Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rutgers!att!cbnews!military From: wdr@wang.COM (William Ricker) Newsgroups: sci.military Subject: USN CVs wont fit in Arabian Gulf? Message-ID: <1990Aug11.015042.19542@cbnews.att.com> Date: 11 Aug 90 01:50:42 GMT Sender: military@cbnews.att.com (William B. Thacker) Organization: AT&T Bell Laboratories Lines: 112 Approved: military@att.att.com From: William Ricker News reports on US response to Iraqi crisis raise questions in my mind about the assumptions in US naval strategy. REPORT on August 7, the Rear Admiral in charge of US DoD Information Agency (the Pentagon PR group) was interviewed on Canadian public radio's "As It Happens" (prototype of US NPR's "All Things Considered"). He reported that a blockade operation in the Persian Gulf (and land operations nearby) would be difficult without air-bases in Saudi Arabia -- because our carriers are too big to operate in the congested waters of the Gulf. I recall his mentioning both the carriers' size and the body of water's size and being pocked with drilling rigs -- deep water obstacles. (The subsequent deployment of the 82nd Airborne & USAF fighters to Saudi airbases makes this a moot, hypothetical question, suitable for SCI.MILITARY.) DATA and ANALYSIS Our current carriers all weigh in at 64kton-93kton, with all but the built-for-wwII Midway class being 78kton & up. Other nations (UK, USSR, France) all have lighter carriers. Our only low displacement "carriers" are the Marines' TARAWA class LHA assault ships, at 39kton. I wondered why they weren't a good ship for this duty -- are the Harriers unsuited to air superiority? or too few? or was this part of the alleged discrimination against admitting that the Tarawa's flight deck was a carrier? Perhaps it has a draft problem, since it has a floodable well-deck below. To evaluate Draft, I convert tons to cubic feet of water and dividing by length and beam to get a number highly correlated to draft (my 1983 Observer's Warships doesn't give Draft) [mod.note: I have added the true draft (from Roger Chesneau's _Aircraft Carriers of the World, 1914 to the Present_ - Bill ] Draft Estimates,ft, by model CLASS Disp(ton)LOA(ft)Beam(ft) Box Wedge Fudge Cone [True] Nimitz 93,405 1092 252 10.9 21.8 32.6 65.3 37 BigE 89,600 1123 248 10.3 20.6 30.9 61.8 36 KH/JFK 80,800 1062.5 250 9.7 19.5 29.2 58.5 35 Forrestal 78,000 1039 238 10.1 20.2 30.3 60.6 37 Midway 64,000 979 258.5 8.1 16.2 24.3 48.6 32.75 Kiev(USSR) 37,000 900 164 8.0 16.1 24.1 48.2 32.83 Clemenceau(Fr)32,780 869 168 7.2 14.4 21.6 43.2 24.58 Invincible(UK)19,500 677.8 90.2 10.2 20.4 30.7 61.3 24 Dedalo(SP) 16,415 622.5 109.3 7.7 15.5 23.2 46.4 26 Colossus(exUK)19,800 693 119.5 7.7 15.3 23.0 46.0 18.5 Tarawa(LHA 1) 39,300 820 106.6 14.4 28.8 43.2 86.4 27.5 NOTES ON TABLE CVL28 Cabot 1943, transfered in 1967 to Spain, as PA01 Dedalo; originally CL79, ordered in 1940. CVL28 was damaged at Luzon in '44. One Colossus class carrier (formerly HMS Vengence, laid down '42) is in service as Brazilian Minas Gerais (A11), ASW carrier, bought '56, entered service '60. another is Argentine 25 de Mayo (R81) Box: Assume hull below water is box LOA*Beam*Draft. Wedge: " " " " is triangular prism LOA*(1/2*Beam*Draft) Fudge: change 1/2 to 1/3 to allow for tapering at bow and stern Cone: Assume hull below water is pyramid/cone with base LOA*BEAM, thus volume LOA*Beam*(1/6*Draft). [mod.note: Hopefully a naval architect will reply with more information. but basically, what you're searching for is the "block coefficient", CB. This is the ratio of the ship's underwater volume to the volume of a block with the dimensions of her length, beam, and draught. CB = (Displacement/density of water) /(length*beam*draught) I'll leave it an excercise for the reader 8-) to calculate this for the above ships; according to Norman Friedman in _Battleship Design and Development 1905-1945_, it varies from about .5 to .7 for battleships. Sorry for the long interruption. We now return you to your regularly- scheduled poster. - Bill ] This suggests the Tarawa class are either (a) much boxier below water-line than real carriers, due to their well-deck, or are deeper than other carriers of their displacement. QUESTIONS Can someone with JANES supply real Draft numbers for these classes? Is the US Navy trend toward super-carriers the problem with getting naval & air superiority in the gulf? Or would smaller carriers have the same problems turning into the wind in a narrow body of water with oil platforms & islands? I have not heard that any of the British ships allocated to the non-Blockade flotilla were carriers; has anyone heard of any carriers currently or ever operating north of the Straights of Hormuz? Could the Midway fit into the Gulf? If so, would its F4's be any use against the MIG23 and Mirages of Iraq? (Midway's WWII decking won't take F14/15/16 stresses.) Is the flightdeck of the Tarawa capable of handling regular Navy aviation, or only the Marine jump-jets & choppers it routinely carrys? -- /bill ricker/ wdr@wang.com a/k/a wricker@northeastern.edu *** Warning: This account not authorized to express opinions ***