Wendel Bollman
Encyclopedia
Wendel Bollman was an American
self-taught civil engineer
, best known for his iron
railway bridge
s. Only one of his patented "Bollman truss" bridges survives, the Bollman Truss Railroad Bridge
in Savage, Maryland
. The Wells Creek Bollman Bridge
near Meyersdale, Pennsylvania
is also standing, although that bridge features a "Warren truss" system.
Bollman was born in Baltimore, Maryland to German immigrants, and was the seventh of eight children. His father died when Wendell was 11, and he quit school to support his family. Bollman began his career with the Baltimore and Ohio Railroad
(B&O) as a carpenter in 1828, just as the B&O began laying track. He left shortly thereafter to build houses. During this period he married Ann Smith; the couple would have 10 children. In 1837 he returned to the B&O as a carpenter, but was soon promoted to line foreman by Benjamin H. Latrobe, II. Although the early B&O bridges in central Maryland were stone arch
types (the Thomas Viaduct
is perhaps the most impressive), wood bridges became common on the line west of Harpers Ferry, Virginia
, and Bollman began to design some of them. In 1848 he was made responsible for all bridges on the line. Noticing that wooden bridges had a life-span of only about 10 years, he began looking at using iron for his bridges. At that time railroads made limited use of iron bridges. After a failure of an iron bridge on the New York and Erie
in 1849, that railroad stopped using them.
Bollman began working on a new truss
configuration for iron bridges, and in 1849 Latrobe found it acceptable for use on two of the B&O's shorter spans. In 1851 Bollman replaced the 124-foot (37.8 m) wooden bridge at Harpers Ferry
. This would become his most famous bridge and was rebuilt many times using his system during the American Civil War
(it came under frequent enemy fire). Bollman used the idea of redundancy of members so that his truss systems did not fail. Although abstract theory was often used to design bridges during this time period, Bollman used math and modeling instead (Hansen, 2008). On January 6, 1852, Bollman was awarded patent No. 8,624 for his unique design known as the "Bollman truss." He left the B&O and founded W. Bollman and Company in 1858 with his partners John Clark and John H. Tegmeyer. The B&O continued to contract with him for bridge design. Not all his designs used the Bollman truss. W. Bollman and Company dissolved about 1863, but two years later Bollman founded Patapsco Bridge and Iron Works which lasted until his death in 1884. His companies built bridges in Cuba, Mexico, and Chile, as well as the eastern United States.
Although far more durable than the wooden bridges they replaced, most of Bollman's bridges have not survived. This is due to changes in railroad equipment, rather than their construction. New technologies for making inexpensive steel
in the late 19th century made its use in railroad bridges practical. Steel bridges could carry heavier locomotive
s and soon wrought
and cast iron
bridges became obsolete; the iron was easily recycled. The Savage bridge survives because it was on an industrial spur for a mill that closed in 1947. The Meyersdale bridge was moved and converted into a road bridge around 1910. The Harpers Ferry Bridge was destroyed in a flood in March 1936.
“Bollman is important not only because he was perhaps the most successful of the latter (self taught engineers) class, but because he was probably also the last. He may be said to be a true representative of the transitional period between intuitive and exact engineering” (Griggs Jr, 2006).
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
self-taught civil engineer
Civil engineer
A civil engineer is a person who practices civil engineering; the application of planning, designing, constructing, maintaining, and operating infrastructures while protecting the public and environmental health, as well as improving existing infrastructures that have been neglected.Originally, a...
, best known for his iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
railway bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
s. Only one of his patented "Bollman truss" bridges survives, the Bollman Truss Railroad Bridge
Bollman Truss Railroad Bridge
The Bollman Truss Railroad Bridge at Savage, Maryland is the sole surviving example of a revolutionary design in the history of American bridge engineering. The double-span truss bridge is one of the oldest standing iron railroad bridges in the United States. It was the first successful all-metal...
in Savage, Maryland
Savage, Maryland
Savage is a historic town located in Howard County, Maryland, about south of Baltimore and north of Washington, D.C. It is situated close to the city of Laurel and to the planned community of Columbia.A rich vein of American industrial history lies in Savage...
. The Wells Creek Bollman Bridge
Wells Creek Bollman Bridge
The Wills Creek Bollman Bridge originally served the Baltimore and Ohio Railroad's Pittsburgh Division main line.Designed by the renowned self-taught engineer Wendel Bollman in 1871, this truss bridge is the last remaining span of the Pittsburgh Division line associated with Bollman...
near Meyersdale, Pennsylvania
Meyersdale, Pennsylvania
Meyersdale is a borough in Somerset County, Pennsylvania, on the Casselman River, southeast of Pittsburgh. In the past, its chief industry was the mining of coal. Meyersdale was first settled as early as 1776, but the growth of the town dates from the advent of the first railroad in 1871. Coal...
is also standing, although that bridge features a "Warren truss" system.
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...
(B&O) as a carpenter in 1828, just as the B&O began laying track. He left shortly thereafter to build houses. During this period he married Ann Smith; the couple would have 10 children. In 1837 he returned to the B&O as a carpenter, but was soon promoted to line foreman by Benjamin H. Latrobe, II. Although the early B&O bridges in central Maryland were stone arch
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...
types (the Thomas Viaduct
Thomas Viaduct
The Thomas Viaduct spans the Patapsco River and Patapsco Valley between Relay and Elkridge, Maryland, USA. It is the first multi-span masonry railroad bridge in the United States to be built on a curve...
is perhaps the most impressive), wood bridges became common on the line west of Harpers Ferry, Virginia
Harpers Ferry, West Virginia
Harpers Ferry is a historic town in Jefferson County, West Virginia, United States. In many books the town is called "Harper's Ferry" with an apostrophe....
, and Bollman began to design some of them. In 1848 he was made responsible for all bridges on the line. Noticing that wooden bridges had a life-span of only about 10 years, he began looking at using iron for his bridges. At that time railroads made limited use of iron bridges. After a failure of an iron bridge on the New York and Erie
Erie Railroad
The Erie Railroad was a railroad that operated in New York State, New Jersey, Pennsylvania, Ohio, Indiana, and Illinois, originally connecting New York City with Lake Erie...
in 1849, that railroad stopped using them.
Truss bridge
A truss bridge is a bridge composed of connected elements which may be stressed from tension, compression, or sometimes both in response to dynamic loads. Truss bridges are one of the oldest types of modern bridges...
configuration for iron bridges, and in 1849 Latrobe found it acceptable for use on two of the B&O's shorter spans. In 1851 Bollman replaced the 124-foot (37.8 m) wooden bridge at Harpers Ferry
Harpers Ferry, West Virginia
Harpers Ferry is a historic town in Jefferson County, West Virginia, United States. In many books the town is called "Harper's Ferry" with an apostrophe....
. This would become his most famous bridge and was rebuilt many times using his system during the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...
(it came under frequent enemy fire). Bollman used the idea of redundancy of members so that his truss systems did not fail. Although abstract theory was often used to design bridges during this time period, Bollman used math and modeling instead (Hansen, 2008). On January 6, 1852, Bollman was awarded patent No. 8,624 for his unique design known as the "Bollman truss." He left the B&O and founded W. Bollman and Company in 1858 with his partners John Clark and John H. Tegmeyer. The B&O continued to contract with him for bridge design. Not all his designs used the Bollman truss. W. Bollman and Company dissolved about 1863, but two years later Bollman founded Patapsco Bridge and Iron Works which lasted until his death in 1884. His companies built bridges in Cuba, Mexico, and Chile, as well as the eastern United States.
Although far more durable than the wooden bridges they replaced, most of Bollman's bridges have not survived. This is due to changes in railroad equipment, rather than their construction. New technologies for making inexpensive steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
in the late 19th century made its use in railroad bridges practical. Steel bridges could carry heavier locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...
s and soon wrought
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
and cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
bridges became obsolete; the iron was easily recycled. The Savage bridge survives because it was on an industrial spur for a mill that closed in 1947. The Meyersdale bridge was moved and converted into a road bridge around 1910. The Harpers Ferry Bridge was destroyed in a flood in March 1936.
“Bollman is important not only because he was perhaps the most successful of the latter (self taught engineers) class, but because he was probably also the last. He may be said to be a true representative of the transitional period between intuitive and exact engineering” (Griggs Jr, 2006).