From: John De Armond
Newsgroups: rec.outdoors.rv-travel,alt.rv
Subject: Re: Trailer dollies
Date: Mon, 08 Jan 2001 04:17:48 -0500

Jim and Joy wrote:

> I need to move my trailer down an incline in my driveway, where there is no
> room to maneuver when hitched to my Suburban. I would like to aquire a dolly
> to move it, but only if it has a braking mechanism on it...Does anyone know
> of such a setup?

Assuming you're trying to do this with the hitch uphill (if it was
downhill, you could use the SUV, right?) Impossible.  I don't use
that word very often but this is an instance.  Regardless of the
amount of braking on a dolly, you will not be able to control the
trailer for the simple reason that there will be little to no weight
on the tongue to hold the dolly tires to the pavement.  Even the
electric trailer brakes won't work since they won't actuate in
reverse.  Even if you're moving tongue forward, you won't be able to
control the trailer on anything other than level ground with a
dolly.  This is experience speaking.

When I lived in Atlanta, I had two experiences of interest.  One, I
tried to tow a small utility trailer down the short but steep paved
hill to my basement using a large garden tractor.  I had done this
several times before by just barely creeping down the hill.  This
time I let it get a tiny bit too much headway.  That was enough. I
rode that sucker down the hill, fully jack-knifed with all wheels on
the tractor skidding sideways, the whole tractor bucking like a
pissed off jackass and me applying all the english I could to keep
the thing from flipping sideways.  Only thing that saved my dumb ass
was the short hill and enough runoff area.

Second experience.  Slightly larger utility trailer, partially
loaded, sitting in my ever-so-gently, almost imperceptibly sloping
yard.  I intended to unhitch it from my truck and hand push it to
its parking place.  As I unhitched it from the truck, got it turned
toward the (slightly downhill) parking place and rolled it up over
the grass depression the wheels had been sitting in, I instantly
realized that I couldn't control the thing.  It ever so slowly
rolled down the yard toward the neighbor's $300k vinyl sided house,
dragging me along with it, grass and mud piling up in front of my
heels - until it hit the God Blessed pine tree!

By the time it hit the tree, it had enough speed to knock limbs out
of the boughs and to pucker the back of the trailer several inches.
Remember this was on an almost imperceptible slope.  I'd pushed cars
around over the same ground many times by standing in the open door
and pushing on the A pillar.  Never even gave the slope a though.

Never again!  Never ever will I even think of unhooking a trailer
without chocks under both sides of the wheels on anything other than
dead-level ground, much less try to move one.

If you're the math type, compute the horizontal force vector the
trailer will exert on you, given the slope and the trailer weight.
Then consider that on dry pavement you can get a coefficient of
friction of about 0.8 for ordinary tires.  That might be 400 lbs of
retarding force if you had an unmanageable 500 lbs of tongue weight
pressing on your dolly.  The consider that you might be able to
generate 100-150 lbs of horizontal force yourself if you're REALLY
stout.  Then compare the numbers to what the trailer can generate.
Not very good odds.

I haven't seen your setup but in general, getting trailers in tight
places is possible with a hitch on the front of the vehicle,
optionally with a long enough hitch bar to allow pivoting over 90
degrees.

John