The History of the Zambezi Bridge from Namibia to Zambia

The History of the Zambezi Bridge from Namibia to Zambia: 1982 - 2004

Dr. Klaus Dierks

The Zambezi Bridge between Katima Mulilo in Namibia and Sesheke in Zambia at Wenela is surely one of the most remarkable engineering structures in the entire southern Africa. But, this bridge has also a historical connotation because this bridge always has been a symbol for Namibia’s independence. The structure is the corner stone and end point of the Walvis Bay to Ndola and Lubumbashi Corridor (Trans Caprivi Corridor). The numerous economic problems, which were facing Namibia before independence, were in many aspects caused by its unique traffic situation. This traffic situation was characterised by its biased transport infrastructure towards South Africa. Nakop as "Namibia's gateway to the outside world" was a first order handicap for the country. Transport activities constituted a major constraint on the development of the economy of Namibia because this one-sided transport situation made Namibia's economy highly dependent on South Africa. South Africa used this “noose or lifeline” situation to hold Namibia at ransom. The only solution was to open the country to the east and the north. The Trans-Caprivi-Corridor with a bridge over the Zambezi River at Katima Mulilo would end Namibia’s “noose situation”.

It was my objective in 1982 to change Namibia’s “noose” transport situation into a “lifeline” situation. Therefore the planning process for a Zambezi Bridge from Namibia to Zambia was started in the same year, when I was the Chief Bridge Engineer in the former Department of Transport in Namibia’s First Interim’s Government. The first planning results revealed the most favourable bridge position on the Katima Rapids of the Zambezi River, a position more or less where the bridge has now been realised. The bridge was planned for a span of approximately 1 000 m and the estimated building costs were 30 Million South African Rand (US $ 15 Million in the middle of the 1980s). However, my planning activities were very unfavourably viewed by the South Africa sponsored “Namibia Interims’ Government of National Unity” of the Eighties, and was one of the main reasons which caused my downfall in the Department of Transport in the year 1986/87. In order to legalise my dismissal, the South Africans had to amend the Public Service Act in Parliament, because such a bridge between Namibia and “Black Africa”, was regarded as high treason in those years. The Windhoek Advocate and SWAPO politician Anton Lubowski (Lubowski was murdered by right-wing South African agents during the election process of the United Nations supervised elections in September 1989) expressed after my dismissal that „one day Namibia will be free and then this bridge will be built by you“.

Before the independence of Namibia, the Zambezi Bridge project was not furthermore followed up. But, with the arrival of independence for Namibia on 21.03.1990 and in my capacity as an elected Member of Parliament and Deputy Minister of Works, Transport and Communication, the realisation of the Trans-Caprivi Highway was one of the top priorities for the Ministry of Transport, not only in regard to planning and design, but also to the financing of the project. The ultimate cornerstone of the Trans-Caprivi project was Bridge 508, the Zambezi Bridge between Namibia and Zambia (the number 508 was allocated to this bridge according to the official Namibian Bridge Register by myself in 1982). Without Bridge 508 the Walvis Bay Corridor would be incomplete. The engineering planning went thus ahead since 1990. Since 1990 I conducted negotiations with the German government for the funding of the Trans-Caprivi Highway and Bridge 508. Finally, with the progress of the planning process, it was found that that the most suitable bridge site was just a few metres within Zambia and on the basalt rocks of the Katima Rapids, just five metres from the old border beacon of 1927 between the then South West Africa and Northern Rhodesia (present-day Zambia), still visible today just at the western abutment of the bridge.

The main reason for the siting of the bridge however was of a financial nature. Namibia would not have qualified for a grant for this bridge, of which the total costs are now 100 Million Namibia Dollar (approximately ten Million US Dollar in 2002). Namibia would have qualified only for a soft loan, which would eventually be repaid by future Namibian generations. But the government of Zambia, as a “least developed country”, qualified for a grant. Therefore, I was able to convince the German government and the German “Kreditanstalt für Wiederaufbau (KfW)” to build the bridge just within Zambia. This would mean that the benefits for the Namibian economy are still the same. This deal saves the Namibian taxpayer 50 Million Namibia Dollars. At the end of 1998 the negotiating process was concluded and Consulting Engineers (Gauff Consulting Engineers and VKE Namibia) were duly appointed to do the detail design and prepare the bridge for tendering. At the beginning of 1999 when everything seemed to be on course, a new obstacle arose. The German government froze all funds for the bridge because Zambia had not honoured its old outstanding debts to Germany. I travelled in a hurry to Germany and maintained that it would not be fair to “punish” Namibia for Zambia’s sins. At the end I could convince the German Minister for Economic Co-operation and Development and the parliamentarian Committee for Development to release the funds and thus to save the project.

The contract for the Zambezi Bridge was allocated to “Concor South Africa and the German Hochtief” in 2002 and the bridge was completed within the tendered time schedule in April 2004 and within the tendered amount. All the abutments and 18 piers were completed in April 2003. The total length of the bridge is 900 metres, with 19 spans. It is built in a radius of 1 600 metres on the Katima Rapids. The bridge is designed to withstand a 100 years Zambezi flood. The two extraordinary floods of 2003 and 2004 have not affected the structural safety of the bridge. The bridge decks were built according to the ingenious German bridge-building method of “Incremental Launching (Taktschiebe-Verfahren)” according to Baur-Leonhardt, which means that the entire bridge deck was built on the western bank under factory conditions and then every segment of 31,4 metres length was pushed hydraulically over the river. Every week since February 2003 witnessed the pushing or launching of a segment, and at the end of 2003, the whole 900-metre deck structure was pushed over the two abutments and the 18 piers on a curvature of 1 600 metres radius from the Katima Mulilo bank to the Sesheke bank in Zambia. At the end, the deck structure had a total mass of 13 000 metric tonnes which had to be pushed with a hydraulic force of 750 tonnes at an average speed of 10 metres an hour. The dimensions of the bridge had only a tolerance of a few millimetres.

At the beginning of 2004, the deck had to be finally pre-stressed for the design traffic loads. Other auxiliary works like the finishing off, the handrails and other smaller work items were duly completed in March 2004. According to the German resident engineer of Gauff Consulting Engineers, Mr. Bernhardt Streit, the concrete built by Namibian and Zambian construction workers was of such a high quality “that one has to walk very far nowadays in Germany to find such high quality concrete”.

The two presidents, Dr. Sam Nujoma and Levy Mwanawasa, officially opened the Zambezi-Bridge on 13.05.2004 in Katima Mulilo.

Sunset at the Zambezi River at Katima Mulilo: February 2003
Copyright of Photos: Dr. Klaus Dierks

View from Katima Mulilo (Caprivi Cabins): View over the Zambezi River to Sesheke in Zambia: Caprivi Region: During the Rainy Season: February 2003
Copyright of Photos: Dr. Klaus Dierks

Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia is built on the Katima Rapids near the Namibia/Zambia Border Beacon (17°28'29,29" south, 24°17'50,04" east) with "S.W.A." (South West Africa) on West Side and "N.A." (Northern Rhodesia) on East Side
Copyright of Photos: Dr. Klaus Dierks

Construction of the Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: Built on Katima Rapids (The Bridge is situated in Zambia, the West-Abutment is 10 m from Boundary Beacon between Namibia and Zambia): Radius: 1 600 m: Total Length: 877, 40 m : 17 Spans @ 47,10 m each with two End Spans @ 38,35 m: Total Width of Bridge: 10,10 m; Incremental Launching of the Deck over the entire Bridge from West to East has still to take place: 18 Piers and the West-Abutment have been completed: Progress on February, 12th 2003: View from West to East: Construction Time: 24 Months as from April 2002: Costs: approx. 9 US $ Million: The Bridge is the last missing Link in the Walvis Bay Corridor from Walvis Bay to Lubumbashi in the Democratic Republic of the Congo
Copyright of Photos: Dr. Klaus Dierks

Construction of the Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: The Eastern Abutment is excavated and the Foundation Base is prepared: Progress on February, 12th 2003
Copyright of Photo: Dr. Klaus Dierks

Construction of the Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: The Piers were constructed with the Aid of a Causeway from both Sides of the River with an Opening in the Middle of the River of 100 m Width during the dry Season: The Causeway, which is in the Process to be removed, consists of a Rockfilldam and Precast Culvert Sections: The Abutments and 18 Piers were built from the Causeway with the Assistance of Cofferdams, all on Spread Footings, mostly on Hard Rock (Basalt) within the River (30 MPa Compression Strength; Max. Height: 19,90 m above foundation, 14,40 m above Low Water, 2,60 m above Highwater (High Flood with 100 Years Probability)): Progress on February, 12th 2003: View from East to West
Copyright of Photos: Dr. Klaus Dierks

Construction of the Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: Incremental Launching of the Deck over the entire Bridge from West to East from West Abutment to East Abutment: First Stage is to put the Reinforcement in to the Segment (Hollow Prestressed Beam 31,4 m long and 10,10 m wide) in the "Reinforcing Bay"; Stage 2 (Day 1) sees the Erection of the Shuttering for Ground slab and the two Webs of the Box Girder, after the assembled Reinforcing has been shifted into the "Casting Bay"; At Stage 3 (Day 2) the casting of the Ground Slab and the two Webs takes place; At Stage 4 (Day 3) the Shuttering is partly removed and the Shuttering for the Top Slab is erected; Stage 5 (Day 4) sees the Concreting of the Top Slab; Stage 6 (Day 5) is a Rest Day in order to provide for the Hardening of the Concrete; At Stage 7 (Day 6) the Prestressing for the Construction Stage of the Box Girder (3 Days Compression Strength of the Concrete: 32 MPa) takes place and at Stage 8 (Day 7, momentary on Monday) the Launching of the 31,4 m Segment to the next Position takes place.
Copyright of Photo: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: Incremental Launching of the Deck: After the finished Reinforcement has been moved from the Reinforcing Bay into the Casting Bay, the Segment (31,4 m long) is casted and prestressed and ready to be pushed into the "Casting Bay": Progress on February, 12th 2003: Seventh Stage: After Reaching of the necessary Concrete Compression Strength (32 MPa; Ultimate Compression Strength: 45 MPa) and the Prestressing, the first Segment is pushed forward by the Length of one Segment over the Bridge Substructure (Abutment and Piers): When the First Segment has reached the other End of the Bridge (East Abutment): 28 Segments @ 31,40 m each will have been pushed
Copyright of Photo: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: Incremental Launching of the Deck: Seventh Stage: The Segment (31,4 m long) which is casted and prestressed and ready to be pushed, needs for the Launching Process a "Launching Nose (Mass 60 Tons)" in order to minimise Positive and Negative Bending Moments during the Launching Process: Progress on February, 12th 2003:
Copyright of Photos: Dr. Klaus Dierks

The Reinforcing Steel in the Reinforcing Bay will be pushed into the into the Casting Bay which is to be seen in the Foreground: Progress: May 2003
Copyright of Photo: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: Incremental Launching of the Deck: Seventh Stage: The Segment No. 7 (31,4 m long) which was casted and prestressed and is today pushed over Pier No. 7 with an average Launching Speed of 10 m/hour: View from the western Abutment: The total Deck Mass is currently 5 000 t: With a Friction Value of 0,02% the Launching Force is 100 t (initially: 300t): At the End, with the total Length of the Box Girder pushed over the River into the final Position, the total Deck Mass will be 13 000 t with a Launching Force of 260 t (750 t): Progress on May, 19th 2003:
Copyright of Photo: Dr. Klaus Dierks

During the Launching Process the Prestressing Strings have to be grouted from Time to Time: Progress: May 2003
Copyright of Photos: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: View to the East: Progress on May, 19th 2003:
Copyright of Photos: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: View to the West: Progress on May, 19th 2003:
Copyright of Photos: Dr. Klaus Dierks

Construction of Zambezi River Bridge (Bridge 508) between Katima Mulilo and Sesheke in Zambia: View to the East from the Katima Mulilo Side: The Box Girder Deck will reach the Sesheke Bank in August/September 2003: After this Date the final Bridge Bearings have to be mounted and the entire Bridge has to be prestressed for the Design Traffic Loads: The Bridge will be completed on Schedule and opened to Traffic during April 2004
Copyright of Photo: Dr. Klaus Dierks

Dr. Klaus Dierks
06. May 2004

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