Talk:Spanish submarine Peral

Displacement
Don't they displace more water when surfaced than when submerged? Or is there a convention in measurement involved here? Midgley (talk) 07:50, 27 December 2011 (UTC)
 * No. Consider the total hull volume. Submerged, it's not floating...  TREKphiler   any time you're ready, Uhura  19:57, 27 December 2011 (UTC)
 * That would depend. An object dragged underwater, (but not flooded), will displace more water than surfaced, equal to the volume that would be above the water when surfaced. However, using ballast tanks to achieve neutral or negative buoyancy reduces the actual displacement of the hull since flooded spaces do not contribute to actual displacement. So, hypothetically, a submarine might displace less while diving, if the volume of its flooded tanks exceeds the volume of its hull which is above the water when surfaced. I've never seen a schematic for a sub that had tanks that looked that large though...(I have not done the math on it). That said, a hull's listed displacement is an estimated figure of its external volume below the water line, fully fueled and loaded, but neglecting innumerable small factors.Ernest Ruger (talk) 03:09, 10 February 2015 (UTC)

Ernest Ruger (talk) 03:14, 10 February 2015 (UTC)== Welded hull? ==

She looks welded. Is she? There's no mention of her hull's construction details here. Are they unavailable?