Tax-payer's money saved, while rail users’ nerves are soothed

Exemplary German Technology from the Kinzig Valley

Hardly anyone takes any notice: A small railway bridge over a side street in the middle of the town of Steinach (Baden, Germany), in the picturesque Kinzig Valley. There are a lot more interesting things to look at - for example the beautiful landscape, which draws untold numbers of visitors year after year. 

But this is where the main Black Forest railway line passes several times a day on its way between Offenburg in the Rhine Valley, and Lake Constance to the south.

The bridge had been in serious need of repair after decades of heavy use by IRE trains. Traffic problems of dramatic proportions were expected. A very special construction process is now set to not only save a few million euro in taxes, but also relieve stress for thousands of railway commuters.

Steinach (Baden, Germany):

Right now, it is nothing more than an ordinary building site: construction work is carried out on seemingly insignificant 12 - 13 meters only. But never underestimate the importance of critical points within a network such as this one.

Die Vössing Bau GmbH (Bochum) was commissioned by Deutsche Bahn Netz AG (Karlsruhe), to build a railway bridge, after they had submitted a concept, which stood out from all the other tenders. The original plan had been to construct two auxiliary bridges with traditional temporary support girders, to then demolish the old bridge and build a new one, while rail traffic would have to be temporarily limited to a single track with long delays. As a result of these delays, supplementary services would have to be organised for the duration of construction.

Vössing Bau on the other hand, came up with an ingenious concept, in which the foundations for the new bridge would be constructed alongside the old; a robust bridge frame would then be constructed atop these new columns. Until that phase, railway service would continue unimpeded, and in one concerted effort, the old bridge would now be demolished, and the new one moved into position in its stead.

DB Netz AG showed much enthusiasm for this plan: Not only could hundreds of thousands of euro be saved in construction costs alone, supplementary rail services could be kept to a minimum, and encumbrances in regards to the local population, as well as regional and national rail commuters would be almost eliminated. And as an extra benefit, there would be no additional traffic jams or hazardous situations on the A33 motorway due to rail commuters using their cars instead.

That was the plan. What actually happened?

Shell Construction

Preliminary work began in March of 2009. It was exactly at that bridge, that all supply lines for an entire district of the town converged - not an insurmountable problem in terms of the construction work, but nevertheless an important factor to consider: The town’s utility lines (electricity, water, waste water) and telecommunication cables had to be protected as well as the high pressure gas lines, which cross the Kinzig Valley at that location.

Shell construction work commenced on July 20, 2009. In addition to the railway embankment, access roads, and housing developments, construction managers also had to deal with the close proximity of large boulders, from the local Kreuzbühl Mountain at Steinach, which made the use of large equipment impossible. In order to guarantee sufficient load-bearing capacity for the foundations, a complete soil replacement right down to the bedrock had to be carried out.

The concrete for the foundations was poured on August 19th. Uhl Kies- und Betongesellschaft (Hausach) delivered a total of 72 cubic meters of C 30/37 concrete with 9 cement mixer trucks, which had a capacity of 8 cubic meters of concrete (19 tons) each for civil engineering. The trucks were quickly filled with a concrete pump equipped with a tall mast. Alois Faist is very proud of his M42 Putzmeister pump, mounted on a MAN chassis: “Its 42 meters maximum extension make it the tallest in the Kinzig Valley area”, he smiles. There is nothing comparable in the region between Freiburg, Lake Constance, Ulm, Heidelberg, and Karlsruhe.

The Putzmeister concrete pump swallows 9 full loads of fresh cement for the foundations alone, which are transported on-site by large mixer trucks from Hausach. The 42m high arm spreads the heavy, muddy-grey mass exactly where it needs to go.

7 tons of reinforced steel were integrated into the foundation.

Vössing’s foreman Werner Zickler and DB Projektbau project head, Dipl.-Ing. Fadil Gündüz, are extremely satisfied with the construction progress so far.

Currently, the concrete for the foundations is hardening. Preparations for erecting the bridge perimeters have already begun, and the formwork elements are ready for deployment at the construction site.

Formwork

For the foundations, Logo.3 system formwork by PASCHAL was used. Wherever possible, single-sided 2.70 x 0.90m high midi-elements were used in horizontal position to save installation time. The foundations were not rectangular, therefore angled outside corners were used, with which practically any angle can be defined.

The polygonal foundations are produced with LOGO.3 formwork, provided by the international formwork specialist PASCHAL, who is headquartered in Steinach.

Logo.3 is manufactured in Steinach, the home of PASCHAL, a stone’s throw away from the construction site. Due to the strong, profiled flat steel frame, Logo.3 is torsion-resistant, and can withstand an amazing 70kN/m² of concrete pressure – that comes to about 7 tons per square meter!

Logo is PASCHAL’s top-selling product, and is one of the most sophisticated formwork solutions in the industry today. Its worldwide unique selling proposition includes frame-integrated RFID transponders, which provide wireless differentiation and identification via an electronic reader; the PC in the administration building displays all relevant data of a formwork element as soon as the data is read, which facilitates exact management and inventory of all elements at the construction site via a state of the art software package. This technology, which has only been developed as recently as 2008, and for which PASCHAL also holds a market leading position, is called PASCHAL Ident. Programming and production of this software was carried out by Planitec, another company with its roots in Steinach.

Excitement on October 30

Everything is going according to plan at the construction site, despite the cramped working conditions. All future planning steps however, have to be carried out like clockwork, and have been coordinated with rail schedules. On Friday, October 30, 2009, at 10pm at night on the dot, a large team of specialists will be standing by to begin a concerted effort to simultaneously carry out various tasks with no margin for error or delays.

All railway services for the line will be suspended. The tracks and underlying gravel will be removed. The old bridge will be completely demolished, all work will be carried out in accordance with safety regulations, and all material will be removed immediately. The new frame, weighing almost 2,500 tons, is standing ready for installation right next to the old bridge. Powerful hydraulic rams are standing by to slowly push the new construction into the prepared space. Now, the embankment, which was torn away earlier, will have to be rebuilt. Then new gravel will be spread, affixed, and covered by new tracks, which will be swiftly welded up to the existing rails on either side of the bridge.

The entire operation must be carried out in just 54 hours. On Monday morning, November 2, 2009 at 5am, two hours before sunrise and at a time when all is still cloaked in darkness, and only the construction site itself will be brightly lit, time will run out. Any delay would mean a hefty penalty for the contractor. And the trains will be waiting.

Background

System formworks have only been developed in the past few decades. One of its inventors was Josef Maier (†2004), founder of PASCHAL, who introduced the very first system formwork to the market in 1964.

PASCHAL employs about 200 staff locally, has 4 branch offices throughout Germany, as well as various partnerships internationally, and trade partners in over 40 countries around the globe. PASCHAL counts among the top 10 formwork manufacturers worldwide, and looks after around 10,000 projects a year.

Uhl Kies- und Baustoffgesellschaft is headquartered in Hausach (Baden, Germany), and will be celebrating 50 years in business this year. The family-owned and operated business employs 140 members of staff, and operates 8 concrete plants and 4 gravel pits.