tek@CS.UCLA.EDU (Ted Kim) (05/22/91)
From: tek@CS.UCLA.EDU (Ted Kim) Frank Crary writes: >Another example if the DDG Arlie Burke (Sp?) class destroyer. Although >it is, in fact, larger than most crusiers, ab3o+@andrew.cmu.edu (Allan Bourdius) writes: >The Arleigh Burke (DDG-51) class is not larger than most cruisers. >It is significantly smaller than a Spruance (DD-963) class >destroyer/Ticonderoga (CG-47) class cruiser. The Burke is definitely not larger than most cruisers. It does, however, displace more than most cruisers due to having all steel construction, rather than the aluminum superstructure common to earlier ships. Ted Kim Internet: tek@penzance.cs.ucla.edu UCLA Computer Science Department UUCP: ...!{uunet|ucbvax}!cs.ucla.edu!tek 3804C Boelter Hall Phone: (213)206-8696 Los Angeles, CA 90024 FAX: (213)825-2273
tek@PRAM.CS.UCLA.EDU (Ted Kim) (05/23/91)
From: tek@PRAM.CS.UCLA.EDU (Ted Kim) [To moderator: This is a correction to my previous posting. If the previous hasn't gone out please use this one instead. I am sorry, I did not check the more upto date sources first. -ted] Frank Crary writes: >Another example if the DDG Arlie Burke (Sp?) class destroyer. Although >it is, in fact, larger than most crusiers, ab3o+@andrew.cmu.edu (Allan Bourdius) writes: >The Arleigh Burke (DDG-51) class is not larger than most cruisers. >It is significantly smaller than a Spruance (DD-963) class >destroyer/Ticonderoga (CG-47) class cruiser. The Burke is definitely not larger than most cruisers. It does, however, displace more than most destroyers and some cruisers due to having all steel construction, rather than the aluminum superstructure common to earlier ships. Ted Kim Internet: tek@penzance.cs.ucla.edu UCLA Computer Science Department UUCP: ...!{uunet|ucbvax}!cs.ucla.edu!tek 3804C Boelter Hall Phone: (213)206-8696 Los Angeles, CA 90024 FAX: (213)825-2273
fcrary@lightning.Berkeley.EDU (Frank Crary) (05/25/91)
From: fcrary@lightning.Berkeley.EDU (Frank Crary) tek@CS.UCLA.EDU (Ted Kim) writes: >The Burke is definitely not larger than most cruisers. It does, >however, displace more than most cruisers due to having all steel >construction, rather than the aluminum superstructure common to >earlier ships. Why does the Burke have an all steel design? I had thought all recient ships used aluminum? By the way, I stand corrected on the Burke's size... I was looking at the displacement numbers. Frank Crary
wcsswag@ccs.carleton.ca (Alex Klaus) (05/29/91)
From: wcsswag@ccs.carleton.ca (Alex Klaus) Frank Crary (fcrary@lightning.berkeley.edu): Ask what was the change that causess the Arleigh Burkes(DDG-51) to made of steel, rather than aluminium. First in the 60's and 70's, aluminium, was used because it was lighter and cheaper. Less weight means more bang for buck. Also the ships structure, was lighter therefore, more internals could be added. This was popular for most major classes in the USN, RN, and other world navies. Although the alumiuim was light, it has one drawback, it burns at very high temperatures. These temperatures are usually achived, with warhead or shell impact. This problem also occur APC, such a M113APC, do not know about M2/M3]. This drawback, was clearly seen in 1982 in the Falklands war. HMS Sheffield was lost after a missile hit, caused an uncontrollable fire[parts of the hull where white hot]. This was after only the remaining fuel exploded not the warhead. Steel might have been more effective is this situtation. Another example was the fires aboard Sir Tristan, and Sir Galahad, both Amphibious ships, that were bombed, major casualties resulted. The Ardent, Antelope(Amazons), class were also had large amount of aluimium in them. Well that all I have on this subject. Hope I helped. Any correction appriciated. -- Alex <<wcsswag@ccs.carleton.ca>>
mikael@ped.gu.se (05/29/91)
From: mikael@ped.gu.se fcrary@lightning.Berkeley.EDU (Frank Crary) writes: >Why does the Burke have an all steel design? I >had thought all recient ships >used aluminum? That was the lesson learned by the British Royal Navy in the Falklands conflict. A pure aluminium ship is a complete death trap when it catches fire. Get hold of any of the books about the Falklands and you'll find horrible descriptions of fire aboard aluminium ships. Steel ships simply are a lot more survivable. Mikael Borgman mikael@ped.gu.se
raob@mullian.ee.mu.oz.au (Richard Oxbrow) (05/30/91)
From: raob@mullian.ee.mu.oz.au (Richard Oxbrow) fcrary@lightning.Berkeley.EDU (Frank Crary) writes: >Why does the Burke have an all steel design? I had thought all recient ships >used aluminum? After numerous fires on ships (Falklands war,Stark vs exocet,JFK vs.Belknap(?)) it has been found that it melts/burns at a relatively low temperature (compared to steel). Naval architects out there like might to comment on the maintenace trades offs, Al may be harder to look after over the life time of a warship than a steel one. richard oxbrow |internet raob@mullian.ee.mu.OZ.AU dept. ee eng, uni of melbourne |uunet ..!uunet!munnari!mullian!raob parkville victoria 3052 |fax +[613] 344 6678 australia |phone +[613] 344 6782
norton@manta.nosc.mil (LT Scott A. Norton, USN) (05/31/91)
From: norton@manta.nosc.mil (LT Scott A. Norton, USN) NO, NO, NO! Sheffield was all-steel. Also, the missile hit in the main hull, slightly above the waterline. The fires were due to flammables such as electrical cable insulation. The experience of USS Tatnall gives, I think, better reason for eliminating aluminum: a minor fire in her aft superstructure seriously warped the director pedistals for her SPG-51's. The maintenance and preservation problems with aluminum also make it undesirable. My own experience trying to get an aluminum handrail rewelded pointed this out to me. It took many tries, waiting for a still day so the argon wouldn't blow away, before we got the job done right. Aluminum-qualified welders are not as common as steel welders. LT Scott Norton <norton@NOSC.MIL>
rollhaus@dtoa3.dt.navy.mil (Charles Rollhauser) (06/04/91)
From: rollhaus@dtoa3.dt.navy.mil (Charles Rollhauser) fcrary@lightning.Berkeley.EDU (Frank Crary) writes: > Why does the Burke have an all steel design? I had thought all > recent ships used aluminum? ... discussion by several posters as to burning characteristics of aluminum, citing Belknap, Sheffield, and British frigates. norton@manta.nosc.mil (LT Scott A. Norton, USN) writes: > NO, NO, NO! Sheffield was all-steel. Also, the missile hit in the > main hull, slightly above the waterline. The fires were due to > flammables such as electrical cable insulation. While theoretically aluminum could burn, there has been no documented evidence that it will burn in shipboard fires. In most cases it will weaken, collapse, and possibly melt at temperatures lower than would happen with steel structure. While these are obviously undesirable characteristics in a warship, the problem is nowhere as bad as it has been made out to be. When Belknap was recommissioned, she had a new ALUMINUM deckhouse, with high temperature insulation protecting vital structure. (The accident - collision with the Kennedy, and the dumping of hundreds of gallons of fuel onto the superstructure - caused a fire involving flammables carried aboard every ship.) > ....Aluminum-qualified welders are not as common as steel welders. LT Norton hit the nail on the head when he cited maintenance problems as the reason aluminum deckhouses have been abandoned by the USN. The problem is this: Structural aluminum is not the same as the stuff of beer cans and rain gutters; it gains strength by heat treating. Welding aluminum is an art in itself, and when it is welded it looses a substantial amount of strength, unless properly heat treated. Sielski gives an account of the history of aluminum as a Naval structural material, and the reasons for its elimination in combatant ship design in "The History of Aluminum as a Deckhouse Material," in the Naval Engineers Journal, May 1987 Vol 99 No 3, pp 165-172. Chuck
002@pnet16.cts.com (J.W.Cupp Lcdr/Usn) (06/06/91)
From: 002@pnet16.cts.com (J.W.Cupp Lcdr/Usn) Another commonly-overlooked problem with Al is the bi-metal joint. On all ships I've been on, the joint where the aluminum superstructure and steel hull were joined was a continuing maintenance problem. Due to the availiability of salt air (!) electrolysis rapidly destroyed the nearby aluminum, and the "fix" was to cut out sections and replace with new aluminum plate. Some sections were replaced almost every maintenance period. -- J. W. Cupp UUCP: humu!nctams1!pnet16!002 Naval Telecommunications Center ARPA: humu!nctams!pnet16!002@nosc.mil Pearl Harbor, Hawaii INET: 002@pnet16.cts.com I am solely and personally responsible for the all of the content of the above post. It is all merely my opinion, and not to be construed as anything else.
military@amdcad (06/11/91)
From: <ames!ames!rutgers!bellcore.bellcore.com!mruxb!patter> The British experience in the Falklands campaign has convinced navies around the world that there is no substitute for steel armour plate in ship building. They tend to reserve aluminum for aircraft these days.
wag5@midway.uchicago.edu (John Wagner) (06/11/91)
From: wag5@midway.uchicago.edu (John Wagner) Suppose that both steel and aluminum were used in construction, such that the steel forms a skeleton hull and panels are then welded over the open spots. The steel might act as a heat sink, provide strength, and separate different panels, thus preventing a spread of damages due to fire(?). Some sort of covering could be put over the whole thing. [An earlier posting mentioned how hard it is to maintain Aluminum-Steel joins. --CDR] John Wagner