Windlass

8 min read

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Combined Machines
Complex mechanisms
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Windlass
Drum and handle lifting

Windlass

Part of Simple Machines

Building and using a windlass — a drum-and-handle lifting device for wells, construction, and hauling.

Why This Matters

The windlass is the oldest and most widespread well-lifting device in the world. Every well, from ancient Mesopotamia to 19th-century farmsteads, used some form of windlass to raise water. It is also one of the most useful general-purpose lifting and hauling devices available: a properly built windlass can raise water from 30-meter wells, haul stone up construction scaffolding, tension heavy ropes, and pull stumps from the ground.

The windlass applies the wheel-and-axle principle in its most direct form. The handle (crank arm) is the wheel; the drum around which the rope winds is the axle. The mechanical advantage equals the handle length divided by the drum radius. A 40 cm handle arm on a 6 cm drum radius gives MA = 40/6 = 6.7:1. Every turn of the handle raises 2π × 6 cm = 37.7 cm of rope.

What makes the windlass practical beyond the simple winch is the addition of holding mechanisms (ratchet, brake, or pawl) and the arrangement for continuous rope travel without running out of rope — the continuous winding drum accommodates many meters of rope, unlike a simple lever arrangement.

Basic Components

Drum: A cylinder around which the rope winds. Larger diameter = more rope per turn but less MA. Smaller diameter = more MA but less rope per turn.

Axle: The shaft on which the drum rotates, or (in the traditional windlass design) the drum and axle are one piece — a cylinder with an axle extending from each end.

Bearings: Two support points that hold the axle while allowing it to rotate. These carry the full load.

Handle/crank: The turning mechanism. Can be a fixed crank arm, removable handle bars, or a large diameter wheel for continuous turning.

Pawl and ratchet: Prevents the drum from unwinding under load when the operator releases the handle.

Building a Simple Well Windlass

This design is for a well windlass, but the same structure serves construction and hauling uses.

The Drum

  1. Select a sound hardwood log, 15-25 cm diameter, 60-80 cm long
  2. Debark and smooth the surface
  3. The log itself is the drum — rope winds around its cylindrical surface
  4. At each end, cut or carve a short axle stub (5-7 cm diameter, 10-15 cm long) — these are what the bearings will hold
  5. Alternatively, drill a central axle hole through the log end-to-end and insert an iron axle rod. This is more durable but requires more precision.

Rope groove options:

  • A plain cylindrical drum works for well windlasses where the rope winds in layers
  • For single-layer winding (more control, less bulk), cut a helical groove around the drum surface — the rope sits in the groove and winds in a single, orderly layer

The Bearing Frame

For a well windlass, the frame straddles the well opening.

  1. Set two heavy timber uprights (10 × 10 cm or larger) on each side of the well, at the same height. They should rise 40-60 cm above the well curb to allow the bucket to clear the rim.
  2. Cut a bearing notch or hole in the top of each upright to receive the drum’s axle stub
  3. The bearing must be:
    • Deep enough that the axle cannot jump out under load
    • Smooth and lubricated to reduce friction
    • Strong enough to carry the full load plus shock from the rope snapping tight

Bearing material options:

  • Simple notch in hardwood upright (adequate for light use, high friction)
  • Iron U-strap mortised into the upright (better — iron bears against iron axle stub)
  • Hollow iron socket bolted to the upright (best — provides a guided bearing surface)
  1. Connect the two uprights with a cross-brace at the top (prevents them from spreading under load)
  2. Secure the uprights to the well curb structure so they cannot tip inward

The Handle

Simple crank arm:

  1. Drill a hole through the drum axle or the drum end, perpendicular to the drum axis
  2. Insert a handle bar: an iron rod with a bent handle end, or a shaped hardwood bar
  3. The handle projects 30-50 cm from the drum axis — this is the “wheel radius” for MA calculation

Removable handle bars: For heavy use where a long handle arm gives too much MA (too slow) for light loads:

  • Drill two holes at different radii
  • Use the inner hole for heavy lifting (more MA), outer hole for fast hauling of lighter loads

Double-handle (for very heavy loads):

  • Two people at the handles (one on each side) double the available input force
  • The handles must be positioned so neither person is struck as the other turns

The Pawl and Ratchet

Without a holding mechanism, the drum will unwind rapidly under load the moment you release the handle — the weight falls, the rope whips, and there is real danger of injury.

Building the ratchet:

  1. From iron plate or hard dense wood, cut a disc 12-16 cm diameter
  2. Around the circumference, file or chisel notches: each notch has a vertical face (to catch the pawl) and an angled face (to allow one-direction movement). Notch depth: 8-12 mm, notch spacing: 3-5 cm around the rim, giving 10-16 notches total.
  3. Mount the ratchet disc on the drum axle, fixed so it rotates with the drum

Building the pawl:

  1. From iron, carve, or cut a simple pivot arm 8-12 cm long
  2. One end has the tooth that engages the ratchet notches
  3. The other end pivots on a pin fixed to the bearing frame (the pawl must pivot on the frame, not the drum)
  4. A simple spring — a bent strip of springy hardwood or a piece of spring iron — holds the pawl tip against the ratchet surface

Directional setting:

  • The ratchet notch geometry determines which direction is held (locked) and which direction is free (allowed to turn)
  • The vertical notch face must face the direction of unloading (the direction the rope would pull the drum if released)
  • Test before loading: turn in the “lifting” direction — the pawl should ride over the notch ramps smoothly. Turn in the “dropping” direction — the pawl should catch immediately.

Rope Attachment

The rope must be attached firmly to the drum so it cannot slip when the drum rotates.

  1. Drill a small hole through the drum surface
  2. Thread the rope end through the hole
  3. Tie an overhand knot (a stopper knot) in the rope end that cannot pass back through the hole
  4. Wind several turns of rope around the drum before attaching the load — the friction of the wraps holds the rope against sliding even if the knot end is under less tension

Operational Use

For wells:

  1. Attach the bucket to the free end of the rope
  2. Release the pawl and lower the bucket hand-over-hand (allow the drum to turn backward slowly, controlling descent with your hand on the drum)
  3. OR: if the well is deep, install a second pawl on the opposite side of the ratchet that locks in the lowering direction — this allows controlled lowering by unclicking the pawl one tooth at a time
  4. When the bucket hits water, release completely and let it fill
  5. Re-engage the lifting pawl
  6. Turn the handle to raise the bucket

For construction hauling:

  1. Anchor the windlass frame firmly (bolt to a beam, brace against a wall, or weight down with heavy stones)
  2. Thread the rope through any redirecting pulleys needed to reach the load
  3. Attach load
  4. Turn the handle; the pawl holds the load whenever you pause
  5. Lower by controlled pawl-release if needed

Longer Rope Needs Larger Drum

A 30-meter well requires winding 30+ meters of rope. This builds up in layers on the drum. Each layer increases the effective drum radius, changing the MA. If this matters for your application, use a very large drum (20-30 cm diameter) so the MA change with layers is proportionally smaller. For construction lifting (short distances), a small drum gives more MA and the layer buildup is minimal.

Maintenance

Daily:

  • Inspect rope at the drum attachment point (highest stress location)
  • Check pawl engagement — the tooth should seat fully in each ratchet notch
  • Feel for bearing heat after use — warmth indicates insufficient lubrication

Monthly:

  • Grease bearing surfaces
  • Inspect all structural joints for loosening
  • Check the drum for cracks (wood) or corrosion (iron)

Rope replacement: Replace the rope when you see more than 10% of the outer fibers are frayed or cut in any 1-meter section. A well rope that fails drops the bucket and potentially kills anyone at the bottom of the well during a repair. Replace proactively, not reactively.