David F. Smith
Member
Oops! Wow! amazing how the brain says "forth" and the fingers type "third"! LOL, thanks for catching that Jason!
People at top of the dummy funnel?
- Thread starter Mark Baber
- Start date
-
- Tags
- funnels
You're welcome, David. I've done the same thing, so no worries.
matthew ewing
Member
I got something right! oh yeah! sorry i'm just proud of myself now. here's another thing that i read, same site; the titanic's rudder was to small for the ship; at full speed it would take nearly a mile and a half to make a complete turn, is this true?
Michael H. Standart
Member
>>the titanic's rudder was to small for the ship; at full speed it would take nearly a mile and a half to make a complete turn, is this true?<<
Not quite accurate. True, the Titanic would have had a fairly large turning circle, but with a ship over close to 888 feet long, that's not entirely unexpected. The rudder may have been a tad on the small side, but it was perfectly adaquate for a liner.
You might want to read Captain Weeks article on the question at https://www.encyclopedia-titanica.org/item/1526/ Note that you need Adobe Acrobat Reader to view this article.
Not quite accurate. True, the Titanic would have had a fairly large turning circle, but with a ship over close to 888 feet long, that's not entirely unexpected. The rudder may have been a tad on the small side, but it was perfectly adaquate for a liner.
You might want to read Captain Weeks article on the question at https://www.encyclopedia-titanica.org/item/1526/ Note that you need Adobe Acrobat Reader to view this article.
Samuel Halpern
Member
Hi Matthew: As Michael pointed out by reference to Capt. Weeks' article, Titanic's rudder was on the smaller side of average. However, for a ship of its size and purpose, the rudder was considered to be adequate. Regarding the turning characteristics, at 20.5 knots the final diameter was measured at 3850 ft during her trials. Thus in a complete circle of 360 degrees, the ship would travel almost exactly 2 nautical miles completely around.
Kristjan Peterson
Member
Hi, If I am right the fourth funnel was not for boiler Was it for air to the reciprocating engine
Kristjan
Kristjan
Michael H. Standart
Member
Yep. That fourth funnel served as a ventilation uptake for the engine room and also as a place to run some of the exhaust pipes from the stoves in the galleys. It was also a powerful visual advertisement as the popular belief held by the public was that the more funnels a ship has, the bigger it is, and the bigger the ship is, the safer it is. As such, some lines tended to include that forth funnel even if it wasn't really necessary.
Lester Mitcham
Member
For the Turbine Engine Room, not for the Reciprocating Engine Room, which was below the Engine Room Casing which was located immediately aft of the 3rd funnel.
David G. Brown
RIP
There is a tendency to view things as what they appear to be and not what they are. The funnels on the Olympic class vessels seem a case in point. Obviously, three of the four swerved boiler furnaces--the supposed purpose of the structures. The fourth is called a "dummy" because it did not serve any of the primary machinery.
But, let's turn the equation around for the moment and assume that carrying soot and hot gasses into the atmosphere was not the primary purpose of any of the four structures. Let's assume for the moment that this was just a desireable byproduct of the real purpose of four big towers of metal on deck.
OK, why would you put a lot of metal 'way up there? It wasn't decoration. And, while 4 big funnels may have helped attract passengers, the Germans got by fine with three. So, what purpose did those huge cylinders serve?
Personally, I believe the four big funnels on the Olympics served primarily to improve the comfort of the passengers. They were in 21st century automotive vernacular "ride control."
Passenger ships are really full of nothing. People weigh very little and the cabins they occupy are mostly filled with nothing but air. The corridors are again empty space. Contrast the emptiness of the passenger accommodations with a cargo ship loaded with iron ore, coal, cotton, or even locomotives. Not much empty space by comparison.
Down on the lowest level of Titanic and the other Olympic class ships was a huge collection of heavy iron in the form of boilers, engines, turbines, dynamos, etc. Above that machinery was all that empty space--air. This weight distribution meant the ship's center of gravity was quite low, something desirable for stability. But, you can have too much of a good thing, even stability.
The low center of gravity meant that unless the naval architects at H&W did something, the ships would have exhibited what is called "snap roll characteristics." They would have rolled over, then snapped back upright. This motion is not only extremely uncomfortable to people, but puts the upper decks of the superstructure and the masts under large shock loads from the "snap" action.
What do do? Well, a sailing warship caught in a go-to-hell storm might snap roll so quickly that it's masts would be broken off. To prevent such an unfortunate occurrence, the solution was to raise a cannon up into the rigging. Yup, hoist cast iron up high so as to reduce the ship's center of gravity. This would increase the period of the roll for greater comfort of both the crew and the sticks. Done correctly, a ship might survive a hurricane in this manner.
OK, back to the Olympics. What is the difference between a cannon in the rigging and those big, heavy cylinders of steel? From a stability standpoint there is no difference other than visual appearance. The four funnels of the Olympic class ships would have raised the center of gravity significantly, thereby increasing the roll time and making the ride all the more comfortable. The height and weight of the funnels would have been carefully calculated to produce maximum comfort without sacrificing the ultimate stability of the ship on which its safety depended.
Why 4 funnels? Well, look at the placement of them relative to the overall length of the ship. The weight had to be evenly distributed so as not to cause either a bow-down, or bow-up trim situation. Three of the four funnels were pretty much fixed in position by the boiler room uptakes. Two of the three fixed funnels were forward of the midships "tipping point." To balance things out the designers had two choices. One was to make the third funnel more than twice as heavy as the forward two. Or, they could simply add a fourth funnel as far aft as the first funnel was forward. This was the easiest and most aesthetically acceptable solution.
The result was a handsome ship with a handsome ride. A superb accomplishment of naval architecture. And, the smoke and soot was taken away from the decks, too.
-- David G. Brown
But, let's turn the equation around for the moment and assume that carrying soot and hot gasses into the atmosphere was not the primary purpose of any of the four structures. Let's assume for the moment that this was just a desireable byproduct of the real purpose of four big towers of metal on deck.
OK, why would you put a lot of metal 'way up there? It wasn't decoration. And, while 4 big funnels may have helped attract passengers, the Germans got by fine with three. So, what purpose did those huge cylinders serve?
Personally, I believe the four big funnels on the Olympics served primarily to improve the comfort of the passengers. They were in 21st century automotive vernacular "ride control."
Passenger ships are really full of nothing. People weigh very little and the cabins they occupy are mostly filled with nothing but air. The corridors are again empty space. Contrast the emptiness of the passenger accommodations with a cargo ship loaded with iron ore, coal, cotton, or even locomotives. Not much empty space by comparison.
Down on the lowest level of Titanic and the other Olympic class ships was a huge collection of heavy iron in the form of boilers, engines, turbines, dynamos, etc. Above that machinery was all that empty space--air. This weight distribution meant the ship's center of gravity was quite low, something desirable for stability. But, you can have too much of a good thing, even stability.
The low center of gravity meant that unless the naval architects at H&W did something, the ships would have exhibited what is called "snap roll characteristics." They would have rolled over, then snapped back upright. This motion is not only extremely uncomfortable to people, but puts the upper decks of the superstructure and the masts under large shock loads from the "snap" action.
What do do? Well, a sailing warship caught in a go-to-hell storm might snap roll so quickly that it's masts would be broken off. To prevent such an unfortunate occurrence, the solution was to raise a cannon up into the rigging. Yup, hoist cast iron up high so as to reduce the ship's center of gravity. This would increase the period of the roll for greater comfort of both the crew and the sticks. Done correctly, a ship might survive a hurricane in this manner.
OK, back to the Olympics. What is the difference between a cannon in the rigging and those big, heavy cylinders of steel? From a stability standpoint there is no difference other than visual appearance. The four funnels of the Olympic class ships would have raised the center of gravity significantly, thereby increasing the roll time and making the ride all the more comfortable. The height and weight of the funnels would have been carefully calculated to produce maximum comfort without sacrificing the ultimate stability of the ship on which its safety depended.
Why 4 funnels? Well, look at the placement of them relative to the overall length of the ship. The weight had to be evenly distributed so as not to cause either a bow-down, or bow-up trim situation. Three of the four funnels were pretty much fixed in position by the boiler room uptakes. Two of the three fixed funnels were forward of the midships "tipping point." To balance things out the designers had two choices. One was to make the third funnel more than twice as heavy as the forward two. Or, they could simply add a fourth funnel as far aft as the first funnel was forward. This was the easiest and most aesthetically acceptable solution.
The result was a handsome ship with a handsome ride. A superb accomplishment of naval architecture. And, the smoke and soot was taken away from the decks, too.
-- David G. Brown
Yuri Singleton
Member
What an interesting post, thank you Dave. I never really looked at it like that, but it makes sense doesn't it.
Now the next question is why were they swept back slightly? Simply asthetics or did that have a functional purpose as well?
Yuri
Now the next question is why were they swept back slightly? Simply asthetics or did that have a functional purpose as well?
Yuri
Samuel Halpern
Member
Dummy funnels are still used today. The Disney Cruise Line sister ships, Magic and Wonder have two funnels. The forward one is a dummy. The original design had an ESPN skybox located in it.
http://www.kingdom-travel.com/Disney_Cruise_Line/Disney_Cruise_Line_Ship_Level_11.shtml
They have been transformed into a new space for teens (called Aloft on Wonder and The Stack on Magic).
http://www.kingdom-travel.com/Disney_Cruise_Line/Disney_Cruise_Line_Ship_Level_11.shtml
They have been transformed into a new space for teens (called Aloft on Wonder and The Stack on Magic).
David G. Brown
RIP
As I look at the new generation of liners, I can't help but notice they have a "wedding cake on steroids" appearance with deck piled upon deck up to the height of a royal yard.
Could it be, I wonder, if all those towering decks aren't serving the same purpose with regard to stability that Titanic's funnels served? Perhaps without all those condo-on-water decks the ships would be too stable and exhibit unpleasant rolling characteristics.
The difference in Titanic's day was that seakeeping was a quality much revered. And, the officers of 1912 all had experience in sail. They knew first-hand the power of wind. Today, sail is considered a quaint activity for yachtsmen. An officer of 1912 would have looked at all that "unreef-able" sail area represented by the high deck house and declined the appointment--knowing full well it would only be a matter of time before one of those floating buildings gets blown into a pier or other unfriendly object.
Ah, but the passengers love those balconies!!!
-- David G. Brown
Could it be, I wonder, if all those towering decks aren't serving the same purpose with regard to stability that Titanic's funnels served? Perhaps without all those condo-on-water decks the ships would be too stable and exhibit unpleasant rolling characteristics.
The difference in Titanic's day was that seakeeping was a quality much revered. And, the officers of 1912 all had experience in sail. They knew first-hand the power of wind. Today, sail is considered a quaint activity for yachtsmen. An officer of 1912 would have looked at all that "unreef-able" sail area represented by the high deck house and declined the appointment--knowing full well it would only be a matter of time before one of those floating buildings gets blown into a pier or other unfriendly object.
Ah, but the passengers love those balconies!!!
-- David G. Brown
Dave Gittins
Member
Some modern cruise ships have some kind of structure hiding the reality of their engine exhausts. Some are just open lattices, such as I've seen on Superstar Virgo.
On the other hand, you can let it all hang out, as on Star Princess. Bad luck if it suggests some kind of industrial works!
On the other hand, you can let it all hang out, as on Star Princess. Bad luck if it suggests some kind of industrial works!
Doug Criner
Member
Two days ago, while on a Caribbean cruise, we were moored next to the new 4,000-passenger Disney ship, Dream. That ship has two large, identical funnels, fore and aft, each housing eight diesel exhaust pipes. Both funnels are festooned with Mickey Mouse ears, etc. So, does the ship have two separate engine rooms? No, the forward funnel is an expensive, nonfunctional fake. Maybe the Disney cartoonists or amusement park creators decided that two funnels looked better than one?
Titanic and her sisters sported four funnels, one of which was fake. Why?
Other examples of such ornamentation come to mind. In my youth, cars with dual exhausts were popular - so I added a fake tail pipe extension to my old crate. And Buick adorns their cars with fake exhaust holes on the fenders. But most of us have outgrown such phases. Maybe, in the case of Titanic, four stacks perhaps conveyed a greater sense of power? Who knows?
Doug
[Moderator's note: This post, originally posted in a separate thread in this topic, has been moved to the pre-existing one discussing the fourth funnel. JDT]
Titanic and her sisters sported four funnels, one of which was fake. Why?
Other examples of such ornamentation come to mind. In my youth, cars with dual exhausts were popular - so I added a fake tail pipe extension to my old crate. And Buick adorns their cars with fake exhaust holes on the fenders. But most of us have outgrown such phases. Maybe, in the case of Titanic, four stacks perhaps conveyed a greater sense of power? Who knows?
Doug
[Moderator's note: This post, originally posted in a separate thread in this topic, has been moved to the pre-existing one discussing the fourth funnel. JDT]
Similar threads
