oli
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Post by oli on Mar 21, 2022 1:09:48 GMT 1
Those of you who haven’t become slightly obsessive - like I seem to have done over the last few weeks - about tow bars/hitches, may not have noticed that some countries do things slightly differently.
I’m the US particularly, vehicles have a very substantial female tube or receiver. Into this you slide a male tube, attached with a horizontal locking pin, which then has a towing attachment of your choice - typically a ball or a drop pin, much as we’d use in the uk. There are several standardised classes of receiver, with different towing and nose weight capacities, and whilst there are different sizes for really big stuff, anything from a normal family car to a big (huge) pick up is likely to use the same size 2 inch system. This means all the parts are interchangeable and rather than just a ball, you also have the potential for a rigid connection with the vehicle, which can be used to mount all sorts of things such as bike racks (which is why I started looking at them) winches, ladder racks and even big cargo baskets. It also means all tow balls are detachable, leaving just a plugable discreet 2” hole and much more substantial than the swan neck type things.
They seem to use the same system in several commonwealth countries like Australia. On the face of it, it seems a brilliant system and I’m trying to work out why we don’t use it here, in the uk. Ford makes two separate tow bars (a 2” receiver and the uk style flat plate with holes to bolt a ball to) for my Ranger, but you can’t buy the receiver version in the UK? Is there something in the EU type approval regulations that the receiver type doesn’t meet?
Oli
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Post by OldGit on Mar 27, 2022 21:40:44 GMT 1
They're not type approved, so insurance would be iffy about paying out. Probably to do with the non-interlocking safety that is required for EU/UK type approval.
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oli
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Post by oli on Mar 29, 2022 21:31:39 GMT 1
They're not type approved, so insurance would be iffy about paying out. Probably to do with the non-interlocking safety that is required for EU/UK type approval. What do you mean by non-interlocking safety? I’ve noticed they seem to have more potential (human error) failure points - pin not being secured properly - and arguably not an issue with the hitch itself, but they tend to use a ball that bolts onto a tongue without anything more than an antivibration washer to stop it working loose. Oli
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Post by OldGit on Mar 30, 2022 18:42:49 GMT 1
I don't have the chapter & verse in front of me but it's something like this.... Type approved removable tow hitch has a visible indication of the interlock being fully engaged, usually it's also impossible to remove the key from the lock unless the hitch is fully fitted and the secondary lock engaged. The type you mention has a removable pin that holds the hitch in the receiver with (usually) an 'R' clip to prevent the pin from working it's way out. That is a manual secondary, there is nothing to indicate that the secondary lock is engaged or prevent you using it in that condition and there is nothing to ensure that you fit the 'R' clip in the first place, with the type approved removable tow hitch, if it is not fully inserted into the receiver, then gravity will demonstrate the fact it isn't to you - i.e., it'll fall out.
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oli
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Post by oli on Mar 30, 2022 22:27:40 GMT 1
That makes complete sense and answers my question perfectly. I wasn’t sure if it was a case of simple convention or (a bit like our three pin plugs) we had a slightly idiosyncratic but arguably safer system.
It’s interesting it never caught on before type approval.
I’ve just thought, does that mean the Dixon Bate style height adjustable plate and the drop pin falls foul of this? (Both obviously use a sliding pin retained with an R clip)
Oli
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Post by Rhubarb on Mar 31, 2022 9:25:04 GMT 1
Ball and hitch we have here are self locking, MFI..Made For Idiots
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Post by OldGit on Mar 31, 2022 15:05:49 GMT 1
I’ve just thought, does that mean the Dixon Bate style height adjustable plate and the drop pin falls foul of this? (Both obviously use a sliding pin retained with an R clip) Oli I'm not sure, to be honest... Possibly its not classed as 'removable'(even though it clearly is)? It also has two locking pins in view whilst hitching up so it would be obvious if the secondaries were not fitted, the design is from a time of 'common sense will apply at all times during use' so its unlikely to get approval these days... I have seen some with a threaded vertical height adjuster so possibly that is the current version?
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Post by valhalla on Apr 2, 2022 22:25:44 GMT 1
I have always been a proponent, and user, of NATO hitches on my vehicles. They also would not comply with the "idiot" regs, but they have the reassurance that you can see that the primary locking sprag is engaged when the hitch is closed, and only then can the secondary locking device (pin) be fitted through the primary. A tertiary R-clip is then also visible when fitted.
I have more-recently had to use 50mm ball-hitches, but never in my life, and never in the future, will I use a swan-neck with which to tow. Only a solid 50mm ball to a drop-plate for me. I hate 50mm hitches, and think they are the work of the devil, because they encourage sane users to become idiots - too much reliance on automatic locks that can be defeated with wear or contamination. Worse than that, there's not much difference between a new 50mm ball and socket, and worn-out components.
The safest system is a WYSIWYG application (what you see is what you get) in my opinion. A Dixon-Bate drop-plate carrying a NATO ring-hitch fits that criterium.
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Post by OldGit on Apr 2, 2022 23:47:16 GMT 1
I have a NATO tow hitch to thank for pushing one of my kneecaps three inches up my leg, it's not there now but it fsking hurt at the time! Ironically it happened on a CASEVAC training exercise, fortunately pre-facebook etc. But yes, you know where you stand (or lie on the ground, screaming in agony in my case) with one of them! A mate of mine, (despite being from Lancashire,) made some hitch adaptors to fit the Discovery 3's & 4's for towing the Sankey trailers, much favoured for offroad-trailer conversion chassis donors, I don't know how or if he got round the type approval stuff, or if anyone cared as it was removable so wouldn't be an issue at MoT time - might be an issue if involved in a collision though.
LR had a big recall / safety check on the Discovery 3's & 4's relating to tow hitch receiver wear, officially the cause was excessive nose weight - but like you, I wouldn't really trust a removable towbar that had been jiggled around once too often.
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oli
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Post by oli on Apr 4, 2022 22:05:59 GMT 1
I don’t tow very often but when I do, I always feel it’s a bit of a leap of faith trusting the ball type couplings, especially bigger trailers which are too heavy to give the joint a good tug up and down to test it’s clicked in.
It makes me wince to so people not using the breakaway chain.
And the carriers that clamp on the tow balls seem very counterintuitive- a rigid flange mounting that then has a ball designed for flexibility, which is in turn clamped by something to attempt a rigid coupling. The 2” receiver will usually take a minimum of 200+kg which it a useful amount.
Oli
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Post by OldGit on Apr 5, 2022 0:41:20 GMT 1
That's a whole different set of physics - nose weight, rolling resistance, gradients and towed mass, fortunately, there are clever people in the regulatory authorities that do the maths for us and give us and the manufacturers a set of parameters to work within. If you consider the cross-sectional area and the contact points on a section of chain, say 8mm, and then look at it's rating for lifting, load restraint etc. then compare it with the contact area and CSA of a towball, you'll see there is a massive safety margin built in to the towing equipment, sure, the loads can get kinetic all of a sudden and you end up with a car & caravan blocking the only road into Cornwall for a while every Easter but despite all that dynamic twisting, pulling and wanting to part company, they generally stay locked together until the recovery boys separate them.
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Post by valhalla on Apr 6, 2022 23:45:57 GMT 1
A mate of mine, (despite being from Lancashire,) made some hitch adaptors to fit the Discovery 3's & 4's for towing the Sankey trailers, much favoured for offroad-trailer conversion chassis donors, I don't know how or if he got round the type approval stuff, or if anyone cared as it was removable so wouldn't be an issue at MoT time - might be an issue if involved in a collision though. I still have my hitch-plate for the NATO hook adaption onto the back of a D3/D4. It had to be quickly removable, as I used to finish towing and arrive home late in the night, and had to get it removed before anyone at work saw it when I was parked in the Managers car-park the following morning...... I got it down to 10mins in the end.
Fortunately, the electrical hook-up was easy to hide behind the access panel in the rear bumper, so nobody was any the wiser. The solid drop-plate was more of a giveaway (to the initiated), but that was always the last thing to be removed before each one (I had four in a row) went back to the leasing-company that covered the Management Car Plan vehicles for the company. That used to take 45mins to "tidy up", but thankfully I had access back then to some nice 90degree air-impact tools at work, so that used to take the work out of getting the chassis-longitudinal fixings out.
I believe that I had the first NATO adapter in the country - nobody else seemed to know of one back in 2005 when I first fabricated it. It did over 10000miles of towing a large ex-Swedish gun-tractor trailer (loaded to the gunwales with cars and spares) up and down to the Highlands, and not even a blister on the paint!
Four D3's were "run-in just nicely" with that little rig on the back; one of them (my third TDV6 HSE) had just 35miles on the clock when it set-out via Durham to pick-up my 2.4tonne digger on the way to the Highlands - I had hoped at that stage that it had enough running-in on it to "loosen it up a bit for the Scottish towing" by the time I got to chez-digger.
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Post by OldGit on Apr 7, 2022 11:26:22 GMT 1
Was it made by Ray?
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Post by valhalla on Apr 8, 2022 23:01:53 GMT 1
Nope, I designed and made it myself. Somewhere (in the depths of the workshop) I still have that unit, I think.... I remember giving one of my ex-colleagues the towing-harness assembly on my leaving day (I regretted that a few years later, as I needed a good, working harness to buzz-out and re-engineer a non-working, early harness that I still have - all the early towing harnesses had a fault in them, and I have one of those!!), but I think I still have all the drop-plate and adapters for the NATO hitch into that. The material was 6mm-gauge steel, fabricated and welded by myself to properly carry into the HD drop-plate genuine LR kit, with adjustable heights for the differing trailers that I have/had; 1 narrow-track single-axle unit, 1 wide-track Sankey single-axle, and the ex-Swedish gun-tractor unit that I palmed onto some local "travellers" just last year.......
Something that occurred to me this evening (as you do....) was that the first two D3's I had were manual, which makes the towing I did even more worrying in retrospect. I am wracking my brains to remember the reg. no.s on those cars, to see if they still exit. I bet the clutches are not originals by now.....
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Post by OldGit on Apr 9, 2022 0:01:14 GMT 1
Ah, right - There's a mate of mine that (amongst other things) makes 'offroad' trailers based on the Sankey trailer chassis, he also fabricated a load of NATO tow hitch adapter plates for D3's & 4's and came up with the idea of anti-pikey plates for the spare wheels... Funnily enough, both my D3's are/were manual gearboxes too, for a while I worked for one of the LRE franchises and it was far easier to teach people to drive offroad in a manual than an auto - we had all the LRE supplied vehicles but the BORDA/LANTRA stuff was a bit more involved than a bimble around a pre-prepared track through the woods with a bit of a water splash at the end... I've recently (January) changed the clutch in mine (and DMF, although to be honest, it would have done the same mileage again but I'd got one in and, well, whilst the gearbox is out....), it was previously changed at 32k when the gearbox was replaced as a 'while it's out' measure, that lasted 138k with a lot of trips to North Africa, towing and recovering oiks from places they shouldn't have really got stuck in greenlaning in UK
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