Recent Blogs
Timber Splicing: Illustrative Scarf and Bolt-hole Dimensions
Explore nominal scarf-joint and bolt-hole dimensions. This drawing tool does not select a structural repair, assess fit or calculate joint capacity.
Timber Arches: Ideal Three-hinged Tied-arch Equilibrium
Compare ideal horizontal thrust and vertical reactions for a symmetric three-hinged parabolic tied arch under uniform load. This is not a structural design calculation.
Swivelling Dumping Car: Ideal Payload-moment Calculator
Compare payload weight and its ideal moments at two horizontal offsets from a tipping axis. The tool does not predict self-dumping or safe payload.
Swivel Shackle Slip Hook: Force-vector Illustration
Explore hook and swivel concepts alongside an illustrative cosine product. The calculation does not determine WLL, allowable load or permitted load direction.
Swinging Derrick Crane: Load-moment Comparison
Compare load times horizontal radius with an entered moment reference. Explore ideal moment arithmetic and illustrated boom geometry without inferring crane capacity.
Swing-boom Crane: Ideal Load-moment Calculator
Compare load-plus-hoist and uniform-boom weight moments from entered weights and distances. Results are moment demands, not crane capacity ratings.
Swing Derrick: Radius and Ideal Swing Calculator
Explore boom projection and ideal swing motion. Compare working radius, an entered moment/radius quotient, angular speed and hook plan speed.
Swing Bridge: Ideal Opening-motion Calculator
Explore a symmetric center-pivot swing bridge. Calculate ideal opening time, angular speed, half-span tip arc and speed from a constant entered slew rate.
Stone Grinding and Polishing: Guided-lap Animation and Calculator
Explore a single guided annular lap with a sliding shaft and universal joints. Calculate rim speed, turn count, guide path and nominal disk area.
Steel Arched Concrete Bridge Mechanism: How Melan Composite Arches Work, Parts, and Thrust Diagram
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 Mechanism: How the Trunnion Pivot, Trip Latch, and Tipping Moment Work
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 Mechanism: How Scherzer Bascule Spans Roll Open with Diagram and Calculator
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 Mechanism: How It Works, Diagram, Parts and Uses Explained
Calculate turnbuckle take-up from equal thread pitch and body rotation. Opposite-hand threads move both ends, doubling the travel per revolution.
Releasing Grip: Latch Animation and Force-Ratio Calculator
Follow a hook-and-latch illustration and compare load divided by an entered force ratio. Includes a worked example and clear limits on what the calculation predicts.
Queen-Post Roof Truss: Ideal Apex-Joint Screen
Queen Post Roof Truss explained — geometry, loads, span limits, and a worked example for residential and barn construction. Practical engineering from FIRGELLI.
Twin-Shaft Pugmill: Hold-Up, Throughput, and Shaft-Turn Ledger
Pug mill explained — how the mixing shaft, paddles and discharge work in ceramics, brick making and soil stabilisation, with sizing math and a worked...
Post Crane: Declared Load and Boom Moment Ledger
A Post Crane is a fixed-mast jib crane for fence posts, utility poles and tower work. See how it works, lift formula, real applications and...
Post Auger: Exact Single-Start Helical Flight Geometry
Post auger mechanics for fence builders, utility crews, and solar installers — torque, flight geometry, soil class limits, and how to size a drive head...
Portable Steam Derrick: Ideal Reeving and Boom Geometry
Portable steam derrick explained — how the boiler, hoisting drum and guyed mast lift heavy loads on construction sites, quarries and rail yards.
Pneumatic Dumping Car: Exact Pivot-and-Cylinder Geometry
Pneumatic dumping car explained — how compressed-air tipping skips work in mining, tunnelling, and foundry haulage, with formulas, sizing, and real-world examples.
Package Elevator (VRC): Declared Two-Post Layout
Explore a material-only two-post VRC. Calculate equal landing spacing and rectangular carriage area and perimeter from entered layout dimensions.
Melan Arch Bridge: Embedded Steel Ribs and Ideal Arch Reactions
Explore the Melan system of curved steel ribs embedded in concrete, with a separate calculator for ideal three-hinged parabolic-arch support reactions.
Log Sawing Machine Mechanism: How a Bandsaw Mill Works, Feed Rate Formula, Diagram and Calculator
Explore a band head saw and log carriage. Calculate tooth-pass frequency and implied feed from band speed, teeth per inch and an entered bite per...
Lever Grip-Tongs: Hiscox Item 1461 Motion Viewer
See how shackle pull closes lever grip-tongs through their connecting links and upper arms. Compare three schematic positions without a lifting-capacity claim.
Hydraulic Sand Ejector: Flow Paths and Unit Calculator | FIRGELLI
Explore a filter-sand ejector illustration and convert pressure and diameter into freshwater head and circular area. Slurry flow and sand capacity are not calculated.