Slowing down a trailer on a downhill: Motoring Motoring Discussion forum

Motoring Discussion > Slowing down a trailer on a downhill	Legal Questions
Thread Author: Skoda	Replies: 11

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Sun 7 Nov 10 13:13

Slowing down a trailer on a downhill - Skoda

I need to tow a braked, single axle trailer, down a hill. How best to approach this?

I've never towed anything of any weight. The tow car is going to be a Ford Transit, more or less unladen -- i'm thinking i should add in some balast to ensure the van dominates weight wise.

The trailer is a single axle medium size utility trailer, it will weigh ~700kgs loaded, which is within it's limits, the van's braked towing limit, and my MAM licence limits.

The route involves one stretch of downhill sweeping left hander, with a steep section ~1/2 a mile in, the rest should be plain sailing.

I took the empty van & empty trailer along the route, up the hill and i could feel a fair amount of influence from the trailer (it's only ~300kgs) on that section. Loaded, with its weight doubled, going downhill... there's going to be more influence.

Basic approach will be in a lower gear to keep the speed under control, but, i think this causes the trailer brakes to come on, i don't think they're electric.

I'm cautious about a situation where the trailer could force the van's back end to the side.

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Sun 7 Nov 10 13:50

Slowing down a trailer on a downhill - Dave_

In the past I've towed trailers with Transits for work. Slow and steady, is the basic technique - if you think about it too much you'll more than likely overreact and create a "situation" where there wasn't one.

I've only jacknifed once, and that was my own fault. I was leaving the A1 at St Neots in an empty van with a 2200kg 4-wheel trailer behind me, the slip road there is a level, constant radius left-hand bend which tightens just before the Give Way lines and I was going far too fast due to the Friday afternoon/POETS effect so it was my own fault. No damage done either.

The trailer is braked by a clever arrangement in the drawbar whereby its own weight transfer increases braking pressure - if it's correctly set up then it should work completely in tandem with the van brakes and you'll hardly notice it's there. With a little trailer like that you'll be well within the limits and capabilities of the combination - even more so if the van has ABS.

Last edited by: Dave_TD {P} on Sun 7 Nov 10 at 13:50

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Sun 7 Nov 10 14:34

Slowing down a trailer on a downhill - hawkeye

I'm going to guess your Transit weights well over 1500 kg unladen so the weight of tow vehicle comfortably exceeds that of trailer and load. As Dave says, take it easy when driving.

When loading the trailer I would advise you to get a good proportion of the load at the front. A rule of thumb is that you should only just be able to lift the trailer hitch by hand, and not for long. If you don't do rules of thumb, get a hitch weight gauge or bathroom scales and load the trailer to the maximum allowed by Ford. This will ensure that the Transit brakes' load-sensing valve on the back axle will "know" to send more effort to the back wheels. A heavy hitch is good for dynamic stability too. You don't need to ballast the van.

Check the trailer tyre pressures and make sure there is no "reverse catch" engaged. This is a device on the hitch of older trailers that stopped the overrun brakes coming on when reversing.

If everything is adjusted nicely, you should be able to feel the trailer brakes come on a short time after you apply the van brakes. Braking should be smooth and snatch-free and you won't have any trouble on your downhill left-hander. Good luck.

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Sun 7 Nov 10 17:56

Slowing down a trailer on a downhill - Skoda

Many thanks for this, it all went fine. Even managed a convincing reverse through a gate and round a corner with the trailer on. Not bad for pretty much a first timer!

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Sun 7 Nov 10 18:11

Slowing down a trailer on a downhill - Iffy

Many years ago I hauled some grain using an agricultural tractor and a two-wheeled Weeks trailer.

We reckoned a full load was about two tons.

Even on a slight decline, you could feel the momentum of the load pushing you along.

Engine braking was the main source of retardation, partly because the rubbishy rod-operated brakes on the tractor didn't work.

Getting down to walking pace was easy enough, but it was a struggle to get the damn thing to come to a full stop.

The run was between two farms a couple of miles apart and there were no steep hills.

Going down a hill fully laden with that rig would have been unsafe at anything much above 5mph.

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Sun 7 Nov 10 18:39

Slowing down a trailer on a downhill - Tigger

If its a small trailer it may not have brakes. If it has brakes take it nice and easy - trailers are at their least stable going down hill, but no need for extremes.

If it doesn't have brakes, take it slower and try to mainly brake on the straights.

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Sun 7 Nov 10 18:54

Slowing down a trailer on a downhill - MD

Low speed and mindful of immediate conditions + brains. I much favour front wheel drive now for tow vehicles (if they are of a sufficient weight).

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Sun 7 Nov 10 22:36

Slowing down a trailer on a downhill - Dave_

>> I much favour front wheel drive now for tow vehicles

Not tried that, although the Escort has got a towbar :)

I'd say the surefootedness of RWD with a load on the back would win me over at any time. I did once have to swap out one of the aforementioned 2200kg winch trailers halfway up a Welsh mountain, we borrowed a brand-new Defender for that one though. It tackled the wet, rutted hillside like it was flat tarmac - unfortunately it wasn't as comfortable or refined as my usual E-reg Transit on, er, the 200 miles of flat tarmac either side of the swap.

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Mon 8 Nov 10 11:54

Slowing down a trailer on a downhill - Fursty Ferret

If it's a Transit with Electronic Stability Control, make certain that it's recognising a trailer attached to it (trailer indicators coming on the dash, for example). Will almost certainly have a separate trailer stability program as a subset of the ESP, and last time I drove one the advice from the handbook in any situation was to brake firmly and trust the computer.

Of course, your mileage may vary. If it's not recognising the trailer through a dodgy electrical installation, you may get extremely unpleasant driving characteristics.

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Mon 8 Nov 10 21:32

Slowing down a trailer on a downhill - hawkeye

>> When loading the trailer I would advise you to get a good proportion of the
>> load at the front...

Trailer loading effects demonstration;

www.youtube.com/watch?v=PFzrWHTG5e8

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Mon 8 Nov 10 21:43

Slowing down a trailer on a downhill - MD

Ex BT Transit (RWD) + single axle trailer partially loaded, moist surface 35 MPH. Stupid woman decides to leave a premises to the left of me narrowly missing me then slows down and does a U turn in front, but stops mid manoeuvre. I brake and the unit slides on and 'T' bones her in rear offside door. Her gob bigger than dent. She loses after a fight and her supporters seeing my photographic evidence. Point is though I will never trust a RWD set up again when towing. I might use it, but I will never trust it. To date the Renault Master FWD has never let me down, today included towing a very heavy two tons.

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Tue 9 Nov 10 08:34

Slowing down a trailer on a downhill - Cliff Pope

If you are braking I don't see how being FWD or RWD makes any difference. You are not transmitting power to any of the wheels.

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