The area where this virtual is located is closed from sunset to sunrise. Please respect the hours of this National Parks Overlook and all other laws while seeking this virtual.
A local landmark since 1994, The Natchez Trace Parkway Bridge stands out as one of the most recognizable structures in Middle Tennessee, and even featured on the popular national coffee chain's “You are Here” collection’s Nashville mug. You’ve seen it many times, but you may not realize just how unique the architecture of this structure is, in fact it is the first of it’s type in the United States.
The Natchez Trace Parkway Bridge is a concrete double arch bridge located about nine miles from the northern terminus of the Natchez Trace Parkway. It is 1,572 ft long and carries the two-lane Natchez Trace Parkway 155 ft over State Route 96 and a wide valley. The 582 ft long main span is symmetrical, while the 462 ft long second arch is not, due to the slope of the valley at the southern end of the bridge. The bridge is rare in that it does not use columns to support the deck from the arch. The weight of the bridge is concentrated at the crown of the arch, rather than being evenly distributed along the arch's length. The lack of spandrel columns results in a clean, unencumbered appearance: it is termed a cathedral arch bridge.
The bridge is the first segmentally constructed concrete arch bridge in the United States. The arches comprise 122 hollow box segments precast in nearby Franklin, each of which was about 10 feet long and weighed between 29 and 45 tons. The deck consists of 196 precast post-tensioned trapezoidal box girder segments, each typically 8.5 ft long. The sections atop the crown of the arch are 13 ft deep. The foundations and piers of the bridge were cast in place.
The arches and deck were constructed using a balanced cantilever method. Each arch was supported by temporary cable stays anchored from the top of the piers and the valley sides until it was fully built. This procedure was chosen in place of conventional shoring towers so that environmental damage to the valley would be minimized. The bridge cost $11.3 million to build, and was completed in October 1993. It was officially opened on March 22, 1994.
The bridge has won many awards for its design, including a Presidential Award for Design Excellence in 1995, and an Award of Merit from the Federal Highway Administration in 1996. The Eleventh International Bridge Conference named it the single most outstanding achievement in the bridge industry for 1994. In 1996, it won the Federal Highway Administration’s Excellence in Highway Design Award of Merit for the best highway improvements on publicly owned land.
If you would like to learn much more about the engineering involved in the construction of this architectural wonder and totally geek out like a member of the TOM Creative Group, we recommend Segmental Concrete Arches on the Natchez Trace Parkway by Donald W. Miller and John A. Corven.
In order to log this virtual:
(a) Please proceed to the overlook at the posted coordinates and post a photo of yourself (or some identifiable object, your gps, a sign, etc.) with the bridge in the background. If you would prefer to post a picture of yourself with the bridge from below, that is acceptable, but you will still need to answer the questions from the overlook.
(b)Message our account with the answers to these questions:
1. When you reach the overlook, facing south, look to your left and you will find a wooden fence, how many horizontal beams make up this fence?
2. At the parking coordinates there are two signs beyond the stone wall. The sign on the right reads” Area Closed Sunset to Sunrise”, what does the sign on the left prohibit?
3. What is the name of this parking area? You will find it on a sign in the grassy median between the parking spaces and the Natchez Trace.
Virtual Reward - 2017/2018
This Virtual Cache is part of a limited release of Virtuals created between August 24, 2017 and August 24, 2018. Only 4,000 cache owners were given the opportunity to hide a Virtual Cache. Learn more about Virtual Rewards on the Geocaching Blog.