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Author Topic: Ideas for future builds  (Read 13845 times)

Offline Spankbucket

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Re: Ideas for future builds
« Reply #75 on: October 31, 2020, 07:24:18 PM »
Having done a google I now think it is the flag of the British East India Company (I thought I recognised it bout couldnt dig it out of the little grey cells!).

Please see: https://www.google.com/search?q=east+india+company+flag&tbm=isch&ved=2ahUKEwj7zMfvst7sAhUJghoKHZzdAmEQ2-cCegQIABAA&oq=east+india+company+flag&gs_lcp=CgNpbWcQAzICCAAyAggAMgIIADIECAAQHjIGCAAQBRAeMgYIABAFEB4yBggAEAUQHjIGCAAQBRAeMgYIABAFEB4yBggAEAUQHjoICAAQsQMQgwE6BQgAELEDOgQIABBDOgcIABCxAxBDUKbdAViTlgJg9p4CaABwAHgAgAFHiAHxCpIBAjIzmAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=MR6dX7vwComEapy7i4gG&bih=657&biw=1396

If it's indeed an HEIC flag why is it showing on the mast of a German Paddle steamer of the 1840's? In the Opium War of 1842 the HEIC deployed a paddle gunboat, 'Nemesis', perhaps that has something to do with it?

Intriguing!

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #76 on: November 02, 2020, 12:00:17 AM »
Very interesting, but also strange and - as you write - not conclusive.
 Doubtless the flag on the antique litho looks like the one of British East India Company.
The Kingdom of Hannover was in personal union with Great Britain from Vienna congress in 1815 until 1837.
This might be a - nevertheless - weak and not very probable coincidence to the flag of British East India Company.
 But this is only a vague presumption. And because the duration of the personal union was only until 1837 -
the boat was build 6 years later, this coincidence is questionable.
May be, it`s not possible to clear the facts of this case after nearly 180 years?
« Last Edit: November 02, 2020, 10:40:05 AM by DamienG »

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #77 on: January 13, 2021, 02:00:29 AM »
Interesting little paddler made by manufacturer and technical designer Ernst Alban (1791 - 1856) in Plau Lake district of Mecklenburg. The boat with wooden frames and iron planking was made in 1845.
Unique the "paddlewheel" with only two vertically geared floats. The boat was propulsed by a little high pressure engine with 20 hp made by Alban.
Model can be vieved in Plau Heimatmuseum.

Thomas

Offline Bierjunge

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Re: Ideas for future builds
« Reply #78 on: January 14, 2021, 06:24:08 AM »
Unique the "paddlewheel" with only two vertically geared floats.
Hi Thomas,
Thank you for the pictures, that's really very special. A rather extreme example of an early feathering wheel with only two floats an a very high excentricity.
To see how it moves, I just made a little kinematic simulation of it:

https://www.youtube.com/watch?v=H8ZRlsQvgeE



Regards, Moritz
« Last Edit: January 14, 2021, 06:13:44 PM by Bierjunge »

Offline Steven S

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Re: Ideas for future builds
« Reply #79 on: January 14, 2021, 10:09:01 AM »
Your excellent animation showing just 2 floats makes it quite easy to understand the mechanism, but looking at figure 11 on the drawing in the top picture there seems to be 8 floats. I may be wrong, but I believe the view showing the 2 floats was just for clarity.

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #80 on: January 14, 2021, 12:44:09 PM »
Thanks very much for this very plastic animation. I hope, that many spectators will see your post.

Offline Bierjunge

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Re: Ideas for future builds
« Reply #81 on: January 14, 2021, 06:54:01 PM »
Your excellent animation showing just 2 floats makes it quite easy to understand the mechanism, but looking at figure 11 on the drawing in the top picture there seems to be 8 floats. I may be wrong, but I believe the view showing the 2 floats was just for clarity.
Sorry, but I don't agree.
Looking at Fig. 3 and Fig. 4, the casting of the hub b-e wouldn't allow to fit more than just two spokes. And looking at the bearing of the control rods n on the fixed excenter o, already with two rods, one of them has to be swan-necked not to impede the other. How could this possibly work with eight rods?



No, Fig. 11 certainly just shows eight different positions to explain the motion:



And finally, the Burgmuseum Plau, where the model is on display, speaks of "Dr. Alban's Raddampfer, der kein Raddampfer ist", meaning "a paddler without wheels".

By the way, the drawings also show other ideas, like Fig. 10 and 12 a variant with entirely parallel motion of the floats, which you would achieve when the excentricity of the control rod bearing and the length of the levers l are identical.

But this would as well result in a kinematic singularity at 3 o'clock and 9 o'clock (when only inertia can tell the float in which way to move), as in the impossibility of asymmetrically shaped floats (which are clearly shown in Fig. 4). Here's another simulation of this purely theoretical parallel version:

https://youtu.be/M6kfl2tLNi0



Moritz

Edit:
In Polytechnisches Journal 1848, Band 109, Dr. Ernst Alban writes:
"Now finally to the wheels. This device shouldn't really be called wheels; for it has nothing in common with it. (...)
It is therefore absolutely necessary that if oscillating shovels are to provide all the advantages that are expected of them, the shovels must go through the water completely independently of each other, and this happens only when only two shovels are used. Here one shovel is always above water while the other is immersed."


« Last Edit: January 15, 2021, 12:06:10 AM by Bierjunge »

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #82 on: January 15, 2021, 03:59:11 AM »
Hi Moritz,

there are some explications by Ernst Alban in the Polyterchnic Journal. What is conspicuous: He seems very convinced about his boat and the construction of the "wheels" - he didn`t speak about wheels, but named
"kreisende Ruder" means "revolving rudders". The steamboat company wasn`t very satsfied about the boat, but it is not quite clear, what they find fault with.
Alban substantiates, that the revolving rudders were much more lighter than conventional wheels, the production was more easy and last not least the resistance of the air through the non working floats was less. I don`t
believe that last point was very important. I rather suppose, that the function of the revolving rudders were hard with big strain to the engine.
As you wrote, the whole construction is only possible with two floats. In every case, this function would be interesting in a model. The 22 m boat could be build in scale 1 : 24 or 1 : 20.

Thomas

Offline Steven S

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Re: Ideas for future builds
« Reply #83 on: January 15, 2021, 09:35:56 AM »
Yes I understand now.  It would be interesting to make a set of these "revolving rudders" to try on a boat as a test

Offline Paddlemex

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Re: Ideas for future builds
« Reply #84 on: January 16, 2021, 05:57:03 AM »

Thanks for the link to the animations Moritz. I had not been able to understand the mechanism from the drawings because I did not see the fixed eccentric pivot point.

Would be an interesting model with a nice splash-splash sound.
Would the not-wheel rudders be synchronized on both sides or off-set by 90?
Synchronized would be hard on the engine and drive train, as Thomas already mentioned, but off-set would give the boat a certain duck-walk swimming.

Jurgen

Offline Bierjunge

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Re: Ideas for future builds
« Reply #85 on: January 16, 2021, 09:29:58 AM »
Would the not-wheel rudders be synchronized on both sides or off-set by 90?
Definitely both sides at the same angle:
Alban writes that when towing or hauling the boat in shallow channels, the wheel could be brought to a horizontal position, bringing all floats out of the water.
Furthermore, he writes that his paddle system is preferably driven by a single cylinder engine, which has its maximum torque at 90 crank angle when the floats on both sides are fully immersed, and passes its dead center by inertia with all floats out of the water:

If the crank goes over the dead centre, i.e. the power of the engine is zero, both blades are above water. The last drive of the engine, of which the force is not yet zero when the shovel emerges from the water, combined with the inertia of the heavy wheels, promotes the quick transition of the crank over the dead points and the wheels over the horizontal; after the transition over the dead centres, however, the new drive from the engine, which increases again immediately after this transition, will promote the entry of the blades into the water to such an extent that they immediately submerge again at the necessary speed and more to exert pressure against the water. At first, this pressure will be lower than later, because the shovel only gradually gets immersed and pushes its surface against the water. As the resistance increases, the power of the engine increases in almost the same proportion, and is increased to the greatest amount when the blades are at their lowest level. (...)
Only a single steam engine is necessary to move these wheels and keep them turning, indeed only a single one must be used, because a double one would more or less cancel out the beautiful harmony between load and force, and all relationships in the movements would be disarranged. (...)
One can easily bring the wheels entirely out of action and influence on the ship and its course, if one leaves them horizontal. This advantage is often very important in shoals and in canals, when you have to get too close to the embankment or the landing areas are shallow.


Moritz

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #86 on: January 16, 2021, 08:49:07 PM »
Yes, the construction of the cooperation of engine and revolving rudders really was wll devised. Ita really interesting little boat. The "Alban" was lengthened in 1848 to 26 m. The end came in 1861, obviously casco and engine was
worn out - not very long time for an iron hulled ship.

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #87 on: January 31, 2021, 02:30:45 AM »
Interesting Rhone freight steamboats "Ocean", "Mediterranee" and "Missouri" - incredibel long hulls.
These boats with 157 and 135 m lenght could bei build in scale 1 : 50/48. The problem of transport could be solved by making the flat long hull in three removable sections.

Thomas

Offline Spankbucket

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Re: Ideas for future builds
« Reply #88 on: February 02, 2021, 07:12:04 PM »
They make me think of canal narrowboats. Were they designed to operate on canals or narrow (and straight!) rivers?

Offline Hankwilliams

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Re: Ideas for future builds
« Reply #89 on: February 02, 2021, 09:52:56 PM »
Obviously this is not the reason. At least the Rhone between Lyon and the mouth is a wide river. Probably the enormous lenght of the casco results by reason of space for freight and and also hydrodynamical
causes - the speed of a displace ship depends of lenght of the hull.

Thomas

 

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