question Breakaway chains for towing

[Maverick]

Hi Guys,

I need some advice and information regarding using chains for the saftey / breakaway set up when I'm towing my howitzer.

 

The gun weigh 5.5ton so in needs to be hefty.

 

Below is a picture of British ferret recovery chains, I was thinking of using something simular but longer as the chains that are pictured are only 2 foot long.These chains are ideal (except length) as they have the large eyes at each end. 3 foot in length would be good?

 

Anyone have ideas or options for me ???

 

 

[Gordon_M]

Not my specialist subject, but here's some advice, mostly based on my experience with lifting equipment for offshore use rather than towing though.

 

If you plan on using it for miles, not just a short breakdown-type tow off the motorway, for example, when you are buying either Bow shackles or D - shackles, buy the versions with long pins which protrude through the end of the shackle and allow fitment of a split pin.

 

These are a little more expensive, and a little more trouble, but much more secure if any traffic officers or DOE people stop you for an examination. Personally I would buy chain and strops and shackles that were individually rated at least twice the gross weight of the towed object, so you are probably talking about 12 ton rating minimum for that application. Ask for test certificates when you buy the stuff if you are buying components. If you are buying assemblies, and most suppliers will assemble for you, crimp ends, whatever, then ask for the assemblies to be numbered and tested too.

 

Chain is about twice as heavy as strop for a given length, so while you want long chain, be aware that a balance should be struck between them - only use chain as long as you need it.

 

If your towed object is pre-pressure crimping, then the US style of four part mechanical strop joint would look better too. You would have to find those second hand and get them numbered / tested as an assembly.

 

Of course you don't really have to do any of this, but if you plan to be using it a lot it would probably warrant doing it right, once, and then just keeping it in good order. There's no statutory test or re-test requirement for towing (as opposed to lifting) appliances that I can quote.

[N.O.S.]

What is the towing vehicle, and what do the safety chain mounts look like on both vehicle and trailer?

 

As long as the breakaway chain/rope is rated comfortably higher than the mounting points, the chain/rope is not likely to fail.

 

For example, if you take GMC 6x6 safety chain mounting eyes, I doubt they would test more than 2 tonne!!!!

[recymech66]

My advice for what it's worth,

 

When you say "breakaway chains" I'm assuming you on about a means of slowing/stopping the howitzer should it become detached from the towing vehicle? well my advice would be to go with chains or strops which are as short as you can get away with. Reason, well if you have breakaway chains which are too long and the unfortunate happens and your howitzer gets away from your wagon then you want the chains to be as short as possible which wont allow the howitzer to stray to far from your wagon, if you imagine the chains being to long then you have the situation were the howitzer will snake uncontrollably and will be a massive risk to yourself and other roadusers.

 

For something that weighs 5.5 Tonne trust me those chains you have are more than adequate. You could opt for some strops which are far lighter and easier to stow, they are very cheap and come with test certs.

 

Hope this helps.

Edited January 16, 2010 by recymech66

[antarmike]

I never use breakaway chains because my towing jaws use lock pins. I personally cannot see why they are needed if all the safety features of the original hitch design are working why there is any possibility of a trailer or towed gun becoming disconnected. For instance with a Nato tow jaw there is already dual methods of preventing the jaw opening and letting the towed trailer go.

 

If we think about 50mm Tow balls and hitches, there are so many recorded instances of them failing, then yes a breakaway chain makes sense. , but in what circumstances can a Nato hitch release the solid 3" ring? I have never heard of one failing. Ever!

[Maverick]

Thanks for the info. At the moment I'm using a 10 ton rated liffting strop / sling but I'm unhappy with this as its designed for lifting 10 ton in a controled manner rather than a short sharp shock action like the gun seperating from the tow vehicle. A pair of chains at 3 ft is the ideal length so the vehicle can turn corners etc without the chains fouling. The main reason for wanting them is added secruity and yes I agree the nato hitch is up to the job a lot more than the ball hitch type but also the truck and gun gets a lot of attention and if a bored official from the DOT or VOSA and or traffic police ever go past at least they can see I've made the effort

[antarmike]

Point taken, but putting a chain on also suggests "I am frightened I may loose my trailer", and may suggest you know (or think) you have a worn or defective hitch, and it might cause a bored official to look closer as to why you feel you need a chain!. I take the attitude that it was made to be used on its own, so I will trust the original design.

 

I howerer am in the situation where I tow airbraked trailers, and if they are to fall off the tow hitch, the red line will tear apart, and the R.E Valve will go into emergency and fully aplly the trailer brakes. That I see as a safer option than having a trailer breakaway, but the chain preventing the hose tearing, so trailer remains unbraked and can snake around if it wants to.

 

The safety in an airbraked trailer is due to the fact it will go into emergency mode and apply the brakes if it breaks away. Using a safety chain defeats the safety system built into the trailer!

Edited January 16, 2010 by antarmike

[recymech66]

Totally agree with Antarmike, Nato towing pintle and towing eye are very up to the job and rarely fail, that said I have been tasked to a couple of jobs over my time as a recy mech were they have failed but this is a very rare occasion.

 

There are some trailers in service which employ a trailer brake away system like the High Mobility Trailer towed behind REME Warrior variants and the 2 small chains used for this are more than adequate.

 

Maverick,

 

I've been a recovery mechanic for many years and trust me that 10t rated strop you are using is MORE than adequate for what you are asking it to do. That said I agree with Antarmike, it's just not needed.

[Gordon_M]

I'm surprised that in the comments, which quite rightly stress the strength of the military setup, that no-one has mentioned the role of these chains in supporting the front of the towed object if it breaks away or digs in.

 

I normally size my tow chains so that I can cross them under the towbar of the towed object, so that if the hitch does fail the front end of something like your howitzer would drop onto the chains and not dig in and polevault.

 

I do think breakaway chains / strops, properly sized, are absolutely essential, if only for the extra safety for your feet provided when hooking up or unlimbering if chains are in place and crossed as described above.

 

No-one else here has ever had a trailer towbar fail to engage the hitch and fall off while trying to attach or detach it then ? Must just be me. :angel:

 

It's astonishing how quickly that towbar falls towards your feet. Well worth the expense. I have this setup on seven of the eight trailers in the garage, the eighth one being the size of one of little Halfords things for carrying things back from Comet and Curries.

Edited January 16, 2010 by Gordon_M

[robin craig]

Maverick,

 

Your post interests me as for one the lack of a location as to where you live in the top of the post is a common irk to me. It denies people the opportunity of knowing an important detail.

 

So, now that I have figured out you are in the UK does your regulatory body not prescribe as to what is required?

 

Here in Canada, specifically Ontario, anything towed is looked at by GVW. Once you reach a threshold then either air or electric brakes are required or over run types.

 

No matter if you are operating commercially or for your own use you get into a commercial category here and both the trailer and the towing truck has to have a yearly safety inspection in our province.

 

I agree with Antar Mike about air and the fact that no chain is required as the breaking of the line will appl the brakes, quickly.

 

With electric brakes one of the pre trip tests we have to perform (and record in a log book) is to remove the break away lanyard and prove that the battery is charged and will apply the brakes, so again no chains, but its a stupid system as many do not perform that check and the result is obvious.

 

The subject of "historic" vehicles and the law here is in a big bitch fight these days as many items such as artillery when made were never fitted with brakes and technically violate the law. There is a local museum that has that problem. People commonly violate the law but do not realise it or choose to ignore it. The police and the safety body that has powers often stop and take such people off the road. Not knowing is never a defence.

 

Anyway, as others have said I think tose chains are good enough but in my mind I would be concerned that they bear no stamped rating on the links neither do they have a rating on an attached tag. That would be the rub if you were stopped by your regulatory authority as you can not prove what they will hold.

 

My 2 cents worth

 

R

[NigeP]

Now I may be completely wrong here, but I thought the breakaway arrangement was supposed to do just that. i.e. Apply the handbrake on the towed vehicle and then break.

 

 

• An emergency breakaway cable must be fitted to the parking brake linkage and the other end clipped or fixed round some fixture on the towing vehicle so that, in the event of the trailer becoming detached from the towing vehicle, the cable will apply the parking brake automatically, before snapping itself. It is not recommended to loop the cable round the towball. (But do so if there is no alternative attachment point.) It is a separate offence not to use the breakaway cable provided.
  

 

I can see the point of the strops and chains, but I would be worried about the towed load catching me up if this was the case.

 

I'm interested as I'm a Arrows Trailer owner and have pondered over this. I got stopped last year on the M5 in one of the big round ups they had for illegal vehicles. No comment was made about the lack of a breakaway cable, but it did get me twitching a bit. I didn't fancy my Land Rover and Trailer joining the car park full of untaxed/un-insured vehicles they had already got.

 

Nige

[antarmike]

Now I may be completely wrong here, but I thought the breakaway arrangement was supposed to do just that. i.e. Apply the handbrake on the towed vehicle and then break.

 

 

• An emergency breakaway cable must be fitted to the parking brake linkage and the other end clipped or fixed round some fixture on the towing vehicle so that, in the event of the trailer becoming detached from the towing vehicle, the cable will apply the parking brake automatically, before snapping itself. It is not recommended to loop the cable round the towball. (But do so if there is no alternative attachment point.) It is a separate offence not to use the breakaway cable provided.

 

I can see the point of the strops and chains, but I would be worried about the towed load catching me up if this was the case.

 

I'm interested as I'm a Arrows Trailer owner and have pondered over this. I got stopped last year on the M5 in one of the big round ups they had for illegal vehicles. No comment was made about the lack of a breakaway cable, but it did get me twitching a bit. I didn't fancy my Land Rover and Trailer joining the car park full of untaxed/un-insured vehicles they had already got.

 

Nige

 

That is the idea with toy trailers you buy from hHalfords...How would you work that on a trailer with a handbrake that is wound on with a handle operating a screw thread? Thin chain that are designed to break after applying a handbrake, don't fit in with the real world of MIlitary tackle.

[recymech66]

Now I may be completely wrong here, but I thought the breakaway arrangement was supposed to do just that. i.e. Apply the handbrake on the towed vehicle and then break.

 

 

• An emergency breakaway cable must be fitted to the parking brake linkage and the other end clipped or fixed round some fixture on the towing vehicle so that, in the event of the trailer becoming detached from the towing vehicle, the cable will apply the parking brake automatically, before snapping itself. It is not recommended to loop the cable round the towball. (But do so if there is no alternative attachment point.) It is a separate offence not to use the breakaway cable provided.

I can see the point of the strops and chains, but I would be worried about the towed load catching me up if this was the case.

 

I'm interested as I'm a Arrows Trailer owner and have pondered over this. I got stopped last year on the M5 in one of the big round ups they had for illegal vehicles. No comment was made about the lack of a breakaway cable, but it did get me twitching a bit. I didn't fancy my Land Rover and Trailer joining the car park full of untaxed/un-insured vehicles they had already got.

 

Nige

 

My bold,

 

I would definately prefer "the towed load catching me up" and ramming me up the arrse and stopping rather than shooting off to one side and running over a Mother and her 3 kids while walking down the pavement.

 

Thats the whole point of safetly tackle when towing vehicle casualties behind a wrecker, should it become detached then it rams you up the rear and stops.

[Gordon_M]

Electric brakes can get quite complicated here in the UK, where electrically-applied trailer brakes are not common at all, compared with the US and Canada, anyway. Many people importing something like an Airstream caravan from the US will just bin or alter the axle and go for standard UK overrun brakes, which are adequate for the maximum sizes allowed here - 23 foot I think.

 

The legal point on electric brakes seems to be that the controller for the electric trailer brakes must be automatic and can NOT be controlled from the drivers seat - which is exactly the way it is designed to operate on your side of the pond.

 

I have one two ton single axle trailer here in Scotland with original electric brakes, and I'm sticking with them, but the trailer brake controller is mounted in the trailer, next to the backup battery, and trickle fed from the towing truck connection, plus I fitted an electrical brake control switch on the tow frame that is be lanyarded to the tow hitch - so any separation will result in automatic application. This complies with my understanding of the rules here, but obviously I'll have to tinker a bit with the settings till I get it right. I have a period electric brake controller to mount in the towing vehicle, but it won't be hooked up.

 

 

I'm not expecting any big problems as I'll never tow it loaded, and I towed it home from the importers with a conventional car hitch ( ... and no brakes) and never noticed it. Didn't do anything silly while towing it like that, though. It has a military type hitch and twin drag chains too.

[NigeP]

That is the idea with toy trailers you buy from hHalfords...How would you work that on a trailer with a handbrake that is wound on with a handle operating a screw thread? Thin chain that are designed to break after applying a handbrake, don't fit in with the real world of MIlitary tackle.

 

I see what you mean. I asked as I was puzzled from what I read in towing regs on a website that I read. A screw opertated brake would be hard to apply from this method. Thank you for enlightening me.

 

My bold,

 

I would definately prefer "the towed load catching me up" and ramming me up the arrse and stopping rather than shooting off to one side and running over a Mother and her 3 kids while walking down the pavement.

 

Thats the whole point of safetly tackle when towing vehicle casualties behind a wrecker, should it become detached then it rams you up the rear and stops.

 

Yes, I can understand that, I didn't understand how the brakes worked (see above).

 

Many thanks

 

Nige

[ashley]

I never use breakaway chains because my towing jaws use lock pins. !

 

Of course Real men who drive jeeps have a locking hitch AND safety chains (on trailor) as a standard fitting :coffee:

 

:-D:-D:-D

 

Ashley

[Maverick]

Hi Guys,

I'm very surprised about peoples views on this.

 

I don’t see the problem with extra security when towing the gun. ?????

 

The gun was built in 1943 and I'm sure they didn’t worry about break away chains back then as they were a little bit busy chasing the enemy across Europe. The gun does have air brakes, they have been serviced and work great but your not telling me the will stop the gun in a instance if it came separated from the vehicle and I’m sure it would make a big mess if it happened on the M25 going across 3 lanes and the central crash barrier

 

I totally agree with recymech66 "I would definitely prefer "the towed load catching me up" and ramming me up the rear and stopping rather than shooting off to one side and running over a Mother and her 3 kids while walking down the pavement"

 

quote Antarmike "I never use breakaway chains because my towing jaws use lock pins. I personally cannot see why they are needed if all the safety features of the original hitch design are working why there is any possibility of a trailer or towed gun becoming disconnected. For instance with a Nato tow jaw there is already dual methods of preventing the jaw opening and letting the towed trailer go"

 

I know of a Dutch guy who came over for W&P in his M35 and M105 trailer and he believed he had attached the trailer correctly using the NATO Hitch, he had used the locking pin but it hadn’t lined up properly but it looked as though it had. It was about 20 miles up the road when he felt a nudging feeling on the back of his truck. The trailer had become unhitch and because it had breakaway chains it stayed behind the truck and just kept hitting him up the rear, it also had air brakes. So there is always a human error in everything we do, the nato hitch may be great but only if its completely set up and used correctly.

 

So when I tow a friends 105 trailer with Airbrakes do I not bother putting on the brake away chains as it will eventually stop because of the break in the airline ???

 

Would the law take a interest because the break away chains weren’t used ??? I think they would.

[antarmike]

Hi Guys,

quote Antarmike "I never use breakaway chains because my towing jaws use lock pins. I personally cannot see why they are needed if all the safety features of the original hitch design are working why there is any possibility of a trailer or towed gun becoming disconnected. For instance with a Nato tow jaw there is already dual methods of preventing the jaw opening and letting the towed trailer go"

 

I know of a Dutch guy who came over for W&P in his M35 and M105 trailer and he believed he had attached the trailer correctly using the NATO Hitch, he had used the locking pin but it hadn’t lined up properly but it looked as though it had. It was about 20 miles up the road when he felt a nudging feeling on the back of his truck. The trailer had become unhitch and because it had breakaway chains it stayed behind the truck and just kept hitting him up the rear, it also had air brakes. So there is always a human error in everything we do, the nato hitch may be great but only if its completely set up and used correctly.

 

 

The locking pin will only go in if the three elements that form the hole are in line. It is frankly impossible to put in the pin and for it toas if it is look in, but for it not be in! For the pin to go in without the catch being seated, the pin has to pass only through the hole in the catch and not through the two holes in the body. This can clearly be seen to not right.

 

I fail to understand how you think it is possible to close the catch, and the put in the seperate sprung pin, entereing it through the hole in the body, and seeing the far end of the pin coming out the other side of the body, without it going through the hole in the catch. If you were using a split cotter pin, yes you could make a mistake and the cotter pin could pass under the catch, but the design of the proper pin is such it would not spring open far enough to pass over the catch, unless the catch was seated.

 

Anyhow read the caveat in my signature and make your own choice what you do, I am only saying what I do, because, being mechanically trained, i don't find putting a pin in a hole difficult!

Edited January 18, 2010 by antarmike

[Maverick]

Quote:

I fail to understand how you think it is possible to close the catch, and the put in the separate sprung pin, entering it through the hole in the body, and seeing the far end of the pin coming out the other side of the body, without it going through the hole in the catch. If you were using a split cotter pin, yes you could make a mistake and the cotter pin could pass under the catch, but the design of the proper pin is such it would not spring open far enough to pass over the catch, unless the catch was seated.

 

The Pin was the correct pin for the M Series style tow hitch and the jaw was closed but the pin passed under the locking mech and passed out the other side giving the look of a fully secured tow hitch.

 

Clearly myself and the US military have it all wrong, I must tell them to stop wasting taxes payers money on putting break away chains on ALL there AIRBRAKED trailers as its not needed.???? (apparently)

 

Quote:

I am only saying what I do, because, being mechanically trained, I don't find putting a pin in a hole difficult!

 

Well I don't need to be mechanically trained to put in a pin in a hole

 

Anyway back to the original subject. Is there any British recovery chains suitable for the job ???

[HotBed]

hi stuart, why not try stallion testing, they are located in henfield, cant fint number at mo, they will make you some nice wire cables the length you want, put ends on of your choice and give you a cert. :-D

 

regards

[Maverick]

Thanks Graham, thats the sort of info I needed, I will look them up on the web.

 

I will see what pictures I can sort out in the week.

[HotBed]

Thanks Graham, thats the sort of info I needed, I will look them up on the web.

 

I will see what pictures I can sort out in the week.

 

sorry, they are between hassocks and hurstmierpoint, to many H s

 

regards

[radiomike7]

Maverick , if you are using a new lifting strop rated at 10 tons it will have a safety factor of at least 5 giving a minimum breaking strength of 50 tons. Be careful not to confuse safe working loads on recovery kit with lifting kit.

[antarmike]

Quote:

I fail to understand how you think it is possible to close the catch, and the put in the separate sprung pin, entering it through the hole in the body, and seeing the far end of the pin coming out the other side of the body, without it going through the hole in the catch. If you were using a split cotter pin, yes you could make a mistake and the cotter pin could pass under the catch, but the design of the proper pin is such it would not spring open far enough to pass over the catch, unless the catch was seated.

 

The Pin was the correct pin for the M Series style tow hitch and the jaw was closed but the pin passed under the locking mech and passed out the other side giving the look of a fully secured tow hitch.

 

Clearly myself and the US military have it all wrong, I must tell them to stop wasting taxes payers money on putting break away chains on ALL there AIRBRAKED trailers as its not needed.???? (apparently)

 

Quote:

I am only saying what I do, because, being mechanically trained, I don't find putting a pin in a hole difficult!

 

Well I don't need to be mechanically trained to put in a pin in a hole

 

Anyway back to the original subject. Is there any British recovery chains suitable for the job ???

 

Sorry, I still don't see how it is possible to close the locking bar correctly, presumably lining up holes in body and lock, and then put a pin through the lined up holes but the straight pin goes through the first hole, misses the next one, then goes through the third! The locking catch is a good fit in the slot in the body so the gap between each of the three lined up holes is less than 0.5 mm. but somehow the pin misses the middle hole. How can this be?

 

I am trying to understand this,but at the moment I can't. Is there any chance you can supply a picture of how this can be achieved and what the assembly looks like when this happens?

 

Perhaps if the US hadn't spent so much on breakaway chains they could have spent more on R&D on tow hitch locking bar/ locking pin design, and ended up with a foolproof design.

 

My comments about not needing breakaway chains refers to use of Nato towing Jaws. Does the hitch which you say failed comply with Nato standards or is it an earlier design?

Edited January 19, 2010 by antarmike

[HotBed]

Sorry, I still don't see how it is possible to close the locking bar correctly,

thats exactly why maverick wants to have breakaway chains :-D