On 5/7/2010 10:34 AM, Clay wrote:> On May 6, 11:21 pm, Jerry Avins<j...@ieee.org> wrote: >> On 5/6/2010 3:08 PM, HardySpicer wrote: >> >> ... >> >>> Go and do an Elec End Major and find out... >>> Amateurs... >> >> Noah was an amateur. The Titanic and the Andrea Doria were built by >> professionals. >> > > Well with the Titanic and the Andrea Doria, the main problem seems to > be not how they were built but how they were captained. They each ran > into a large object. You know that more scuba divers have died on the > wreck of the Andrea Doria than passengers died on the ship when it > sank? I've been on some deep wrecks but not that deep - it is too > dangerous.The Titanic was built with steel -- particularly rivets -- that didn't meet spec. The force of the collision popped all the rivets in one strake, opening the side of the ship like (if you remember them) a key-opened coffee can. The Andrea Doria was designed for the luxury trade. To spare the upper-deck passengers the need to duck through those oval doorways, the bulkheads ended one deck below the weather deck. Design calculations showed (correctly) that flooding any one compartment wouldn't impair the ships maneuverability, and that it would stay afloat even with two flooded compartments on each side. That's where bad captaining came in. The Stockholm hit the Andria Doria right on a bulkhead, opening two compartments to the sea. The Stockholm's prow penetrated the Andrea Doria's hull above the waterline. (An Andrea Doria passenger was later found unhurt in the Stockholm' chain room.) The crumpled bulkhead caused the leaks. The crew delayed (or neglected) flooding a compartment on the other side to minimize list. When she listed far enough to put the top of the short bulkheads under water, flooding spread from compartment to compartment and she eventually capsized. The Stockholm returned to port under her own power, carrying many of the Andrea Doria survivors. Actually, the Andrea Doria went down because I had put a hex on it the day before. Story on request. Jerry -- "I view the progress of science as ... the slow erosion of the tendency to dichotomize." --Barbara Smuts, U. Mich. �����������������������������������������������������������������������
amplify frequencies
Started by ●May 6, 2010
Reply by ●May 7, 20102010-05-07
Reply by ●May 7, 20102010-05-07
Jerry Avins <jya@ieee.org> wrote: (snip)> The Titanic was built with steel -- particularly rivets -- that didn't > meet spec. The force of the collision popped all the rivets in one > strake, opening the side of the ship like (if you remember them) a > key-opened coffee can.According to a book I had not so long ago, they used both steel and wrought iron. Steel was new, and there were many required tests to assure that it met spec., and the spec. was strict. Wrought iron was well understood, and it was believe that it didn't need to be tested so carefully. Before this book, I didn't really know about wrought iron. (And they didn't really understand it back then, either.) As I understand it, the wrought iron process separates the iron from the impurities. When done right, the impurities form fibers that strengthen the result in a specific direction. That is, the resulting material is anisotropic. In a rivet, you want the strong direction to be along the rivet axis, which would happen if done according to the well known process. It seems, though, that construction was rushed. (To meet schedule, maybe even already selling tickets for a specific date.) The claim, then, is that it was the poor quality wrought iron rivets that caused the problem. There was even a test done on one brought up from the wreck, showing that the grain was in the wrong direction, and it failed way to easily. Also, it seesm not to be the previously thought problem with a low temperature brittle phase of steel. (I think steel, not iron.) It seems that the Titanic was built with both steel and iron, for both rivets and plates, during the transition from one to the other. -- glen
Reply by ●May 7, 20102010-05-07
On 5/7/2010 2:54 PM, glen herrmannsfeldt wrote:> Jerry Avins<jya@ieee.org> wrote: > (snip) > >> The Titanic was built with steel -- particularly rivets -- that didn't >> meet spec. The force of the collision popped all the rivets in one >> strake, opening the side of the ship like (if you remember them) a >> key-opened coffee can. > > According to a book I had not so long ago, they used both steel > and wrought iron. Steel was new, and there were many required > tests to assure that it met spec., and the spec. was strict. > > Wrought iron was well understood, and it was believe that it > didn't need to be tested so carefully. Before this book, I > didn't really know about wrought iron. (And they didn't really > understand it back then, either.) As I understand it, the > wrought iron process separates the iron from the impurities. > When done right, the impurities form fibers that strengthen > the result in a specific direction. That is, the resulting > material is anisotropic. In a rivet, you want the strong > direction to be along the rivet axis, which would happen if > done according to the well known process. It seems, though, > that construction was rushed. (To meet schedule, maybe even > already selling tickets for a specific date.) > > The claim, then, is that it was the poor quality wrought iron > rivets that caused the problem. There was even a test done > on one brought up from the wreck, showing that the grain was > in the wrong direction, and it failed way to easily. > > Also, it seesm not to be the previously thought problem with > a low temperature brittle phase of steel. (I think steel, > not iron.) It seems that the Titanic was built with both > steel and iron, for both rivets and plates, during the transition > from one to the other.Thank you. I knew that the failed rivets were wrought iron, but oversimplified. You did a good thing to set the record straight. Jerry -- "I view the progress of science as ... the slow erosion of the tendency to dichotomize." --Barbara Smuts, U. Mich. �����������������������������������������������������������������������
Reply by ●May 7, 20102010-05-07
Jerry Avins <jya@ieee.org> wrote: (snip on Titanic rivets, steel, and wrought iron)> Thank you. I knew that the failed rivets were wrought iron, but > oversimplified. You did a good thing to set the record straight.I think it was: "What really sank the Titanic : new forensic discoveries / Jennifer Hooper McCarty and Tim Foecke" -- glen
Reply by ●May 8, 20102010-05-08
"Jerry Avins" <jya@ieee.org> wrote in message news:vaWEn.176$gv4.169@newsfe09.iad...> On 5/7/2010 10:34 AM, Clay wrote: >> On May 6, 11:21 pm, Jerry Avins<j...@ieee.org> wrote: >>> On 5/6/2010 3:08 PM, HardySpicer wrote: >>> >>> ... >>> >>>> Go and do an Elec End Major and find out... >>>> Amateurs... >>> >>> Noah was an amateur. The Titanic and the Andrea Doria were built by >>> professionals. >>> >> >> Well with the Titanic and the Andrea Doria, the main problem seems to >> be not how they were built but how they were captained. They each ran >> into a large object. You know that more scuba divers have died on the >> wreck of the Andrea Doria than passengers died on the ship when it >> sank? I've been on some deep wrecks but not that deep - it is too >> dangerous. > > The Titanic was built with steel -- particularly rivets -- that didn't > meet spec. The force of the collision popped all the rivets in one strake, > opening the side of the ship like (if you remember them) a key-opened > coffee can. > > The Andrea Doria was designed for the luxury trade. To spare the > upper-deck passengers the need to duck through those oval doorways, the > bulkheads ended one deck below the weather deck. Design calculations > showed (correctly) that flooding any one compartment wouldn't impair the > ships maneuverability, and that it would stay afloat even with two flooded > compartments on each side. That's where bad captaining came in. > > The Stockholm hit the Andria Doria right on a bulkhead, opening two > compartments to the sea. The Stockholm's prow penetrated the Andrea > Doria's hull above the waterline. (An Andrea Doria passenger was later > found unhurt in the Stockholm' chain room.) The crumpled bulkhead caused > the leaks. The crew delayed (or neglected) flooding a compartment on the > other side to minimize list. When she listed far enough to put the top of > the short bulkheads under water, flooding spread from compartment to > compartment and she eventually capsized. > > The Stockholm returned to port under her own power, carrying many of the > Andrea Doria survivors. Actually, the Andrea Doria went down because I had > put a hex on it the day before. Story on request. > > Jerry > -- > "I view the progress of science as ... the slow erosion of the tendency > to dichotomize." --Barbara Smuts, U. Mich. > ��Ok Jerry, I'm curious. If you dn't want to post the sory to comp.dsp, please e-mail it to me. Best wishes, --Phil Martel
Reply by ●May 8, 20102010-05-08
On 5/8/2010 12:47 PM, Phil Martel wrote:> "Jerry Avins"<jya@ieee.org> wrote in message > news:vaWEn.176$gv4.169@newsfe09.iad...>> ... Actually, the Andrea Doria went down because I had >> put a hex on it the day before. Story on request....> > Ok Jerry, > > I'm curious. If you dn't want to post the sory to comp.dsp, please e-mail > it to me.It's a short bit of nonsense. Driving downtown on the West Side Highway one day before the sinking, a friend and I passed the Andria Doria in her slip on the Hudson River. She had impressive lines with her sweeps and projecting bow. To my slightly educated eye, I judged that her hull shape would make her more comfortable than many other ships in a gale, but less able to ride out a hurricane. (The same hull features that minimize rolling in heavy seas promote overtopping in heavier ones.) She looked to me more like an artist's conception than a naval architect's work. For a tool, that's ugly. My friend remarked on the ship's modernistic appearance and called her beautiful. My utilitarian soul (I've since mellowed) demurred. I replied that she looked ugly to me, and I wouldn't mind at all if I never saw her again. She went down the next day. (I always had admired the Stockholm. A seaman's ship.) Compare http://www.returntothedoria.com/wp-content/uploads/2008/08/andrea_doria_51.jpg to http://www.familytreeheritagelibrary.com/ship/S.S.%20Stockholm.jpg Jerry -- "I view the progress of science as ... the slow erosion of the tendency to dichotomize." --Barbara Smuts, U. Mich. �����������������������������������������������������������������������
Reply by ●May 8, 20102010-05-08
Clay <clay@claysturner.com> wrote: (snip)> Well with the Titanic and the Andrea Doria, the main problem seems to > be not how they were built but how they were captained.The recent report on the Turkish Air crash last year explains a problem with the altimeter, but in the end it was still the captains fault. They had plenty of time and warnings, but didn't take action early enough. Possibly too much reliance on automated flight instruments. Another consideration is the dynamics of a three person flight crew. One co-pilot can easily correct a mistake by the captain, knowing it is only between the two of them. It is much more difficult with two co-pilots for one to point out a possible mistake by the captain. Similar problems with a three person flight crew also contributed in the Tenerife crash some years ago. -- glen
Reply by ●May 8, 20102010-05-08
On 5/8/2010 4:19 PM, glen herrmannsfeldt wrote:> Clay<clay@claysturner.com> wrote: > (snip) > >> Well with the Titanic and the Andrea Doria, the main problem seems to >> be not how they were built but how they were captained. > > The recent report on the Turkish Air crash last year explains a > problem with the altimeter, but in the end it was still the > captains fault. They had plenty of time and warnings, but didn't > take action early enough. Possibly too much reliance on automated > flight instruments. > > Another consideration is the dynamics of a three person flight crew. > One co-pilot can easily correct a mistake by the captain, knowing it > is only between the two of them. It is much more difficult with > two co-pilots for one to point out a possible mistake by the captain. > > Similar problems with a three person flight crew also contributed > in the Tenerife crash some years ago.Culture is part of the picture. It is considered unacceptably bad form in many cultures to question someone with higher rank or seniority. Jerry -- "I view the progress of science as ... the slow erosion of the tendency to dichotomize." --Barbara Smuts, U. Mich. �����������������������������������������������������������������������
