Winch Principles

Things to consider before purchasing a winch

·         Gross Value Weight (Wt)

This is the TOTAL weight of the load plus any extra fittings, attachments, luggage etc

·         Speed

If you need a winch for motor sport, speed is very important! The Winch-in time could mean the difference of many precious seconds!

There are winches specifically designed for sport, COMEUP have the Cub, Cap, MadX and the Blazer. The max line speed (no load) is as fast as 50 metres per minute!!!

Speed is not important in self-recovery or general use.

·         Usage Volume

An important fact to consider with usage is the power source, engine (hydraulic) or battery (Electric). Consistent use will drain the power, whereas very occasional use will take little toil. Hydraulic winches use the PTO on the engine to operate and therefore need the engine running during use.

Operating an electric winch can cause the battery life to drain, some particular models of winches come with a dashboard which shows the remaining battery life. It is best to keep the engine running so that the alternator can trickle some charge. Please contact us if you are unsure.

·         Environment

If you are using your Winch for Self-Recovery or Sport, the chances of it getting wet and muddy are high to guaranteed. Look for a winch with sealed housings to keep out dirt particles and water. The COMEUP Seal Gen2 range is completely submersible and is designed to operate in such environments.

If your winch will be attached to a trailer i.e. for pulling vehicles, plant or caravans, the chances of the winch getting very muddy are less likely, you still need a winch with impenetrable housing to keep road residue and dirt out, but a submersible winch will not be necessary.

The rope/wire must also be able to withstand these elements too. Synthetic rope is less likely to be affected by water and dirt, as long as it is dried and maintained. This is done by winching out the full rope to dry it out and allow any dirt to crumble and remove before winching back in.

Wire rope can degrade over time and weather, and anyone who has cut their hand on wire rope will tell you: always wear gloves!

·         Surface Drag (S)

Not everyone will consider this important factor. Pulling a vehicle on a flat road doesn’t take much. The world’s strongest man can pull a jet aeroplane along tarmac and most of us could push a 4x4 on a flat road, but have you tried pushing the same vehicle on gravel?!

The type of terrain obviously affects the power required to pull an object/vehicle. Examples of common types of surfaces in order of resistance are: Metal, Sand, Gravel, Soft Sand, Mud, Marsh and Clay. There is an equation below which factors the Surface Drag (S) in order to help you determine the power of the winch you require.

·         Gradient of Resistance

This is the angle or incline of the surface you will be pulling on. For example, if your winch is to be attached to a trailer, you must look at the angle of your ramp. If your winch is going to be used for Self-Recovery, this surface could vary massively, and who can predict where you may get stuck?

·         Load Rating

Load and speed vary according to how much wire rope is on the drum. The first layer of rope on the drum delivers the slowest speed and the maximum load. The top layer of rope on the drum delivers the maximum speed and the minimum load. For this reason, all Automotive, powersports and Industrial winches are rated at their first layer capacities.

·         Winching Principals

Here is an equation to help you understand the Winch Principles and help you decide which winch will be best for you:

Surface Drag (S):

 Surface Type / Surface Drag (S)

  • Metal = 0.15S

  • Sand = 0.18S

  • Gravel = 0.20S

  • Soft Sand = 0.22S

  • Mud = 0.32S

  • Marsh = 0.52S

  • Clay = 0.52S

Gradient Resistance (G):

 Angle / Gradient (G)

  • 3º = 0.06G

  • 5º = 0.11G

  • 11º = 0.2G

  • 17º = 0.3G

  • 26º = 0.44G

  • 35º = 0.58G

  • 45º = 0.71G

Rolling Pull Effect Required (kg) = (Wt x S) + (Wt x G)

Example:             To pull a 2T vehicle through mud on a 26º angle:

Ø  Vehicle TOTAL weight (Wt)          =2,000Kg (2T)

Ø  Surface drag of Mud (S)              =0.32

Ø  Gradient of 26º  (G)                    =0.44

=             (2,000Wt x 0.32)               +             (2,000Wt x 0.44G)

                640kg                                +             880kg


This figure is the rolling force required to pull a 2T vehicle up a 26º mud slope.

If this confuses, you must remember that this is based on a ‘pulling’ winch. IF this winch could ‘lift’, it would have the capacity to ‘lift’ 2T.

Something else to think about:

A COMEUP E10 is the industry favourite for Caravan Transport; it can pull 10,000lb which is 4.46 Tonnes. Now consider that a Caravan weighs between 5 and 8 Tonnes AND they are pulled up a 17º metal ramp onto the trailer, it will only take 3.6* Tonnes of rolling pulling force. So the E10 can manage this with no issue! If the caravan didn’t have wheels, it would be a different outcome!

*(8,000kg x 0.15 (Surface Drag for Metal))+(8,000kg x 0.3 (Gradient for 17º)) = (1,200kg)+(2,400kg)

Rolling Pull Effect

Winch Principles