401W1 Winch Drive Planetary Gearbox Reducer — Single-Stage

At 1,300 Nm output, the 401W1 handles drum torques that the 400W1 (870 Nm) cannot reach — extending the single-stage winch drive envelope from approximately 540 kg maximum line pull on a 300 mm PCD drum up to approximately 800 kg. Combined with FEM M5 continuous-duty rating, 96% mechanical efficiency, and compatibility with axial piston, orbit, and electric motors, the 401W1 serves the mid-range hoisting applications on construction sites, offshore platforms, and marine vessels where the single-stage compactness (58 kg, short axial length) is as important as the torque and brake capacity.

① Calculate the maximum suspended torque

T(load) = maximum personnel load x gravity x drum PCD radius. For a 4-person rescue basket at 400 kg (4 x 80 kg + 80 kg basket) on a 250 mm PCD drum: T(load) = 400 x 9.81 x 0.125 = 490 Nm at the drum.

② Calculate the brake holding torque at the drum

T(brake at drum) = brake torque x gear ratio. For the 401W1: T(brake at drum) = 270 x 6.2 = 1,674 Nm at the drum.

③ Verify the safety factor

SF = T(brake at drum) / T(load) = 1,674 / 490 = 3.42. Most jurisdictions require SF ≥ 1.5 for personnel lifting (EN 14492, ASME B30.7). The 401W1 exceeds this by a wide margin. The same calculation with the 400W1 (130 Nm brake): SF = 792 / 490 = 1.62 — compliant but with far less margin for dynamic loads, cable weight, and safety factor degradation over brake disc life.

Personnel Hoists and Man-Riding Winches

Construction site personnel hoists, window-cleaning platforms, and industrial man-riding winches that lift 2-4 workers plus tools to heights of 10-60 metres. The 401W1 270 Nm brake provides the safety factor margin that regulatory bodies (EN 14492, LOLER, ASME B30.7) require for any winch carrying human occupants. The single-stage compactness at 58 kg allows integration into the narrow drum housings that personnel hoists use to minimise the shaft footprint on the building facade.

Offshore Platform Winches

Utility winches on offshore oil and gas platforms, wind turbine installation vessels, and subsea construction spreads. These winches handle tool baskets, hose bundles, and equipment containers at heights and over water where a dropped load creates both a safety hazard and a marine pollution risk. The 401W1 sealed housing resists the salt spray and high-humidity environment that degrades open-gear winch mechanisms, while the 270 Nm brake meets the offshore industry standard for dual-brake or high-safety-factor single-brake installations on non-personnel lifting applications above water.

Marine Anchor and Mooring Winches

Small vessel anchor winches and mooring line tensioners on workboats, barges, and coastal vessels. The 401W1 at 1,300 Nm handles anchor weights up to approximately 600 kg on a standard 300 mm drum, with the 270 Nm brake holding the anchor against current and wave drift forces when the vessel is at station. The slewing drive planetary gearbox handles the deck crane rotation on the same vessel, and the marine auxiliary drives power the capstan and windlass.

Does the 401W1 require a second independent brake for personnel lifting?

Most jurisdictions (EN 14492-2, ASME B30.7) require two independent braking mechanisms for personnel hoisting: a primary service brake and a secondary emergency brake. The 401W1 integral 270 Nm brake serves as one of these two brakes. The second brake is typically provided by a motor-mounted brake, a separate calliper brake on the drum, or a counterbalance valve with an independent pressure-holding function in the hydraulic circuit. The specific dual-brake configuration must be validated against the applicable local standard before the winch is certified for man-riding.

What is the maximum personnel load the 401W1 can safely hold on a 300 mm PCD drum?

Brake holding torque at drum = 270 x 6.2 = 1,674 Nm. At 300 mm PCD (radius 0.15 m): maximum holdable line pull = 1,674 / 0.15 = 11,160 N = approximately 1,138 kg. With the regulatory 1.5x safety factor for personnel: maximum working load = 1,138 / 1.5 = 758 kg. This covers a 4-person work platform (4 x 80 kg workers + 80 kg platform + 120 kg tools and materials = 600 kg) with a 26% margin above the regulatory minimum.

How does brake disc wear affect the safety factor over time?

As the brake disc wears, the spring compression decreases and the brake torque reduces proportionally. A new 401W1 brake delivers 270 Nm. At the end of the disc service life (minimum thickness), the brake torque may have degraded to approximately 220-240 Nm. The safety factor calculation must be performed at the END-OF-LIFE brake torque, not the new-condition value. Inspect the brake disc at every 2,500-hour interval and replace when it reaches the minimum thickness marked on the disc. For personnel lifting, the inspection interval is typically mandated at 500-1,000 hours by the applicable lifting equipment regulation.

Can the 401W1 winch drive be used in an explosive atmosphere (ATEX/IECEx)?

The standard 401W1 is not ATEX/IECEx certified. For winches operating in explosive atmospheres (offshore oil and gas well service, chemical plants, grain handling), the hydraulic motor must be intrinsically safe (no electrical ignition source), and the gearbox housing must not generate surface temperatures exceeding the gas group T-class limit. The 401W1 housing surface temperature at continuous full-load duty is typically 40-55 deg C above ambient, which is within T4 class limits (135 deg C surface) in most ambient conditions. Contact Κορέα Ever-Power for a thermal assessment if ATEX compliance is required.

What hydraulic motor displacement pairs best with the 401W1 for a 15 m/min hoisting speed?

At 15 m/min on a 250 mm PCD drum: required drum speed = 15 / (3.14 x 0.25) = 19.1 rpm. Motor speed = 19.1 x 6.2 = 118.4 rpm. If the available pump flow is 30 L/min: motor displacement = 30,000 / 118.4 = 253 cc/rev. This is a standard low-speed, high-torque orbit motor size (for example, Eaton Char-Lynn 2000 series, Danfoss OMP/OMR 250). For higher hoisting speeds, increase the pump flow or reduce the motor displacement — the 401W1 input speed limit of 1,000 rpm is rarely the constraining factor in single-stage winch applications.

How does the winch drive planetary gearbox handle shock loading from a sudden load pickup?

A sudden load pickup (for example, lifting a load off the ground with slack cable) generates a torque spike at the drum that can reach 2-3 times the steady-state lifting torque. The 401W1 is rated at 1,300 Nm continuous, with a peak capacity of approximately 2,600 Nm for transient events. This covers normal pickup shocks. However, snatch loading (deliberately jerking a stuck load free) can produce torques exceeding 5x steady-state — this is outside the gearbox design envelope and risks permanent gear damage. Use a load-limiting valve in the hydraulic circuit to prevent snatch-load torques from reaching the gearbox.

Man-riding winch on an offshore platform utility crane. The 401W1 brake safety factor calculation came in at 2.8 for our maximum personnel load — well above the LOLER minimum of 1.5 and comfortably within our company standard of 2.0. The unit passed the 6-monthly thorough examination without any findings across the first two inspections. Brake engagement is consistent and the holding test (full load, 10-minute static hold) showed zero drift. For a personnel lifting application, that consistency is everything.

Anchor winch for a 35-metre aluminium patrol vessel. The 401W1 handles a 280 kg anchor on 60 metres of 12 mm chain at 8 m/min hoisting speed. The sealed housing was essential — the winch is mounted on the foredeck and takes green water over the bow in heavy weather. After 14 months including two typhoon seasons, the seals are intact and the oil is clean. The 270 Nm brake holds the anchor against 3-knot current drift without any creep. Class survey passed without comment.

Window-cleaning platform winch for a 22-storey commercial building. The 401W1 lifts two technicians plus equipment (total 320 kg) at 12 m/min. The brake safety factor certified at 3.1 — exceeding our insurance company minimum of 2.5 for suspended personnel platforms. The 4-star rating is because the technical documentation supplied with the unit did not include a pre-formatted brake safety factor certificate template. For personnel lifting, the end user always needs this document for their safety file and having a template pre-filled with the unit serial number, brake torque, and ratio would save approximately 2 hours of administrative time per installation. The drive itself is mechanically sound and the certification process was smooth once we prepared the documentation manually.