KaiserBill
03-24-2015, 07:21 PM
http://www.allwheeldriveequip.com/images/trucks/975e2e2c-d0c9-462a-b231-830e939c44ca.jpg
The question of winches I think it a very important one. How much winch is enough? Is there such thing as too much winching power? Personally, in the words of Jeremy Clarkson "More Power" is always my rebel yell when it comes to winches!!!! So, let's use a few help rudimentary formulas easily found on the DP Winch Manual for any one of their winches.
http://www.team-twg.com/documents/dp-winch/service-operating-manuals/winch-application-manual.pdf
You'll find on page 12 of the manual referenced in the link you'll find a useful formula: (weight of vehicle * surface drag) + (Gradient Resistance Value * Weight of Vehicle) = Effort Required to recover said vehicle.
So, they have a list of surface type drag coefficients and for example let's use Clay (Clinging) .50 , let's say our vehicle weighs 5,000lbs and our slope of incline is a 100% grade or 45 degree angle. So they calculate the resistance to the gradient at being 1/60th times every degree above 0 degrees. So that leaves us with a .7500015 or .75 gradient resistance coefficient factor. So now we have (5000*.50)+(5000*.75)= 6250 ft-lbs of force required to recover this object from a thick clinging clay up a 100% grade. Which isn't a bad estimate.
In reality you would also want to factor in the the surface area of the vehicle that is contact with the mud. It is very possible that your vehicle is submerged up to the frame in deep mud. Which of course would require more force to extract the vehicle than if it is merely the tires stuck in mud. This is especially true if the vehicle itself has become disabled.
Another factor that is often over looked is the angle of the pull itself. Once you start to pull on the vehicle from an angle that is greater than 20 degrees from horizontal-- such as when the vehicle is stuck at the bottom of a hill and you need to get a steep incline and the anchor point is at the top. If you have 60% grade or 30 degree angle you can loose up to 65% of your single line pulling force. That is because you actually pulling the vehicle up and then forwards. So, that is an important thing to remember when you are out winching your vehicle... the anchor point should be less than 20 degrees higher or lower than the center line of your vehicle.
So, what are your options in these scenarios? Well option is a snatch block(s). Depending on your winches capabilities: 10,000lbs, 12,000lbs, 18,000lbs or greater line pull will determine if your vehicle requires 1, 2, or more Snatch Blocks to self recover from sticky situations. Now, a snatch block doesn't affect the winch lines breaking strength or the winches shear pin. A snatch block or series of blocks will only increase your mechanical advantage. The goal is to maintain a specific line load while increasing the applied force to the object being pulled out. Also the more snatch blocks you use the more cable you pay out and greater the load and be distributed across the wire ropes length. So, if you have one block and you have an 2 x 10,000lbs per length of the line so you support now a pulling force of 20,000lbs. Now, you can use very complex systems with multiple pulley snatch blocks that will allow you take a extremely heavy object reduce the line load to an acceptable amount across the entire length of the line being used. One of the down sides with this system is that if you have 200ft of wire rope (or synthetic) on your drum-- if you use 1 snatch block you're down to 100 feet maximum distance, 2 your down to only 50 feet of useable distance, and 4 will move you down to being only 25 feet away from the anchor or recovery vehicle! But with four blocks you can basically increase your pulling power by a factor of four. So, snatch blocks have their usable limits if you need to make an extremely long recovery.
http://www.4-wheeling-in-western-australia.com/images/winching-DLP-SR3x-Tree.jpg
So, then a bigger winch is the answer? Well, I would say, yes. It is always best to put the biggest winch on your vehicle possible for off road applications or extreme recovery operations. So, if you have a Jeep that weights in at 5,000Lbs or 7,000lbs I would get a winch with a single line pull of at least 2.5 times the gross vehicle weight. This will give you the maximum pulling effort in the most extreme single scenario. Then I would get a snatch block rated for 2 times what ever my winch is rated for. So if I have a 12,000lb winch single pull capability I would want at least one snatch block with rating of 24,000lbs (probably for safety purposes I would go up to 30,000lbs and me I would get 2) and this will keep you safe when you do single, double or triple line pulls.
Now, what sort of power option? Well, I'm a fan of either hydraulic or Engine Driven via PTO (usually on the transmission or transfer case) systems but some run off an engine PTO i.e. Unimogs my self. They offer usually the highest power outputs and have the benefit of not depending on the battery (or batteries to operate). The downside is you need to have the engine operating to work the winch. Or you need to have a secondary power source to run the winches i.e. auxiliary engines. However, that being said you usually get the greatest pulling power with a winch that is either run from an engine PTO or Hydraulic motor driven. These units are usually for very large vehicles or for very difficult recovery operations where maximum single line pull strength is required over the greatest possible distances.
The electric units are great. They tend to top out at 24,000lbs usually (and that is usually only for a 24volt system). The more common 12volt system usually operate at 18,000lbs max. Which usually more than enough to move a truck that weights 4-7,000lbs GVW off road with a single line pull under most circumstances. Under that the 9,000lbs-12,000lbs units I usually consider being for moderate off-road applications. They are for people who aren't going to find out what is is like drive in 30+ inches of mud. Usually one of these units will give the average off-road enthusiast the greatest value and utility from the winch. And the installation of an electric winch is far simpler in a Jeep than a hydraulic or pto powered type unit would be.
As for myself-- I'm putting a DP Winch I won at auction (government) recently that is rated at 25,000lbs low mount for the front of a 5-ton FMVV truck. It is a nice winch. I will need to alter my truck to use a hydraulic system but I got it for like $1800 plus tax with 300ft of wire rope on it. So, I couldn't pass it up. It will be great on "The Duke" with the new CAT3116 in it. I just need to set it up to operate with a hydraulic pump and system. Other then that it will give me about nearly 2 times the maximum single line pulling force of my vehicle when fully loaded and with a series of snatch blocks-- I'm going with 4-- it will be able to pull 100,000lbs almost so... You know I think I have it covered. I really cannot fit a larger unit on the truck in the front without doing major modifications. However, I'm happy with this unit.
It is a pretty meaty winch weighing in at 625lbs plus wire rope and mounting brackets. When completely mounted it should weigh in at about 850lbs with hydraulic reservoir and so on. But it will really increase my off-road capabilities.
The question of winches I think it a very important one. How much winch is enough? Is there such thing as too much winching power? Personally, in the words of Jeremy Clarkson "More Power" is always my rebel yell when it comes to winches!!!! So, let's use a few help rudimentary formulas easily found on the DP Winch Manual for any one of their winches.
http://www.team-twg.com/documents/dp-winch/service-operating-manuals/winch-application-manual.pdf
You'll find on page 12 of the manual referenced in the link you'll find a useful formula: (weight of vehicle * surface drag) + (Gradient Resistance Value * Weight of Vehicle) = Effort Required to recover said vehicle.
So, they have a list of surface type drag coefficients and for example let's use Clay (Clinging) .50 , let's say our vehicle weighs 5,000lbs and our slope of incline is a 100% grade or 45 degree angle. So they calculate the resistance to the gradient at being 1/60th times every degree above 0 degrees. So that leaves us with a .7500015 or .75 gradient resistance coefficient factor. So now we have (5000*.50)+(5000*.75)= 6250 ft-lbs of force required to recover this object from a thick clinging clay up a 100% grade. Which isn't a bad estimate.
In reality you would also want to factor in the the surface area of the vehicle that is contact with the mud. It is very possible that your vehicle is submerged up to the frame in deep mud. Which of course would require more force to extract the vehicle than if it is merely the tires stuck in mud. This is especially true if the vehicle itself has become disabled.
Another factor that is often over looked is the angle of the pull itself. Once you start to pull on the vehicle from an angle that is greater than 20 degrees from horizontal-- such as when the vehicle is stuck at the bottom of a hill and you need to get a steep incline and the anchor point is at the top. If you have 60% grade or 30 degree angle you can loose up to 65% of your single line pulling force. That is because you actually pulling the vehicle up and then forwards. So, that is an important thing to remember when you are out winching your vehicle... the anchor point should be less than 20 degrees higher or lower than the center line of your vehicle.
So, what are your options in these scenarios? Well option is a snatch block(s). Depending on your winches capabilities: 10,000lbs, 12,000lbs, 18,000lbs or greater line pull will determine if your vehicle requires 1, 2, or more Snatch Blocks to self recover from sticky situations. Now, a snatch block doesn't affect the winch lines breaking strength or the winches shear pin. A snatch block or series of blocks will only increase your mechanical advantage. The goal is to maintain a specific line load while increasing the applied force to the object being pulled out. Also the more snatch blocks you use the more cable you pay out and greater the load and be distributed across the wire ropes length. So, if you have one block and you have an 2 x 10,000lbs per length of the line so you support now a pulling force of 20,000lbs. Now, you can use very complex systems with multiple pulley snatch blocks that will allow you take a extremely heavy object reduce the line load to an acceptable amount across the entire length of the line being used. One of the down sides with this system is that if you have 200ft of wire rope (or synthetic) on your drum-- if you use 1 snatch block you're down to 100 feet maximum distance, 2 your down to only 50 feet of useable distance, and 4 will move you down to being only 25 feet away from the anchor or recovery vehicle! But with four blocks you can basically increase your pulling power by a factor of four. So, snatch blocks have their usable limits if you need to make an extremely long recovery.
http://www.4-wheeling-in-western-australia.com/images/winching-DLP-SR3x-Tree.jpg
So, then a bigger winch is the answer? Well, I would say, yes. It is always best to put the biggest winch on your vehicle possible for off road applications or extreme recovery operations. So, if you have a Jeep that weights in at 5,000Lbs or 7,000lbs I would get a winch with a single line pull of at least 2.5 times the gross vehicle weight. This will give you the maximum pulling effort in the most extreme single scenario. Then I would get a snatch block rated for 2 times what ever my winch is rated for. So if I have a 12,000lb winch single pull capability I would want at least one snatch block with rating of 24,000lbs (probably for safety purposes I would go up to 30,000lbs and me I would get 2) and this will keep you safe when you do single, double or triple line pulls.
Now, what sort of power option? Well, I'm a fan of either hydraulic or Engine Driven via PTO (usually on the transmission or transfer case) systems but some run off an engine PTO i.e. Unimogs my self. They offer usually the highest power outputs and have the benefit of not depending on the battery (or batteries to operate). The downside is you need to have the engine operating to work the winch. Or you need to have a secondary power source to run the winches i.e. auxiliary engines. However, that being said you usually get the greatest pulling power with a winch that is either run from an engine PTO or Hydraulic motor driven. These units are usually for very large vehicles or for very difficult recovery operations where maximum single line pull strength is required over the greatest possible distances.
The electric units are great. They tend to top out at 24,000lbs usually (and that is usually only for a 24volt system). The more common 12volt system usually operate at 18,000lbs max. Which usually more than enough to move a truck that weights 4-7,000lbs GVW off road with a single line pull under most circumstances. Under that the 9,000lbs-12,000lbs units I usually consider being for moderate off-road applications. They are for people who aren't going to find out what is is like drive in 30+ inches of mud. Usually one of these units will give the average off-road enthusiast the greatest value and utility from the winch. And the installation of an electric winch is far simpler in a Jeep than a hydraulic or pto powered type unit would be.
As for myself-- I'm putting a DP Winch I won at auction (government) recently that is rated at 25,000lbs low mount for the front of a 5-ton FMVV truck. It is a nice winch. I will need to alter my truck to use a hydraulic system but I got it for like $1800 plus tax with 300ft of wire rope on it. So, I couldn't pass it up. It will be great on "The Duke" with the new CAT3116 in it. I just need to set it up to operate with a hydraulic pump and system. Other then that it will give me about nearly 2 times the maximum single line pulling force of my vehicle when fully loaded and with a series of snatch blocks-- I'm going with 4-- it will be able to pull 100,000lbs almost so... You know I think I have it covered. I really cannot fit a larger unit on the truck in the front without doing major modifications. However, I'm happy with this unit.
It is a pretty meaty winch weighing in at 625lbs plus wire rope and mounting brackets. When completely mounted it should weigh in at about 850lbs with hydraulic reservoir and so on. But it will really increase my off-road capabilities.