Section 2 of 5
Trusses
Each type solves a different problem. 6 guides, filed by what the structure is doing rather than by where the bridge is.
In this section
- The Truss Is the BridgeThe roof gets the attention; the truss does the work. How a triangulated frame turns bending into tension and compression, and why that lets timber span further than a beam.
- The Burr ArchAn arch superimposed on a truss so the two share the load. Common, effective, and argued about ever since.
- The Town LatticeA criss-cross of planks pinned with treenails, patented so it could be built by anyone with sawn lumber and no fine joinery.
- Howe and PrattWhich members take tension and which take compression — the distinction that decides where iron replaces wood.
- Smith and ChildsLater proprietary types sold as kits with instructions. What standardisation did to bridge building.
- The Longest Covered Span in the CountrySmolen–Gulf, its length, and what building at that scale demands of a timber structure.
Every entry names the truss and what that truss solves. The roof is treated as the engineering decision it was: timber lasts decades dry and years wet.