Mystery Bridge Nr. 52: The Bridge from Brazil

Photo taken by Nathan Holth

Here’s a pop quiz for you readers, with regards to this mystery bridge:

1. When was the oldest swing bridge in the US ever built and

2. When was the first time a bridge was ever relocated in the US?

This Mystery Bridge takes you to Florida and in particular, this bridge. Located over the Suwannee River at the Lafayette and Suwannee County border, the Drew Bridge features a swing bridge with a Warren through truss design. The name Drew comes from a family that consisted of George Franklin Drew, who governed Florida from 1877 to 1881, and his sons, George L. Drew and Franklin Drew, who operated a lumber business near the site of the bridge and purchasd a large segment of the Suwannee and San Pedro Railroad in 1899 and extended the line to Mayo, to accomodate their business. They purchased this bridge, located somewhere in Brazil, in 1900 and  was put into service after being transported to its current site  in 1901. It served traffic until the railroad was abandoned due to competition in 1921. Since that time, the bridge has been sitting abandoned in an open position. The bridge was named after the elder Drew, who died in 1900.

Nathan Holth visited the bridge earlier this year and is looking for some information as to the date of the construction, the bridge builder, and whereabouts is the bridge located. The reason for this (and one can see it through the information and photos he took on the trip) are the features of the bridge- both in terms of portal and strut bracings as well as the way the bridge was constructed, both in terms of materials used as well as the how the bridge parts were assembled (and reassembled upon its relocation. It is clear that the bridge has been in its current location for 113 years. However, the inscriptioions on the steel, combined with the design have it being pointed to the construction date of between 1870 and 1885. More information can be found via link here:

Link: http://www.historicbridges.org/bridges/browser/?bridgebrowser=florida/drewbridge/

If you have any information that is important to the research on this bridge, please contact Nathan Holth using the contact information on his website. You can also place your comments here for readers to read.

Because of its unique design and history, the Drew Bridge is one of the candidates for this year’s Ammann Awards in its respective category. 🙂

 

Height detector test: New innovation for high truss bridges?

Photo taken in August 2013

In light of the I-5 bridge disaster over the Skagit River in Washington State, whose cause was a truck hitting the portal bracing of the Warren through truss bridge, questions have flown around as to whether a witch hunt to eradicate them is worth all the billions of dollars to be spent, or if it makes more sense to restrict them further for a fraction of the price and if so, how?

What about the usage of height detectors? This concept may be unusual to many engineers and politicians, but they are being used in many regions of the country today.

Like this one in Le Sueur, Minnesota. Located along the Minnesota River, the largest community of Le Sueur County with 4,000 inhabitants is the birth place of William Mayo, one of the founders of the world-renowned Mayo Clinic in Rochester, two hours to the east of town. While the town has a nice city center to the east of the railroad, it does have a thorn on its side, something city officials are hoping to get rid of when the railroad decides to abandon its line between Mankato and Shakopee, which is this deck plate girder bridge:

 

 

 

 

 

 

 

 

 

 

 

This railroad bridge crosses Hwy. 93 and has provided numerous headaches for drivers for two reasons: 1. The hill leading to the underpass is steep and after going underneath the bridge, you end up on the Minnesota River bridge and 2. The underpass is too narrow and too low for trucks to pass, forcing many truck drivers to use the exit to the north of town (at Hwy. 112 and US Hwy. 169). As the railroad is very active on this line, state and local authorities for many years have tried to place warning signs on both ends of the crossing, even warning drivers from as far away as US Hwy. 169 to consider other options if their load is too wide or even too narrow.

This concept was found just east of the interchange on Hwy. 93. How it functions is simple: if an overheight truck passes by the detector, an alarm will activate warning drivers of the danger ahead forcing him to change his course. A secondary alarm is activated warning police and other officials of the danger ahead so that they can act quickly and stop the person before reaching the underpass or bridge with a low clearance.

Given the lack of ability of some drivers to pay attention to weight and height restrictions of many bridges in the country, with the resulting factor being damage or destruction of the structure, this concept may be the best solution to the problems involving bridges with these handicaps. With millions of bridges with height restrictions on America’s highways, the cost for replacing every single structure would be so exorbitant that it would put the entire country back into an economic recession that would be worse than the one we just saw recently in 2008/09. This is not counting the cost for environmental impact and mitigation surveys and the design of the structure. In Minnesota alone, at least two dozen of these bridges are still in operation on the state’s highways, many of which still have some years of service left, like the Hwy. 7 Bridge west of Montevideo. This Parker span has spanned the Chippewa River since 1959 and is in tip-top condition.

Photo taken in December 2010

 

 

 

 

 

 

 

 

 

 

 

 

This leads us to our question for the forum:

Do you think that height and weight restriction devices like the one in Le Sueur would be the most effective way to keep overweight and/or oversize vehicles from utilizing bridges with such restrictions? If so, how can we ensure that these people obey these restrictions without damaging or destroying the bridge? If it is not a viable solution, what alternatives would you recommend?

You can place your comments here on this page, or on the Chronicles’ facebook or LinkedIn pages. By doing so, you might have some ideas to share with others, who might find them interesting and useful. Furthermore it will help many people who think replacement is the only option to look at more reasonable options which can save money and force many people to think common sense.  Looking forward to your thoughts on this innovation, which seems to be a very effective solution to our height and weight problems on the roads.

Note: The Skagit River crossing reopened to traffic on 15 September after crews replaced the temporary Bailey truss spans with concrete beams spans, built at the site where a section of the truss bridge collapsed. More information can be found here.

The Minnesota River crossing featured a 700 foot truss bridge (400 foot Pennsylvania, 200 foot Parker and 100 foot Warren pony) built in 1923 by the Wausau (Wisconsin) Bridge and Iron Works Company, replacing an iron Post through truss bridge. It used to carry US Hwy. 169 before it was relocated to the west and served as a bypass in 1967. The bridge was replaced with a current structure- a concrete slab bridge- in 1984. A photo of the Post truss can be found here as well as the 1923 span (here).