Caisson Bridge Casebook

Somewhere between two banks an engineer once stood with chalk and doubt, and drew a line where nothing had ever stood. Caisson Bridge Casebook keeps those lines: stone arches Rome left standing for two thousand years, iron trusses that rattled under the first locomotives, cable spans that hang whole cities in the air. Each bridge arrives as a plate from a drafting table, thin outlines, cool harbour blues, measurements set in narrow figures. Open one and you get the year, the river, the engineer who signed the drawings, and the quiet reason the span holds itself up. The Casebook opens as a chart room: a Span of the Day plate, then panels leading to the Atlas of bridges sorted by structural type, the Load Bench, your Crossings and the Assay. On the Load Bench you tilt the phone and watch a deck answer, the arch pressing its load into the abutments, the suspension cable pulling it up to the towers, the cantilever balancing out over nothing, with the readings shifting as you lean. Crossings is your own field record: photograph a bridge you walked over, name it, note the water beneath, keep the date. The Assay asks about spans, spandrels and the people who calculated them, and explains every answer afterwards. Everything sits on the device, offline, ready the moment it opens.