|Bridge Name||Facility Carried / Feature Intersected||Location||Structure Type||Construction Date and Builder/Engineer|
Blome Road Bridge
||Blome Road Over Raiders Run||Indian Hill: Hamilton County, Ohio||Metal 6 Panel Pin-Connected Pratt Through Truss, Fixed||1888 By Builder/Contractor: Queen City Bridge Company of Cincinnati, Ohio and Engineer/Design: William H. Harrison|
|Rehabilitation Date||Main Span Length||Structure Length||Roadway Width||Main Spans||NBI Number|
|1990||79 Feet (24 Meters)||94 Feet (28.7 Meters)||12.8 Feet (3.9 Meters)||1||3137430|
Crossing a tributary of Sycamore Creek, this attractive bridge was built in 1888 by the Queen City Bridge Company, perhaps the only surviving example of a bridge built by this company. It is a pin connected Pratt through truss bridge. The structure is composed of six panels. It is most noted for its slight skew, rare among pin-connected truss bridges. Although modern railings are in front, the original pipe railings remain behind them. They are highly unusual because they pass through the vertical members, and also the endposts. This railing design is clear evidence that railings in this era were not built with protecting the trusses in mind. A horse-drawn carriage would not be likely to cause much damage.
Hamilton County built a beam bridge underneath the truss bridge, making the truss essentially decorative and non-functional for supporting the load of vehicles. This method of preservation causes controversy because many historians do not like that the truss no longer functions to support load. However, another perspective is that this method eliminated the need to repair or retrofit the truss to continue to support traffic at a high weight limit. Thus, it limited alterations to the original truss design and materials. This particular example of adding beams under the bridge was especially unobtrusive because the beams were added under the floorbeams. Sometimes the floor beams would be removed with this method, which would alter the bridge, but this was not the case here. No single method of preserving a truss bridge is perfect, and each has its pros and cons. Each historic bridge should be evaluated individually prior to commencing with a project, considering all alternatives, including this one.
Information and Findings From Ohio's Historic Bridge Inventory
The bridge carries 1 lane of a 2 lane road over a stream in the village of Indian Hill. There are stop signs at either end of the bridge for traffic control. The adjacent quadrants are wooded. A sign on the bridge identifies it as an Indian Hill Historical Society Historic Landmark.
The skewed, 1 span, 94'-long, pin-connected, Pratt thru truss bridge was built in 1888 and underpinned with a steel stringer superstructure in 1990. The truss floorbeams rest atop the stringers. The truss is traditionally composed of built-up compression members and eyebar tension members. The upper chords are toe-out channels with cover plate and battens. The verticals are toe-out channels with lacing. The upper lateral braces are T-shaped sections that connect to the upper chords with U-shaped clips. The bridge has lattice portal bracing. There are two lines of pipe railings that connect to the end post coverplate with cast-iron pieces. U-shaped hangers pick up the built-up floorbeams at the lower panel points. The end panel floorbeam hangers are an unusual detail of threaded rods that pass through a cast-iron separating piece between the lower chord eyebars and are fixed by a plate to the lower flange of the floorbeam. The bridge is supported on stone abutments with concrete extensions to accept the underpinning girders.
Underpinned with steel stringers in 1990. Floorbeams have section loss and have been strengthened with welded plate at the webs. Some welded repairs to the inclined end post cover plates at the bearings. The underpinning has relieved the truss of live loads but the truss lines continue to function as trusses.
Summary of Significance
The 1888 pin-connected Pratt thru truss bridge was designed by engineer William H. Harrison and fabricated by the Queen City Bridge Company of Cincinnati. It is an early and complete example of its type/design
that reflects the work of a local builder prior to the era of standardization. The bridge has details that are not common to other builders, including the floorbeam hanger detail and the pipe railing detail with cast-iron pieces
The bridge is one of over 150 extant pin-connected truss bridges dating from 1874 for pony trusses and 1876 for thru trusses. Twenty six predate 1888 and represent the era of experimentation that evolved into standardized designs by about 1888. This example has moderate significance because the genre that is so well represented in Ohio.
Bridge Considered Historic By Survey: Yes
Click on a thumbnail or gallery name below to visit that particular photo gallery. If videos are available, click on a video name to view and/or download that particular video.
Original / Full Size Photos
|A collection of overview and detail photos. For the best visual immersion and full detail, or for use as a desktop background, this gallery presents the photos for this bridge in the original digital camera resolution.|
Mobile Optimized Gallery
|A collection of overview and detail photos. View the photos for this bridge in a reduced size which is useful for mobile/smartphone users, modem
(dial-up) users, or those who do not wish to wait for the longer
download times of the full-size photos. Alternatively, view this photo gallery using a popup slideshow viewer (great for mobile users) by clicking the link below.
Browse Gallery With Popup Viewer
© Copyright 2003-2013, 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 of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.