Winches and Winching

Many people see winches as a must have accessory, but, most newcomers to off roading lack the knowledge to make informed decisions about which winch to purchase, and become lured by brand names and marketing blurb. Results are often a winch which is not suitable for their needs, and has cost a lot of money to purchase and install.
This article uncovers the common misconceptions and deals with the appropriate winches and winching systems, and uncovers the real issues people need to know before spending a lot of hard earned cash on a winch.

Types of Winch

Winches fixed to a vehicle come in three main types, these are electrical, hydraulic, and mechanical; and as their names suggest it is the chosen method of propulsion which identifies them, each has pro’s and cons, and varying prices.

Electric Winches

Electric winches are fairly simple and cheap, they utilise a 12 or 24 volt DC electric motor to propel them, and they drive through a gearbox which is usually a multi stage planetary unit to a drum which contains the winch rope. Electric winches contain a solenoid or contact box, this is usually mounted within the winches frame or housing, and they have a load brake to hold a load when the winch is under tension or load.
Electric winches need connecting to a battery, correct installations demand a specific type of battery to ensure the winch receives the correct amount of power for it to operate at its maximum or rated pulling capacity, these are usually a separate battery. Using a separate battery ensures the vehicles main battery is not discharged so the vehicle can still be started and driven, even if the additional battery is totally discharged, these additional batteries are charged through a split charging circuit. Split charging circuits are a simple or complex device (depending upon type) to allow one alternator to charge more than one battery without discharging the vehicles main battery (see electrical section for more information).

Electric winches can be run with the engine stopped, this can be an advantage if the engine is flooded in water, vehicle’s will usually have enough charge in the battery to allow the winch to pull it clear of the water in most instances.
Motors are the prime mover in electric winches, always consider a good quality motor, many of the cheaper winches utilise cheap motors for low purchase costs, this can be false economy if you need to do a lot of winching, but beneficial if only used periodically. Winches have a “duty cycle” or amount of time they can winch, this is expressed as a percentage usually, the higher the duty cycle, the longer the winch can be used. This determines the classification of a winch, the higher the duty cycle the better the motor is, in simple terms; if a winch has a 50% duty cycle it can be used for 50% of the time, the other 50% of the time it must stop for cooling. If the winch has a duty cycle of only 10% it must run for 10% of the time, for a 10 minute period the winch can operate for 1 minute, and stood for 9 minutes, this would be a light duty winch.

How do we determine these time periods, often it is the other problem with an electric winch, heat; you operate an electric winch until the motor cannot be touched by bare hands, once it reaches this temperature it must stop before it burns out the motor. Burned out motors are the biggest problem for inexperienced users, they are run for too long and the motors overheat, many inexperienced users will continue pulling with a winch even though the motor is overheating, rather than stop a pull and let the motor cool down. This is where we determine our duty cycle, if we winch for 3 minutes with a 10% duty cycle winch it must be left for 27 minutes to cool before winching again.
If we winch for the same 3 minutes with a winch rated at 50% duty cycle we can leave it to cool for only 3 minutes before commencing winching, here we see the relevance of the duty cycle, it saves our expensive purchase from damage.
Many winches are now fitted with a thermiometric device, it sounds grand but is only an electronic thermometer which illuminates an LED (light emitting diode) on the handset or controller when it reaches or nears its overheating temperature.
Never ever be tempted to cool a motor by pouring water or other liquid onto it, this will cause thermal shock and crack the insulation on the insulted portions, and in certain cases it can crack the metal casing or housings. Pouring water onto a hot winch may cool the external surfaces of a winch, but not the crucial internal surfaces which do the actual work, thus leading to a burned out motor if winching commences.

Gearboxes are the transmission stage of a winch, they nearly all use planetary gearboxes on electric winches as they are durable, reliable, and cheap to manufacture to high standards now demanded by legislation for such equipment. Other types of gearbox are the worm drive, these are considerably stronger than planetary types, but considerably more expensive. Gearboxes also allow other functions such as freewheeling or even more than one speed to be selected, these are operated by a clutch lever, this needs to be a durable construction as many of the cheaper plastic items are easily snapped off. Freewheeling is the ability to disconnect the motor/gearbox assembly from the drum, this allows the rope to be manually pulled from the drum, this is beneficial as it saves the battery and only the correct amount of rope is pulled out. This speeds up recovery operations as pulling the rope out by hand is much quicker than winding it out with power.

Power solenoids control the power to the motor, there are two main types fitted to the unit, these are usually those mounted above the motor in a plastic housing, or the bridge over types, these are usually mounted over the rope drum. Both systems are fine as long as they are accessible for maintenance when out in the field; solenoids over the motor tend to be a little prone to impact damage due to their size, those over the drum can be damaged from bunching rope, or anything snagged in the rope. Detachable type solenoids are now fitted to many winches; these are better for off road work as they can be removed from the winch and mounted elsewhere on the vehicle. This is beneficial as mounting under the bonnet offers considerably more protection from the elements such as rain during normal driving, or sludge, mud, and impacts from flying debris from other vehicles in convoy while off road. Always mount detachable solenoids as close to the motor as possible, and ensure it has reasonable cooling air, remember these solenoids and winches are not waterproof, at best they will be supplied as water resistant.

Rated capacity is another important aspect to consider, for larger vehicles (Fourtrak’s) always aim for a minimum rated maximum pull of 9500lbs or higher; this will be covered in detail later.

Current draw is a vital aspect of an electric winch, if our auxiliary battery is of too low a CCA (cold cranking amps) it will not give the maximum pulling power from the winch, it will flatten the battery quickly, and can often considerably shorten battery life. Manufacturers will give two forms of battery specification, these are the minimum CCA a winch needs to operate a winch, or a battery CCA range.
Minimum CCA must always be exceeded when selecting a battery, if it states a minimum 600CCA always aim for 20% higher, this would mean a battery with a CCA of around 720amps.
Winches with a battery range specify a minimum CCA and a maximum CCA, always aim for the maximum CCA without exceeding it; this is because with modern DC motors can draw excess current which will damage the motor. Many winches with thermiometric temperature measurement devices may find that exceeding the maximum power requirement can effect the electronic measuring range, this may operate the system at too low or too high a temperature. This means it will possibly shorten winching times due to incorrect temperature readings, or too high a temperature reading will burn out the motor.
Looking at two 9500lb winches current draw is interesting, these are both rated pulling at 8000lbs, one draws 480 amps while the other draws 350 amps, such current draws identify several other problems. The winch drawing 480 amps will flatten its battery much quicker than the winch drawing 350 amps; the winch drawing 480 amps will also heat up its motor much more quickly and have to dissipate this extra generated heat.
When looking at current draw it is vital to make like for like comparisons between different winches from the same manufacturer, and different winches from different manufacturers.

Line speed is a factor which must be taken into consideration, this is the speed at which the line will be retrieved by the winch at a pre-determined load, manufacturers vary these parameters in their specifications, so always check like for like.

Rope capacity is something which can vary from winch to winch, this is basically the diameter of rope, and the maximum length rope of a specified diameter that the winch drum can hold, and this varies from winch to winch. Most manufacturers will specify a minimum rope diameter for a specific winch, never use anything of a lesser diameter as it will not be strong enough to cope with the winches pulling power, and can snap; this can be fatal to inexperienced users. At this minimum diameter the manufacturer will specify a minimum quantity or length which the winch will hold, always aim for 100’ (30 metres), many cheaper winches may only have a capacity to hold 80’ of rope.
Increasing the diameter above the recommended minimum will decrease the amount or length of rope a winch will hold.

Electric winches operate by plugging in a control or wander lead, this simply plugs into the winch and are fitted with a two way switch, this allows us to power the rope in or out, these come in various lengths. Technology also allows us to have a wireless variant, this is basically a transmitter, and a receiver which plugs into the winch; for a beginner I would recommend sticking to the wander lead as wireless options can be overly expensive and complex.
Wander leads may also contain a number of other features; these would normally include a safety switch to switch on the wander lead, a useful safety addition; and any thermiometric warning device such as an LED or warning buzzer.

When checking our specifications to select electric winches we must check the following:

Current draw.
Duty Cycle.
Line Speed.
Auxiliary Battery CCA Capacity.
Line or Rope Capacity.
Freespooling Capabilities

Beneficial options would include:

Thermiometric or temperature measuring systems or warnings.
Detachable Solenoids.
Extended Length Wander Leads.
Wander Leads With Integral Safety Features.

Hydraulic Winches

Hydraulic winches are similar in operation to the electric winch, they tend to use a worm type gearbox for strength, and the electric motor is replaced with a hydraulic motor which is much more powerful than an electric motor.
Hydraulic systems are much more expensive than electric winches, and for good reasons; they are waterproof as standard, have a 100% duty cycle, so no stopping to allow the motor to cool down, and are driven from the engines power. Hydraulic winches are much more durable, this, combined with a 100% duty cycle means they tend to be used for competition use, or by regular or industrial users due to their higher operational speeds and continual pull.

Hydraulic systems operate from a hydraulic pump which is driven from a gearbox power take off (PTO), or from a belt drive on the engine; this is normally through a clutch, this provides the correct oil flow and pressure. The oil is fed from a reservoir, this can be located anywhere on the vehicle, from the pump the pressurised oil is fed to the control valves, these; control the flow to the hydraulic motor to operate it in forwards or reverse, from the valves a return pipe is installed to the reservoir.
As we can already see, we need to purchase these additional items, so much more expense as we already have with a correctly installed electric winch, but the hydraulic pump costs more than a battery, and hydraulic lines cost more than electric cable. Valves come in a variety of types, these are normal spool valves which are fitted inside the vehicle, and operated directly by hand, or electrically operated solenoid valves which are remotely located, these, are operated from switches inside the vehicle. Electrically operated valves are slightly more complex and less reliable, but remove the need to run high pressure lines inside the vehicle, this is beneficial if a hydraulic pipe bursts and sprays high pressure oil around the inside of the vehicle, so much safer.

Hydraulic winch specifications are crucial in selecting a pump, most specify an operating pressure of around 2000PSI, and a flow rate varying between 50-70 LPM (litres per minute), this matching is crucial to operate the hydraulic winch correctly. Some systems are now being developed to run from the vehicles power steering, while these provide the correct operating pressure, these are very much down on flow, it is the flow which dictates the winches operating speed. These systems might provide the pulling power, but will be very slow in operation due to this considerably reduced flow rate; this is why it is important to match hydraulic systems correctly, much as we match the components in an electrical system.

Many people have fitted these systems powered from power steering systems, only to find many other problems, these are mainly overheating of the power steering fluid as its reservoir is so small, it does not have enough capacity to dissipate heat. Prolonged use heats up the oil, with a reservoir we have the capability to increase its oil capacity to around one gallon or 5 litres, and this dissipates heat more effectively than the tiny amounts stored in a power steering system.
Overheating a power steering systems oil causes more damage to the system, the pump works flat out to try to provide enough flow, this accelerates wear on the power steering pump, this, with overheated oil breaks down the oil. Worn oil does not lubricate correctly, this also accelerates wear on the vehicles steering rack, so it can cause numerous other problems, problems which are expensive to repair.
Many people manufacture their own reservoir, this is usually from mild or stainless steel; this conducts heat much better than the plastic reservoirs on power steering systems, home made tanks can also be made larger to hold more oil. Commercial oil coolers are available for hydraulic systems, for off road winches these are rarely necessary unless the climate is extremely hot, most people make a reservoir to fit their vehicle and weld in a few additional cooling fins.

Installing a hydraulic winch is within the capability of the average DIY orientated individual, but there are a few rules to remember, always use hydraulic fittings of the correct rated pressure, and follow the pipe sizes recommended by the manufacturer. Install solid steel hydraulic lines rigidly to the chassis and connect the winch, valves, and hydraulic pump to the steel lines with flexible hydraulic hoses, if solid lines are installed directly to the components, the body flex will tear them apart. Never install flexible hoses tightly, ensure there is a curve in them to allow for any body or chassis flex.

Capstan Winches

Capstan winches are rarely seen these days, but are still used by rescue organisations, water authorities, and certain emergency organisations; capstan winches are simply a tapered vertical drum mounted to the vehicles crankshaft front pulley. This winch does not contain its rope on a drum in the same way that an electric or hydraulic winch does, it is carried separately, and is a special type of rope that is used. This means that the length of rope is its limiting factor, rope can be as long as 1000 metres as this is a standard length of rope manufacture, or as short as 10 metres, and still be used with a capstan winch. Its load rating is considerably less than a hydraulic or electric winch which will be explained later, but it does not suffer from heat build up, and it’s a consistent pulling capacity as it is not reduced by layers of rope on the drum, as other types are.

Capstan winches were the original winches, the drum is wide at the bottom, narrows to the middle in a gentle curve, this curve widens towards the top, and the top is not as wide as the bottom. Rope is wound from the bottom of the capstan drum, three laps are wound vertically upwards, the dog clutch is engaged and the engine is started and its revs set to the recommended speed on the hand throttle. The operator stands in front of the vehicle, to one side, the spare rope is pulled and this starts the winching, the rope coming off the drum is laid on the floor to the side of the vehicle as it travels forwards along the rope. The operator has to walk backwards, this is the downside, but as soon as tension is released by the operator, on the rope coming off the drum, the winch stops pulling, it is this friction which generates heat through the rope as it slips is what precludes plastic ropes from being used. The friction would build up enough heat to melt synthetic or plastic ropes, the ropes for capstan winches are usually made from braided Dacron, or a braided Dacron core with other heat resisting outer layers.
Capstan winches offer the benefit of suspending a load with a skilled operator, and their pull is so precise that they are still used by emergency services as they can winch an injured person off a cliff face. They can also pull the tiny electronic communication cables through ducts without damage, or water authorities can pull very expensive nets across rivers without damage.

This is why they are still manufactured and fitted to certain vehicles, but rarely seen on 4X4 vehicles, other than original classic vehicles; to all intents and purposes we will dismiss them for 4X4’s.

Understanding Specifications

Earlier we said we would look at the pull of a winch in detail, this is because our winch rating of 9500lb is not a true rating, it is its maximum pulling power, many beginners do not understand this, so it will be explained in detail.

Two terms need understanding before we continue, these are laps and layers; one lap is simply one turn of rope around the drum, a layer is when enough laps are wound onto the drum to fill it from one end to the other. Layers have an effect on the winch, if the rope is wound completely off the drum; except the last five laps, then it is wound back on, this is the first layer, as the rope hits the end of the drum it winds back over this first layer to form a second layer. Many winches contain as many as five layers, as each layer forms it reduces the winches pulling capacity, maximum pull is only achieved on the first layer only, the second layer reduces pulling capacity, and the third layer reduces pulling capacity again.

As each successive layer is wound on we notice the winding speed increases, so why is this.

Effectively this is because as each layer of rope is wound onto the drum its diameter increases, this raises its gearing, and the increased diameter winds on more rope per revolution than the last layer. In simple terms it is like loading our vehicle to capacity and adding its maximum weighted trailer, if we liken each layer to a gear, the first layer being first gear, layer two second gear, and so on; we may pull off in first gear reasonably well as the gearing is designed to cope with this weight. If we try this in second gear it will slip the clutch and soon burn it out, it will not pull away in third, fourth, or fifth gears as the gears are too much for the engine and gearing to cope with; it is the same for our winch.

Looking at a Warn specification for one of their current models we see they list pull by layer, this also gives line speed, and current drawn in amperes.

For the first layer it will give us a pulling capacity of 9500LBS, as this fills the drum and begins the second layer the pulling capacity drops to 8000LBS, the third layer drops to 6000LBS, the fourth layer drops to 4000LBS, the fifth layer drops to 2000LBS. If we have five layers on our drum, and 100’ of rope we can ascertain that the first 20’ will give us maximum pulling power, 20-40’ will give us 8000LBS of pull, we can mark our rope at these intervals so if we are winching alone, we have a visible indicator on our rope. This prevents damage to our winch where maximum pulling power is needed.

Winch Ropes

Winch ropes come in two differing types, these are the aircraft grade of steel or stainless steel ropes, these are the most common and come supplied with many winches; and the newer synthetic replacement ropes which are becoming popular.

Traditional wire ropes are durable and adequate for most uses, they are cheap to replace, but are made from several smaller strands of wire twisted together, these can sometimes snap with wear, or over time; and form small strands which snag. These are sometimes called fish hooks as they are similar in appearance, but penetrate the skin easily, particularly while handling the rope; if several appear it will reduce the ropes pulling strength.

Synthetic ropes are now manufactured to replace the traditional wire rope, these are stronger for a given size, and float in water; as well as not having the capability for the strands to snap and form fish hooks. Dyneema is the trade name for synthetic ropes, they are manufactured from a specially treated high density polyethylene which is used in a number of applications from bullet proof vests to ballistic panels in bullet proof vehicles, so it is strong. Synthetic ropes are much stronger than an equivalent sized steel rope, but considerably more expensive to purchase, but is worth the additional expense if funds permit.