cosrec

For sure not going to break any equipment with that one.

Up to now i have avoided snatch blocks. But having suggested ways of making a vehicle hold more we are now at a piont were we have run out of winch capacity. I have avoided the subject because there are so many old wives tales its hard to belive what is right or wrong this is my take on the subject if you can can put up a convincing argument i am willing to change my mind. You have a winch with a known maximum capacity. on the winch is a rope selected to be safe at that capacity the snatch block you use will be matched to that size rope. Repeat that again matched to that sized rope. Who ever made that block will have many tests and done research on its developement. At the end of the day be it a single pulley single pully with tieback or multiple pully it will end up with some means of attaching it to a load. Depending on if its used for winching or lifting they factor in a SWL ratio of between 2 and 7. They then mark up the block and give it a capacity. The capacity is what they recommend at the piont where you attach the load be it a shackle a hook or what ever. Oftence people say thats cobblers i have a 10 ton snatch block with tie back and a 10 ton winch so am subjecting it to 30 ton and have used it for years no problems. Like i say willing to will change mind if somebody can come up with good argument.

Spot on thats what they are designed to do. When you get them well down with a sleeper gun plank or girder between them i think they are as good an anchor what do you think I asked a guy what they were for at a recovery show in the late 70s and he told me he then went on to tell me he had designed the whole piece of kit he talked to my father and i for 1/2 hr and showed us round. The one he was demonstrating was on a MAN 6x6 . It turned out he was effectivelly Mr EKA although i have forgot he real name.

Anybody know what the hooks on the back of the legs are for anybody who has used a scammell with an EKA might

Going back to my post where i tried to show how before trying to winch anything we max out on holding power i used a scammell pioneer as an example. I did this for two reasons 1 it hurts no one to suggest what a vehicle equipped with a winch suitabley rigged has the power to do. Indeed it might just make them aware of the forces involved 2 its easier to go for it from the start than to set do so much then pull forward and re rig unless you are certain you have got it right. What about other vehicles all can use some or other of the ideas i mentioned. will give some tips later Some thing to make you think everything that goes against you in doing a recovery eg gradient damage wt etc do the sums then work it back against your own vehicle then you know if you are in with a chance If not can i get some more gradient to assist me (eg throw it in a dyke) can i disable my front wheels some how can i move to that mud over there and pull it We do it daily [ATTACH=CONFIG]33360[/ATTACH]

Great vidieo and it shows how effective scotches are. When set up correctly. It also confirms what i said about winching back untill you are about at the top of scotch and then tensioning cable. Also next time you have the oppertunity try them at the rear as i suggested it will increase your holding power no end and more than make up for not having front wheel locked. indeed i will bet if you have good ground conditions and winching level you can go to the piont where it rears up. I know scammells are not the best of kit for lifting but if you make it rear while winching straight out the back you are getting almost the best out of it

Not treading on my toes i like to learn as well

Well done i would have given the driver an upping as well. I know you were not anywhere near your limit on rope but the vidieo shows how well meant help is rocking the scammell and could under the wrong circumstances have caused damage. A little tip on loaded artics where you have a nice big area to work. Oftence instead of trying to pull the complete lot out at once reposition so that you are at almost 90 degrees to the front of unit then winch the artic will jackknife round fairly easily with out even moving the trailor keep winching and its still an easy pull because the length of the trailer from neck to first axle acts as a lever and screws the trailor out across the ruts you might have to keep reposition and start again the other way but using this method you can get some heavy artics out of deep mud with a relativly small winch.

Quite right and thanks for pointing out if you look at my post i did put a a bit in about getting someone to press the brakes and disable the front axle but my grammer got mixed up and more important i had completely forgot there are no front brakes from there on all calculations are out by 4 tons. For recovery the scotches work best when they are pulling down hard on the chassis as the load comes on the pull down transfers an amount of the line pull into load on the axle which in turn will cause more wieght to go on to the scotch. If the scotch has a good hold you can end up transfering wieght of the front end and on to the rear causing even more sinking of the scotch.

thats exactly the piont i am making i never said the blocks were usless i was angling at what is the point in using needlessly when the truck would slide back anyway

Ok so now we are in a position to actually winch something got a good winch with good rope on it with an end thats safe to fasten to. How about before using it we work out how much or little the vehicle will actually pull. Take for example the pioneer guessing its wt is 12 tons Using the calculations we have we can work out that stood on level road with hand brake on disabling back wheels and no front brakes WT 12 x Damage resistance 4 divided by total wheels 6 it will slide back at a bit over 8 tons not a great amount for what is a relativley big vehicle. Try those scotch blocks that come with the pioneer this will disable the front wheels WT 12 x Damage resistance 6 divided by total wheels 6 thats better it will take a little over 12 tons to move it now but a little more would be handy Stiff leg/spades add 1/3 to 1/2 to what a vehicle will hold. Take the scotch blocks out and put them under the rear most wheels winch with handbrake of until almost ready to go over the top put handbrake on bring cables for scotch blocks together with a shakle and hang on to crane take tension on crane you now have the equal of a set of stiff legs. get some one to press brrakes to disable them recalculate WT 12 x Damage resistance 6 divided by total wheels 6 x 1/3 16 tons getting a bit more like it perhaps another two stiff leg spades would help. Try throwing a sleeper each side in the back bogie arrange it so that the top is sitting on the top of the rear most axle and under the second axle this will mean as you winch back with handrake of to top of the scotch block the second axle will try and climb over the rear axle. You have now created the second set of stiff legs do the sums again WT 12 x Damage resistance 6 divided by total wheels 6 x 2/3 20 tons to move it lot better. Feeling greedy and want more though. Any thing in the calculations that can help us. How about adding a bit of gradient resistance. Before rigging up scotch blocks and putting sleepers in try putting truck down that dyke side that happens to be in right place dont need much of gradient to increase pull by 1/2 that will give you another 6 ton thats 26 tons of holding power. So for only a little work and and some thought we have increased our holding piont from 8 to 26 tons. Also given you a problem if you want to utilise it the winch aint big enough.

Hi i was going to leave Snatch blocks for a while but thought i must give a little warning. A long time ago i bought ten snatch blocks from a dealer in North Yorks These new and still in greased wrapping I was made up and knew i had got a bargin. To discribe them they where very well made quality pieces of kit. The actual pully was made of alloy with four drilled holes in it The pulley was approx 10 inch in dia the side check plates were also of alloy around it was a steel strip 2.5 inch wide main frame with a swiveling hook attached. The side gate to get the rope in and out was secured with one of those antiluce fasteners. we put 4 on each of two heavy wreckers we had which were equipped with twin 6 ton hydraulic winches. they had no makers markings on them nor any SWL. They were worked hard over the next 5 years and never gave any problems A well documented article then appeared in our trade magazine AVRO news a recovery operator (who ceased trading very shortly after)in the states had been on a recovery righting an overturned artic. A snatch block had let go killing a state trooper and blinding another. the next edition showed a line sketch of the snatch block and what to look out for The pully was machined to accept 1 1/2" fibre rope its safe working load was 1.5 ton Guess what i had 10 of them did any more survive

Before during and after the war britans milatery spent a great deal on RD into getting winch ropes to wind on correctly under load. Ranging from the pendalum rig they retro fitted to the DT 980/981 trucks to the overley complicated mechanism they fitted on the scammells and Leyands Guys with horizontal winches. The nearest to a good solution was developed as you state by the US when it introduced i believe the M62 wrecker with a sort of inverted pendilum rig on both front and rear winches. All these ideas were never complete success however as they ignored a basic fact a winch must have the correct fleet angle between its self and the load it is winching or its fairleads. Modern day civilian wrecker designs have over come this to a degree by mounting twin narrow drum winches high up on the boom but still need operator intervention at times to keep things in order. Unless they start building wrecker chassis 90ft long with drum at one end and fairleads at the other or move over to constant line pull capstan winches we are stuck with the fact that safe operation of these winches is down to operator knowledge

For recovery, the slower the better I will second that Mike if for no other reason than it gives more time to stop if things arnt going right A little more on winch ropes. The end of the winch rope is terminated with a machine or hand splice a lead collar (think its called a Tulurit unless thats a trade name) bulldog clips or i have actually seen knots. How ever its done as long as its done correctly it is of secondary importance to the little steel piece thats fitted inside the loop called the thimble. Why is it so important. Down to point loadings again if you look at the cross section of the mounting piont on a hook say its only very small it creates high point loads on the wire. if its missing completely the wires working load is reduced to 1/4 of what it should be. So if your thimble is missing damaged are stretched my advice would be dont use it. The guy who comes to do our Lolar examinations carries a 4 inch cordless grinder in his van and cuts the ends of any wires he finds damaged to stop there use. The cure is not a bad as you think our local ships riggers charge £5 for swagging a new end on cheap for peace of mind. When you have used a winch and are stowing it away allways hook it on to something and stow with a little weight on it. This stops it unwinding and saves the risk of using it next time with lose coils some of which you may not see causing damage to the rope or trapping of coils. We hear more heated words between drivers over this when one has had to strip the whole line of and rewind at the side of a busy motorway than anything else. Just out of curiosity have a look at any 4x4 slide bed recovery or plant truck you come across you will be amazed how many have winches that look as though they have spagetti taffled round them and damaged thimbles. Dont look good and potentialy dangerous

Adding snatch blocks increases the chances of a successful recovery, because the force required to pull something depends on how fast you are pulling it. Adding snatch blocks slows down how quickly the stuck vehicle is pulled out the mud. the slower the casualty can move forward, the less force is required to pull it. Addind snatch blocks also give time for the suction of the mud to break, allowing the casualty to move forward. Force = Mass multiplied by Acceleration. reduce the acceleration and you reduce the force required to achieve it. I supose you could add in wind resistance as well the slower you go the less of it. being practical people i think both can be ignored for the differance it makes in a recovery situation unless you are using a glider launching winch. the question i asked was if a vehicle has hit its limit on holding force how would adding a snatch block (with out using deadman etc) alter anything. I agree suction can be a problem but this can be overcome by applying force then walking away and having a cup of tea

Care of winch ropes there are two trains of thought on this one is winch ropes are indestructable (talking wire here) they thrive on hard work and neglect the other is advise issued by the manufacters of these ropes they should be lubricated with this or that spec oil and inspected daily used or not. people who rely on these ropes for a living on winches that are worked hard eg mariners crane operaters miners tend to follow the advise of the rope manfacturers. Every body else leans one way between these two tains of thought. The actual rope is made up of many actual mini ropes which each time are wound in or out roll and flex over one another causing friction or wear. The very least you can do for winch rope is at least when you change an oil filter pore it over the drum. Even if you never use the winch it will stop it going rusty.

in reply to last three posters am i wasting my time adding these tips or am i talking sense. Little question for two of posters how does adding snatch blocks make vehicle winch more if you have hit limit on holding power. reason i ask is most ex mod vehicles have winch thats matched to its wieght or are we talking deadmen ground anchors etc

A few tips on winch ropes. The biggest cause of wear (and eventual breakage on winch ropes) are abrasion, point loading, and sudden shock Abrasion causes premature wear on the rope and can be caused by something as simple winching at an angle with front mounted winches on the US militry trucks on which there are no winch rollers. Cure line the truck up or use a snatch block to give a chance of direction. Even on vehicles fitted with fairlead rollors winching to one side for any distance will cause great wear to rope. Cure winch so far then stop pay rope out again and relay evenly across drum before starting to winch again or better still realign truck or use snatch block Point loading earlier in post somebody put pictures of a fibre rope hooked back on to its self and the damage it did exactly the same happens with wire ropes going around an axle say and hooking back to its self is a definite no. this is easy to spot and easy to cure less easy to spot is say winching up an embankment and the rope is cutting through the earth you dont know what you are pulling against. Buried just below the surface could be a rock or an old piece of metal. This will kink or break you rope as sure as doubling back on its self. Cure back up with recovery vehicle so rope is clear of earth or throw a sleeper or wooden rollor for rope to pull over A point loading that caught me out and put me in hospital. A heavy winching job on a mixer i rigged up and all was within SWL limits. When the lads reconstructed what had happened as the tension was applied the rope had come up from the axle and was resting on a pinch bolt on front hanger this created a point loading in wire snapping it. Cure this applies to all recovery jobs dont rig up and then go for it apply some moderate load then stop have a walk round check the run of ropes take loops out of cables put packings in to save chaffing suprising how many times you will save some damage to a radiator or brake line say not mention that expensive rope you have just paid for. Shock loading How can that happen My winch only comes in very steady. Easy your mate is stuck down a 45 degree slope you work out you can pull him up embankment with a pull of 8 tons 2 tons less than the winch capacity. You go for it and up it comes nice and steady mate thinks i will give a hand and starts to drive vehicle lurches forward then drops back Suddenly you are imposing a moving load against your equipment maybe 20 tons not good Cure get mate out of vehicle and stand along side you if you cant winch it with out his assistance driving then you have not got right kit or your not rigged right. Hope you find these tips useful

Was it a blue one . There is one at the M.I.R.A testing grounds all it has done aparently is tension wire rope central reservation barrier when they were carrying out research on them. there is an old runway there. I went there on numerous occasions taking amblances for crash testing but for the life of me cant remember the name of the place. Its a nuneton last time i went was 2 years ago but it was always parked in same place but was still in use. have put link to where i saw it but the site is huge <iframe width="425" height="350" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=CV10+0TU&sll=53.800651,-4.064941&sspn=11.979639,28.081055&ie=UTF8&hq=&hnear=Nuneaton+CV10+0TU,+United+Kingdom&ll=52.553685,-1.464958&spn=0.000188,0.000428&t=h&z=14&output=embed"></iframe><br /><small><a that hasnt worked what have i done wrong

Some of the lads who haul off the docks put a self sealing female on the red line and a palm on the yellow line. then they have a male coupling fastened to a palm. that way depending on which air line its fitted it can couple to either sort of cou[plings Palm couplings are available from any of the comnercial fleet factors and are very cheap

Some old motor bikes had them ticklers on them BSAs ?? By the way when they start handing out medals as big as dinner plates for dedication to your hobby i think you guys will be at top of list Brilliant

Sorry to keep banging on this thread but i posted out of shear anger at the way this job was carried out. I have posted scince to give what i believe to be friendly advise and hopefully save people grief. I think SeanN has finally done what i cant put into words and summed up the whole job. Its not rocket science a little bit of research will give you a whole load of knowledge. Perhaps even make you a bit of money in the process heres a link to show you what can do if you think things through. http://tow411.yuku.com/topic/44761/t/Toyota-Landcruiser-wrecker-vs-23000kg-excavator.html

Had a look for pictures of ones i have fitted no sucess but will keep looking heres a link of internet for civilian one looks about same distance from back of cab to me http://classicunimogs.com/manuals/hiab_brochure_06.pdf

Honest that 550 will fit in a 27in envelope and fold dont chop it i will do a bit of research for you and dig out some photos. I am 100 percent sure the only 550 that was different was the marine versions which had stainless pins. Two versions of extending booms fitted one was oval and the other was square as per you photo both fitted in same envelope when fitted

Maybe just a case of mounting Hiab round 180 degrees there easy to alter to get arm swing so its facing right way. Apart from lever positions i thought all 550s were the same. Just a thought some of tank would then be under cab ????