Re: Tugs & Firing Arcs

> On Thu, 11 Nov 1999, What else is on this list of things you're not
supposed 
to tell me? wrote:
> > Terrestial trains can be miles long, why couldn't tugs tow
kilometer-long
> > strings of barges?
> 
> Terrestrial trains have rails to keep them together. They also have 
> airbrakes taht activate all along the train length in addition to the 
> Dynamic Braking system in the Locos. 
> 
> Terrestrial Tugs may tow a set of barges all lashed together, but
usually 
> they will push those from the rear where they can use vectored thrust 
> (the rudder) to steer them through the water. Space doesn't have the 
> hydrodynamic properties of water (a long thin object is happy moving 
> sideways as well as straight) so that rear ended unit isn't as
effective 
> in steerage. Think of the physics.
> 
> Lash a bunch of castored plates (castors on all four wheels) together
end 
> to end with play. Then pull them along. Now slow down suddenly. Good
luck 
> getting them all to stop. The Tug is going to have to have a Hard 
> connection to those items. Any flexible connection will be a pain in
the ass.

   Why couldn't there be the equivelent of air brakes on the barges in
space?	Each barge could have a small propulsion system controled via
radio signals from the tug.  Computers would sense the position of each
barge and make fine adjustments.  Since they'd only be used when
stopping,
not much fuel would be needed, just don't try to stop too quickly.

Enjoy,
Tom Granvold				<thomas.granvold@eng.sun.com>