Electric Winch. Image Credit: IR | Capstan Winch. Image Credit: David Round | Hand Winch. Image Credit: David Round

 

Industrial winches are mechanical devices used to pull a heavy load, typically horizontally. They are used to pull in, let out, or otherwise adjust the tension of a rope or cable. Simple designs consist of a rope or cable wound around a drum or barrel. The drum rotates in a horizontal axis and may be powered by steam, a hydraulic motor, or an electric motor. Industrial winches are designed to move heavy loads and come in a variety of configurations. Most winch drums are made of fabricated steel and designed for a specific loading capacity.

How Winches Work


This video shows an industrial winch in use.
Video Credit: Summit Racing

 

Product Selection

The GlobalSpec SpecSearch database allows industrial buyers to select industrial winches by type of winch, type of gear, winch size, drum size, line type, brake type, performance specifications, power options, duty cycle, product options and additional features.

 

Types of Winches

There are several types of winches available to suit user needs. General winch types are described below.

  • Capstan winches have a vertical winch drum used for horizontal pulling. They allow for the line to be released from the drum at any angle, which is advantageous in maritime operations. Modern capstans can achieve high line pulls and high speeds. They are powered manually, electrically, hydraulically, or pneumatically.
  • Friction winches have two grooved drums arranged in-line to run the line using friction and a larger drum to reel in the rope for storage; the crushing pressure of the running rope under tension is taken by the grooved drums directly, without deforming any wire beneath as in conventional winch.

 

Friction Winch. Image Credit: Cranes

  • Hand winches are manual devices that are suitable for a variety of lighter-weight applications. They have a handle as a lever arm and barrel axis as the fulcrum.
  • Theater winches are designed for stage applications such as moving sets.
  • Utility winches are general-purpose devices that are suitable for a variety of lighter-weight applications.

Types of Gears

Three basic types of gears (spur worm, and planetary) are available for industrial windhes. The gear (also known as drivetrain) has an effect on winch operation, and should be considered when selecting a device. Below is a description of the types and the various features that will affect winch operation.

  • Planetary gearing is the most popular and affordable type of winch gear. The name comes from the design, which is similar to planets revolving around a sun. The winch uses a small planetary gear and a coaxial shaft capable of large reductions in a small space. This device is used for handling high bearing loads with smooth operation, and provides good resistance to torque loads. They are between worm and spur gear types for the amount of drivetrain friction and amp draw with a transfer efficiency of 65%.

    • Advantages
      • Low cost
      • Low weight
      • Compact size
      • Good resistance to torque loads
      • Smooth operation
    • Disadvantages
      • Brake required to hold load
      • Drum gets hot when spooling

    Planetary Gear. Image Credit: Wiki Commons

  • Worm Gearing provides high ratios by using right-angle shafting, two gears, and a self-locking mechanism. The device has a worm engaging a perpendicular worm wheel. The worm is restricted by fixed bearings and can only rotate without moving in an axial direction. The screw thread on the worm engages the teeth on the worm wheel and when rotated, the worm pulls or pushes the worm wheel, causing rotation. Worm gears are known for their endless endurance, high reliability, and a transfer efficiency of 35-40%. They are best used when large speed reduction ratio is desired, such as in electric winches and capstans.

    • Advantages
      • Self-braking
      • Good at lowering load under power
      • Robust drivetrains
    • Disadvantages
      • Mechanically less efficient
      • Heavier
      • Expensive
      • Difficult to mount
      • Slow line speed
      • Higher amp draw than planetary winches

 
Worm Gear. Image Credit: Howstuffworks.com

  • Spur Gearing is a simple gear using two or more parallel shafts with gears operating in the same plane. Generally, there is one large gear on the motor shaft and a smaller gear on the winch shaft. Spur gears are the most efficient type of winch gear with a75% transfer efficiency. Spur gearing produces less friction and greater efficiency than planetary and worm gearing, but requires a braking system.

    • Advantages
      • Most efficient
      • Fast
      • Do not need a strong break
      • Low internal gear friction
    • Disadvantages
      • Not easily mounted to vehicles
      • Expensive
      • Not widely available on the market

    Spur Gears. Image Credit: Promark Offroad

Winch Size

To accurately calculate the size of the winch that’s needed, buyers need to consider several specifications, including the weight of the item being winched. To gain a better understanding of the application requirements, an industrial buyer should ask the following questions.

  • Is the load rolling or dead weight?
  • What type of surface is it being winched over?
  • What type of gradient, if any?
  • What distance does the object need to be winched over?

Light Duty Winching generally requires 1.5 times the gross weight of the load.
Heavy Duty Winching requires 2 to 2.5 times the gross weight of the load.

 

Design Tip: The resistance force from a mud hole or a steep incline can double or even triple the weight of the load, requiring far more recovery power to get started.
 

Choosing a heavy winch is advantageous because a larger motor causes the winch to do less work and run for a longer period of time without overheating. A larger motor will also increase the lifespan of the winch. Heavy winches draw fewer amps and put a lighter load on the electrical system being used.

 

Drum Size

The size of the drum can play a role in the operation of the winch.

  • In a small drum, the layers of cable pile up and reduce the power of the winch more quickly. They require less space, however, which can be advantageous when working in confined areas.
  • A large drum calls for a larger housing in order to make room for the cable to wrap around the drum and for power to remain the same.

Line Type

Industrial winches come with a pulling component which attaches the drum or barrel with the object being pulled. Their strength is rated via diameter and the tensile strength of their materials. Tensile strength varies according to the type, characteristics and diameter of the line. There are several options available for this component.

  • Wire rope, also known as cable, is made of metal strands, including all grades of steel and other metals. It has been in use for many years and is the most widely available winch line. Some cables are made of synthetic wire or hybrid materials. The make-up of the wire can affect the strength and flexibility of the rope based on the number of strands there are. Wire is identified by the number of bundles and strands. A line of carbon steel wire with seven bundles of 19 strands would be labeled as 7x19.
    • Advantages - best for utility tasks, more durable under abrasion, less expensive, heat resistant and can be spliced (but not easily).
    • Disadvantages - metal cable holds a high amount of tension and can cause serious damage if it breaks and backlashes, susceptible to crushing when it is not properly respooled, and heavy.

      

Image Credit: 4wheelparts.com

 

Design Tip: Dampen the winch line with a heavy blanket, coat, chain, or tree branch. The extra weight slows down the cable down and reduces the backlash effect.
  • Synthetic fiber cable includes rope made of fibers such as polypropylene, polyester, and natural rope fibers. Braided cables are commonly available for increased strength. Fiber is new in the industry and is offered as an upgrade.
    • Advantages - best for use in muddy and wet applications, lightweight, easy to handle and floats in water, low risk of backlash, easy on hands (no burrs, stray wires or burns).
    • Disadvantages - more expensive, prone to chafing, susceptible to damage from heat as low as 150 degrees Fahrenheit.

    Image Credit: 4wheelparts.com

  • Strap/ Web: describes all the material webs, straps, and belts available.
  • Chain: often used in heavy duty or industrial applications. It includes metal link chains.

The best type of line available is known as aircraft quality. It has a wire core construction instead of a nylon core construction.

 

Line Length

Line length defines the standard length of line, or storage capacity of winch drum. While more line allows the user to reach further, it is not always the best option. Rated pull is determined from the first layer of line so all the wire needs to be spooled out to get maximum pull. More line also increases the chance for kinks and the drum getting jammed. Many winchers choose to carry extra line with them for emergency purposes, but use less line on the drum initially.

 

Line Pull and Speed

Winches are rated in line pull, and are usually measured in pounds, or kilograms. Line pull is the amount of force the winch needs to move an object. It is a combination of the mechanical capacity of the winch and the tensile strength of the line on the drum. Line speed and rated pull are measured with the first layer of wire rope on the drum. The first layer of line is more powerful than the last layer, with the rated pull dropping 20% after the first layer over the base layer and 10% more for layers after that. Below is a chart of the typical rated line pull per layer of an 8000-lb. winch.

 

 

 

Types of Brakes

Winches come with built-in dynamic brakes. If the winch is going to be used with heavy loads or on steep angles, buyers should select a winch with both dynamic and mechanical brakes.

  • Dynamic Brakes use the resistance from the winch motor to electromechanically stop and hold a load only when there is power connected to the winch. Dynamic brakes are adequate for most applications, but should never be used for hoisting.
  • Mechanical Brakes automatically hold the load if there is a power loss by using friction within the winch gears. They offer better control and prevent rollback, but add weight and body size to the winch.
    • Band Brake is an extra brake fitted onto the drum. They can be operated manually or automatically.

Performance Specifications

There are many specifications to consider when selecting a winch, including rolling weight and load capacity. The video below describes some of the important specifications discussed in this section.

 

 

Rolling Weight

Rolling weight is used to determine the rated line pull (RLP) needed to safely pull a rolling load up an incline. Use the chart below to determine the correct line pull needed. To use this chart, determine the percentage of slope (or grade) and then match the slope with the weight of the rolling load to locate the corresponding winch RLP. Some applications may require larger capacity winches than indicated, so rounding up is recommended.

 

Percent of Slope (grade) = (ramp rise/ramp length) x 100.

 

A 10% slope is a rise of one foot in ten feet. All loads shown are for single-line operation and are based on first layer rope performance. You could experience a loss of up to 13% pulling capacity per layer of wire rope. Double-line operation with an optional pulley block approximately doubles the capacity of the winch.

 

Load Capacity

Load capacity of the winch is the amount of load that can be pulled up an incline. Loads will resist motion based upon the following.

Total weight should include all the contributing factors of the load.

Surface drag characteristics of the surface to pull across is a very important factor in winching. The table below shows the percent of the total weight of the load used to initiate motion.

 

Surface Type

Surface Drag (S)

Hard flat road

.04

Grass

 .14

Sand (hard wet)

.17

Gravel

.20

Sand (soft wet)

 .20

Sand (soft/dry/loose)

 .25

Shallow mud

.33

Bog

 .50

Marsh

.50

Clay (clinging)

 .50

 

For example, the rolling resistance of the functioning vehicle on a flat gravel surface is the surface drag multiplied by the weight of the vehicle.

 

5,000lbs. x .2 = 1,000 lbs.

 

Gradient resistance is the incline the load is being pulled up and must be considered to determine rolling resistance. In general, the gradient resistance is 1/60th of the weight of the load for each degree of slope. The height and distance are defined in terms of a ratio. Use the table below to find the gradient values for the height and distance ratio.

 

 

 

To calculate the resistance on a slope, the following formula can be used:

 

(Weight of load x Surface drag) + (Gradient value x Weight of load) = Effort required.

 

Design Tip: Rolling loads offer the least resistance, while stuck loads place the most strain on the winch. Take this into account when choosing the pulling power of the winch.
 

To calculate the load capacity (maximum pull capacity) for rolling loads, use the formula and chart below.

 

Rolling load capacity = rate line pull x factor found in chart.

 

Rolling Load Capacity

Percent Incline

Multiply by:

Percent Incline

Multiply by:

Level Surface

10.00

30 (17°)

2.61

5 (3°)

6.67

50 (26°)

1.86

10 (6°)

5.02

70 (35°)

1.53

20 (11°)

3.40

100 (45°)

1.29

 

 

Effects of pulley angle. Image Credit: Portablewinch

 

Power Options

GlobalSpec enables industrial buyers to search for winches with a variety of power supply options.

  • Hand powered winches have manual take-up operation by using a rotating lever. The winch handle is the lever arm, the barrel axis is the fulcrum, and the load is applied at the barrel face. By dividing the distance between fulcrum and face into the length of the handle, the result (in an ungeared winch) is the amount of the user’s advantage. As the load increases, the additional gears give better leverage by taking up slack quickly.
  • Powered motor:
    • Electric motors use single-phase or three-phase voltages and are often coupled with a direct drive to maximize power output. They come with permanent magnet (PM) or series wound motors. PM motors are less expensive and draw 10-15 percent fewer amps but are less tolerant of abuse and heat. Series wound motors are better for heavy-duty use.
    • Pneumatic motors use compressed air and flow valves to control winch speed by varying air flow.
    • Hydraulic motors are powered by pressurized hydraulic fluid and transfer rotational kinetic energy. They have a high duty cycle
    • Gasoline powered engines are powered by gasoline and are convenient for portable applications.

Motor

Advantages

Disadvantages

Application

Electric

Economical and efficient

Clean and simple

Energy mostly available

 

Speed control expensive

Explosion proofing expensive

Difficult to protect from extreme environments

Stationary applications, ships, vehicles.

Hydraulic

Small size

Speed control easy

Need power pack needed

Pipes and hoses needed

Earth moving machines, piling equipment, farming, commercial use and mobile cranes.

Pneumatic motors

Small size

Speed control easy

Suitable for harsh environments

Compressor needed

Pipes and hoses needed

Noisy

Torque drops with speed

Mining on and off-shore oil and gas. Environments with high risk of explosion.

Power Requirements

Power is defined as the ability to deliver an expected performance over a designated time. Winch power is expressed by the equation below.

 

Design Tip: In practice, sufficient power needs to be installed to overcome efficiency losses from cable on sheaves, cable on the drum, gearbox, electric or hydraulic motors and supply lines. Always install extra power.

 

 

P = (V x F)

P = power in kW
V = speed in meters/min
F = load in kg (1 kg approx. 10 Newton)

 

The graph below shows an example (follow the blue lines) of a load (F) of 27 Tons, a speed (V) of 16 meter/min, giving an 88kW power requirement for an electric motor and a 300 liter/min, 190 bars of pressure needed for a hydraulic motor. The power on in the graph below roughly accounts for losses, so it is the installed power needed.

 

27 Tonne 16 m/min
264779.55 N .2666 m/sec
264.779 kN  

 

264.779 kN x .266 m/s = 70.6078 kW
At 80% efficiency:
70.6078 kW / .8 = 88.25975 kW

 

 

 Winch Power Graph. Graph Credit: Haacon

Design Tip: If more pulling power is needed, spool out more cable. This can be done by choosing an anchor point further away from the load or by using a snatch block to double back the cable. A double line pull increases the winch power by almost doubling the capacity.
 

Duty Cycle

Most electric DC or AC powered winches cannot be operated continuously. The maximum normal duty cycle is 1 to 3 minutes on and a 20 minute cool-down period. For more frequent operation needs, refer to long cycle or longer duty rating electric units, and continuous duty rated hydraulic.

 

Linespeed and drum torque
There is a direct link between linespeed and life-time. The life-time is based on the drum torque and drum cycles. Increasing the linespeed while keep the drum torque constant, reduces the time to reach the total number of drum cycles, thus reducing the life-time.

Options

  • Snatch block/pulley block is used for double-line winch operation and redirection. A pulley block lets you offset the winch but retain a straight shot, with a hook for mounting and a pulley for the wire rope. The block also increases the winch’s pulling capacity when the pulley block is hooked directly to the load and the winch is hooked to a mount nearby. Although it lowers the speed and causes lower ramp draw and longer run time, it is often safer when pulling an abnormal load; however, for every pulley used, there is a frictional loss of approximately 10% per pulley.

    • Double line - Adding a double line to the winch doubles the line pull capacity. It’s useful for self-recovery applications using an anchor point, such as a tree. 

 

How to double pulling power. Image Credit: Portablewinch  

  • Freewheel is the ability to pull cable freely from the winch drum by hand under no-load conditions.
  • Clutch release is the ability to control load release with a clutch instead of a winch motor.
  • Lifting is not recommended because winches are designed as pulling devices. Some winches can be configured for lifting applications. There are four criteria needed to adopt a winch for lifting: safety ratio, no free-spool clutch mechanism, a secondary brake, and a safety holding chain or device if the load is going to be suspended. If using a winch to lift, the product must comply with health and safety laws. Winches should never be used for the lifting or transportation of people.
  • Dual counterbalance valves are used to block the flow to hydraulic motors when there is no incoming flow and prevent the motors from cavitating when releasing a load under power. They can also be used to prevent the winch from freewheeling in the neutral position.
  • Foot control valves have an adjustable relief valve that can be used to drop existing circuit pressure to the desired operating pressure. Adjustable stops can limit or block pedal travel in either direction and can be used to limit the flow.

Features

Industrial winches are also available with features such as:

  • Pressure rollers push the slack wire to the drum to help spool the wire better on the drum.
  • Slack rope devices sound an alarm or stops when it detects slack wires.
  • Limit switches count the number of drum revolutions and limit the upper and lower stroke to maintain drum life.
  • Spoolers guide the wire onto the drum to ensure the wire is flush with the drum.
  • Mounting with a plate is the most secure way to mount a winch. Mounts come in a universal, custom ordered or multi-mount design. Multi-mount plates allow the user to move the winch from front to rear. The mount must be able to handle the pulling force and weight of the winch. Another consideration is a mount that allows for access to the drum to respool the cable.

 
Winch with line. Image Credit: Winches Inc.

Applications

Industrial winches are used in a variety of areas, including:

  • Automotive
  • Construction
  • Industrial
  • Military
  • Marine
  • Mining
  • Railroad
  • Recovery
  • Oilfield

References

Basic Technical Winch Information

Choosing Winch Power

Finding the Right Electric Winch

Maritime Dictionary

Planetary Gear, Worm Gear, and Spur Gear Winches

The difference between a winch and a hoist

Which Winch?

Winch Advisor

Winch Application Manual

Winches for Industrial appliance

Winch Options

Winch Selection Guide

Read user Insights about Industrial Winches

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