Truss bridge design hits the minds of people who often think about historic bridges. The picturesque design of the truss bridge lends itself an almost global appeal. For several years, historians and travelogues alike have documented the truss bridge and promoted its preservation the most, compared to any other type of bridge. For centuries, timber was used as primary material for building trusses, perhaps also for truss bridges. Later, wooden trusses were recommended for the bridge.
During the late 1700s, construction companies started erecting wooden truss bridges across the States, and half a century later, America became the global pioneer in the wooden truss design. Several factors contributed to wooden truss bridge design's quick rise in America. During mid-1700s, America had a weak transportation system, and this limited system was further deteriorated by the Revolutionary War. During the late 1700s, America required a much improved and expanded system. In addition, men and timber for milling timber were limitless, despite the iron industry not having widespread influence. Therefore, wooden truss bridges turned out the ideal solution.
During early 19th century, different builders came up with multiple bridge designs for promotion. Thanks to the highly fluidic and competitive industry, almost all builders projected their offerings to be economical, easy to build and feasible for extended lengths. At this time, builders had little knowledge about truss bridge mechanism and their limitations. Therefore, for additional length and increased strength, builders commonly resorted to a truss and arch combination design, often referred to as "hump" or "camelback" bridges, due to the arch appearance. Recommended website for more info.
Contrary to popular belief, builders originally didn't cover wooden truss designs. The covering offered lateral bracing, which made the whole structure more wind shear-resistant. However, the covering existed primarily for protecting the truss from weatherization. Normal lifespans of covered bridges were at least 30 years; the non-covered versions would barely last 10 years. But, chemical preservatives like creosote, when applied to timber, could also offer shelter from weatherization. At the start of the 20th century, builders started using creosote more than the actual cover.
Several patented truss variants started emerging during the 1800s: Town lattice truss and Howe truss, to name a few. Ithiel Town's lattice truss was easy to construct and simple, which made many builders opt for it. The Howe truss was another popular truss variant, which was based on stress analysis data. The truss used vertical tension metal rods and diagonal timber compression members. This combined use of wood and metal materials for the bridge was called "combination truss", and it was a major transitional element in all-metal truss' eventual development. Howe truss' popularity was, to an extent, attributable to its comparatively simple build. The design negated the requirement for carpenters to peg and notch wooden jointed bridges, courtesy the use of basic connection junction boxes and vertical threaded iron rods.
Wooden truss bridges made it easier to efficiently span large crossings. The bridges not just facilitated transportation, but increased interest and awareness in bridge building as well. Consequentially, builders created various truss types and several wooden bridges throughout the 19th century.
During the late 1700s, construction companies started erecting wooden truss bridges across the States, and half a century later, America became the global pioneer in the wooden truss design. Several factors contributed to wooden truss bridge design's quick rise in America. During mid-1700s, America had a weak transportation system, and this limited system was further deteriorated by the Revolutionary War. During the late 1700s, America required a much improved and expanded system. In addition, men and timber for milling timber were limitless, despite the iron industry not having widespread influence. Therefore, wooden truss bridges turned out the ideal solution.
During early 19th century, different builders came up with multiple bridge designs for promotion. Thanks to the highly fluidic and competitive industry, almost all builders projected their offerings to be economical, easy to build and feasible for extended lengths. At this time, builders had little knowledge about truss bridge mechanism and their limitations. Therefore, for additional length and increased strength, builders commonly resorted to a truss and arch combination design, often referred to as "hump" or "camelback" bridges, due to the arch appearance. Recommended website for more info.
Contrary to popular belief, builders originally didn't cover wooden truss designs. The covering offered lateral bracing, which made the whole structure more wind shear-resistant. However, the covering existed primarily for protecting the truss from weatherization. Normal lifespans of covered bridges were at least 30 years; the non-covered versions would barely last 10 years. But, chemical preservatives like creosote, when applied to timber, could also offer shelter from weatherization. At the start of the 20th century, builders started using creosote more than the actual cover.
Several patented truss variants started emerging during the 1800s: Town lattice truss and Howe truss, to name a few. Ithiel Town's lattice truss was easy to construct and simple, which made many builders opt for it. The Howe truss was another popular truss variant, which was based on stress analysis data. The truss used vertical tension metal rods and diagonal timber compression members. This combined use of wood and metal materials for the bridge was called "combination truss", and it was a major transitional element in all-metal truss' eventual development. Howe truss' popularity was, to an extent, attributable to its comparatively simple build. The design negated the requirement for carpenters to peg and notch wooden jointed bridges, courtesy the use of basic connection junction boxes and vertical threaded iron rods.
Wooden truss bridges made it easier to efficiently span large crossings. The bridges not just facilitated transportation, but increased interest and awareness in bridge building as well. Consequentially, builders created various truss types and several wooden bridges throughout the 19th century.
No comments:
Post a Comment