welding on tow hooks

[Nivapulledout]

On my last trip back to NZ i had the project of building a new front bumper and mount for the new runva winch I had bought.
Time was pressed at the end and when it came to mounting the tow hooks I did not have the bolts to go through two 50x50 box so I just welded them on.(plus that left a route for water to get into the new bumper I made)
Since coming back overseas I have been reading posts and all about how people are touchy about towhooks and their ratings.

Both of mine were bushranger 10000bl ones and when I welded them I put a triple bead around the base and then filled the bolt holes as well. And I have huge faith in them not coming unstuck

now the Niva is only 1600 kgs and my winch is 6000lb so any load I am putting on these hooks is well under rating, however will people/clubs frown on these hooks because they are welded on? I am guessing the only problem they will have is that possibly the heat has changed the granular structure. However as I did not quench them and they were allowed to cool by air they should not have hardened and become brittle.

I would like to know everyones opinions on what your views are. Easy enough to cut them off and bolt them next time I am back home if people take offence to the way I mounted them.

I would post pics but cannot work out how, think I need an album and be a higher member. dont know how to get there.

[DaveM]

To post pics you need to host them on photobucket or similar, and copy the link.

I doubt there are many clubs that would accept welded on hooks.

[coxsy]

the structure of the steel may of changed just by welding with three beads thats a lot of heat, heating and cooling will put stress on the steels, I am a fitter welder and have some understanding of what you are saying , by welding in some form we have built this modern world, the weight of the niva will not be enough to cause those hooks to move , run with it for now seen worse things done and hold together

[Nivapulledout]

cheers for the replies and views.

here is a link to the pic of what I have done


http://i843.photobucket.com/albums/zz35 ... 0129-1.jpg

[turoa]

To be honest, if you asked me for a tow, i would probably reject your request. I have been told that the general rule of thumb is that 1" of weld will hold 1 ton. A tow hook is what? 2" long. This means that there is only 4 tons worth of strength holding that hook on. A decent snatch will put more than 4tons of strain on it.

Also it will put alot of leverage on those bottom welds of that box. Nice welds though.

[dazza85]

To be honest, if you asked me for a tow, i would probably reject your request. I have been told that the general rule of thumb is that 1" of weld will hold 1 ton. A tow hook is what? 2" long. This means that there is only 4 tons worth of strength holding that hook on. A decent snatch will put more than 4tons of strain on it.

Also it will put alot of leverage on those bottom welds of that box. Nice welds though.

I'm with him ... the whole leverage thing because of the spacer alone would make me me think twice ...
The things to consider are how is the hook mounted - bolts welds etc and what is it mounted to
there are a couple of pics on here somewhere that show welds that have let go - the hook was bolted onto a small plate that was welded onto something else

[Pedro]

i have complete faith in the welding, looks really nice, but what has the heat done to structure of the steel, we/you do not know what material the hook is made from, if the hook was tempered in any way you have certainly altered it from factory specs, if you have introduced micro cracking from the heat you will have a issue,
the chances are you will get away with it, how ever if it fails i have seen bits of hook embed themselves into a solid dirt bank about a foot deep, we had to pick axe to get it back, would not be a good feeling to see the hook go and see a mate go down,

my 0.02c or is that 0.10c now ??


pedro

[coxsy]

now I've seen the photo's oh dear not a good idea

[Bulletproof]

I would refuse to tow you with a welded hook.

No club that I know of would allow you on a trip with welded hooks

Your lada may be light but the suction of a bog is much much more and has to be allowed for with snatch towing.

My guess is that if someone got injured or killed because of the welded hooks you could be accountable

Cheers Richard

[tweake]

at the end of the day,
hooks are rated, bolts are rated.
the strength of the welds is unknown, strength of hook is now unknown. its just asking for trouble.

incidentally i understand the kid who got poor kid who got killed with the tow ball was hit with the whole hitch. it had been broken at some stage and welded back up.
the cost of getting it wrong can be some ones life, so please get it right.

[Nivapulledout]

Right this is the reaction I was worried about.
Even though I am pretty sure it will be ok(millions of structures around the world are carrying weight on weld) and if that pulles off then my winch should pull off for sure.
As for the injuring people. the only time people get injured is if someone does not abide by the rules of recovery and that is "no person should be standing in the two circles which have a radius equal to the length of the winch rope of which the centres are all the attachment points."
The amount of you tube vids I have seen of kiwis doing some trial or tracks and people are standing next to winch ropes as high as the trucks is bonnet in bog is unbelievable. Injuries are preventable !!!!
I will change the tow hooks when I get home as it is an unknown and if I get stuck and get refused a tow(not that I will need one he he) then I wont be a happy camper.

thanks for all the imput

Ps the law of recovery is anything bellied in mud is 1/2 weight of vehicle for a recovery pull the only exception is for a tank which because of the flat bottoms create extra suction and that is 2 x weight of vehicle so could apply to 4x4 if they have full underbelly rock guards.

max strain on attachment points are from shock loading up to 2x weight of vehicle and vertical pulls(ie winching down a steep bank) so the max load that could ever be put on my little shitter is 3-4 ton. Another reason to like light 4x4s

I have My recovery cards(all the formula) still from the army and if anyone wants a pic of them to print and laminate I will post them, very handy to work out what your pull is going to be, not so important with light vehicles but when you are pulling a 35t D8 bully out of deep mud and you stuff up the calculations it could be a difference of 5 ton which can lead to massive gear failure.

[gimmemud]

I think they are meaning when/if the hook or base snaps then you've got a stretched rope aiming for the back of the head of the driver not caring if there is a rear windscreen in it's way.

[Nivapulledout]

very true. or the massive hole it will leave in the grill/back end of the truck.
I was thinking just for shits and giggles before I cut them off to possibly get them load tested. wondering if there are any company's out there that would do this??? or could do a 4:1 or 3:1 pull with the bumper up against a wall or bank.

[tweake]

i don't know what that pipe and packer is welded to but its possible it will rip it right off unless its actually end of the chassi.

also the packer gives the hook leverage so your more likly to twist it up/down. i would have made that packer a lot longer.

the point with the welding is it may be perfectly fine, an engineer etc may cert it fine, you could test it all fine, but none of that will mean anything to the guy in the bush who is about to snatch ya. hes going to take one look and wonder if its fully engineered or more likely just some rough nut weld job.

[Nivapulledout]

I need the spacer block to clear the bumber. What I will do is buy some 120mm grade 8.8 bolts and bolt through both box section. that should solve all the problems.
Thanks for all the advice and views most appreciated, I wont make the same mistake for the rear bumper when I do it.
Will post pics of the finished product sometime in Feb when I get home to make the changes. see what everyone thinks.

[albundy]

Bloody nice welds though cobber
Al

[Pedro]

Right this is the reaction I was worried about.

As for the injuring people. the only time people get injured is if someone does not abide by the rules of recovery and that is "no person should be standing in the two circles which have a radius equal to the length of the winch rope of which the centres are all the attachment points."

that covers the rope, assuming one end stays attached to the non broken hook, as for the broken off hook it will travel like a bullet for many hundreds of feet if not further, the one i witnessed where the hook sheared the bolts off, embedded into a bank about 50 feet from launch point, we had to pick axe the bugger out to have a look to see what happened, it embedded about 1 ft from a person sitting on the bank. so the phrase "the only time" covers ropes only with a little assumptions.

Cheers

Pedro

[tweake]

I need the spacer block to clear the bumber. What I will do is buy some 120mm grade 8.8 bolts and bolt through both box section. that should solve all the problems.
Thanks for all the advice and views most appreciated, I wont make the same mistake for the rear bumper when I do it.
Will post pics of the finished product sometime in Feb when I get home to make the changes. see what everyone thinks.

can you move the hook forward a bit? if so make a longer spacer and put a third bolt in.

[Smurf]

I need the spacer block to clear the bumber. What I will do is buy some 120mm grade 8.8 bolts and bolt through both box section. that should solve all the problems.
Thanks for all the advice and views most appreciated, I wont make the same mistake for the rear bumper when I do it.
Will post pics of the finished product sometime in Feb when I get home to make the changes. see what everyone thinks.

can you move the hook forward a bit? if so make a longer spacer and put a third bolt in.

And put crush tubes inside the box section

[Nivapulledout]

yeah was already thinking of doing crush tubes as well.
I cannot move the spacer fwd anymore as it will hit the bumper, check out the pic of it with it fitted.

http://i843.photobucket.com/albums/zz35 ... C00139.jpg

Very true about the unattached objects flying Pedro. Another good reason not to have anyone standing around. hardest thing in the world to get people to do because they all want to see the action.
I was winchman on a wrecker with a 25T winch cable doing a 80+ton pull (4:1) and the cable broke. like a big snake, lucky all the energy had been lost by the time it hit the back of the wrecker. I was the only one within of 200m for that pull so it was lucky we had made sure everyone was back. pity my pants did not fare as well he he.

[darinz]

I think you have missed the real point.
Those hooks are designed to straighten in an overload situation and not break. You have now completely stuffed them as the welding will have altered the steel they are made of. Yes the welds look really good etc but that isn't the point. They are designed to be bolted and the rating is only relevant when bolted.

So you really need to cut them off, through them away and bolt on some new ones.

As for the max load being 2x the weight of a vehicle, maybe in the classroom but in real world situations I've seen 9000lb (4500kg) winch with triple line pull fail to move a 2000kg truck. So 12,000kg (approx with losses) failed. You aren't taking into account what happens when you hook up a submerged log or something like that. And that happens a lot.

[DaveM]

As for the max load being 2x the weight of a vehicle, maybe in the classroom but in real world situations I've seen 9000lb (4500kg) winch with triple line pull fail to move a 2000kg truck. So 12,000kg (approx with losses) failed. You aren't taking into account what happens when you hook up a submerged log or something like that. And that happens a lot.

Have to agree, as you also need to take into account that not all muds created equal. I've seen bogged vehicles on the edges of rivers, and the suction caused meant we couldn't retrieve the hilux even with 2 9500lb electric and one Safari PTO winch.
Took many hrs on a shovel because as soon as we took a shovel load out, it was almost immediately replaced with more

[Nivapulledout]

Ok I get the point. cut hooks off and through bolt with crush tubes is the plan.

And I understand that if you are going extreme you can get more than 2x pull. locked wheels , sunk in thick mud and obsticles like you say can make you go above. And I am not planning on going that extreme in my little niva , "Ok you say but you never know" well then I will have already have bolted new hooks on and should not be a problem. Fingers crossed.

before I do any 4x4 I am going to do a proof pull(after I change the hooks) I am thinking of a 3 to 1 with the bumber up against a ditch, this should check both the hooks and winch mounting up to about 8 ton. (over 4 times weight of vehicle)
Or maybe I should do a 2:1 which should give me a 5.4 ton pull which is still almost 3 times WOV. as there is no full chassis on ladas they can have a tendency to just rip all the panels off.
Any Ideas on this, what have you guys proof tested your winch and mounts to?

[darinz]

Don't stress them if you don't need to.
Just make sure you follow the mounting advice above and you should be fine.
Due to the welds you did, I will assume you have at least half an engineering idea so just make sure you don't increase the leverage on any mounting you do. If you have to space the hooks up then spread the load over a greater distance.

I like a lot of the guys here have seen hooks ripped of a chassis and fly ALONG way and then go through things. They have more than enough force to kill someone so if in doubt get first hand advice from someone who REALLY knows what they are talking about.

PS Don't feel people are getting at you over this. It is just that lives cann be at stake if it is done wrong.

[pruggerdore]

All has been said and said well, however you keep making reference to the max your winch can apply but snatching isnt winching and the force applied from the jerk of an enthusiastic driven 3 ton vehicle is tremendous and virtualy uncalculatable. Im not sure if you realise people are talking about snatching not winching. Personaly I think there is little chance of your welds being an issue but what the welds have done to the integrity of the hook is of a bigger concern. Whateva way you look at it Its all an unknown potential and therefore needs redoing. Another reason to have everybody doing the same thing is that you dont want to be having this debate everytime someone goes to put a rope on it.

[dazza85]

Snip X but snatching isnt winching and the force applied from the jerk of an enthusiastic driven 3 ton vehicle is tremendous and virtualy uncalculatable. Im not sure if you realise people are talking about snatching not winching.
Snip x

I was thinking the same thing ...

Try putting ya snatch strap around a large log somewhere and give it a decent snatch ...
You may be very surprised at what happens

I also wonder about the leverage created by the block ... I am not an engineer .... Just looked at a lot of posts on here ...
I would have thought that it would be better to bolt it directly to the chassis - with crush tubes and maybe some renforceing plate atached with some of your first class welding and then take a grinder to ya bumper to fit ...

What do people think ???

[Nivapulledout]

Thanks again for the comments. I do realise you are not getting at me. This is what the forum is for. sorting stuff out so that accidents can be prevented.

Engineering background was 7 1/2 years Army heavy diesel Mech +2 years working for MTU/Detroit Diesel after getting out and now 6 years as a superyacht engineer.

Not keen on losing the spacer as it is not a huge amount of leverage and the box is 50x50x 5 and with the ends capped and through bolting I personally think that is not going to be a problem.I may put extra gussets on the side to add extra strength though.

I guess the reason I keep referring to winching is because it should be the preferred method of recovery after a tow has not worked.(just what I have been taught) If a winch is a available. why use a method that as you all say puts huge amounts of stress onto your tow mounts and vehicle and can/has caused injury to both vehicle and machine.
You guys repeatedly point out that snatching can bent hooks and rip them off, caused by the huge loads of snatching etc.
I understand that you have to use a snatch if that is the only thing available but before you do every possible way of reducing the load. eg digging,
People seem to think it is a winch challange and dont have the time to set up a proper winch layout or dig a bit, but spending a bit of time to reduce the load and increase safety is worth it in my book!!!! the longest one recovery pull took my team 18 hours to set up and it came out first pull , the pull only took 20 min and pack up another hour. but nothing broke and no injurys.

Just as I said in my new to site post, I am used to big stuff not the NZ 4x4 seen. still adjusting.


thanks again (he he see what replies we get now)

[albundy]

People seem to think it is a winch challange and dont have the time to set up a proper winch layout or dig a bit, but spending a bit of time to reduce the load and increase safety is worth it in my book

Couldn't agree with ya more dude. Half the time we are too lazy, snatch=instant gratification, out and on ya way in no time, usually . My mates from Oz come over every year for a grade 5+ trip we do annually on the Westcoast sth island. They can't for the life of themselves understand why we use ropes and not snatch straps for vehicle to vehicle recovery. I change my hooks every 2 years as they are all out of shape by that time any ways, and they are mounted as close to the chassis points for load sharing as possible. As for winch mounts and testing, I've winched the pig up near vertical banks, winch directly mounted to plate built into front bar.
As you say this is what the forum is for, and for once we have a very interesting recovery type discussion developing . Love a good hard recovery . You never stop learning. You going to post up those recovery calc cards we can print off?
Al

[coxsy]

heres my ones

[albundy]

Thanks cobber, I'll sort that at work tomorrow all laminated and everything and it can live in the truck.
Al