HistoricBridges.org Menu: HistoricBridges.org Menu:


We Recommend These Resources:
Bach Steel - Experts at historic truss bridge restoration.

HistoricBridges.org: Bridge Browser

Seven Mile Bridge

Moser Channel Bridge, Piegon Key Bridge, Knight's Key Bridge

Seven Mile Bridge

Primary Photographer(s): Nathan Holth

Bridge Documented: November 24, 2017

View Photos
and Videos
View Maps
and Links

Key Facts

Location
Marathon: Monroe County, Florida: United States
Structure Type
Metal Deck Girder, Fixed and Approach Spans: Concrete Closed Spandrel Deck Arch, Fixed
Construction Date and Builder / Engineer
1912 By Builder/Contractor: American Bridge Company of New York, New York and Terry and Tench of New York, New York and Engineer/Design: Joseph C. Meredith and William J. Krome

Technical Facts

Rehabilitation Date
1938
Main Span Length
80 Feet (24.4 Meters)
Structure Length
35,720 Feet (10887.5 Meters)
Roadway Width
Not Available
Spans
335 Main Span(s) and 210 Approach Span(s)
NBI Number
Not Applicable

Historic Significance Rating (HSR)
View Information About HSR Ratings

Bridge Documentation

This bridge is the longest of the numerous bridge composing the Florida East Coast Railway Extension, which was converted to highway usage in 1938 as the initial structures for the Overseas Highway (US-1). The bridge was abandoned in 1972. One of the unique features of this bridge is that half of the bridge is composed of steel plate girder spans, and the other half is composed of concrete deck arch spans, making this a visually contrasted bridge. Roughly 9,090 feet of the bridge is concrete arch spans, while the rest of the bridge was built using steel. The differences in span type were due to issues such as water depth and wave height. Although HistoricBridges.org lists the main span design of this bridge as a metal deck girder (reflecting the bridge as seen today), the original bridge featured a through truss swing span as the main span over Moser Channel. The demolition of this swing span in 1982 is perhaps the single most devastating loss of heritage among the surviving pieces of the Florida East Coast Railway Extension in the years since the bridge structures have been abandoned from highway usage. The bridge is also missing a span near Pigeon Key. The section leading east from Pigeon Key remains in limited vehicular use as an access to Pigeon Key. A unique timber ramp structure leads up to the main bridge at Pigeon Key. A final section of bridge is missing, one of the concrete arch spans near the western end. West of the missing arch span is about 3,460 feet of the western end of the bridge which has been restored for pedestrian use as a fishing pier.

View Historic American Engineering Record (HAER) Documentation For This Bridge

HAER Data Pages, PDF - HAER Original Plan Sheets, PDF

View Historical Articles About This Bridge and the Florida East Coast Railway

View Historical Pamphlet About The Florida East Coast Railway

View National Register of Historic Places Nomination Form For This Bridge

Above: Historical photo showing swing span in its final years of usage.

Above: Historical photo showing swing span in its final years of usage.

Above: Historical photo showing swing span construction.

Above: Historical photo showing girder span construction.

Above: Historical photo showing arch span construction.

Above: Historical photo showing swing span in open position.

Above: Historical photo showing train on bridge.

Above: Historical photo showing conversion of bridge from railroad to highway use.

Divider

Photo Galleries and Videos: Seven Mile Bridge

 
View Photo Gallery
Bridge Photo-Documentation
Original / Full Size Photos
A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer
View Photo Gallery
Bridge Photo-Documentation
Mobile Optimized Photos
A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer

Divider

Maps and Links: Seven Mile Bridge

Coordinates (Latitude, Longitude):

View Bridge Location In:

Bridgehunter.com: View listed bridges within a half mile of this bridge.

Bridgehunter.com: View listed bridges within 10 miles of this bridge.

Google Maps

Google Streetview (If Available)

Bing Maps

OpenStreetMap

Apple Maps (Via DuckDuckGo Search)

Apple Maps (Apple devices only)

MapQuest

HERE We Go Maps

ACME Mapper

Waze Map

Android: Open Location In Your Map or GPS App

Flickr Gallery (Find Nearby Photos)

Wikimedia Commons (Find Nearby Photos)

Directions Via Sygic For Android

Directions Via Sygic For iOS and Android Dolphin Browser

USGS National Map (United States Only)

Historical USGS Topo Maps (United States Only)

CalTopo Maps (United States Only)


Divider
 
Home Top

Divider

About - Contact

© Copyright 2003-2021, HistoricBridges.org. All Rights Reserved. Disclaimer: HistoricBridges.org is a volunteer group of private citizens. HistoricBridges.org is NOT a government agency, does not represent or work with any governmental agencies, nor is it in any way associated with any government agency or any non-profit organization. While we strive for accuracy in our factual content, HistoricBridges.org offers no guarantee of accuracy. Information is provided "as is" without warranty of any kind, either expressed or implied. Information could include technical inaccuracies or errors of omission. Opinions and commentary are the opinions of the respective HistoricBridges.org member who made them and do not necessarily represent the views of anyone else, including any outside photographers whose images may appear on the page in which the commentary appears. HistoricBridges.org does not bear any responsibility for any consequences resulting from the use of this or any other HistoricBridges.org information. Owners and users of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.

Admin Login

Divider