ATC ???

[Dustydog]

I suspect ATC or it's equivalents, has not been widely adopted so far becasue of cost.

To some extent I'd ask is ATC necessary ? and the accurate answer is no - providing everyone loads and drives caravans correctly. However there can be little doubt that some people fail to load or drive correctly, so the assistance ATC can provide is beneficial, but it hasn't reached the public's or politicians minds in the same way the Seat belts ABS braking and daylight driving lights etc have.

Perhaps in the future ATC will bee seen as one of those essential back up safety devices and produce insurance incentives or made a legal requirement.

There would of course be difficulties becasue it can only be fitted to trailer with brakes and that would exclude sub 750KG garden trailers, and some other commercial trailers.

Not sure I agree Prof.

loads , weights etc absolutely mandatory. But way back in the 70s I used a Scott stabiliser on many caravans and cars. You may recall it was a massive friction damper with a big leaf spring. IMO it went a long way to damp out snaking oscillations. Today its big brother is built into to the Al-ko hitch. ATC to me is like a match. You don‘t need it until something untoward happens. One strike and it could save your life and outfit. I’d advocate having it without question even if in most cases it doesn’t get used, but.......

 

[RogerL]

I got my insurance through CAMHC and they gave me a discount for having ATC I can’t remember if it was 10 or 15% discount so it saves a bit of the cost, I can’t agree with the statement above that says if everyone loads and drives correctly it is unnecessary, I understand the reasoning of saying that but even the best loaded van at speeds within limits for the road they are on can still get caught out by HGV’s especially car transporters and side winds gusting from the side and causing a bit of instability, maybe in a perfect world or utopia such things would never occur, but we’re living in a totally chaotic world, and utopia it certainly ain’t.

BP

In the olden days, we coped without stabilisers - then Scott-Halley introduced the blade-type stabiliser which Bulldog copied but it was regarded as a "nice to have" - just as Alko ATC is a "nice to have" because sensible loading is the primary way to get a stable tow, stable in the sense that any deflection caused by external influences dies down quickly and doesn't accelerate.

 

[otherclive]

Clive , pin 9 permanent live. Live even when engine Not running.
Only had flashing red once. Coincidence maybe but I had not released the handbrake. Releasing that and reconnecting the 13 pin again everything
was fine. Some other sites say tow for 50 yards and check flashing red has gone green. If not then you shouldn’t tow in case the malfunction activates the brakes later on if not already on!

Dusty
Thanks I knew it was pin 9 supply. But my less than perfect terminology has been picked up. 😂😂😂😂

 

[Jcloughie]

I can’t agree with the statement above that says if everyone loads and drives correctly it is unnecessary, I understand the reasoning of saying that but even the best loaded van at speeds within limits for the road they are on can still get caught out by HGV’s especially car transporters and side winds gusting from the side and causing a bit of instability, maybe in a perfect world or utopia such things would never occur, but we’re living in a totally chaotic world, and utopia it certainly ain’t.

BP

I agree, as one who does try to purchase a logical outfit then load correctly. I find that it can be the case that you still end up with an unstable outfit often for no obvious reason.

In 1990 I bought a new small Compass Shadow. So badly balanced that it was back heavy even empty. When loaded towards the front to give the desired nose weight is was dangerous to tow. It went back to Compass twice. They denied there was a problem but installed 10kg of ballast behind false walls. I took it to an mot testing centre who said it should not be on the road. I tried to get the Caravan Club to support me but I guess they didn’t want to upset an advitiser.

A few years ago I towed my Lunar Clubman with a Peugeot 5005 (Mitsubishi Outlander). OK but not brilliant. Swapped for the Volvo V70. Which much improved the experience.

I have, occasionally felt the ATC apply but it’s never had to come on in earnest.


John

 

[JezzerB]

I agree entirely Prof. I won't go on as it is posted elsewhere what we towed for over 30I miles without atc and never a wobble and we did have some seriously hairy moments like not seeing a humpback bridge sign and getting the outfit airborn. Again not even a wiggle and we did overtake transporters and drive to Scotland in hurricane Brian! Pegasus Verona behind a daci a duster was always solid as a rock . Mind people say trucks are tail light. NOPe.

 

[JTQ]

First, I must state that IMO correct loading as opposed simply to correct balancing is vital for stability, but in itself correct loading is not a sure-fire recipe for stability under all on road conditions.

Even the most stable of towed units can be provoked to instability, and the provocation could well be unintended.

If you are forced to undertake a real life equivalent of the "Elk" test that could easily find where the stability envelope's limits are. A real situation could be a vehicle ahead dropping its cargo, one very real one once being a loaded bike rack leaving a car.

Other examples include the feared car transporter, you or it passing each other. Here the van's stab side is subjected to a series of local bow wave disturbances from the multiplicity of vehicles on it, as each travels past the van's yawing centre. If that speed difference of passing is fast or slow enough to excite the units natural frequency, it can be sustained long enough for a snake to develop, before the excitation has passed and the unit's inherent stability returns.

These are not everyday occurrences, many of us tow for a lifetime with a tame unit and don't encounter one, but “can” be encountered and here the ATC massively increases the chances of it being nothing more than a nasty couple of seconds with no further ramifications.

Much like seat belts, airbags, crumple zones and various stability controls added to cars, totally unneeded kit, you can drive a lifetime without ever needing them or feeling any advantage from them, or then that lifetime might be compromised without them.

 

[JezzerB]

Totally agree, although we've always been fine personally at £400 Ithink it should be a mandatory Standard fitment on all new caravans.

 

[Gafferbill]

Beehpee............

Does your CAMHC caravan insurance policy stipulate that when towing, ATC must be active and fully operational at all times to maintain cover.
My policy with them has this requirement since they know my caravan is fitted with the system.

My understanding is that ATC keeps a record of its operations in a log file so could be accessed by an insurance assessor following a towing claim.

Logic tells me that insurance claim data held by the CAMHC must show them that caravans fitted with working ATC are less likely to make a claim requiring them to pay out.

.........that's an evidence based safety recommendation

 

[littlebasher]

When i bought my last caravan, it came down to a choice between 2 dealer specials - otherwise identical caravans from two competing dealers

Other than the colour scheme, the difference came down to two things;

One came with ATC and but no Dometic hob extractor
The other came with a pointless extractor fan but no ATC

Which do you think i chose?

On previous caravans, I've had the ATC come on in anger (on a well loaded caravan), once when swerving to avoid an object in the road and another time being passed by the dreaded car transporter (that i could argue was comfortably exceeding the 60mph speed limit).

I wouldn't be without ATC now, and it makes no sense to me why anyone would choose not to have it. Who's to say what's around the next corner or what other circumstances could arise where it would be a significant benefit.

 

[Beachball]

But if we upgrade our caravan i would hope it comes with this ATC as a standard fitment but we only had our present van since early last year

 

[Johnb]

I got my insurance through CAMHC and they gave me a discount for having ATC I can’t remember if it was 10 or 15% discount so it saves a bit of the cost, I can’t agree with the statement above that says if everyone loads and drives correctly it is unnecessary, I understand the reasoning of saying that but even the best loaded van at speeds within limits for the road they are on can still get caught out by HGV’s especially car transporters and side winds gusting from the side and causing a bit of instability, maybe in a perfect world or utopia such things would never occur, but we’re living in a totally chaotic world, and utopia it certainly ain’t.

BP

Same here for small discount.

Have to totally agree with your views about even the best balanced vans can experience unexpected instability.
We travel quite frequently to see daughter and family who live in Lowestoft. Our route takes us past Kings Lynn.
I was caught out overtaking a vehicle that had joined the A47 on the last stretch before becoming the A17 (south of Kings Lynn travelling north).
Without any warning, no side wind, no particular turbulence (it was a car I was passing) the van suddenly twitched and, as we all know, you certainly feel it in the seat of your pants.
In this case I am sure it was ruts in the outside lane and if so they were completely invisible. In addition who would expect ruts in the outer lane?
Van soon settled back to stable and I can't remember feeling the ATC react.
What I'm saying in a long winded way is that no matter how careful we all are there are unforeseen circumstances that can catch us out. Ruts being one but obviously a violent maneuver to avoid a completely unexpected and impossible to foresee situation.
ATC is simply an extra safeguard that all van's should have in much the same way all vans have lights and direction indicators.
Surely to ignore technical developments because everyone should load and drive their van correctly is at best naive and at worst potentially dangerous.

 

[Johnb]

But if we upgrade our caravan i would hope it comes with this ATC as a standard fitment but we only had our present van since early last year

If you really feel you need it why not have it retrospectively fitted Beachball?
You seem to use your van a lot. Obviously its a case of balancing your concern with cost and only you can answer that question.

I know where my vote goes!

 

[ProfJohnL]

Not sure I agree Prof.

loads , weights etc absolutely mandatory. But way back in the 70s I used a Scott stabiliser on many caravans and cars. You may recall it was a massive friction damper with a big leaf spring. IMO it went a long way to damp out snaking oscillations. Today its big brother is built into to the Al-ko hitch. ATC to me is like a match. You don‘t need it until something untoward happens. One strike and it could save your life and outfit. I’d advocate having it without question even if in most cases it doesn’t get used, but.......

I do indeed remember the Scott and other similar friction stabilisers, and how the introduction of the AlKo coupling friction stabilisers took over the role. And I also agree it makes sense to arm your self with ad any assistance to help with maintaining control of your outfit. But as things stand, none of these systems are compulsory, and its up to the user to decide if they want to fork out to purchase them, or indeed use them.

ATC compared to Scott and Friction Hitches, are considerably more expensive so cost is a greater factor.

It worth pointing out that the Scott, the friction hitch, and the ATC type systems all work in different ways, and affect the towing experience. It may not be realised that Scott type units not only resists lateral motion, but the downward pressure of the reaction arm produces some additional nose load which also tends to improve the stability safety margin compared to the friction hitches.

 

[otherclive]

I do indeed remember the Scott and other similar friction stabilisers, and how the introduction of the AlKo coupling friction stabilisers took over the role. And I also agree it makes sense to arm your self with ad any assistance to help with maintaining control of your outfit. But as things stand, none of these systems are compulsory, and its up to the user to decide if they want to fork out to purchase them, or indeed use them.

ATC compared to Scott and Friction Hitches, are considerably more expensive so cost is a greater factor.

It worth pointing out that the Scott, the friction hitch, and the ATC type systems all work in different ways, and affect the towing experience. It may not be realised that Scott type units not only resists lateral motion, but the downward pressure of the reaction arm produces some additional nose load which also tends to improve the stability safety margin compared to the friction hitches.

I actually think that the Scott and later iterations were more effective than Alko hitch stabiliser, but quite unwieldy. They also seemed damped pitching more effectively too. But before an "expert" shoots me down perhaps its my memory

 

[Dustydog]

It’s not your memory Clive. If I remember the Scott was set up using a torque wrench. The amount of friction resistance Per lb ft was quoted on a chart .

As far as ATC and other genuine safety devices I believe they should be mandatory. Remember cadence braking and double declutching. Thank goodness we have abs systems, and syncro gearboxes. Isn’t ATC in a similar category?

 

[Beachball]

If you really feel you need it why not have it retrospectively fitted Beachball?
You seem to use your van a lot. Obviously its a case of balancing your concern with cost and only you can answer that question.

I know where my vote goes!

Actually Johnb This coming weekend is our third break this year (With my wife a nurse working for the NHS ) on Covid -19 . Also we just had a big bill repairing the Control panel and a brand new Caravan battery (we might have had it done if we didn"t have that bill ) .

 

[Jcloughie]

This was the very best stabiliser I had fitted many years ago. South African, and they still may be used there.



In the mirror you could actually see the van moving from side to side them coming straight quite naturally. Big downside was they really stick out and hurt the shins.

I wonder though if they would work with or against ATC.

John

 

[Johnb]

Anyone remember the "double scott type" I've seen them in Europe but can't remember seeing any in the UK
They had two "arms" , pone either side of the hitch itself. If I remember correctly these were attached to a couple of shorter arms to, as it were, hold them apart.
Not a very good description I'm afraid but I bet some can remember them.
As for the scott. I seem to remember having to kick the thing into position because of the resistance. As others have said, they did seem to be effective. and yes Clive, I agree withe the damping - didn't they effectively reduce the weight on the tow ball? Or have I got that completely wrong.

 

[Beehpee]

DD the CAMHC insurers asked if the van had it and that was all, I’d have to be daft to have it and not connected, it would be interesting to know if it logs usage because if I plug it in and goes green and I set off, if it packs up on the way and I had an accident a look at any log may well show it wasn’t on, be interesting to know what outcome might be, I’m glad van came with it fitted and it’ll be plugged in every tug without fail, would I have had it fitted ? Hard to say, it’s a bit like tyron bands some swear by them others think money wasted, now I’ve got it and I’ve got peoples points of view on here I’m really pleased it’s fitted, seems to be more positive info than negative.

BP

 

[ProfJohnL]

.... didn't they effectively reduce the weight on the tow ball? Or have I got that completely wrong.

No they didn't reduce the load on the tow ball - Quite the opposite!.

If you recall, depending on the unit you had it either had a blade or rod. Before it was engaged it pointed down, so you had to lift it to be able to engage it. You will remember how much effort it was to lift it into position, probably at least 40 or 50 Kg. As you lifted it you may have noticed the hitch also lifted somewhat, At this stage it wasn't engaged so the caravan nose load on the tow ball hasn't changed.

The effort you had to use to lift the reaction arm is important becasue, as soon as the reaction arm has been engaged, the force that you needed now has to be supplied by the caravans A frame, and teh A frame is supported by the cars Tow ball!

So the use of these reaction arm stabiliser increases the load on the cars ball hitch, and should be considered when observing the tow bars S value limit. - though its unlikely that many of these older types of stabilisers were in use when the EU Type approval for S values was implemented.

 

[otherclive]

No they didn't reduce the load on the tow ball - Quite the opposite!.

If you recall, depending on the unit you had it either had a blade or rod. Before it was engaged it pointed down, so you had to lift it to be able to engage it. You will remember how much effort it was to lift it into position, probably at least 40 or 50 Kg. As you lifted it you may have noticed the hitch also lifted somewhat, At this stage it wasn't engaged so the caravan nose load on the tow ball hasn't changed.

The effort you had to use to lift the reaction arm is important becasue, as soon as the reaction arm has been engaged, the force that you needed now has to be supplied by the caravans A frame, and teh A frame is supported by the cars Tow ball!

So the use of these reaction arm stabiliser increases the load on the cars ball hitch, and should be considered when observing the tow bars S value limit. - though its unlikely that many of these older types of stabilisers were in use when the EU Type approval for S values was implemented.

Thanks Prof. I’m not even sure that I measured noseweight back then. Thankfully times have changed.

 

[RogerL]

I actually think that the Scott and later iterations were more effective than Alko hitch stabiliser, but quite unwieldy. They also seemed damped pitching more effectively too. But before an "expert" shoots me down perhaps its my memory

I think you're exactly right there - although the blade stabilisers did need regular adjustment so many many not have been adjusted optimally, unlike the Alko hitch

 

[Johnb]

No they didn't reduce the load on the tow ball - Quite the opposite!.

If you recall, depending on the unit you had it either had a blade or rod. Before it was engaged it pointed down, so you had to lift it to be able to engage it. You will remember how much effort it was to lift it into position, probably at least 40 or 50 Kg. As you lifted it you may have noticed the hitch also lifted somewhat, At this stage it wasn't engaged so the caravan nose load on the tow ball hasn't changed.

The effort you had to use to lift the reaction arm is important becasue, as soon as the reaction arm has been engaged, the force that you needed now has to be supplied by the caravans A frame, and teh A frame is supported by the cars Tow ball!

So the use of these reaction arm stabiliser increases the load on the cars ball hitch, and should be considered when observing the tow bars S value limit. - though its unlikely that many of these older types of stabilisers were in use when the EU Type approval for S values was implemented.

This is intriguing me. I've just checked what the Caravan Club (as it was in 2009 when the advice was printed) and they say this:

"There are two main categories of trailer stabiliser: first those which are designed only to reduce yawing, and secondly those which act both horizontally and vertically. This dual action type therefore reduces pitching as well as swinging, by introducing a link between vehicle and trailer which helps to reduce sinking at the hitch. This is referred to as a load equalising stabiliser. In the case of the Scott Stabiliser it is claimed for an average outfit that the effect is to take about 10 kg from the vehicle's rear axle, placing 6 kg of this on the front axle, and 4 kg on the caravan axle. This explains the otherwise puzzling claim that a stabiliser "reduces noseweight".
Because of this effect care needs to be taken in using such a stabiliser.

Research and experience show that for good dynamic stability a static noseweight of around 7% of a trailer caravan’s Actual Laden Weight (ALW) is required, giving values typically in the range 50 to 80 kg. A load equalising stabiliser reduces this, and so they are particularly useful when a caravan has an inherently high noseweight. It is far safer to reduce noseweight to the correct value by fitting such a stabiliser than by placing heavy weights behind the caravan axle. Far better still is to choose a car and caravan combination with compatible noseweight figures in the first place, but establishing the actual noseweight characteristics of a caravan prior to purchase is often difficult. "

 

[RogerL]

This is intriguing me. I've just checked what the Caravan Club (as it was in 2009 when the advice was printed) and they say this:

"There are two main categories of trailer stabiliser: first those which are designed only to reduce yawing, and secondly those which act both horizontally and vertically. This dual action type therefore reduces pitching as well as swinging, by introducing a link between vehicle and trailer which helps to reduce sinking at the hitch. This is referred to as a load equalising stabiliser. In the case of the Scott Stabiliser it is claimed for an average outfit that the effect is to take about 10 kg from the vehicle's rear axle, placing 6 kg of this on the front axle, and 4 kg on the caravan axle. This explains the otherwise puzzling claim that a stabiliser "reduces noseweight".
Because of this effect care needs to be taken in using such a stabiliser.

Research and experience show that for good dynamic stability a static noseweight of around 7% of a trailer caravan’s Actual Laden Weight (ALW) is required, giving values typically in the range 50 to 80 kg. A load equalising stabiliser reduces this, and so they are particularly useful when a caravan has an inherently high noseweight. It is far safer to reduce noseweight to the correct value by fitting such a stabiliser than by placing heavy weights behind the caravan axle. Far better still is to choose a car and caravan combination with compatible noseweight figures in the first place, but establishing the actual noseweight characteristics of a caravan prior to purchase is often difficult. "

Australians and Americans refer to this concept as "Weight Distribution Hitch" (WDH) which they use a lot as their trailer noseweights (tongueweight) are much higher than in Europe.

 

[JTQ]

As I used to have to put quite a lifting load into seating the Scott's spring bar it is challenging to think that "load" then taken by the "A" frame actually reduces the force down onto the tow ball.
There is more than a little confused thinking here between towball, "noseweight" and axle loading coming in, surely?