SV: Trailers

adrian.johnson@sympatico.ca wrote:

>>==> I concur, though you may find because you're hauling it behind,
if
>>you were going at speed, drag would possibly keep is straight behind
you
>>(think dragging a glider behind a plane). 
> 
>If you go *straight ahead* at speed, the trailer will stay straight
>behind you thanks to air drag. If you brake, or turn, it won't stay
>there any more than a glider will stay straight behind a towing plane
>which slows down or turns. (Which is to say "not at all" even at
>supersonic speeds, unless the glider also has a full set of
maneuvering
>surfaces *and* either a pilot of its own or is remote controlled from
>the towing plane.)
> 
>***Adrian:  Hang on a sec, though.  A glider is on 250' of 5/8"
>polypropylene rope (give or take).  A trailer is on a wee little
hitch...
>There is a lot of difference between how you tow a glider and how you
tow >a trailer, and an awful lot could be done with clever *hitch*
design, I'd
>think.

The hitch is more rigid than the glider's rope, certainly. That means
that the trailer has less freedom to move around relative to the
tractor than the glider has... but it *also* means that trailer applies
a far greater sideways force on the tractor than the glider does on the
towing aircraft whenever the tower/trailer team attempts to change its
direction of movement.

>I'm sure with some careful thought and good engineering, you could
>design a hitching mechanism that used hydraulic/pneumatic/electric
>actuators to damp out unwanted swaying/pivoting of the trailer,

Not without transferring the corresponding forces to the towing
vehicle. So, either the towing grav/GEV vehicle is itself equipped to
parry those forces (ie., its own powerplant and transmission is
dimensioned to maneuver two vehicles), or the trailer is equipped to
take care of them (ie., it has its own very-nearly-full-sized grav/GEV
propulsion), or the team needs to move very slowly to avoid crashing
into the neighbourhood :-/

Regards,

Oerjan Ohlson
oerjan.ohlson@telia.com

"Life is like a sewer.
What you get out of it, depends on what you put into it."