Blog 2
Albert Bridge

Albert Bridge

  1. Structure Information

The Albert Bridge, shown in figure 1,  is located in central London where connects Chelsea and Battersea over the Thames River. It was completed in 1873 but had to undergo repair in 1884 and 1973. The Albert bridge was desperately needed at the time because the existing Battersea Bridge was decaying and the Victoria Bridge that was just up the river was getting too congested. To ease up traffic, Queen Victoria’s husband, Prince albert suggested to build a toll bridge. Rowland Mason Ordish was hired as the architectural engineer for this project as he had an extensive background with other large projects like Crystal Palace and St. Pancras railway station.

Figure 1

  1. Historical Significance

This bridge was so innovative at the time that Ordish patented his design. This bridge was a combination of a suspension bridge and a cable stayed bridge. This actually was not the first time that this design was used. Before Ordish built the Albert Bridge, he built and designed the same bridge in Prague and in his eye, it was a success. So he kept his design and used it for the Albert bridge. This bridge turned out to be and engineering failure. Like what we learned in class today and at the mellinnium bridge the frequency from people crossing the bridge caused it sway so much that load restrictions had to o be set.  There is still a sign before at each end of the bridge that tells troops to break step while crossing the bridge. Walking at different paces helped reduce the movement of the bridge. This bridge did go under reconstruction just a short 9 years later but I will go into more detail about that in the next section.

  1. Cultural Significance

Even though this bridge was needed at the time it caused a lot of trouble for the people in the area.  The owners of the existing bridge, Battersea bridge, did not want the Albert bridge to be built because they thought they were going to start losing money as less people would need to use it. But in 1864 Parliament passed an Act that made the Albert Bridge Company compensate the owners of the Battersea Bridge annually during construction and agreeing to buy the previous bridge once the new one was complete. In order to get enough money to do this Prince Albert came up with the idea to make the new Bridge a toll bridge. Even though this was a viable solution it just never worked, mainly because the engineering failed. Since the bridge was so unstable load restrictions were enforced which limited the amount of people to cross it. With a limited number of users, the bridge was not profitable since most of the money was going towards payment for the older bridge.  Just 6 years after the bridge was completed the Metropolitan Board of Works Purchased the bridge and immediately got rid of the tolls.[1]

Nine years later the Chief Engineer for the Board of Metropolitan Board of Works inspected the bridge and found that the steel cables were already showing signs of wear. He decided to replace the wood deck and replace the steel cables with steel links… little did he know that this design wasn’t any better. This bridge was still causing so much structural issues that there was a plan to demolish the bridge. Fortunately for the bridge, World War I and II caused the demolition of the bridge to be delayed. Once the wars ended there was a campaign to keep the bridge because all of the local people really thought it was one of the beauties of the London river. In 1971-1973 the bridge went the major structural rework. Two addition piers connected by a steel beam that ran through the middle of the deck was added along with all new decking. [2]

Today the bridge is still in use but there is still load restrictions on the bridge. It is still loved by many people today because of its vibrant colors. To increase the visibility of the bridge it was painted pink, blue and green. This bridge was loved so much that it was used as back drops in movies like Absolute Beginners, Maybe Baby, and A Clockwork Orange (Never heard of these movies but still kinda cool that it was used as a backdrop!).

  1. Structural Art

Right off the bat I can say that this Bridge is not structural art. First, it failed from an engineering standpoint and was incredibly unstable to use it efficiently. Second it was extremely expensive. It was originally estimated that it would cost 70,000 GBP and would only take 1 Year to build  but it took 3 years to complete and the total cost was over 200,000 GBP. Thirdly, it had way too much ornamental detail.

  1. Structural Analysis

As stated earlier this bridge was a combination of a suspension bridge and a cable stayed bridge. It is a suspension bridge where the deck is connected by vertical hangers to the steel link chains which run across the two towers. The cable stayed portion of this bridge is a fan design. This can be seen where the stays are connected to the deck and inclined to the top of the towers. This can be seen in the figure 2 below; the suspension hangers are highlighted in red and the diagonal cable stays of the bridge are highlighted in yellow. In figure 3 you can see the suspension of steel chains which were not part of the original design. You can see the cable stays and the vertical hangers in figure 3. For the suspension portion of this bridge the load is transferred from the deck to the suspender cable which are then transferred to the suspension cables and into the towers. For the Stay bridge portion the diagonal cables stransfer the loads from the deck to the towers.

Figure 3

 

Figure 3

 

For the structural analysis portion of this I made a few assumptions to simplify the calculations since it was a combination of 2 bridge types. The first assumption I made was that the suspension portion of the bridge takes a majority of the load so I will neglect the cable stay portion. The next assumption I made was that there is a roller connection in the top of the bridge  towers so that means that the horizontal components in each side of the tower will be the same. For the loads I assumed a live load of 3 tons since the there is a weight limit of 5 tons and I assumed the dead weight of the bridge to be 56 kips/ft. Below are my calculations for the max forces in the cables for the main span and the side spans.

 

 

 

 

  1. Personal Response

Before I went to this bridge I did a little research and found out it was a combination if a suspension bridge and cable stayed bridge. From looking at the pictures I had a real difficult time seeing exactly how it was a combination of the two because of lighting in the pictures. Even when I saw the bridge in person from a distance I still had a difficult time since the cable are going in every direction. But when I walked across the bridge I could see how the suspender cables attached the deck to the suspension cable and then to the tower. The same goes with how the stay system worked. Being there in person definitely helped me understand the load paths.

References

  1. https://www.britainexpress.com/London/albert-bridge.htm
  2. https://historicengland.org.uk/listing/the-list/list-entry/1358138
  3. https://londonist.com/2016/10/secrets-of-albert-bridge

 

 

Comments

  1. jgarrett39 says

    I really like the design of this bridge! It combines my favorite two types of bridge forms. It’s a shame that the original design did not work so well. I also think it’s funny that it had so many structural problems that it may have been easier to destroy, but the people of London wanted to keep it. Not sure if they felt bad for it or actually liked it! I also liked your structural analysis, really showed what is going on in different parts of the bridge.

  2. This bridge is very interesting to me since it’s both a cable-stayed bridge, and a suspension bridge. Since it was a combination of both did it make it hard for you to figure out the exact load path? Also do you think this bridge showcases the idealizations we discussed in class for cable-stayed bridges and suspension bridges? Or do you think the bridge shows cases where these idealizations do not exactly hold true?

    • When I had only looked up pictures of this bridge it was very difficult for me to see the load path since there were so many cables going in every direction but when I went to go visit the bridge and walk across it; the load bath became o whole lot easier to see. I do think that this bridge showcases the idealizations we used in class

  3. zcollinson3 says

    Sup bro, do you think the cable stays were put in place primarily in order to stiffen the deck, or for some other reason?