Bridges
A bridge is an architectural feature that provides passage over any obstacle. Commonly used to traverse the quickest path over impassable terrain or bodies of water. Bridge and road construction was revolutionized by the Ancient Romans with the invention of mortar. Thier mortar was made from ground volcanic rocks and allowed the Romans to build larger and stronger structures. The Romans built roads and bridges across Europe, Africa, and Asia which was vital for trade and communication within the Roman Empire.
Truss bridges
Truss bridges are one of the oldest types of modern bridges and is the base for many other types of bridges. The design of truss bridges was easy for 19th and early 20th century engineers to analyze and design. Its load-breading structure is above the bridge and connects trusses in a triangular pattern for the most strength.
Most early truss bridges were constructed with wood and later iron to prevent degradation. Many wooden truss bridges were covered bridges which would protect the materials which held the weight of the bridge.
Truss bridges can span short lengths and use materials efficiently. They were most commonly built from the 1870s to the 1930s.
Arch Bridges
An arch bridge are possibly the oldest existing stable bridge type. They were one of the first choices of the Greek and Romans and the oldest arch bridge still standing today dates to 1300 BC. Arch bridges work by transferring the weight of the structure and its loads to the bottom of the arch. It can be made of a series of arches or a singular arch.
Ancient bridges were made of masonry and stone. Modern arch bridges are often made of steel and reinforced concrete.
Arch bridges can only span short lengths unless many arches are used. They are not the most effective in use of materials but are simple to design.
Central Park Bow Bridge
The Central Park Bow Bridge was the first cast iron bridge in the park and is the second oldest bridge of its type in America. It was built between 1859 and 1862. Originally the commissioners requested a suspension bridge but designers created this low-lying bridge to compliment the landscape of Central Park. It is named for its graceful shape that is reminiscent of the bow of an archer or violinist.
This image is strikingly similar to "Brothers and Sisters" which could possibly also be an image of the Central Park Bow Bridge.
References
- History of Bridges. (n.d.) Retrived from http://www.historyofbridges.com/
- Central Park Conservancy. (2015). Bow Bridge. Retrived from http://www.centralparknyc.org/things-to-see-and-do/attractions/bow-bridge.html