Recent Blogs
Wooden Road Bridge Truss
Wooden road bridge truss explained — how timber chord and web members carry traffic loads, with sizing math, real spans, and a worked rural-road example.
Suspension Bridges
Suspension bridges carry deck loads through main cables into anchorages. Learn the cable mechanics, sag ratio math, and real spans engineers use to size them.
Shears with Winch or Tackle Block
How a shears lifting rig works — the geometry, the tackle block math, and how riggers use it to set heavy loads on bridges, masts,...
Deck Bridge Trusses
Deck bridge trusses carry traffic on the top chord with the truss below. Learn the engineering, span ranges, and real highway and rail bridge examples.
Bridge Truss
Bridge Truss explained — how the chord and web members carry load, design formulas, real span examples, and how civil engineers size and detail them.
Lewis (stone Lifting Wedge)
The Lewis stone lifting wedge lets masons lift multi-ton blocks from a single socket. Learn the geometry, load math, and how Roman and modern crews...
Wharf Crane
How a Wharf Crane works — luffing geometry, slewing drives, and load curves used by port operators to transfer 40-80 tonne containers and bulk cargo...
Truss Roof
Truss roofs span wide structures using triangulated members in pure tension and compression. See how engineers size them, with a worked example.
Toggle Stump Puller
Toggle stump puller explained — how the over-centre toggle multiplies pull force, sizing math, real land-clearing examples, and field troubleshooting tips.
Timber Splicing
Timber splicing joins two timbers end-to-end to transfer load across the joint. Learn scarf, halved, and bolted splices used in heavy timber framing.
Timber Cords and Arches
Timber cords and arches explained — how laminated timber arches carry roof loads in gymnasiums, churches, and warehouses. Geometry, sizing, and failure modes.
Swivelling Dumping Car
How a Swivelling Dumping Car works in mining and construction haulage — tipping geometry, payload limits, and named site examples for muck removal.
Swivel Shackle Slip Hook
How a Swivel Shackle Slip Hook works, the geometry behind safe load release, and where rigging crews use it on logging, towing and crane jobs.
Swinging Derrick Crane
Swinging derrick cranes lift heavy loads in tight footprints. Learn the mast-and-boom geometry, slewing math, and real construction lift examples.
Swing-boom Crane
Swing-boom cranes pivot a fixed-length boom around a vertical mast to lift loads in tight construction sites, workshops, and loading docks. See specs and sizing.
Swing Derrick
Swing derrick explained — boom geometry, slewing radius, and load math for construction crews lifting heavy material on tight urban jobsites.
Swing Bridge
How a Swing Bridge works — pivot pier, slewing drive, wedge supports, and end-lift mechanics for movable bridges in marine and rail infrastructure.
Stone Grinding and Polishing Machine
How a Stone Grinding and Polishing Machine works — abrasive heads, contact pressure, feed rates, and real fabrication-shop sizing math for granite and marble slabs.
Steel Arched Concrete Bridge
Steel Arched Concrete Bridge explained — how steel ribs embedded in concrete carry load, design ranges, span limits, and real bridge engineering examples.
Square Box Side-dumping Car
Square box side-dumping cars tip their load sideways on construction and mining sites. See how the pivot, latch, and counterweight work, with real numbers.
Rolling Lift Bridge
Rolling lift bridge explained — how Scherzer-style bascule spans roll back on curved tread plates to clear shipping channels for rail and highway traffic.
Right and Left Hand Turnbuckle
Right and left hand turnbuckle explained — how the opposing threads tension cables, rigging, and guy wires, with sizing math and a real worked example.
Releasing Grip
Releasing grip mechanisms let construction crews drop loads on demand — how the trigger, jaw, and safety latch work in cranes, pile drivers, and lifting...
Queen Post Roof Truss
Queen Post Roof Truss explained — geometry, loads, span limits, and a worked example for residential and barn construction. Practical engineering from FIRGELLI.
Pug Mill
Pug mill explained — how the mixing shaft, paddles and discharge work in ceramics, brick making and soil stabilisation, with sizing math and a worked...