| UP (discussion topics) |

On Riders: Shape and Armor



view full message
>From: Onno Meyer <Onno.Meyer@arbi.informatik.uni-oldenburg.de>
>Subject: cherryhlist
>Date: Fri, 28 May 1993 17:18:52 +0200 (MET DST)
(...)

Riderships have no vanes, according to _HB_ they are manta-shaped to accomodate the engines and still provide one very small cross-section to pass high-velocity chaff or dust. Another thing I can't believe, but it sounds nice.

(...)
	Onno


view full message
>From: Jo Jaquinta <jaymin@maths.tcd.ie>
>Subject: CherryhList -- M-drive
>Date: Mon, 31 May 93 9:55:33 BST
from: Onno Meyer
> Riderships have no vanes, according to _HB_ they are manta-shaped
> to accomodate the engines and still provide one very small cross-section
> to pass high-velocity chaff or dust.
> Another thing I can't believe, but it sounds nice.
Actually the small amount of microscopic dust and such in normal space "vacuum" is enough to produce drag when travelling at near relativistic speed. Or so I've heard. I've never sat down and worked out the calculations.
				Jo


view full message
>From: Onno Meyer <Onno.Meyer@arbi.informatik.uni-oldenburg.de>
>Subject: cherryhlist
>Date: Wed, 2 Jun 1993 08:16:32 +0200 (MET DST)
> (...)
> 	Actually the small amount of microscopic dust and such in normal
> space "vacuum" is enough to produce drag when travelling at near
> relativistic speed. Or so I've heard. I've never sat down and worked out
> the calculations.
But at these speeds a ship cannot hope to DEFLECT the dust, it has to absorb the impact. _HB_ said the rider had an ablative edge. In this case, the shape of the ship doesn't matter, only the ratio between exposed area (the front side, I assume) and the volume shielded by this front armor (that is, the length). If a given armor thickness is required, it would be the best solution to build an vertical shield.
  __________________________        ____________________________
 /                         |        |                          |
/__________________________|        |__________________________|
   hull (a)                             hull (b)
Assuming the same length for both hulls and a 45 degree angle in hull (a), model (a) needs about 50% more armor than hull (b).

Of course, I do realize that the bricks I propose are not as nice as the design described in the books. Perhaps the designers wanted a beautiful ridership.
	Onno 


view full message
>From: David Zink <zink@Panix.Com>
>Subject: Re: C. J. Cherryh List
>Date: Fri, 4 Jun 1993 09:17:46 -0400 (EDT)
Onno Meyer wrote:
>   __________________________        ____________________________
>  /                         |        |                          |
> /__________________________|        |__________________________|
>    hull (a)                             hull (b)
> 
> Assuming the same length for both hulls and a 45 degree angle in hull (a),
> model (a) needs about 50% more armor than hull (b).
This is wrong: since what matters is the visible cross-section, they each require the same amount of armor. Since hull a is slanted, however, its true thickness will be less. This can simplify design issues.
		Hull A				Hull B
     __________________________        ____________________________
    /////                     |        |||||                      |
   /////                      |        |||||                      |
  /////                       |        |||||                      |
 /////                        |        |||||                      |
/////_________________________|        |||||______________________|
From this direction =====> each is five deep, but from this direction
\
 \
  \
   \   |
    \  |
     \ |
______\|
Hull A is much thinner, therefore engineers need be less creative in attaching the material.

Riderships may also be more prone to skimming the edges of atmospheres. Especially the thin atmospheres of moons.
	-- David

Copyright by the authors of the individual messages.
HTML formatting by Andreas Wandelt .