Crossing the Mississippi river can be a feat for road travelers, but what about railroads? You may be surprised to learn that there are actually many railroad bridges that span across the well-known river. In this article, we’re exploring how many bridges cross the Mississippi, the different types of railroad bridges, and the history behind these substantial structures.
Railroads have been crossing over the Mississippi river since the mid-1800s, and even today, the number of railroad bridges continues to grow. According to the United States Geological Survey (USGS), there are currently 31 bridges that span across the Mississippi river. Each bridge has its own purpose, such as providing rail transportation between two cities, or serving as a connecting point between two railway systems.
Of the 31 bridges, the most historically significant bridges that cross the river include the High Bridge, the historic Eads Bridge, the Grand Avenue Viaduct, and the Burlington Northern Santa Fe (BNSF) Bridge. Of those, the High Bridge was the first steel-girder bridge ever built across the Mississippi river. The Eads Bridge is the oldest bridge still standing and is considered an engineering feat. The Grand Avenue Viaduct, built in 1929, helped alleviate the traffic congestion caused by the ever-growing rail traffic in the cities that surround the river.
The bridges are typically constructed in one of two ways: with trusses or with girder systems. A truss bridge has a series of small steel sections that allow for a lightweight, strong bridge. Girder bridges, on the other hand, have web-like skeletons to help create a sturdy bridge. While both types of bridges are designed to support the trains that pass over, their method of construction can make a huge difference in the efficacy, durability, and cost of a bridge.
These bridges, however, are often more than just a physical link across the Mississippi river. They’re also a historical link that has connected and united people and places that were once disconnected by the mighty river. Throughout the years, different railroad bridges have been a source of transportation, commerce, and even entertainment. Each bridge has its own rich and unique history. The High Bridge, for example, was put into service in 1892 and is still used to this day.
Railroad bridges that span the Mississippi river may be nearly 170 years old, but that doesn’t mean their use is obsolete now. In fact, railroad bridges are still being built or replaced to accommodate the growing number of freight and passenger trains that travel across the river each day. The multiple bridges across the river serve as a testament to the long history of railroad transportation in this part of the US.
The Construction Process
Despite the varying materials used to build the bridges, their construction usually follows the same basic process. The first step is to select a bridge design, based on the type of bridge needed. This will determine the sizes and shapes of the steel and concrete components that will be used. Next, engineers build the bridge’s superstructure and substructure. This will include the piers and beams that make up the bridge’s foundation, as well as its towers and spans.
From there, contractors will place the tracks and tie down the rail lines so the trains can run easily across the river. As the construction progresses, the engineers must pay attention to the model codes to ensure the bridge is built properly and with safety in mind. Finally, if testing is needed, it can be done to ensure the bridge’s stability and the safety of the railroad cars.
The Advantages of Crossing the Mississippi by Rail
In addition to the obvious convenience of being able to cross the Mississippi river by train, there are also many benefits to the route. Since most of the bridges that span the river are built on the same axis, trains traveling across them can easily maintain a consistent speed. This makes it possible for freight and passenger trains to reach their destinations quickly, without having to slow down or turn as much.
In addition, trains don’t require as much fuel to cross the river as automobiles, making them an environmentally friendly choice for commuters. With the large number of bridges that span the Mississippi river, trains can bring people from one side of the river to the other without having to stop or turnaround, increasing efficiency and saving time.
Safety Considerations for Crossing the Mississippi by Rail
Crossing a river as large and powerful as the Mississippi comes with some inherent risks, and railroad bridges are not exempt from this. In fact, because they’re carrying large vehicles and heavy cargo, they pose a higher risk than other bridges that span the river. This is why it’s necessary for bridges to be checked regularly and thoroughly inspected to ensure the integrity of the structure and the safety of the passengers and cargo.
Though these inspections can add to the cost of construction and potentially cause delays, they are essential to keep passengers safe. The Federal Railroad Administration (FRA) requires both routine and special inspections of railroad bridges to ensure their longevity and safety. This includes inspecting the bridge’s capacity, stability, and condition, as well as looking for any signs of corrosion.
Future of Railroad Bridges
Though the number of railroad bridges currently crossing the Mississippi river is impressive, the engineering and construction team at the USGS believes that this number will only continue to grow. They are continually looking for ways to increase safety and access for rail traffic, and that includes building new bridges when needed. In the years to come, there’s a good chance additional railroad bridges will be added to the list, each playing a key role in connecting people, communities, and businesses that span the River.
Environmental Impact of Railroad Bridges
Though the environmental impact of bridges is often overshadowed by their economic benefits, the bridges that span the Mississippi river can have a significant environmental impact. The construction of bridges can disrupt local ecosystems, and theiroperations can have a direct effect on air and water quality in the surrounding area.
It’s important to note that railroad bridges are regulated by the Environmental Protection Agency (EPA) and must meet strict air and water quality standards. To minimize their environmental impact, bridge builders use materials and technology that reduce pollutants and help conserve natural resources. From monitoring water quality to planting native vegetation, railroad operators are doing what they can to ensure that the bridges that cross the Mississippi river minimize their environmental impact.
Final Thoughts
Thanks to the numerous railroad bridges that span the Mississippi river, cities, towns, and villages are better connected than ever. Whether it’s freight transportation or passenger travel, these bridges provide a safe and secure crossing that has countless economic and environmental benefits. With the ever-evolving technology and advances in materials, the number of railroad bridges crossing the Mississippi river is sure to continue growing and serve communities for years to come.
