.

The shield tunnel boring machine, manufactured in Schwanau, Swabia, was installed in the start shaft from June 1997; driving began in October 1997.

After 440 m, as scheduled, the tunnel boring machine was "generally overhauled" in a "station" - a concrete block made of overcut bored piles - with the bentonite level completely lowered under compressed air (approx. 2 bar), and the excavation tools were changed altogether.

In the current area, as was to be expected on the basis of the subsoil outcrops, things did not proceed so "smoothly". The typical Hamburg subsoil conditions, with the soil formations changing again and again over the shortest distance, placed the highest demands on the tunnelling. In cohesive soils, the advance rate dropped to as little as 5 mm per revolution and minute (in sandy soils up to 30 mm).

However, the main problem during driving was the extreme wear of the excavation tools, which had not been taken into account to this extent; they were subjected to extraordinary stresses, especially when driving through the boulder clay. The outer tools in particular were affected, covering a distance of approx. 45 m per revolution; at an advance speed of 5 mm per revolution, this results in a distance of approx. 9 km for one meter of tunnel advance. Individual discs "survived" only 25 m of advance.

The change could not be limited to the tools to be removed from the main spokes under atmospheric conditions. Thus, it became necessary to enter the face in the current area at points where ground conditions permitted, in order to also renew the tools on the side arms, on the center cutter and in the caliber area, as well as to carry out necessary repair work on the cutter wheel, in some cases under pressures of up to 4.0 bar.

In April 1998, parallel to the driving, work also began on securing the houses to be driven under to the north of the Elbe.

The injections were made from two central shaft structures, from which injection lances were bored in 2-3 levels at a depth of approx. 8-10 m in a fan-shaped arrangement under the buildings.

This arrangement allowed uniform consolidation and prestressing of the earth structure by injecting the uppermost level, which could then be selectively lifted by injecting the lower levels if settlement occurred during driving underneath.

The accuracy in this compensation injection process was in the range of a few millimeters.

The tunnel boring machine reached the target shaft approx. 60 m north of Bernadottestraße in February 2000.

After that, the south and center escape tunnels were driven under compressed air in pipe jacking from the 4th tube and connected to the west tube of the existing tunnel in the contactor of an injection block.

4.3 The segment production

A period of 22 months was available for the production of the total number of segments, starting in August 1 997. Tunneling assumed an average advance rate of 6 m/day, with a possible increase to 9.0 m/day. The production capacity was adjusted to these specifications. Production and storage of the segments took place on the Hansaport site, where a production area of approx. 20,000 m2 , 9,000 m2 of which were covered, was leased. From here, the finished segments were loaded onto rail cars and transported directly to the shaft via the existing rail siding.

The segment production process essentially follows the individual steps described below:

The blanks were produced in a circulation system with one working line and three return lines, equipped with four mold sets equal to 36 individual molds. With an occupancy of one cycle per 24 h, up to 36 elements could be produced per day. Concreting and vibration of the individual segments took place centrally in a noise-enclosed concreting chamber. After concreting and surface treatment, the concrete began to harden. The resulting hydration heat and its distribution in the concrete body had to be controlled throughout the curing period in such a way that, on the one hand, a temperature of 60° C was not exceeded in the core cross-section and, on the other hand, the temperature difference of neighboring cross-section parts remained below 20° C. The temperature of the core cross-section was controlled in such a way that the temperature difference of the neighboring cross-section parts remained below 20° C. In order to maintain these limits in a controlled manner at all stages of production, the segments were carefully post-treated using the so-called heat recovery process. In this way, the natural heat generation from hydration could be utilized and no further external energy had to be introduced into the element.

After stripping the segment, the still warm element was immediately wrapped again in insulation and stored in the temporary storage area in the hall. Once it had adjusted to the ambient temperature, it could be transferred to the outdoor storage area on the 5th or 6th day at the earliest. In order to be able to follow the uneven progress of tunneling, the outdoor storage facility had a capacity of up to four production months.

The segments had to be fully equipped in the manufacturing plant so that they could be transported directly into the tunnel after delivery to the construction site. For this equipment, another area of the hall was set up in which the sealing frames including the transverse webs were glued into the grooves provided for this purpose in the segments and the pressure distribution plates and the kaubit strips were applied to the joint surfaces.

Due to the extraordinary demands on the quality of the segments, the entire manufacturing and logistics process was carried out according to a quality assurance plan drawn up for this purpose. In this plan, the life cycle of each individual segment was tracked and documented in the individual steps, including all information on the concrete and reinforcement.

4.4 The qualification tests

In connection with the production of segments, it became necessary to carry out suitability tests on the segments prior to production. Their purpose was to optimize the formation of the segment joints in terms of load-bearing capacity and coupling properties and to prove the suitability of the selected joint formation and sealing profiles. For this purpose, shear and spalling tests have already been carried out. Torsional stiffness and load transfer tests as well as tests on the selection of a suitable seal have already been carried out. In addition, a large-scale test on a 1:1 scale was carried out in the fall of 1997.

4.5 The ramp structures

Due to the importance of the freeway for Hamburg and trans-regional through traffic, traffic restrictions during the construction period of the overlay could only be minimal. A construction method therefore had to be found for building the overlay on the north ramp for which no scheduled traffic interruptions would be required. To this end, the slab over the freeway was constructed in sections on a stationary shoring system at the mouth of the tunnel, and the tunnel tubes were continuously extended in the incremental launching method without interfering with flowing traffic. For the as-built condition, the highway deck was designed as a slack-reinforced beam deck with a closed underside.

After completion of the shifting operation, the slab for the final state was given a top chord slab as the base of the mezzanine floor, on which further construction was then to be carried out using conventional frame skeleton structures.

The shifted floor became part of the main superstructure of the superstructure, which was calculated as a two-story sliding frame with horizontal and vertical bedding.

The new operations center, from which the control and monitoring of all four tubes of the Elbe Tunnel is carried out, was built on this superstructure.

In October 1997, work began on the south ramp.

Following the approach shaft of the shield drive, the tunnel tube in this construction lot was built in rectangular cross-section between diaphragm walls using the cut-and-cover method in waterproof concrete. The excavation pit was sealed against the groundwater by an underwater concrete base or a lower soft gel base and an upper HDI base, which also serve as bracing for the excavation pit. The bases, like the tunnel structure itself, are founded on grouted piles.

The walls of the trough structure, made of waterproof concrete, were constructed using the diaphragm wall method, and the base of the structure was also founded on grouted piles. In addition, an underwater concrete base had to be installed in a section of the trough structure.

In another section, the trough structure could be constructed in an embanked excavation pit, founded on driven in-situ concrete piles.

The south operations building was erected in the immediate vicinity of the southern exit portal. This building integrates the southern ventilator station of the smoke extraction system, serves to house all operational equipment for supplying the southern half of the 4th tube, and accommodates a fire department standby station for the Elbe Tunnel with social rooms and a vehicle hall.

4.6 Interior work

Following the construction of the inner shell, the interior work was carried out with the construction of the baffle walls for the operational equipment and the carriageway superstructure. The 4th tube of the Elbe Tunnel was commissioned at the end of 2002.



  • Country: Germany
  • Region: Hamburg
  • Tunnel utilization: Traffic
  • Type of utilization: Road tunnel
  • Client: Bundesrepublik Deutschland
  • Consulting Engineer: Freie und Hansestadt Hamburg, Baubehörde
  • Contractor: Dyckerhoff & Widmann AG, Philipp Holzmann AG, Bilfinger + Berger Bau AG, Wayss & Freytag AG, Hochtief AG, Ed. Züblin AG, E. Heitkamp GmbH
  • Main construction method: Trenchless
  • Type of excavation: Shield machine (SM)
  • Lining: Reinforced concrete segments
  • No. of tubes: 1
  • Tunnel total length: 3,100 m, including 2,561 m driven by shield
  • Cross-section: outer diameter 14.14 m; inner diameter 12.25 m
  • Contract Volume: approx. 800 mill. DM
  • Construction start/end: 1995 till 2002
  • Opening: 2002