Guide written by:
John, DIYer & IT developer, Brighton
A winch is a lifting and pulling tool. Are you the Hulk? Can you lift a heavy load yourself? A winch is essential. A rope, cord, or cable attached a drum winds up and raises or pulls a load on the other end. Depending on usage, they can be portable, stationary, manual, electric, or hydraulic.
What is the capacity of a winch?
The winch capacity is the maximum weight that the winch can pull. It is expressed in kilograms and is always given for the first row of cable wound on the drum, that is to say when the cable is almost completely unrolled. The more rows of cable wound on the drum, the less the force of the winch. This loss is estimated at 13% per row. This capacity is often given for a rolling load with a perfectly horizontal cable.
It is therefore imperative to select a greater capacity than your intended use, both to take account of the loss of power during winding, but also to account for the additional force from gravity and friction. Considering a capacity 50% greater than the weight to be towed is not unreasonable, it is even prudent. If you wish to use your winch for lifting, make sure that the capacity is not expressed in rolling load. Lifting requires a different calculation of force than a rolling load.
Speed of traction explained
For a given power, there is a trade-off between traction speed and load speed. A heavy load will be towedslowly. Do not be surprised that the speed of hauling a load is low with a winch even if it is very fast when the winch is empty. A winch loaded typically pulls 1.5 meters per minute. A faster-than-average winch will have a more powerful engine, which will result in increased instantaneous power consumption. This is something you should keep track of if you are running on a car battery.
How does a winch work?
There are different types of winches, manual or powered by an external power source:
- Manual winches are the simplest. They have a modest traction capacity - up to two tons for the bigger ones - and the only source of energy is you and your arms. Ideal for construction and small loads. You’ll need to work out those deltoids.
- Electric winches, connectable to a car or truck battery (12V or 24V), or to a main (220V). They have a higher capacity than the manual winch for a reasonable cost. The only problem, they heat up. The energy dissipated as heat is proportional to the square of the energy consumed - expressed in Amperes. Basically, it means that a winch without a thermal fuse, also known as overload protection, can burn out if it pulls too much weight. Taking a winch with a much higher capacity than your needs is another way to guard against this risk. In addition, such a winch can consume more than 400 amps in 12V (400 A). If this winch is connected to a vehicle, it is essential to have a battery in good condition, fully charged, and to let the car run during and after using it. It is also necessary to allow it time to cool down, which means electric winches should be limited to intermittent use. There is no question of lifting or pulling loads without taking a break, as this may cause damage.
- The mechanical winches are driven by a heat engine. They are heavier and more expensive than electric winches but allow continuous work. For a vehicle, they require a specific installation and are not easily transferable from one vehicle to another.
- The hydraulic winches are connected to a hydraulic circuit which drives the drum. They offer the availability and robustness of mechanical winches. Installation on a vehicle requires a specialist. It is imperative that the hydraulic circuit to which it is connected has sufficient pressure and flow to actuate it. There are often winches operating with a circuit of 120 to 160 bar at a flow rate between 45 and 60 litres per minute. These winches are reliable and more powerful (max load and speed) than the previous two but are heavy and expensive.
How do I operate a manual winch?
There are two types of manual winches. Crankwinches and lever winches.
The former offers a modest traction capacity, between 500kg and 1t, for a length of the strand that rotates around 10m. The latter makes it possible to pull heavier loads (about 2 t) but do not generally allow more than one meter to be wound. Understand, the first is perfect for pulling a boat onto a trailer while the second is perfect for felling trees.
The addition of amuffle - a kind of pulley - makes it possible to double themaximumload for the winch. In return, the traction speed will be divided by two. We can’t have it all.
What is reduction?
The reduction makes it possible to adapt the force and the speed of the energy source, of an engine or of your arms, to a given load. The reduction is also related to the trade-off between speed and strength - remember the story of the heavy weight that is being pulled slowly. To simplify, the reduction will transform fast movements of medium force into a slow winding of the cable on the drum and this to draw a consequent load. It is, therefore, thanks to this reduction that the winches are capable of prowess.
There are three types:
- Straightforward:provides fast winding speed. Requires brake and high-power motor.
- Screws: very robust and safe, they are slow to unwind. Their design makes any brake superfluous.
- Planetary or epicycloid: robust and cheap making them the uncontested stars of the market. They also require a brake.
What is the correct cable length?
Choosing a cable that is too long means taking two risks. First, losing power in compared to the standard capacity of the winch. Remember that the more rows of rope wound on the drum, the less the power of the winch. Second, a long cable may become entangled to the point of jamming the drum. It may, therefore, be advantageous to have only the amount of cable strictly necessary, even if it is necessary to attach an additional strap between the cable of the winch and the load.
Cable or synthetic rope?
Carbon steel cables are resistant to friction and heat. They are, however, sensitive to pinching and crimping. Their linear mass makes them dangerous in the event of breakage or if the load is detached. They are more expensiveand heavierthan the synthetic cables. They do not resist rubbing or handle heat well. On the other hand, they are less likely to cause accidents, provide superior performance, and can be interlocked.
Is the charging port dangerous?
Loads handled with a winch are heavy. The energies involved are considerable, which implies high risks in the event of an unexpected release of the load. It is therefore advisable to choose a suitable winch. In addition, devices such as an automatic brake, which blocks the drum when stopped or in the case of breakage of the winch supply, or a pawl on a winch, will secure the load to a safe stop. Finally, comply with the manufacturer’s recommendations for the maintenance and verification of your equipment, particularly with regard to the cable (wear, corrosion, pinching, etc.).
There are words that I do not understand, can you clarify?
That’s alright, but only because it’s you:
- Rewinding guide: A device for winding the cable in an orderly manner on the drum and thus avoiding the formation of knots.
- Guide rollers: A device consisting of rollers against which the cable can roll. Thus, on the one hand, the cable always comes in front of the drum and this reduces the risk of friction.
- Anti-gyratorycable: A cable consists of several strands. They themselves consist of several steel wires helically wound. The core of an anti-gyratory cable is braided in the opposite direction to the outer strands, which cancels out the gyration forces. They prevent the load from turning on itself once in the air.
- Motor: A permanent magnet. Low-cost motors. They consume less than so-called coils in series but are more sensitive to heat and wear. Watch out for loss of power in cold weather.
- Brake: It immobilizes the drum when the winch is not actuated. Very safe to prevent uncontrolled spinning, the brakes prevent the unwinding of the cable manually unless a decoupling system is used to uncouple the drum from the transmission.
- Transmission: A mechanical device that transfers energy from the power source (motor, crank, a hydraulic pump) to the receiver, here the drum.
- Laying: Pulling or lifting a load with a rope or a line.
- Line: A generic name for the ropes.
A quick summary on winches
Reserve manual winches are for small loads or for mobile use where finding a source of energy would be difficult. Power winches are less tiring and safer. Do not use an electric winch for heavy use due to the risk of overheating. An overload protection will prevent you from unpleasant surprises. The thermal and hydraulic winches allow for intensive use at the cost of a higher investment and a more difficult installation. Finally, invest in a winch and quality accessories considering the risks to which you are exposed when hauling heavy loads.
For DIY enthusiasts interested in knowing how to choose the accessories related to winches, follow the advice of our editors and discover their Guides:
How to choose your low current cables
How to choose your cable passage
- How to choose your wires and cables
And to work safely:
Guide written by:
John, DIYer & IT developer, Brighton, 70 guides
Since I was a child, I was always interested in manual and technical works. Always fascinated by woodworking, I took advantage of my first flat as a playground. On the cards: electricity (of course, safety first!) and some partition walls; but also decorating with the help of the missus, made-to-measure furniture and little tricks to optimise the space, all the while remaining as original as possible. When the little one arrived, I started building bits and pieces for him! Lacking space, I have not got a permanent workshop and certain tools I dream about but are not part of my collection. Not to worry, I already know a lot about DIY and I have a high-tech profile that I hope will guide you in your decisions!