Technical aspects and innovation

The Bridge’s basic structure is made up of four iron towers each 61 metres high, raised in pairs on both sides of Bilbao’s river and which constitute the Bridge’s pillars, linked between them by a 160 metre long crossbeam situated 45 metres above the high tide level.

Fully assembled with iron pieces,

which were rolled in the workshop and joined together with red-hot rivets, as welding techniques were not well-developed at the time of the bridge’s construction. To secure the structure, the Bridge uses 8 steel suspension cables (4 on each side) anchored in foundation blocks located at both ends of the Bridge (in Portugalete and Getxo), approximately 110 meters away from the towers. In addition, the structure’s towers are braced in the perpendicular direction to the crossbeam by steel cables anchored in the piers that run parallel to the river, about 60 meters away.

The upper horizontal crossbeam, from which the gondola hangs, "gravitates" between the towers.

It’s suspended by 70 steel cables called hangers. In fact, the structure is not welded or riveted to the towers or pillars, but only supported by these hangers, which bear a significant portion of the weight, and supported by the corbels, a kind of capitals attached to the towers that help to evenly distribute the weight of the deck. Hence the nickname “hanging”, as the crossbeam truly hangs from the towers, although many associate it with the suspension of the gondola.

The current carriage was built in 1999 and is equipped with twelve electric motors.

In its origins, a cable and pulley traction system was used, powered by a steam boiler located in one of the two towers of the Bridge. The current gondola is the fifth in the history of the Bridge. Vehicle and passenger transportation takes place inside it, hanging from a 36-wheel, 25-meter-long carriage that moves along the tracks of the upper horizontal beam. The control station is located on the ground floor of one of the towers in Portugalete, for better visibility.

The transfer frequency is eight minutes.

The current travel duration between the two banks of the river is one minute and a half.

The gondola has a capacity for 6 vehicles (passenger cars) and 200 passengers (100 in each cabin), and can be supplemented with 6 motorcycles or bicycles.
Two panoramic elevators have been installed to access the walkways for tourist visits, one on each side of the Bridge, accessible through the terraces.
The Puente Bizkaia was the first transporter bridge built in the world, but its technological uniqueness does not only lie in the development and operation of a transfer mechanism (gondola, carriage, and rail), but also in its spectacular iron structure and the use of steel cables to secure that structure.

INNOVATION IN THE BRIDGE

The company which took over the concession in 1995 was clear right from the beginning that significant changes had to be introduced in the operation of the concession to enable it to continue providing the service and continue conserving the monument.

At the beginning the innovation was orientated towards the technology:

The existing gondola was substituted for another more in line with the technological progress.
Innovative boarding halls were constructed with automatic systems.
The payment systems were unified, eliminating the personal ticket offices and installing self-payment systems.
The entire installation is automated via the control room.

Oriented towards the market, opening new business lines and boosting the

  • Panoramic terraces were installed above the boarding halls.
  • Souvenir and convenience stores were opened.
  • Panoramic lifts were placed in the pillars of the towers in order to access the pedestrian footbridge.
  • Complementary activities were developed consisting of third parties commercially using spaces for advertising and technical purposes.

Chronology of the Construction

and the subsequent modifications to the Vizcaya Bridge

1887

Preparation of the draft project for a suspension bridge with a mobile vehicle adapted to large estuaries, in secret conversations between Alberto Palacio and Ferdinand Arnodin.

1887

November 5.
Simultaneous presentation of the invention patent application by Alberto Palacio, in Bilbao, and Ferdinand Arnodin, in París.

1888

February 20.
Presentation of the Vizcaya Bridge construction project.

1890

February 12.
Concession of the licence to build the bridge between Portugalete and Getxo, after overcoming the technical reluctance of the engineers from the Ministry for Promotion’s Public Works Department.

1890

 April 7.
Constitution of the company “Martín Alberto Palacio y Compañía” with the aim of constructing and operating the Bridge.

may
1890
july
1893

Construction of the Vizcaya Bridge, with Alberto Palacio as works director, Ferninand Arnodin as constructor and with the technical assistance of the engineer A. Brull.

The pillars are made of profiles forged in Le Creusot. The replaceable cables are of mild steel from the Firminy wireworks. The wiring by the workshops of Ferdinand Arnodin in Chateauneuf-sur-Loire. The deck is made up of a beam with Saint Andrew crosses made of mild steel by the Altos Hornos de Vizcaya blast furnace rolling mill, Assembled at the Zorroza workshops in Bilbao. The suspension of the beam is mixed, using vertical suspension cables and inclined shrouds. The energy supplied by a two cylinder vertical steam boiler with water pump, produced by Henri David in Orleans, moves the cables which pull the gondola. The motor system is placed in a large hut placed between the two towers on the Getxo side.

The original conception by Alberto Palacio to obtain the movement was a cart moved by compressed air (Mekarsky system).

1894

The company is concerned about the complication of a steam boiler situated high up and the services for its operation.

1901

An electric motor is installed to replace the boiler in the same place. The lift which was not able to be installed before due to the lack of electric supply is installed in Tower 2. The stairs are passed to Tower 1.

1937

June 16.
Members of the Military Engineers Corps made controlled explosions of the parabolic bases of the Vizcaya Bridge on the Getxo side to make it temporarily useless for the enemy forces, and not to destroy it completely.

1939
1941

Reconstruction of the Vizcaya Bridge, with the project by the engineer José Juan Aracil, works management by Luis Alberto Ribed and construction by the company Sociedad Ibérica de Montajes. The parabolic cables, the deck, the suspension system, the cart, the gondola and the anchoring block on the Getxo side were all replaced. The only two significant modifications from its original design related to the beam and the suspension system.

The mixed suspension by suspension cables and shrouds characterised the empirist period of the first generation of suspension bridges, in which the function of the shrouds was analogical to that of the braces of the beam bridges. But the coexistence between both elements created uncertainty which made it impossible to make the calculation and adjustment between both suspension systems. The frequent breakages and the difficulties in the maintenance led to their almost generalised replacement, and occurred in the construction of the Brooklyn Bridge in 1935, or in the construction of the Rouen shuttle bridge.

However the elimination of the shrouds in the Vizcaya Bridge reduced its rigidity and therefore forced an increase in the beam’s inertia, which went from having an edge of two metres in the original project to three metres in the reconstruction. The primitive Saint Andrew crosses method was also changed for a Warren bean which had the advantage of being more reduced secondary efforts.

The new beam, the cart and the gondola were made by the company Compañía Anónima Basconia, the cables by the company Sociedad Franco Española de Cables, the suspension cables and the reconstruction of the top of the towers on the Getxo side were done by the company Sociedad Ibérica de Montajes and the new anchoring blocks in the Getxo side by Erdaide and Barrenechea.

The previous machine house was taken down and the new one, slightly smaller, was placed in a large hut higher up at the end of the deck at Getxo. The replacement of the electrical motor, which had been installed in 1901, was done by the company Eguren.

Initially the movement was controlled from a lookout point situated in the middle of the gondola.

1941

June 19.
Inauguration of the restored Vizcaya Bridge.

1945

Elimination of the driving cabin in the gondola and the introduction of a cabin on the pillars on the Getxo side on the deck, attached to the machines hut next to Tower 2.

1964

April 14.
Substitution of the gondola for a new unit built with aeronautical criteria and technique in Props and using materials resistant to marine corrosion.

1991

 March15.
Installation of a lighting system for night time performances with over 900 lighting points.

1995

December.
Preparation by the future operating company of a General Report on the State of the Bridge’s Structures and Mechanisms.

1996

A non-postponable programme is prepared to remove auxiliary elements which are at risk of collapsing, making urgent reinforcements and repairs and to create auxiliary elements necessary to proceed to the following general repairs:

  • Removal of the old mobile scaffolding.
  • Repairs to the cart.
  • Balancing the tension of the gondola’s cables.
  • Replacement of the cast iron pulleys for polythene ones.
  • Trial with polythene wheels for the cart.
  • Repair of many track beams.
  • Construction of a motorised auxiliary cart (scaffolding).
  • Replacement of the stairs in the towers.
  • Restoration of the workshop, purchase of a winch and other machinery.
  • Repair of the primary and secondary structure at many points.
  • Studies in order to reduce the state of tension.
  • Restoration of the anchoring block in Portugalete.

1997

The following work was carried out:

  • Construction of a second moving scaffolding.
  • Construction of a climbing cart to repair cables.
  • Finite elements structural analysis contract.
  • Design and testing of a system to reinforce cables.
  • Design of a new type of sheet rail.
  • Reinforcement of 106 rail beams.
  • Installation of a welded continuous rail.
  • Removal of spotlights and 29,000 Kg of electrical cables and apparatus.
  • Full painting of the Bridge.
  • Reinforcement of cables at 29 points.
  • Changing the screws.

1998
1999

The following work was carried out:

  • Departments on the ground floor.
  • Ticket vending machines.
  • Construction of a scaffolding and auxiliary elements.
  • Rail.
  • New gondola.
  • Main cart
  • New boarding halls.
  • Automated system for services.
  • Pedestrian walkway.
  • Panoramic lifts.
  • Security installations.
  • Security system for the shops.
  • Lighting.
  • Vending and cancelling machines.
  • Substitution of the stairs in the tower.
  • Installation of the lifeline.

2000

The following work was carried out:

  • Repair of the top cables.
  • Partial repainting.
  • Small structural repairs.
  • Reinforcement of two cables.
  • Restoration of the deck’s lower structure.

2001

A new light lighting system is installed.

2002

Load resting criteria were corrected and trials were performed with anti-friction wheels.

2003

Some broken cords were repaired and the Creditrans application was introduced .