Recent Blogs
Leg-of-mutton Sail Mechanism Explained: How It Works, Parts, Uses, and Aerodynamic Force Diagram
A historical leg-of-mutton sail profile with a first-order lift-only calculator using triangular area, wind speed, entered lift coefficient and declared mathematical axes.
Lateen-rigged Felucca Mechanism Explained: Sail Diagram, Parts, Rig Geometry & Uses
Explore the two-masted lateen-rigged felucca and an interactive yard-hoisting diagram with adjustable yard, mast, halyard and rake proportions.
Floating Dry-dock: Ballast, Buoyancy and Ship Support | FIRGELLI
Learn how a floating dry-dock lifts a supported vessel. Distinguish displaced-water volume from ballast pump-out volume using a clear buoyancy example.
Stevedore Knot Mechanism Explained: How It Works, Parts, Uses, and Sheave Jam Calculator
Learn how the Stevedore Knot works as a stopper knot for sailing rigs and load handling, with sizing rules, worked examples, and comparison to figure-8...
Steam Fire Engine Mechanism: How a Steam-Powered Pump Works, Parts, Diagram and Calculator
Steam Fire Engine explained — how the boiler, pump, and steam cylinder deliver firefighting water pressure, with a worked example for municipal brigades.
Single Eccentric Reversing Gear: How It Works, Diagram, Parts, Formula and Uses Explained
Single Eccentric Reversing Gear explained — how Stephenson-era engineers reversed steam locomotives with one eccentric, slip-link, and gab hook. Diagrams, math, examples.
Ship's Steering Gear Mechanism: How Rapson Slide Hydraulic Rudder Actuators Work
How a ship's steering gear works — hydraulic rams, rapson slide geometry, torque sizing, and real examples from cargo ships, ferries and naval vessels.
Screw Anchor Mechanism Explained: How Helical Ground Anchors Work, Parts, Uses & Torque Formula
Screw anchors hold signs, guardrails and utility poles by threading helical plates into soil — here's how they work, the holding-capacity formula and field examples.
Schooner Rig Explained: How a Two-Masted Fore-and-Aft Sail Plan Works, Parts and Drive Force
Schooner rig explained — how the fore-and-aft two-mast layout drives offshore sail-training vessels, with sail-area math, worked example, and trade-offs.
Pivoted Step: Declared Point-Load Moment Geometry
Pivoted steps swing out of the way under load or for storage. Learn how engineers size them for buses, fire trucks, RVs, and rail platforms.
Pirogue: Displacement and Rectangular-Prism Comparison
Pirogue design explained — hull geometry, paddling load, stability limits, and real-world use from Louisiana bayous to West African fishing fleets.
Ice Bicycle: Historical Attachment and Coefficient Comparison | FIRGELLI
Read about Hiscox’s runner-and-toothed-rim ice bicycle and compare two entered friction coefficients. Traction, stopping distance and safe riding conditions are not calculated.
Fleming Loop Mechanism Explained: How Curved Road Alignments Bypass Obstacles
Fleming Loop explained — how this navigation deviation routes traffic around fixed obstacles, with formulas, worked examples, and real road-design applications.
Boat-detaching Hook: Historical Mechanism & Lever Calculator
Explore a historical boat-detaching hook with a hinged tongue, retaining eye and release lever. Compare ideal lever force and attachment-point travel.
Vertical Bucket Wheel: Ideal Water-delivery Calculator
Explore bucket pickup and delivery. Calculate ideal carried volume, rim speed and hydraulic power using an assumed lift of 0.85 wheel diameter; actual wheel performance...
Two-masted Lug Rig: Ideal Lift and Component Comparison
Explore a dipping foresail and standing mizzen. Compare an ideal lift magnitude and selected component without predicting boat speed, rig loads or reefing limits.
Topsail Schooner: Historical Rig and Sail-area Comparison
Explore a square-topsail schooner rig and compare entered sail area with displacement. Also convert weight and compare area and angle inputs; no sailing performance is...
Timber Hitch: Rope Arrangement and Illustrative Geometry
Explore the timber-hitch rope arrangement and illustrative wrap dimensions. The calculator does not predict grip, capacity or safe rigging.
Rolling Thrust Bearing: Basic L10 Rating-life Calculator
Calculate basic rolling-bearing L10 life from catalogue rating, equivalent axial load and constant speed. The calculation does not guarantee service life or select a bearing.
Three-quarter Lug Rig: Historical Two-mast Arrangement
Explore Hiscox’s two-mast rig with two lug sails and a bowsprit-stayed jib. Adjust an illustrative mast layout; sail forces and performance are not calculated.
Cutter Sailing Rig: Sail-area and Displacement Ratios
Explore a traditional cutter rig, calculate conventional sail-area/displacement and displacement/length ratios, and compare a chosen headsail-area allocation.
Ten-wheel Freight Locomotive: Historical Tractive-force Estimate
Explore the 4-6-0 wheel arrangement and a historical starting-force estimate from cylinder size, pressure and driver diameter. Actual train capacity is not predicted.
Swinging Oar-lock: Ideal Pin-force Calculator
Explore ideal oarlock force from handle force and inboard/outboard lengths. Compare a perpendicular-force scenario without inferring hardware capacity.
Swinging Ball-bearing Pedal: Basic Bearing-life Calculator
Explore a historical ball-bearing pedal and a generic L10 calculation. Compare basic rating life from dynamic rating, equivalent bearing load and relative speed.
Streetcar Sand Box: Animation and Adhesion Comparison | FIRGELLI
Follow a rail sander’s hopper, valve and delivery pipe. Compare two ideal stopping distances from entered speed and adhesion coefficients.