*Scratches head

Its been a while since I've played Dread Lords... If I recall correctly, back in the day we would first strip a design of its functional parts. We would then save the designs (called them frames or something). Then any new game we started should start with those designs loaded (you still need to research larger hull techs to access the larger frames though).

There is no way to save a design in one game, and have another game load it if the game has already been started. The whole loading process only occurs during the whole creating a game process. If I recall correctly, games will remember ship designs even if you delete the files outside the game (never tested it though).

At least in TA, and I think in earlier versions, ship designs are remembered and available for your next game, but with a significant catch.  The catch is that up until you save, quit and later reload the game, the designs are remembered and become available when you've researched all the techs needed to build them.  After you quit, restart, and reload your saved game, however, those saved designed are no longer available to you.

As DivineWrath pointed out earlier, you can save a stripped ship design as a "template" (there's a "save design as template" checkbox), and then in future games view and "use" that template in the ship designer (click on the template tab).  Ships saved as templates are not affected by the save/reload problem I mentioned above.

Read through the above 2-3 times, didn't see this mentioned:

It has been a while, but I'm fairly positive that you need to enable the checkbox in options to save ship designs to the hard drive.  I seem to remember that there was a time when it wasn't checked by default.

And while the stripping advice may be helpful for creating templates, it's not necessary for ships; all you need is the correct technologies.