Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!tut.cis.ohio-state.edu!att!cbnews!military From: ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) Newsgroups: sci.military Subject: Re: [Re: H202 Submarine Propulsion (was Re: Nicknames)] Message-ID: <1990Aug28.030957.22224@cbnews.att.com> Date: 28 Aug 90 03:09:57 GMT References: <1990Aug23.015058.2999@cbnews.att.com> Sender: military@cbnews.att.com (William B. Thacker) Organization: Indiana University, Bloomington IN. Lines: 31 Approved: military@att.att.com From: ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) >As for quiet, yes, they're extremely quiet when sitting dead in the water >or motoring along at low speed. But if you are doing something that needs >long-range mobility underwater, they simply can't do it at all. They do >not have the speed or endurance; for long-range work, they are surface >vessels, and noisy ones at that. > >It is important to understand that conventional and nuclear submarines >are two very different types of vessels with very different characteristics. >A nuclear sub is not just a conventional sub with a more expensive propulsion Very true. Look at the shape of a typical WW2 diesel sub (and even USS Nautilus, the first of the nuclear boats). Look at the bow. It looks like the bow of a suface ship, with a straight vertical line. The entire hull has an oval cross-section, with the long dimension vertical. Why so? The subs were designed to spend much of their time on the surface, and were a compromise between surface and under- water handling. Now look at a typical nuclear powered sub (from Skipjack on.. I can't remember if the Skipjack was nuclear powered, or a diesel powered test model for the new shape). The hull is cigar-shaped. The cross-section is circular instead of oval. The new hull shape emphasizes underwater performance over surface handling, as these subs spend most of their time submerged. In fact, they make awful surface ships the few times they needed to be - usually during sea rescue in storms.