question Breakaway chains for towing

[N.O.S.]

Just for the sake of clarity, where on a Matador are you suggesting attaching breakaway chains? You have identified were they go on your vehicle, but where should they be on a standard, unmodified Matador?

 

And whilst we are thinking about it where on a standard Scammell Explorer do you think is the best place to attach break-away chains?

 

I guess you would have to modify both vehicles in order to attach chains? If I wanted to use safety chains I would probably drill a couple of holes in appropriate places or attach some brackets somewhere and bolt on a couple of suitably sized lifting eyes. Would be a better engineering solution than wrapping something around the rear crossmember (Expl) or towing spring (Mat).

[antarmike]

I have seen a Scammell Pioneer pull out its rear towing spring. Attaching a chain around the rear towing spring does not give a complete solution to "what could possibly go wrong will go wrong"

Edited January 27, 2010 by antarmike

[Bodge Deep]

I have seen a Scammell Pioneer put out its rear towing spring. Attaching a chain around the rear towing spring does not give a complete solution to "what could possibly go wrong will go wrong"

 

So where then Mike?

Must be somewhere

[N.O.S.]

I have seen a Scammell Pioneer put out its rear towing spring. Attaching a chain around the rear towing spring does not give a complete solution to "what could possibly go wrong will go wrong"

 

My thinking exactly, hence my post. I imagine it might be more likely that a towing spring would break than a hook suffer "structural failure". I've seen a broken one. After all, who knows what terrible metal-altering experiences a ww2 Matador or Pioneer hook or towing spring might have suffered in its long hard life? :shocked:

 

There are some hooks out there which are not solid metal, but hollow - and with quite a thin wall at that. I have a couple of these in stock but decided to take a good old solid one off a Matador when choosing a hook destined for 'use and abuse' on the back of a large wheel loader.

 

But if it is not practical to attach safety chains by any other means - because the vehicle has not yet been fitted with suitable mounting points - then do you not agree around the rear crossmember has got to be safer than no safety chains at all?

 

I hardly think anyone is talking 'complete solution here', just one more sensible, practical step towards making these rigs a bit safer for other road users in today's world. :thumbsup:

Edited January 27, 2010 by N.O.S.

[antarmike]

My thinking exactly, hence my post. I imagine it might be more likely that a towing spring would break than a hook suffer "structural failure". I've seen a broken one. After all, who knows what terrible metal-altering experiences a ww2 Matador or Pioneer hook or towing spring might have suffered in its long hard life? :shocked:

 

There are some hooks out there which are not solid metal, but hollow - and with quite a thin wall at that. I have a couple of these in stock but decided to take a good old solid one off a Matador when choosing a hook destined for 'use and abuse' on the back of a large wheel loader.

 

But if it is not practical to attach safety chains by any other means - because the vehicle has not yet been fitted with suitable mounting points - then do you not agree around the rear crossmember has got to be safer than no safety chains at all?

 

I hardly think anyone is talking 'complete solution here', just one more sensible, practical step towards making these rigs a bit safer for other road users in today's world. :thumbsup:

 

The spring I saw did not break, it flexed so far it pulled out of the chassis. A combination of the spring shortening, as it bent, and the severely curved spring forcing the bolt on brackets with the slots that carry it to bend away. Amazingly the bolt at the bottom of the open ended slot did not fail.

 

The brackets were hammered back into place and the spring refitted. Some Matadors have a chain from the rear cross member that goes to the tow hook bolts, to limit how far the spring can flex, but not all hace it.

[gritineye]

That just enforces the reason for using chains, it is nothing to do with weather a hitch can come undone, but about the unexpected. I read somewhere that the official fix for bent spring mounting plates was to straighten them and change them side to side!...:shocked:

 

A good friend of mine with many years in round timber work told me that they always used safety chains as they couldn't work out how to test for metal fatigue out in the woods.

[griff66]

right thought i would join in ! used to work for a civvy company in the falklands early 90,s we had land rovers fitted with nato towing hitches at front and rear for pulling ground pwr units water meth rig etc and will never forget one day when a work mate hooked up a pwr unit pushed down the top of towing hook expecting it to lock but due to crud it did,nt , he went belting off towards the helicopter next thing he saw was ground pwr unit overtaking him heading to s61n !luck would have it it went up a bank instead but he had eyes like a racehorse on steriods for quite a while after that!:cool2:

[antarmike]

right thought i would join in ! used to work for a civvy company in the falklands early 90,s we had land rovers fitted with nato towing hitches at front and rear for pulling ground pwr units water meth rig etc and will never forget one day when a work mate hooked up a pwr unit pushed down the top of towing hook expecting it to lock but due to crud it did,nt , he went belting off towards the helicopter next thing he saw was ground pwr unit overtaking him heading to s61n !luck would have it it went up a bank instead but he had eyes like a racehorse on steriods for quite a while after that!:cool2:

 

The pin will only go through the holes, if the lock is closed. This would have alerted the person to the problem. There was obviously no attempt to fit a pin. Any comment I have made about the very high reliability of the Nato hitch, is when it is used correctly, and this includes fitting the pin. Fitting the pin is confirmation that the lock bar is in place.

 

This incident as described here realtes to misuse of a Nato hitch, not keeping mating parts clean, not fitting the safety pin provided, ready for use on a handy little chain.

 

If you aren't prepared to use something in the way intended, then you may well come unstuck.

Edited January 27, 2010 by antarmike

[antarmike]

That just enforces the reason for using chains, it is nothing to do with weather a hitch can come undone, but about the unexpected. I read somewhere that the official fix for bent spring mounting plates was to straighten them and change them side to side!...:shocked:

 

A good friend of mine with many years in round timber work told me that they always used safety chains as they couldn't work out how to test for metal fatigue out in the woods.

 

At the time the Pioneerwas one of two attempting to pull 100 tons of vehicles up the side of the steam ploughing field at GDSF, double hading. There was a second lead tractor coupled ahead of the one which had its towing spring jump out. This does not equate in any shape or form to a single Scammell Pioneer pulling a trailer.

 

My comments relating to not really needing chains when using a Nato tow hitch, cannot be applied to a Scammell Pioneer anyway, because they do not have a Nato tow hitch fitted. The Towing hook they use only has a single level of security to the locking mechanism, in the form of the spring that pulls the latch up, closing the jaw. If the Spring were to fail, gravity would cause the latch to drop, and the trailer would be free to jump the hook.

 

If you read my posts, I have only ever suggested not needing chains when a Nato tow hitch is being used, correctly in all rspects.

 

You will have to decide foryourselves whether this type of Towing jaw is inherently safe, of whether a secondary safety system should be employed.

Edited January 27, 2010 by antarmike

[antarmike]

... then do you not agree around the rear crossmember has got to be safer than no safety chains at all?

 

I hardly think anyone is talking 'complete solution here', just one more sensible, practical step towards making these rigs a bit safer for other road users in today's world. :thumbsup:

 

My view is if something is safe, adding further safety devices does not make it safer, because it was safe already.

 

If it is safe to sit in a deck chair in my front garden, reading a good book, wrapping myself in bubble wrap and donning a crash helmet does not make me any safer.

Edited January 27, 2010 by antarmike

[antarmike]

http://hmvf.co.uk/forumvb/attachment.php?attachmentid=21759&d=1264549020

Are the safety chains on this setup merely hooked onto the tractor. The image does not appear to show shackles, but rather a hook?

 

Surely if saftey chains have been decided upon to reduce the risk of the unexpected from happening, why use hooks which could be expected to jump off if a severe bump ot jolt was encountered. Is this picture really showing best practice?

[Bodge Deep]

Perhaps not, but better than no chains at all because you think that nothing could possibly go wrong so why bother?

 

The man who never made a mistake... etc etc

[griff66]

yes you are right antarmike use things as they are designed to be used, when we stopped laughing we explained to him that it was down to not following procedures !:cool2:

[Maverick]

Quote

Just for the sake of clarity, where on a Matador are you suggesting attaching breakaway chains? You have identified were they go on your vehicle, but where should they be on a standard, unmodified Matador?

 

And whilst we are thinking about it where on a standard Scammell Explorer do you think is the best place to attach break-away chains?

 

I would never tell anyone where to place anything related to safety on there vehicle, its not my vehicle so I don't know the set up. its down to the individual. I would think safety chains could be fitted to any vehicle with some mods.

 

Quote

The pin will only go through the holes, if the lock is closed. This would have alerted the person to the problem. There was obviously no attempt to fit a pin. Any comment I have made about the very high reliability of the Nato hitch, is when it is used correctly, and this includes fitting the pin. Fitting the pin is confirmation that the lock bar is in place.

 

This incident as described here realtes to misuse of a Nato hitch, not keeping mating parts clean, not fitting the safety pin provided, ready for use on a handy little chain.

 

If you aren't prepared to use something in the way intended, then you may well come unstuck

 

Some people obviously think the world is perfect and so is everyone on it. Anything to do with humans usually has a amount of human error attached to it. How many times has someone forgotten to do something or change or check something especially if your being distracted by something or someone ???

 

Quote

My view is if something is safe, adding further safety devices does not make it safer, because it was safe already.

 

The US Army have been fitting chains and fixing points on all there vehicles and trailers since WW2 clearly the believe this is worth doing to reduce accidents and does make it safer.

 

Quote

If it is safe to sit in a deck chair in my front garden, reading a good book, wrapping myself in bubble wrap and donning a crash helmet does not make me any safer.

 

I don't think deck chairs do 45mph and weigh about 5.5 ton, I suppose you could get killed by one if it fell out the sky?? If this became a real regular possiabity then you would protect yourself against it ?

[LeeEnfield]

And I thought it was just me....:undecided:....don't feel so bad now knowing other are like this

 

Nope, not just you, either. :laugh:

[antarmike]

Well, I am only stating a personal preference, not insisting others follow my advice.

 

My Matador and Douglas use towing jaws and a loose pin. The pin in held in place by a rotary cam. The handle operating the cam has a heavy ball end that keeps the mechanism hanging vertically, in the locked position, under the influence of gravity.

 

Maybe one day gravity will fail and the cam will turn into ther horizontal position and the pin will float out, but should gravity fail, lossing my trailer will be the last of ny worries. I do not intend to plan for a failure of gravity. It has never let me down so far.

 

No I am happy not to feel the need to modify my Matdor in this respect, and whilst I have gravity on my side, keeping the locking mechanism in the correct place I don't feel the need for chains.

Edited January 27, 2010 by antarmike

[Bodge Deep]

Ah yes but as you so eloquently put a 'jolt' could dislocate the breakaway chains on a tanker so why not the locking cam handle?

[croc]

I seem to be in the minority but I am with Mike on this one. Why add extra levels of complexity to a system that already works? You spend so much time messing about with all the extra "safety" stuff that you end up forgeting to do the hitch up right in the first place...

It's a bit like putting blankets on winch ropes in case they snap, rather than rigging it properly. If you are so unhappy with something that you have to start relying on safety devices, then sort the main problem out rather than making up new ones.

[HotBed]

all stuart wanted to know was wether his chains were man enough or where he could purchase some that are, his lorry is AMERICAN, not BRITISH and the americans fit chains on their vehicles.

As i know stuart personly, i know that he likes his lorry and gun as near perfect as he can get, as the american army fit them, why are certain people saying he should t have to fit them, there is no need to fit them, to get his exhibit right he HAS to fit them, the BRITISH army dont fit them, i am sure he is not bothered what the british do, just what is nescessary to get his exhibit as it would have been in vietnam

 

i also know that sometimes he has help fitting gun to lorry at the shows and that can be be a distraction in itself, so the fitting of chains will certainly help his conscience when he goes down the road

[antarmike]

Ah yes but as you so eloquently put a 'jolt' could dislocate the breakaway chains on a tanker so why not the locking cam handle?

It would have to dislodge it upwards and maintain it exactly horizontal, long enough for the pin itself to ride out. At anything more or less than horizontal to pin is still locked. The very nature of the cam is that it is a fiddle to find the exact spot at which the pin can pass it. Beside which the odds of it happening are further reduced because the lever is as likely to rotate anti-clockwise as it is clockwise, amnd there is only a release point when it goes clockwise.. But an upward jolt would tend to throw off a hook, it would tend to make the locking handle want to travel vertically, which it can't, it can only rotate, and the very same upwards force that might cause it to rotate, is actually jamming the pin in the hole, making it more difficult for it to turn.

Edited January 27, 2010 by antarmike

[antarmike]

If you were seriously worried that a spring might break, or a tow hitch might snap due to fatigue or misuse during the war, the real solution for piece of mind would be penterating dye, revealer or magnetic flux/ magnetic particle crack detection or X-raying and replacing any part that fails NDT techniques.

 

It is possible to accurately assess the state of fatigue, and the likelyhood of failure through these and related NDT tecniques.

 

Rather than saying my tow hook might snap of because it has been abused or may be fatigued, but I am not going to replace it, but rather I will use chains ( that are only limited in how much they can control an uncoupled trailer, and might still lead to damage and an accident), it would be better to invest the money in NDT testing to identify a likely failure and to replace those tow hitches and mounting points identified by NDT as problem areas.

Edited January 28, 2010 by antarmike

[N.O.S.]

Re. the last two posts - can you be more a little more specific about the thickness and number of layers of bubble wrap, Mike?

[antarmike]

Re. the last two posts - can you be more a little more specific about the thickness and number of layers of bubble wrap, Mike?

 

Actually I was thinking of two layers of the small bubbles or one layer of the large, but actually it may be less safe to sit and read a book in a deck chair, in your own garden, wrapped in bubble wrap and wearing a crash helmet,

namely you are more likely to get heatstroke on a summer's day, and you are also more likely to get yourself sectioned under mental health legislation....

 

Can I help with a specification for crash helmets, suitable for deck chair book reading??

Edited January 28, 2010 by antarmike

[HotBed]

you are also more likely to get yourself sectioned under mental health legislation....

 

is that not OCD ? :-D

[Maverick]

Based on the what I have read, tomorrow I shall turn off all the airbags in my car as I have a seatbelt so they aren't needed and whilst at work I will only use the one safety catch on my Atlas crane legs and not use the other 2 safety features fitted in the factory and during my lunch break I will write to all the military powers to tell them to stop wasting money with fitting chains and chaining points on all the vehicles and trailers.

 

I don't think so, thanks but I'll be sticking with my over complicated set up knowing that if the brown stuff ever hit the fan at least I had a back up plan in place rather than being so sure that a mistake would never happen and have no second option. While I wait for the law to turn up I could wait in my safe deck chair wrapped in bubble wrap. ???