The basic form of the two stacks formed by the cross section of a water-drop-shaped construction, having a conventional curvature in the front region and is tapered rearwardly.
On this basis, the so-called sampan rested structure consisting of a front and rear cap is rounded square protruding fins that reminded away at the tail of an aircraft.
Directly below the sampan Kostruktion was a band running around the chimney, which gave it extra depth and another dimension and recalled the classic oval shape of the ship's smokestack first half of the twentieth century.
The design of the chimneys was streamlined, aerodynamic and gave the impression that the America even if it was anchored at full speed on the high seas traveling. On the impact of the speed of this design was deliberately been taken in the preparation, because that was what was expected of a transatlantic liner next to safety, comfort and good service.
False or real- what was the forward dummy funnel for ?
Only the rear chimney of America was real and the emission of energy production residues of the Steamboat. The call stack a dummy in the lower part of an emergency generator was housed, as well as during the australis was also a storage room. During the time as a Troopship West point behergergte the top of the dummy chimney as highest structural survey of the vessel (even higher than the Crow's nest) a lookout with 360-degree vision, provided real chimney exhaust them not disabled.
During the first half of the twentieth century the number of funnels was a symbol of strength and reliability of a ship. A chimney alone could not meet the expectations of the passengers then applicable to a large transatlantic liner.
Many other ships had until the middle of the twentieth century dummy chimneys, including such well-known as the Titanic and the Normandie.
The Sampan construction and the funnel increasing
William Francis Gibbs, the naval architect of America, set standards in design and innovation of its ships. But as it is just the way with innovation, not everything always goes as planned.
America for the very low funnels were planned in sampan article in its originally conceived design:
America's funnel on the cover of Percy Faith's "Passport to Romance" (1955)
Top of America's real (aft) funnel in Newport News. You can see the openings of the six uptakes of the boilers and two fan openings.
-Picture: United Newsreel screencap-
Problems with soot and other combustion residues depositing on the decks
The low chimneys of the original design from 1939 proved to be a bad design because they are extremely dirty and the ash and oil-laden exhaust gases could not effectively derive the decks. But even after the increase of the chimneys remained, as on many steam ships, this problem remains partially.
The combustion residues lay particularly in unfavorable wind conditions and slow speed on everything darkened the decks and could, if you were standing in the wrong place, even soil clothing. In some rare cases, they even got into the ventilation system and deteriorating air quality inside the ship.
While these annoyances on the America not so much weight many, they were the more intensive use on the outside deck Australis to a problem that could never be found a 100 percent solution. The extended rear deck structures, including a swimming pool with Lido Deck, was a central meeting place and Freizeitgestaltungsort on the Australis. Especially in this area, the deposited oil residue and ash particles were a nuisance, especially in the pool water. The sports deck just behind the chimney got a great deal from combustion residues. Every morning, had it with a fire hose be completely rinsed to be used by passengers can. To counter this, the chimney was in 1969 an increase by an essay. Since the successes they have achieved was limited, he was removed in the mid 70s.
Mechanisms to reduce the combustion residues
The problem of debris on deck was counteracted by solid technical side, but only with moderate success. The America possessed since its construction over several systems to better control the exhaust gases. The technically most elaborate were the Dustcatchers. Of the six boilers of America (three in front, three behind the engine room) ran individual riser pipes in the chimney. Here was the position of so-called dust catchers, whose task was to filter combustion residues such as ash, soot and oil particles by centrifugal force. To the flue gases were introduced from below into the dust catcher. There they passed a spiral blade mechanism that caused them to spiral to circulate. In the resulting centrifugal force ash particles and other debris were thrown out and fell on the sides of the dust catcher dust through openings in return ducts, where they fell into collecting systems by gravity down. The exhaust pipes of the six boilers were not bundled on the Dustcatchern individually and left the chimney.
The second system to reduce emissions to cover residues were fans at the chimney, which should provide additional buoyancy.
The third system was the chimney itself, the sampan construction already described above should use the air flow while driving, to generate lift for the exhaust gases.
Was the dummy funnel really in danger of collapsing when removed in 1979?
In 1979, around the ship as Italis to make in the course of renovation work again operational for passenger transport, the front dummy chimney was removed. What remained was a shapeless stump acting as one of the belles housed in the lower part of the chimney backup generator in place. The Bugle, was originally located at the top of the chimney, was simply mounted on the roof of the stump.
As justification for the partial removal of the dummy chimney ChandrisReederei gave the strong corrosion, supposedly composed by the danger of collapse.
Whether the state of the chimney was really so dramatic, can not use due to lack of sources. What is certain is that he was not in good condition cosmetically. Many rust spots and dents would need to be repaired.
Since at this time but the two chimneys Passagieremfinden to anyway were considered outdated and the Italis had to keep up with the competition of newer ships, the question about a repair not arise.
Even further was the fact that it was at Chandris plans to extend the constructions of Italis and replace both chimneys by a large new one. Although these plans were never realized then, but the dummy chimney stood in the way or path.
The remaining real chimney, which should be replaced in the long term, but it seemed much too high and uneingebunden without his twin in the remaining structures of the Italis. To mitigate this problem somewhat, the circumferential band in the upper part of the chimney was equal to the cap painted black so that the chimney look slightly lower (because wider) worked.
right: funnel in faded Italis- blue aboard Alferdoss.
-Picture: Vie et mort de l'America Standbild-
left: Australis funnels with smoke pipe extension.
If you looked at the remaining chimney of stranded American Star, a lot there to a large circular hole. But how it got there?. Was it decay? Islanders have there something valuable away for them? The answer may sound incredible, but it is narrated credible. It was vandalism of the Spanish military. A combat helicopter fired a missile at the highly visible target, although dozens with the dismantling of the interior were employed islanders on board at this time. The fleeing from the ship will have found all these action sure but funny. There was also a victim to complain: A hanging from ropes just grand piano fell through the horror caused in the water and sank.
The ballistic "Schorsteinsprengung" however, remained largely inconsequential. The still intact statics of the chimney was not impressed by the explosion.
Vortex dust catchers aboard America.
The "culprit" circling over the wreckage.
-Picture: Das Wrack der America/NDR-
The resulting damage.
-Picture: Das Wrack der America/NDR-
1932: Santa Rosa. rounded top, canted and vertical fins , teardrop base. White band just painted on.
1940: America. rounded top, canted and vertical fins, teardrop base. Oval white band.
1952: United States. slightly rounded top, fins not rectangular to funnel axis but in horizontal position, teardrop base, no vertical fin. White band just painted on.
1958: Santa Paula. very slightly rounded top, fins not rectangular to funnel axis but in horizontal position, oval base, no vertical fin. White band just painted on.
Infobox: Evolution of Gibbs' sampan- funnels
Original height of the funnels.
-Picture: Cropped part of advertising for Welin Lifeboats-
Origianl height: The funnels partly dissapear behind the superstructure when seen from the sports deck.
Advertising poster with one of America's funnels for the german market.
-Picture: United States Lines-
Rear view of funnels.
Picture: courtesy of Bill Lee (Steelways Cover 1948)
This construction should improve the flue by their aerodynamic properties and provide buoyancy to compensate for the lack of height and so can allow the low chimneys, which should drive the streamlined appearance of America to the extreme.
Sampan designs experimented with Gibbs back in the early 30s with four identical liners for the Grace Line with success, but with higher chimney structures.
In the design of low chimneys of America Gibbs, overestimated the effectiveness of the system, however, the sampan devised buoyancy was not strong enough to compensate for the lack of height. Thus, the chimneys had to be subsequently increased by 5 meters due to heavy soot deposits on the decks, which greatly altered the appearance of the ship.
A further development of the design has also been applied to the unequal sister ship, the America, the United States, by Gibbs, but this time the same in combination with very high chimneys.
Original short aft funnel of America is fitted by shipyard workers while still hanging on a crane.
Please Note: Text on this page is only electronically translated.
This will be replaced by a better translation as time allows.
SAMPAN FUNNELS SPREAD THEIR WINGS
A major change in funnel design and effectiveness from the SS America to the SS United States was suggested by Howard E. Lee, Jr., a Newport News Shipbuilding engineer.
Originally the progression of the SS United States funnels in comparison to the SS America's wasn't spectacular at all: they simply would have been bigger, if constructed as originally designed. So much bigger than any of their predecessors, they were, in fact, the biggest funnels ever installed on any ocean liner in the world.
The America's original squat funnels resulted in soot deposits on passenger decks; a problem only discovered on the vesselís sea trials. Simply raising the Americaís funnels was an expedient that proved to be largely Ė but not entirely Ė successful.
Gibbsí original design of the United Statesí funnels was based on following this solution, which included making the new linerís funnels even taller. But when this theory was tested in wind tunnel models at the shipyard, the results were not as good as expected.
Thatís when young and talented NNS engineer Howard Lee offered a simple, yet extremely effective solution: Changing the angle of the funnelsí fins from being parallel to the raked funnelsí tops to a basically horizontal orientation (plus a slight slope upwards at the aft end) to provide the desired airflow uplift effect. Wind tunnel tests of his modification exceeded all expectations.
Lee's idea was the result of his experiences with building and flying model airplanes in his teen years, coupled with a later interest and proficiency in flying small aircraft. Thus, he provided one of the biggest steps in the evolution of Gibbs' sampan funnel design; a complete success when incorporated into the United Statesí funnels and those of several follow-on liners and cargo ships designed by Gibbs.
Above: Howard E. Lee, Jr. (left) studies the results of his airflow uplift improving repositioning of the funnels squat fins during the Big Uís smoke model tests.
Left: The key difference between the SS America's and SS United States' sampan construction.