| Porters Bridge in Richardsmere |
| By Rita M. Suffness |
| Porters Truss Bridge Connected with Nationally Prominent Engineers |
| The Porters, or Richardsmere Bridge, is a metal Pratt through truss designed and built in 1885 by the Wrought Iron Bridge Company under the supervision of Charles H. Latrobe, as documented in the Minutes of the Cecil County Commissioners. He was a noted Maryland engineer and principal in the Baltimore Bridge Company. The structure was located on US Route 1, an important transportation corridor on the Eastern Seaboard of the United States, before the State Road Commission bypassed the 6,000-foot section of US Route 1, on which it was located, in 1933. |
| The bridge, soon to be removed due to its damaged condition, spans 121 feet across Octoraro Creek. Resting on stone masonry abutments, the truss consists of six panels fabricated of pin connected eyebars and riveted channels with lacing bars on the inclined end posts, top chords and cross struts. The posts are composed of two heavy channel beams joined by riveted bracing. The intermediate posts are composed of one channel with two riveted cover plates. The tension members are wrought iron eyebars with sleeve nuts. The inclined end posts have "Carnegie" stamped on them. The bridge was officially closed to all traffic in January 1978 following a severe storm that washed out the east approach roadway. It is so severely deteriorated that it would not be feasible to repair it. |
| The bridge is located in a village called Richardsmere, initially settled in the nineteenth century as “Porters Bridge” to accord with the name for the covered wooden structure over Octoraro Creek located north of the core of the settlement. This crossing of the Octoraro Creek was established at a very early date to provide access to Stephen Porter's Mill. This mill, the sole structure existing at that time, is shown on Map 6 of the Commis-sioner's Road Book of the Western Portion of Maryland, 1792. The Commissioners acted on the need to establish a public road in the May 12, 1794 order of the Cecil County Levy Court. The order re-quired the laying out of a "Publick Road from Brick MeetingHouse in East Nottingham to Stephen Porters Mill on the Octoraro Creek". This road was shown on map 7 of the Commissioner's Road Book. |
| By 1858 about one half dozen struc-tures had been built on the opposite side of Octoraro Creek from Porter's (later Magraw's) Mill, consti-tuting the small commu-nity of Porters Bridge. It was shown in the rendering of the "Mill and Farm Property of H. S. Magraw, Esquire" in the 1877 atlas. Three buildings owned by Magraw (residence, grist mill and an unidentified structure) on the west side, and a "Building Association" structure, a blacksmith shop, saw mill and dwellings owned by J. Fortune, J. Coats, A. Moore, N. Barnett, and J. G. Richards on the east side. The covered bridge, re-placed in 1885 by the exist-ing truss struc-ture, was shown in the 1877 Lake, Griffing and Stephenson Atlas of Cecil County and provided access between Magraw's Mill and house on the west side of Octoraro Creek with these other structures. |
| The first mention of what would be the fruitful arrangement between Charles H. Latrobe and Cecil County, resulting in this replacement of the wooden bridge with the metal truss, appears in the July 9, 1884 Commissioners' Minute Book, with the recommendation that a "competent engineer be employed to prepare plans and specifications and supervise construction of bridges". The appointment of Charles H. Latrobe was noted in the July 15, 1884 entry. On July 24, 1884 the Clerk was advised to advertise in the Democrat and the Whig for proposals for the masonry work to his specifications. By the time of the August 6, 1884 entry, bids had been received for the construction or repair of the substructures and superstructures of Gilpins, Baldwins and Marley bridges, and the superstructures of Haines, New, Porters, Basin Run, Rowlandville and Conowingo bridges. Latrobe's share was to be five percent of the net cost of the work. Of the six latter structures only four truss bridges are extant, among them the Porters Bridge, New Bridge, Conowingo Bridge, and the Basin Run Bridge. |
| Evidently Latrobe generated the designs quickly, for on October 1, 1884 proposals from six bridge companies for constructing iron bridges at Basin Run, New and Rowlandville were evaluated. The Commissioners on September 24, 1884 evaluated proposals from seven bridge companies for the construction of the Baldwins and Porters Bridges. Alex Wilson Company bid $4200 for Baldwins Bridge; the Penn Bridge Works bid $7460 for both; the F. H. Smith Edgeware Company bid $7300; the H. A. Ramsey and Company bid $7988; Nelson and Buchanan bid $8140; the King Iron Bridge Company bid $7042. The winning bid (lowest proposal) submitted was by the Wrought Iron Bridge Company for $6815. |
| The designs of the Porters Bridge, New Bridge, and the Conowingo Bridge are simple Pratt through truss bridges. The word "Carnegie" appears on several truss members in Porters and the New Bridges. Based on the fact that the Carnegie Mill was rolling steel since 1870, these two structures may have at least some steel members because of the Carnegie stamp, and may be representative of early hybrid iron/steel structures in the area (should chemical analysis prove the composition of the members). The possible incorporation of some steel members is all the more significant given that, according to Chard, 10 low-carbon structural steel did not become generally available for truss bridge construction until the 1890's, when the Bessemer and open hearth processes permitted its manufacture. In that respect, these bridges may be experimental in incorporating steel members before such members became widely available. |
| Charles Hazlehurst Latrobe, Supervising Engineer of Porters Bridge |
| Charles Hazelhurst Latrobe (1833-1902) was the grandson of Benjamin Henry Latrobe, who was the most highly skilled architect practicing in the United States from the time he arrived from England in 1796 until he died, at age 56, in 1820. Charles was, in turn, the son of Benjamin Henry Latrobe (1806- 1878) who was chief counsel and chief engineer for the Baltimore and Ohio Railroad, and president and chief engineer for the Pittsburgh and Connelsville Railroad, among others. Charles was born in Baltimore, Maryland in 1834, eldest of the five children of Benjamin Henry Latrobe and his wife Maria Hazlehurst. |
| After attending St. Mary's College in Baltimore and learning the rudiments of his profession in his father's office, he worked for the Baltimore and Ohio Railroad. A few years later he went to Florida as the chief engineer in charge of construction on the Pensacola and Georgia Railroad. Stationed at Tallahassee when the state seceded from the Union, he enlisted as a lieutenant of engineers in the Confederate Army, and completed the grading, bridge-building and rail-laying on the last twenty miles of the Pensacola and Georgia. At the close of the war Latrobe returned to Baltimore, which was his home until his death in 1902. |
| He became partner of Smith, Latrobe and Company when it was organized in 1866. It was one of the most important bridge building companies in the United States during the late nineteenth century not only because of its reputation and the widespread nature of its many important commissions, but also because its officers were nationally famous engineers, among them, Charles Shaler Smith. It was incorporated as the Baltimore Bridge Company in 1869. Charles Shaler Smith was the President and Chief Engineer, and Charles H. Latrobe was the Secretary and Associate Engineer of both firms. Frederick Henry Smith was identified as Associate Engineer and General Superintendent, and Benjamin H. Latrobe, the father of Charles Hazelhurst Latrobe, as Consulting Engineer. An 1885 advertisement in Railroad Gazette cited C. Shaler Smith's work as a "designer and builder of bridges and viaducts". The firm was listed in the 1887 Poor's Directory. |
| In George W. Howard's The Monumental City, Its Past History and Present Resources1 (page 14), the company listed offices in both Baltimore and New York, further underscoring its importance. The Baltimore Bridge Company, in its advertisement on page 14, offered the design and construction of iron, steel and composite bridges and roofs, with patent wrought-iron viaducts and trestles as a specialty. Most importantly, "County Road-Bridges" featured prominently in the advertisement, with the statement that "Commissioners can obtain any desired information. . . , with Lithographs send on application." Another advertisement stated that the company's output, totaling five million dollars, included over thirteen miles of bridges along with roofs, depots, foundations, round houses, and piers. The company went out of business in 1890. |
| Charles H. Latrobe was appointed engineer of the Jones Falls Commission in Baltimore in 1875, when his cousin, General Ferdinand Claiborne Latrobe, entered on his first term as major of the city, remaining in the employment of the city until 1899. He and his company designed and built the retaining walls along the Falls and designed and constructed metal bridges across the valley at St. Paul Street, Calvert Street, and Guilford Avenue. He built a number of other bridges in Baltimore, such as Pratt, Lombard, Gay and Biddle Street Bridges and the drawbridge at Block Street. He also laid out the terraced gardens along Mount Royal Avenue and was in charge of the improvements and extensions in Mount Royal, Druid Hill and Patterson Parks as the engineer and general superintendent of public parks, a post he had until 1899.2 Latrobe's designs were evidently noted for their structural beauty.3 What may possibly be one of Latrobe's bridge designs is shown on page 32 of The Monumental City (The Baltimore American Illustrated Edition, 1895).4 |
| The prominence of the Baltimore Bridge Company is also highlighted by Thomas Scharf in his History of Baltimore City.5 It is specifically mentioned along with the Patapsco Bridge and Iron Works, the Clarke Bridge Company, and the H. A. Ramsey and Company as being engaged in the important industry of metal bridges. Latrobe and his firm also executed several commissions for the Peruvian government. At Arequipa he constructed an aqueduct 1,300 feet long and 65 feet high and at Verrugas, on the Callao-Oroya-Huancayo Railway, he built the most famous of his bridges. Spanning one of the deepest gorges in the Andes, it was 575 feet in length and had a central wrought-iron pier 252 feet high, said at the time to be the tallest bridge in the world. It was framed in the United States, then taken apart for shipment and re-erected in ninety days. |
| The Latrobe family had been previously associated with Cecil County, as Charles' father, Benjamin Henry Latrobe, along with Cornelius Howard and John Thompson, had surveyed various routes across the peninsula for a proposed Chesapeake and Delaware canal about 1801.6 |
| Maryland’s Nineteenth Century Truss Bridges, |
| The range of truss patterns seen in Maryland`s highway bridges built in the nineteenth century is quite narrow, for they are of three types only--Pratt, Bowstring and the Whipple Trapezoidal Truss. These became the most common types utilized for truss bridges after the Civil War, as recognized by eminent bridge engineer and historian J. A. L. Waddell in 1884, who stated that "at least ninety percent of all American iron highway bridges are built on these systems."7 As expected, most of the Maryland examples are Pratt trusses, the most popular and long-lived of the truss patterns, utilized in its original form or in variations, such as the Parker and Camelback, well into the twentieth century. |
| Porters Bridge is a Pratt Truss, named for Thomas and Caleb Pratt, who were issued a patent for a truss bearing their name in April, 1844. The diagonal tension members of the web were constructed of wrought iron and the vertical compressive members of wood. It was one of the few bridge forms that continued to be widely utilized well into the twentieth century. Milo Ketchum in 1908 wrote that the Pratt truss was commonly built with pin-connected joints and it was preferred for spans of 170 to 240 feet.8 The United States, in contrast to Europe, had utilized the pinned connections extensively in the nineteenth century. So widespread was the use of pinned connections that in 1896 the Scientific American could state that the pinned method was a distinctive feature of American bridge design.9 However, there were limitations to pinned connections which could only be solved by utilizing another method of assembly. In the last quarter of the nineteenth century riveted connections came to be favored, until in the twentieth century they were used almost exclusively, according to Charles C. Schneider. 10 |
|
| An additional change of considerable importance that occurred with the truss type was the substitution of steel for iron. By the beginning of the twentieth century utilizing iron for bridges in the United States was obsolete. Steel was universally accepted for its greater strength, and thus the promise that the bridges would not have to be replaced as readily.11 |
| Notes |
| 1. The Monumental City, It’s Past History and Present Resources, (The Baltimore American Illustrated Edition, 1873), p. 13-14. |
| 2. Obituary of Charles H. Latrobe, The Sun, (September 20, 1902), p. 7. |
| 3. Malone, Dumas, Editor, Dictionary of American Biography (Charles Scribner's Sons, New York), p. 26-27. |
| 4. The Monumental City (The Baltimore American Illustrated Edition, 1895), p. 32. |
| 5. Thomas Scharf. History of Baltimore City, (Philadelphia: Louis H. Everts Company, 1881), p. 425. |
| 6. George Johnston, History of Cecil County, Maryland (Elkton: by the author, 1881), p. 384. |
| 7. J.A.L. Waddell The Designing of Ordinary Iron Highway Bridges (New York: John Wiley & Sons, Inc., 1891), p. IV. |
| 8. Milo Ketchum, Highway Bridges, pp. 7-8. |
| 9. "Railroads and Bridges, Scientific American, LXXV (July 25,1896), p. 58. |
| 10. "The Evolution of the Practice of American Bridge Building," Transactions of the American Society of Civil Engineers, LIV, June, 1905, p. 222. |
| 11. Chard, Jack, Making Iron and Steel: The Historic Processes: 1700-1900, (The Roebling Chapter of the Society for Industrial Archaeology, Bogota, New Jersey, 1986). |
| Rita M. Suffness, Cultural Resources Manager, has a B.A and M.A in Architectural History and has been documenting historic structures, including bridges, for twenty years as a Historic Sites Surveyor with the State of Maryland. |
