Recovery and Towing

[paulob1]

Okay, I have some 16mm, some 12mm and some 9mm (off my 9 ton crane) cable available, I want to make up my own ropes of differing lengths...what is the best way to do it. I also have a winch witha cut off cable, this is a 20 or 30 ton winch, not sure but it is sure massive...how do I terminate that...where can i get the thimbles etc etc...

 

should I use the three grip method or is there a better way, ie four grips, or similar, something that I can do without any specialist tools or are there better ways...

[robin craig]

The wedge socket as you call it is for me a great device.

 

I have made a number of custom / bespoke winch mounts for people and always favoured these as the termination over a swaged end or one with cable saddles.

 

The advantage as I saw it for the applications was that in the middle of nowhere with limited hand tools a cable that had become damaged could be reworked to remove that section and still be functionable even though it was a tad shorter.

 

The people I was building mounts for were the type to be off road for a number of days away from workshop facilities.

 

Over here Crosby made them.

 

 

R

[Stormin]

The wedge socket as you call it is for me a great device.

 

I have made a number of custom / bespoke winch mounts for people and always favoured these as the termination over a swaged end or one with cable saddles.

 

The advantage as I saw it for the applications was that in the middle of nowhere with limited hand tools a cable that had become damaged could be reworked to remove that section and still be functionable even though it was a tad shorter.

 

The people I was building mounts for were the type to be off road for a number of days away from workshop facilities.

 

Over here Crosby made them.

 

 

R

 

From what I've read the wedge socket is the strongest type of end fitting. The only one that doesn't reduce the strength of the wire rope. Maybe someone else can confirm?

[gritineye]

Useful wedge socket info and a warning here: http://www.csao.org/uploadfiles/magazine/vol9no1/91wedge.htm

[N.O.S.]

Good call, Bernard. We never clipped them (on dragline rigging) - don't think we ever lost one.

[gritineye]

Depends on usage, one fitted to a crane can have the wedge loosened by hitting the ground, if it is not clipped it could work loose after a few hits. A dragline would should not suffer from this problem, depending on driver skills, :-D although a winch cable could suffer a few knocks.

Edited August 25, 2010 by gritineye
see below

[N.O.S.]

You've never seen me press the wrong brake pedal and drop a dragline bucket :shocked:

 

But yes it is something to consider carefully. They do need to be tight - as that link cautions.

Edited August 25, 2010 by N.O.S.

[gritineye]

also I'm thinking the angle of the cables to the crane would be too steep for the scotches to work effectively, or am I missing summat?

 

By way of explaining my comment about the scotch cable angle, I have put together a little video I took last year. None of the three Explorers had the correct length cables, so we had a play to see what worked best, the ground was baked really hard so it was a good test.

 

We all have working scotches now!

 

 

[cosrec]

By way of explaining my comment about the scotch cable angle, I have put together a little video I took last year. None of the three Explorers had the correct length cables, so we had a play to see what worked best, the ground was baked really hard so it was a good test.

 

We all have working scotches now!

 

 

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

[cosrec]

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]

[cosrec]

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

[Stormin]

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

 

Are they there to press the spec lift frame closer to the ground?

 

One question with that photograph. How do you recover the recovery vehicle from that ditch?

[AndyFowler]

You've never seen me press the wrong brake pedal and drop a dragline bucket :shocked:

 

But yes it is something to consider carefully. They do need to be tight - as that link cautions.

 

You seen this clip Tony ? It has two rather understandable expletives if anyone is easily offended !

[recymech66]

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

 

 

Cosrec,

 

Maybe not what they were originally designed for but we used the hooks to hold a gunplank in place crossways to increase anchorage in bad ground. Foden has similar design legs.

[recymech66]

Are they there to press the spec lift frame closer to the ground?

 

One question with that photograph. How do you recover the recovery vehicle from that ditch?

 

 

Lift the stiff legs and winch in, hopefully the weight of the original casualty will be sufficient to allow the wrecker to winch itself backwards.

[Stormin]

Lift the stiff legs and winch in, hopefully the weight of the original casualty will be sufficient to allow the wrecker to winch itself backwards.

 

The key word there being "Hopefully"

[recymech66]

The key word there being "Hopefully"

 

 

Done this many times successfully, but when it doesn't work just try something else and "hopefully" that will work.

[Tony B]

nice one Andy! Now Cobber lets start adding up the damage. One million, two million....:-D

[N.O.S.]

You seen this clip Tony ?

 

:shocking: I have now, Andy!

[cosrec]

Cosrec,

 

Maybe not what they were originally designed for but we used the hooks to hold a gunplank in place crossways to increase anchorage in bad ground. Foden has similar design legs.

 

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.

[cosrec]

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.

Edited August 27, 2010 by cosrec

[rbrtcrowther]

I think i know where you are coming from:confused: The three hooks in the crane at work are 1/ headache ball single fall 3.3 tons (very small) 2/ main block 3 falls 9 tons and 3/ The bloomin heavy we hardly ever use 9 falls 25 ton block. Its huge but has the same rope size just alot more pulleys. all the SWL's are marked on the hook. The winch is only rated at about 3.3tons. The wire has a rating of about 7.8 tons and the test piece broke at 12 tons!

A flat webing strop has a safety factor of about 7 so our 10 ton hoist straps should lift 70 tons new. as the gear gets nearer the hook the factor is reduced for shackles, chains ect and the crane itself is tested to a factor of 12 percent overload. Its down to the abuse the strops are subjected to on the ground and in use. Eg a boat hull is an irregular shape and loads a strop in odd ways so they have a huge factor of safety. shackles and chains are less prone to abuse and the crane itself is only really at risk from operator error and having a huge safety factor is pretty pointless.

 

Keep the info flowing i'm learning new stuff all the time:D

[cosrec]

Right you have a snatch block(s) and the rope is a nice fit in it and you are 100 percent sure that its not designed for use with fibre or synthetic rope. How are you going to use it. My advice not at all until you have checked a few more things.

1 the whole thing is in general good order and free from damage reason obvious

2 the pully is lubricated and rotates nicely Reason when you start using in anger it is suggested that up to 10 percent of power of winch is lost in every block used i think this is an over exageration but if the block is well lubricated then you have done what you can

3 most blocks wether fitted with hook or shackle at load bearing end can swivel make sure they do easily reason it seems to the nature of things that when to have a long line out round a block and you take up the strain there always seems to be three or four twists in the rigging. if well lubricated these will spin out as you apply more load

4 check what ever is used to hold gate which allows rope to enter block is fitted and working correctly reason over the years i have never had a block that has failed but we have had many that have been been bent or distorted beyond safe use because they havent been tightend fastened correctly

 

Ok got some snatch blocks in good working order what can you use them for

 

1 gain a Mechanical Advantage (more power)

2 cause a change of direction

3 carry a load

4 spread a load

[rbrtcrowther]

Also they can be used to reduce the speed of the pull eg. when pulling a casualty back on to it's wheels when you need more controll. Very usefull if you have a stupidly fast mechanical winch like the one on the explorer. It will also halve the load on the winch brake if you have to pay out the winch under load (a near impossible thing to do with a scammell vertical winch without shock loading)

 

We'll be on to Strops and rigging soon:D........Mmmmmmm....endless round slings....:bow:The greatest invention ever:-)

[cosrec]

Right we have rigged up the winch with a single snatch block the rope leaves the truck round the block and is anchored back to the truck. For every ton that is applied to the line approx 2 tons is applied to the hook on the block Simple. Now say instead of hanging back to the truck you decide to use a deadman of set to one side you have long length of rope out and every ton you apply provides roughly 2 tons at the hook . you keep winching in and as you do an angle starts to develop between the out and return line. If you keep going you may end up with an angle on the two ropes of 90 degrees. At this piont the load on the hook will be only 1.6 tons A bit further the angle becomes 120 degrees the load will be only 1 ton and a bit further 170 degrees the load on the hook will be only 1/12 th of a ton not a lot when you are still putting the same energy into the system.

Like a lot of things in recovery if you understand what is happening you can oftence spin it round and use it to your advantage. In this case say you have a stuck vehicle with a strong steel rope stretched to a deadman if you slip a snatch block on the middle of the rope and fasten it to a landrover say as you take the load if the angle is 170 degrees and you apply 1ton to the block you are actually putting a load of 6 tons to the line either side of the block. 6 tons of line pull will sure move a lot. As long as you are aware of the forces involved it could probaly get you out the $*^& at some time.

Another time the above comes in handy is if you are using a block to give a change of direction if the angle is only slight what ever you fasten to can a lot less strong than you first imagine.