Snow and Sand anchors

[BG1]

Hi,

I'm researching the Sand and Snow anchors that 4X4 vehicles use in very extreme conditions IE:- Snow {the loose powder Snow) that does not form a snow ball because it to cold and dry. Sand,(the very loose wind blown desert sand). I have looked at the "plough style" and peg Style and I am looking for people who have had the successes and the failures with this style of equipment, but which really does work in Snow and Sand with a fully laden expedition 4x4 on the end of the winch rope, I would like to hear your comments from you.

Regards Brian

[Dutchgit]

Dig a hole and bury your spare wheel in it to attach the winch rope to. You'll safe yourself some weight.

[headhunter]

Welcome Brian.

What sort of trips are you planning and in what type of vehicle.

If you are more specific about the areas you plan to visit, there may be people on here with practical experience of the conditions you expect to encounter in such places.

John

[BG1]

Welcome Brian.

What sort of trips are you planning and in what type of vehicle.

If you are more specific about the areas you plan to visit, there may be people on here with practical experience of the conditions you expect to encounter in such places.

John

Hi John,

I actually work for the Off Road Attribute Team at Land Rover at Gaydon and I am looking at which of the systems really do work in these extreme conditions. IE:- when you are on your own with no support vehicle to pull you out and you have no other way to get out, than use the land anchor systems that are available. But my question is" Do they really work in the Dry loose snow and loose wind blown Sand and pull a fully laden vehicle out of an axle deep position ?. I am looking for anybody who has the experience of using these things in anger and found that they work or they do'nt.

I am looking for the failures and the successes when using the anchors that people buy and use when they are serious 4x4 and they have to rely on the equipment that is around them at the time to get them out of a problem.

So I am asking for peoples opinions and views based on experience of use of this equipment, useing this forum is the best way of accessing a lot of people from all over at once.

Regards Brian

[santalars]

Hi,

As being a geotechnical engineer I at least have some ideas of material strengths rather then in recovery under extrem conditions.

Therefore:

in loose sands you may get a resistance of 6.4 kN/m2 (0.64 tons/m2) to a depth of 0.5m. Multiply this by the projected area the plow will have and you get a rough idea of what pullout forces to expect.(if the anchor is 0.4 * 0.3m it will be 77 kg only)

This improves the deeper you dig the plow in. E.g. if you get it to sit beween 0.5 an 1.0m you will have a resistance of 25.5 kN/m2. (300 kg with 0.3 * 0.4m and approx 700 kg with a spare wheel)

As you can see this is not much to expect for worst case sand which is mainly the reason whu you get stuck in it.

Powder (snow) would be much worse. However, you will not be able to drive close to more then 0.5m powder and underlaying snow will have settled (consolidated) and will provide much better resistance.

So:

use a spare wheel in soft sand and a tree in powder snow (long ice anchors at the poles)

[BogMonster]

I can't comment on snow or sand as neither is something I get stuck in, but I can say from lots of experience that in deep peat which is most of the terrain here, pretty much anything standard is hopeless - I have military pin and tube anchor and a Pull Pal copy built by a forum member and either of them will put out very easily in the sort of stuff you get stuck in - mainly because beneath the surface there is no strength at all so the anchor pulls out (pin and tube) or through under the ground (plough anchor). I should imagine that once buried, a plough anchor behaves much the same in snow and sand as it does once it is through the turf mat in wet peat, in other words the substance has no inherent strength and the only answer is to keep adding cross sectional area to the spade until you eventually get to the point where the resistance to pulling it through matches what you need to extract yourself. I've had situations where I have been not really very stuck (could easily have got out with a pull from another vehicle) and only just got out with both anchors chained together plus drive assistance. I keep meaning to make an extra wide spade for my plough anchor (probably about 36" wide x 24" long") but it is a "round tuit" job

I've also tinkered with the idea of modifying the anchor so that once the spade is fully buried, it can be allowed to rotate round to 90 degrees to the direction of pull, as I think that would help its resistance in extremely soft ground but you need to have exactly the right angle for spade entry otherwide it won't bury properly, so just altering the fixed angle of the spade wouldn't work. Another vapour build idea at the moment though

[headhunter]

Brian

Thanks for the clarification. I am sure there will be some interest in your post with further knowledgeable replies.

Winch anchor debates on here are usually very informative.

Have you tried a search of the forum technical archive.

There should be further useful winch anchor tips there.

John

[TheRecklessEngineer]

I don't know how similar ground anchors are to sea anchors, but I've only ever found that danforth anchors will hold in sand or silt (marine equivalent to loose sand or powerdery snow). The primary anchor, normally a plough or CQR just pulls through. The ground anchors I have seen are all plough type - never seen a danforth type design...

A danforth looks like this:

There have been times that these anchors have dug themselves in so well, I have been unable to extract them from the bottom.

[BogMonster]

Apparently they work quite well, though the one I have on my RIB isn't really Milemarker rated so I haven't tried it

[leeds]

I have seen the Danfoss type anchors used with some success in sand quarries in Denmark. The Danish lads swore by them and at them. They commented that no conventional ground anchor sold by 4 x 4 shops worked in the sand quarries. They swore at these anchors because they were so big and heavy. Not suitable for an overland truck due to size and weight.

Have recently tried a conventional ground anchor in desert conditions. Even behind a desert shrub bush it pulled straight out. After 3 attempts resorted to burying the spare wheel and that worked. Later on used the conventional ground anchor in mud with success.

The looser the ground the bigger the effective surface area the ground anchor needs to have. Hence straight into weight/storage problems.

If you are going to dig a ground anchor in forget these folding shovels get a decent spade!

Regards

Leeds

[Turbocharger]

So we want a large area but low weight - it's a perfect TRIZ problem.

Depending on how you define the problem, the blade can be seen as a moving or stationary object. Since we have to carry it around, I'd say it's a moving object. So - improving the area of a moving object increases the weight of the moving object. TRIZ matrix says:

The TRIZ Matrix proposes the following Principles to solve this contradiction:

Improving 5: Area of moving object without damaging 1: Weight of moving object

2. Taking out

Separate an interfering part or property from an object, or single out the only necessary part (or property) of an object.

17. Another dimension

To move an object in two- or three-dimensional space.

Use a multi-story arrangement of objects instead of a single-story arrangement.

Tilt or re-orient the object, lay it on its side.

Use 'another side' of a given area.

29. Pneumatics and hydraulics

Use gas and liquid parts of an object instead of solid parts (e.g. inflatable, filled with liquids, air cushion, hydrostatic, hydro-reactive).

4. Asymmetry

Change the shape of an object from symmetrical to asymmetrical.

If an object is asymmetrical, increase its degree of asymmetry.

Anybody inspired to any useful ideas from these principles?

[Mo Murphy]

No, John

[steve_d]

I'm assuming the vehicle is being prepared for this specific problem as in a planned desert or snowbound expedition.

If so then perhaps the bonnet or Defender rear door could be suitably modified and strengthened so that it can be removed and used as a snow or sand anchor. It would provide the surface area required in this situation and not take up stowage space.

Steve

[santalars]

Technically there could be holes in the anchor plate as long as they are not too big. (comparable with tese fork style spades...don't know what they are called in english) Many small holes should work as long as it's not more than half of the surface area. However this will weaken the structure. Plate extensions should also be removable as otherwise the anchor will not dig itself in anymore into firm ground.

However, I don't think it's the right way of thinking.

The most usefull arrangement using conventional anchors is having a rear winch. You will not be able to drive very far into somthing that is that soft that it would not support an anchor (except peat). That means there must be some firm ground along the way you came and you could use the anchor in that.

Also it may not be wise (if alone) to pull youself further into the mess as you might come to a piont where nothing goes.(see last point)

My third suggestion would be to carry 200m of 12 - 15mm dia rope with you. A good rope will have a breaking resistance of up to 2500 (3000) kg. This will significantly increas your chances to find a tow point.

Last idea: have a sattelite phone and call for help

[BogMonster]

A good rope will have a breaking resistance of up to 2500 (3000) kg.

I wouldn't dream of using something with a 3000kg breaking strain! 24mm nylon which is a suitable tow rope has a breaking strain of 12000kg...

You are right about the "except peat" bit though

[streaky]

For soft desert sand there is only one choice....the Original Pul Pal.

A couple of people have said to bury a tyre in soft sand and use that as your anchor to winch from.....have you ever tried to dig a pit in soft sand deep enough to bury a land rover wheel? We' tried it during one of our recovery workshops and trust me....it takes forever. The pit just fills in with sand as you try to dig it out.

It might be okay for the damp sand that you find on beaches....but for wind swept fesh fesh or soft talcom powder like sand it's a waste of energy.

Yes...you & your mates will eventually be able to bury it but you'll have expended a huge ammount of energy in the process and in a desert environment that's a dangerous thing, plus....once you've burried it a few feet below the surface.....you'll have to dig it out again afterwards.

If your vehicle is stuck in such a way that it can't be driven out by deflating the tyres to less than one bar then you'll need something more than a buried wheel to get you out. As a desperate last ditch effort to extract the truck then give it a go.....but the best option is to carry a proper ground anchor like a Pul Pal.

Just another point about the rear mounted winches.....this concept is fine on level ground but what about when you've driven or have been sucked into a soft sand bowl? It makes no difference then which end your winch is.

A few years ago Myself, JW Riyadh and six bigger than life US soldiers spent approximatly 4 hours with a hand cranked Tirfor winch pulling a Series III lightweight out of a sand bowl the size of a football field.

[BogMonster]

I bet that was fun

[Turbocharger]

The more I think about this, the less suitable steel seems for this purpose. Streaky's brought some real-life experience to this thread (and I don't have any) but how's this for an idea:

One of the TRIZ principles above suggests inflatables, such as filling bags with compressed air to expand their area. Sand behaves quite like a fluid, so burying sandbags (or pulling a large open-mouthed bag over a great distance to fill it up) and coupling a rope to them would work, but it'd be a lot of effort / need a lot of rope.

Then I realised, the bag doesn't have to be closed, a one-sided bag (like a parachute) would probably work. All you need is to capture a large area of sand, such as a parachute would. The area doesn't need to be continuous for it to work, so a net would be a suitable canopy for the parachute. In my diagram below I've suggested a webbing net (such as they use on driver's windows on race cars, but larger). I've used round-section tubes to form a frame, and ropes would be attached at A, B, C & D. It would dig itself down if it was rigged properly, although there might need to be a cross-brace from A to B, and C to D to stop it collapsing as it slid underground until the sand was at level E-E.

I've hidden the critical dimensions from my technical assembly drawing so Ze Enemy can't copy it, but I think it covers the principle in my head. Big parachute, big area, lightweight and collapsible for storage.

[headhunter]

I recall some earlier trials in fine sand using a spare tyre without success see here - http://forums.lr4x4.com/index.php?showtopi...&hl=caption

John

[alex milton-haynes]

really interesting to read you can use a spare wheel to recover yourself, may be usefull oneday if i venture overland!

[leeds]

For soft desert sand there is only one choice....the Original Pul Pal.

A couple of people have said to bury a tyre in soft sand and use that as your anchor to winch from.....have you ever tried to dig a pit in soft sand deep enough to bury a land rover wheel? We' tried it during one of our recovery workshops and trust me....it takes forever. The pit just fills in with sand as you try to dig it out.

It might be okay for the damp sand that you find on beaches....but for wind swept fesh fesh or soft talcom powder like sand it's a waste of energy.

Yes...you & your mates will eventually be able to bury it but you'll have expended a huge ammount of energy in the process and in a desert environment that's a dangerous thing, plus....once you've burried it a few feet below the surface.....you'll have to dig it out again afterwards.

Just another point about the rear mounted winches.....this concept is fine on level ground but what about when you've driven or have been sucked into a soft sand bowl? It makes no difference then which end your winch is.

Have only used spare wheel burial routine once. Devon 4x4 ground anchor was just pulling through soft sand. Admittedly we were in an unusal situation being beached and stalled on a sand dune in the Simpson desert with the fickle land rover fairy(FLRF) playing her tricks so that the 110 would not restart. Being above the anchor point meant that the pull on ground anchor was in wrong plane so it would not bite. So buried the spare wheel. Luckily only top foot of sand was very loose so the digging job whilst being hard work it did go in reasonably straight forward. Pulled 110 off the crest and bump started it OK. FLRF then went elsewhere to play her tricks as 110 performed ok afterwards.

To extract the spare wheel used shortest possible link and pulled it backwards through all disturbed sand. It worked for us in circumstances that we found ourselves in.

I have front and rear winches on the 110. If you are stuck in a soft sand bowl then it does not really matter which end the winch is at. Having said that the rear winch gives me the option of going backwards if that is the most sensible route. It is really about options and having more then one tool/technique in your recoyery storage locker

Regards

Leeds

[jwriyadh]

The only ground anchor I have used is the PullPal, this worked fine in sand, just give it enough length of pull to allow it to burrow down far enough to reach compacted sand. The alternative is to carry one or two winch extension straps to allow placement well away from the soft sand area.

Please dont use winches and ground anchors to build false confidence into people taking a single heavily laden vehicle into an area where common sense would dictate they should not be.

jwriyadh

[leeds]

The only ground anchor I have used is the PullPal, this worked fine in sand, just give it enough length of pull to allow it to burrow down far enough to reach compacted sand. The alternative is to carry one or two winch extension straps to allow placement well away from the soft sand area.

Please dont use winches and ground anchors to build false confidence into people taking a single heavily laden vehicle into an area where common sense would dictate they should not be.

jwriyadh

Hi jwriyadh, was not trying to give false confidence to people. Was trying to explain how I found the burying the wheel lark. I do carry a 30 metre extension line, plus can nick the rear line if need be. Am not sure of lenth of straps etccarried but another 15m +

Overland vehicles should not be heavily laden as that causes all sorts of problens

Regards

Brendan

[reads90]

For soft desert sand there is only one choice....the Original Pul Pal.

Agreed

I have a fold up Pul Pal style ground anchor which was used and abused in mud and stuff on the winch challenge events in the uk . But took it round Australia with me when we did our trip. And 400 ks north of Perth we got stuck half way up a massive sand dune in the middle of no where ,( and i mean Australia in the middle of no where and not uk in the middle of no where). We could not go back , as we had a trailer on . So i set up the ground anchor with the winch in the very soft sand. I had never tried the my ground anchor in sand before but was sold to me on the basis that it would work. And it held as the winch pulled the fully loaded 90 and the 1 ton trailer i had on the back, up the sand dune no problem and held very well