. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . structure aseries of what were in reality primi-tive single bridges, each distinct fromthe other, yet forming one continuousroadway. The trestle-bridge is in this sense anadaptation of the primitive form, aseach bent takes the place of a stonepier for the support of the horizontalbeams on top. Modern trestle-bridgesare braced in the direction of theirlength from bent to bent so that, ina sense, they form one structure,though each row of upright timberscarries the load in a perpendicular di-re
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . structure aseries of what were in reality primi-tive single bridges, each distinct fromthe other, yet forming one continuousroadway. The trestle-bridge is in this sense anadaptation of the primitive form, aseach bent takes the place of a stonepier for the support of the horizontalbeams on top. Modern trestle-bridgesare braced in the direction of theirlength from bent to bent so that, ina sense, they form one structure,though each row of upright timberscarries the load in a perpendicular di-rection. The bents are made wide atthe bottom, when the trestle is of suf-hcient height to require it, in order toprovide lateral stiffness to the whole,and to resist wind pressure. Historians tell us that the PonsSublicius was the first bridge everbuilt over the Tiber at Rome. Thisbridge was constructed of timber in thereign of Ancus Martins and was en-tirely without bolts or ties. It wasmade in this way so that it could read-ily be taken down. This feature was,no doubt, deemed to be a military ne-. TYPICAL TRESTLE BRIDGE USED IN ) CONSTRUCTION. these about 2,127 miles were made upof trestles. Speaking on this subjecthe says, The wooden bridge and thewooden trestle are. purely Americanproducts, although they were inventedby Leonardo da Vinci in the sixteenthcentury. A tree fallen across a stream was nodoubt the earliest suggestion of a bridgeoffered by Nature and from this theroughly hewed beam or plank withends resting on cither bank was prob-ably the origin of all forms of con- cessity at the time, for on a later daythe Romans hastily threw down thebridge over which the hostile army ofLars Porsena was about to enter thecity, and they accomplished the com-plete destruction of the bridge in theshort time that Horatius and twoRoman warriors were able to checkthe advance of the Etruscan host bylighting in single combat with threeantagonists at a time where they couldnot be
Size: 2613px × 956px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
