By MAURIPRO Sailing Specialists · Updated July 2026
How Does a Sailboat Winch Work?
A sailing winch converts rotational input from a winch handle (or an electric motor in powered units) into high mechanical advantage through an internal gear train and ratcheting pawl system. When you wrap a line around the drum and turn the handle clockwise, internal pawls engage a toothed ring gear, transmitting force to the drum while preventing reverse slip. Most Andersen models use a three-pawl primary stage and a six-pawl secondary stage, delivering gear ratios between 1:1 and up to 50:1 depending on winch size.
Self-tailing winches add a fixed stripper arm and a rotating jaw at the top of the drum that grips the tail of the line automatically, freeing one hand during trimming. Electric boat winches replace manual handle input with a 12V or 24V DC motor mounted below or inside the drum housing, activated by a push-button or remote switch at the cockpit. The core mechanical operation — pawls, drum, gear stages — is identical between manual and electric variants.
Standalone answer: A sailboat winch works by translating rotational force through a pawl-and-gear system inside a drum, multiplying load capacity while a self-tailing jaw or electric motor handles line tension automatically.
Self-Tailing vs Electric: Which Andersen Winch Do You Need?
When a Self-Tailing Winch Is the Right Choice
A self tailing winch is the standard choice for most cruising and racing sailboats under 50 feet where crew is available to grind. Andersen's self-tailing range covers sizes #8 through #62, with the mid-range #16 through #28 models being the most common fitment on 30–45 foot cruiser-racers. The self-tailing jaw on Andersen units is adjustable for line diameters from 6mm to 16mm, and the three-speed gearing (available on #28 and larger) provides low-effort fine-trimming on upwind legs without switching handle modes.
Compared to a Harken winch in the same size class, Andersen self-tailers are noted for a stiffer jaw grip under load and a fully sealed drum base that resists saltwater ingress in offshore conditions. The stainless steel drum construction eliminates anodizing wear — a common failure point on aluminum-drum competitors — making Andersen a preferred choice for bluewater sailors who prioritize longevity over minimum weight.
When to Upgrade to Electric Boat Winches
Electric boat winches make the most sense on shorthanded cruising boats over 40 feet, where genoa loads regularly exceed 800–1,000 lbs and two-speed manual grinding is physically exhausting. Andersen's electric range operates on 12V or 24V DC systems, with 24V recommended for boats over 45 feet to reduce current draw and cable sizing requirements. A 24V Andersen electric unit on a 50-foot boat draws approximately 40–60 amps under peak load, which means your battery bank and charging system must be sized accordingly before installation.
A power winch also dramatically improves safety when sailing shorthanded at night or in heavy weather, where a tired crew member can manage sail trim at the push of a button rather than grinding under load. Electric models retain full manual operation capability — insert a standard boat winch handle and they function identically to a manual self-tailer, which is essential redundancy offshore.
Standalone answer: Choose a self-tailing Andersen winch for crewed boats under 50 feet; upgrade to an electric model for shorthanded passages, boats over 40 feet, or when sheet loads consistently exceed 800 lbs.
How Are Sailboat Winches Sized? Andersen Sizing by Boat Length and Sail Area
Andersen uses a numerical sizing system where the winch number corresponds directly to the maximum working load in hundreds of kilograms at the lowest gear ratio. A #16 winch handles up to 1,600 kg (3,527 lbs) at maximum mechanical advantage; a #40 handles up to 4,000 kg (8,818 lbs). The practical rule of thumb is to calculate your maximum sheet load — roughly 0.00431 × sail area (sq ft) × wind speed² (knots) in pounds — and select a winch whose rated load exceeds that figure by at least 25%.
| Boat Length / Type | Typical Sail Area | Recommended Andersen Size |
|---|---|---|
| 25–30 ft daysailer / racer | 250–350 sq ft | #8 or #10 |
| 30–38 ft cruiser-racer | 350–550 sq ft | #16 or #22 |
| 38–50 ft bluewater cruiser | 550–900 sq ft | #28 or #40 |
| 50–65 ft offshore / performance | 900–1,400 sq ft | #46 or #62 |
Halyard winches are typically sized one step down from sheet winches on the same boat, since halyard loads are more constant and less dynamic than sheet loads during tacking. Always verify your line diameter falls within the drum's recommended range — Andersen drums accept 8–14mm on mid-size units and up to 18mm on #46 and larger models.
Standalone answer: Size an Andersen winch by matching its load rating (winch number × 100 kg) to at least 125% of your calculated maximum sheet load for the boat's sail area and typical wind conditions.
How to Use a Sailboat Winch: Self-Tailing Operation Step by Step
- Lead the line: Ensure the sheet or halyard leads to the winch drum at a fair angle — 5–10° below horizontal — to prevent riding turns.
- Wrap the drum: Take 3–4 clockwise turns around the drum before loading. Never fewer than 3 under load.
- Seat the self-tailer: Feed the tail up through the stripper arm and seat it firmly in the jaw. The jaw should grip without slipping when you apply light hand tension.
- Insert the winch handle: Use a standard or locking winch handle — Andersen drums accept both standard 12mm square-drive and locking-type handles.
- Grind in gear: Clockwise rotation engages power mode. On three-speed winches, switch direction of handle rotation to shift between gear ratios without removing the handle.
- Ease carefully: To ease, palm the drum while using the self-tailer jaw as a brake — never release the tail suddenly under heavy load.
Standalone answer: To use an Andersen self-tailing winch, take 3–4 clockwise wraps, seat the line in the jaw, insert a winch handle, and grind clockwise — switching handle rotation direction changes gear ratios on three-speed models.
Andersen Winch Maintenance: Stainless Steel Construction and Service Intervals
One of the core advantages of Andersen Sailboat Winches over competitors is their all-stainless-steel drum and top-cap construction, which eliminates the galvanic corrosion and anodizing degradation common on aluminum-drum sailboat winches. Andersen recommends a full strip-and-regrease service every 12 months for boats sailed in saltwater, and every 24 months for freshwater or light-use vessels. The internal components — pawl springs, pawls, and bearing races — are accessible after removing the top cap and drum, which requires no special tools beyond a rubber mallet and a circlip pliers.
Use a waterproof marine grease (Andersen specifies a lithium-complex NLGI Grade 2 grease) on all bearing surfaces and a light dry lubricant on pawl springs to avoid attracting grit. Never use WD-40 or penetrating oils inside a winch — they dissolve grease and cause pawl failure. After reassembly, test all gear stages under light load before returning the boat to sailing. With correct maintenance intervals, an Andersen stainless drum winch should deliver 15–20 years of reliable service in offshore conditions, significantly outlasting painted or anodized aluminum alternatives.
Standalone answer: Andersen winches require a full strip-and-regrease service every 12 months in saltwater use, applying NLGI Grade 2 lithium-complex marine grease to bearings and a dry lubricant on pawl springs.
Frequently Asked Questions
How are Andersen sailboat winches sized?
Andersen winches are sized using a power ratio system that matches the winch's mechanical advantage to your boat's sheet loads, typically calculated from sail area, boat length, and line diameter. A larger power ratio number means more mechanical advantage but slower retrieval. MAURIPRO recommends using Andersen's official sizing guide, which cross-references these variables to select the correct winch model for your rig.
How does an Andersen self-tailing winch work?
Andersen self-tailing winches use a rotating stripper arm and jaws at the top of the drum to automatically grip and feed line as you crank, eliminating the need for a second crew member to tail the sheet. The drum's internal gear system — typically two or three speeds — multiplies your input force. MAURIPRO carries Andersen self-tailers in aluminum and stainless steel across multiple sizes for both racing and cruising applications.
When should I choose an Andersen electric winch over a self-tailing winch?
Andersen electric winches are the right choice when shorthanded sailing, offshore passages, or physically demanding sail handling makes manual cranking impractical or unsafe. Electric models handle the same line sizes and loads as manual self-tailers but add push-button power for heavy headsails or main halyards. MAURIPRO recommends Andersen electric winches for bluewater cruisers and performance boats over 40 feet where load demands regularly exceed 600 kg.
How many Andersen winches do I need on a sailboat?
Most sailboats require a minimum of two primary winches for headsail sheets, plus additional winches for halyards, reefing lines, and the mainsheet depending on rig complexity. Andersen offers single-speed, two-speed, and three-speed models to suit each position's specific load and speed requirements. MAURIPRO advises consulting Andersen's sizing chart to match each winch position to its expected line load rather than fitting identical units throughout.
Can I retrofit an Andersen electric winch where a manual self-tailing winch is currently installed?
Andersen electric winches are designed with standardized base footprints that often allow direct retrofit onto existing manual self-tailing winch mounts, provided the deck structure supports the added weight and wiring access is feasible. Electrical requirements typically include a dedicated 12V or 24V DC circuit rated for the specific model's peak amperage draw. MAURIPRO recommends verifying your boat's mounting pattern and electrical system capacity before selecting an Andersen electric winch for retrofit installation.
Questions? We're Here to Help
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