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Author Topic: Rope Geared Paddle Engines  (Read 6496 times)

Offline derekwarner_decoy

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Rope Geared Paddle Engines
« on: October 16, 2006, 04:47:52 PM »
Hi PD's - I first read some four years ago of  'rope geared OZ Paddle engines' & this had me  :thinking  :ohno 'how can this be'  :?: but over the past week we have seen additional references provided &   :?

I am sure we can visulise the STEEL rope steam powered winding gear @ say 5 RPM but on 10 foot diameter drums   :music   :hmmm   :hmph

But how do we see 300 RPM being 'ROPE' geared down to 50 RPM @ the paddle shaft considering the relatively high torque requirement :?:

Like I thought thats why the Chinese & Romans invented wooden pegged wheel sets [the for-runners of metal gear sets] - the Dutch did it for water wheels, the Frogs & Brits used it for milling wheat for bread even the Scotts probably used similar gearing for milling the finest quality barley to make that OFF coulor black goop for  :beer

If any PD has a  :idea:  :roll:   :hehe , please share it :gather  - with us - Derek
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

paddlesteamerman1

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Gearing of Rope Engines
« Reply #1 on: October 16, 2006, 04:57:51 PM »
Hey PD's

For the Rope to be geared down from 300rpm to 50rpm wouldnt you have the rope spinning on a smaller circumference at the engine then gear it up (or down) which ever, so that the rope is turning a larger circumference by the time it is at the paddle shaft meaning that every, in this case, 6 revolutions of the rope wheel (?) at the engine means 1 revolution of the rope wheel (?) at the paddle shaft.
It would work the same way with cogs wouldn't it? Like on the Pev, AA, Oscar W, Emmylou, you name it, the pistons spin a smaller cog that then in turn spins a larger one therefore making the larger ones revolutions slower, so I imagine it would be the same for rope drive???

Just an idea!!

Offline AlistairD

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Rope Geared Paddle Engines
« Reply #2 on: October 17, 2006, 08:34:42 AM »
I have seen a paddle steamer with the wheels  powered by wh t looked like a giant rubber band. This was the DE NEDERLANDER in  Rotterdam. She had been rebuilt from a paddle steamer hull that had seen static  use for about 60 years, and the only engine they could find was a small  horizontal one from a dredger.
 She also had a diesel engine driving a screw, and was alter  sold to German owners, who run her out of Kiel as FREYA. The steam engine sees  little use nowadays. There is a window in the deck and you can look down through  the glass and see the steam engine, which is not moving
 http://www.raddampfer-freya.de/
 Â 
 Alistair
Alistair Deayton
Paisley
Scotland

Offline Roderick Smith

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rope drive
« Reply #3 on: October 17, 2006, 09:57:08 AM »
I am having to work from memory here, and use some approximations.
Belt drive worked in lots of industrial situations, such as sawmills and engineering workshops.  I guess that they had to handle just as high a torque as driving a paddlesteamer required, and did so at higher rpm than would exist on a paddlesteamer.

The small Dutch car DAF (c1960) used belt drive, with a coned takeoff shaft to provide a simple automatic transmission.  Probably at less torque than a paddlesteamer.

Ski lifts run with a rope drive, with just a half wrap around a bull wheel (2-4 m diameter).  My quess is that this required more torque than a paddlesteamer.  At 2 m/sec rope speed (7 km/h), the wheel is running at about the same speed as a paddle wheel.  The ski example does include a tensioner.  Cable trams were (and are, in San Francisco) similar.

Back to paddlesteamer: I doubt 300 rpm take-off shaft: 5 piston strokes per second.  Far more likely to be no more than 120 rpm.
A simple half wind can handle quite high torque, particularly if there is a tensioner.  My year 12 applied maths text had one such polar integration: even with quite low coefficients of friction, the overall grip was high (and 1.5 wraps was something like 10 times more gripping than 0.5 wraps).
Did the applications have single rope or two?
There must be some disadvantage, or the application would have been more common.  Chain drives need a lot of lubrication, and don't like dust (which can add a lot of internal resistance, and soak up power).  PS Adventurous (Echuca, Australia) has long chain drives to the stern wheel, and the operator has trouble with the chain jumping the sprocket if going too fast.

Regards,
Roderick B Smith
Rail News Victoria Editor

Offline derekwarner_decoy

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Rope Geared Paddle Engines
« Reply #4 on: October 17, 2006, 05:07:04 PM »
Hi PD's & this is a real   :rant subject & but am not going to start  & quote theorems that I cannot answer  :great [like I did with the P1, V1/TA1  = 1/2 case of bananas], but.....

The publication 'Mechanical Engineering Science' by Hannah & Hillier ISBN 027303602201 provides plenty on 'moment, work & energy'....'fiction' & 'uniform motion in a circular path' but none give me the answer on a ROPE Drive

Think of a rope capstan on Captain Cooks Endeavour  = five full turns of rope paying on & paying off & all being kept taught by the hour glass spindle .... but at what speed  :?:  :?:

Today I  :gather with a group of eminent  :respect senior engineers [some with 1/2 an alphabet of LETTERS post their surname] from the Steel Industry & they just looked at me in dismay as if to say "are you sure you don't need a  :vacat  Derek  :?: "

So in reality I think this is a lost art in knowledge, was probably a cheap and inefficient method of coupling energy from the driver to the driven over chains or spur gears with the latter requiring a certain level of accuracy in alignment

Still, someone may offer further  :news - as all comments to date  are  spectulative :oops  or  :nono - Derek  :hehe  :music
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

thewharfonline

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Rope Geared Paddle Engines
« Reply #5 on: October 17, 2006, 06:35:41 PM »
My thoughts...probly random as I am still very little in Engineering knowledge...forward and backward all good...other stuff a little more difficult but here goes!

Chain drive works with like a giant bike chain...I had a photo accompanying the Pyap showing this. Now conisder a large rope not a thin one but a large one. It then works the same as chain gear but is simply a piece of rope...I don't know how the rope stays...some kind of claws on the gears or something but this then turns it...

Just my thoughts...they seemed to make more sense in my head!

paddlesteamerman1

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Rope Geared Paddle Engines
« Reply #6 on: October 17, 2006, 06:41:00 PM »
That was exactly what my post is meant to be getting at. And it does make perfect sense. Would it be able to change 'gears' like a bike, with the chain or rope moving from one cog/wheel to another or does it just stay the same?

thewharfonline

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Rope Geared Paddle Engines
« Reply #7 on: October 17, 2006, 06:53:37 PM »
I would say that it would have to remain the same I can't picture it easy for the rope to easily 'swap gears' as a bike chain would.

I would think as well though using a rope could be difficult in the way the rope could snap...so might it have been a wire rope? Much stronger and more durable and I've heard of them being used before on the Murray...sometimes with devastating effects when they snapped.

Incredibly random but if the wheel were magnetic maybe that could hold a wire rope...farfetched modern paddler idea there I think! Who knows that might work though!

Offline Roderick Smith

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rope drive
« Reply #8 on: October 17, 2006, 07:01:08 PM »
All three forms of drive would be set up with a fixed gearing, with the gear ratio chosen for the best performance for the range of duties to be performed.
This is true also of railway steam locomotives and of traction engines (but possibly steam lorries had a transfer case' there was one with a well-known paddleboat owner at the Echuca festival, so he could be asked).

One could have a gearbox on a geared paddlesteamer drive, but (AFAIK) none did.  Some paddlevessels fitted with tractor engines and transmissions have retained the gearing.  If gearing a steamer, presumable a transfer case, to be changed only when stationary, would be appropriate.  I don't know of any Australian steamer which did this.
Chain-driven paddlesteamers did not have the equivalent of a derailleur bicycle gear (too hard to do with the size of the chain, and the force being transmitted).  They could have been fitted with a transfer case (high/low), but weren't.
Likewise rope drive: fixed gearing.

I was reading of adjustments to the lookalike Lady Augusta in 2003.  At Murray Bridge, the floats were cut back slightly to be smaller.

On a displacement hull, there is a hull speed which is finite.  No matter how much power is supplied, the boat will go no faster.  A screw (and presumably a paddle) will cavitate.

On a paddle boat with diesel-electric drive, the electrics can give the effect of a gearbox.  Not many Australian ones had this drive.  Avoca did (traction motors and controllers from scrapped Adelaide trams) until it came to Mildura, when it was fitted with hydraulic transmission.

Regards,
Roderick B Smith
Rail News Victoria Editor

paddlesteamerman1

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Rope Geared Paddle Engines
« Reply #9 on: October 17, 2006, 07:37:17 PM »
Also, wouldn't the chain have too much pressure on it (to taught) to change from a larger to smaller, or vicer verser? It really just sounds, if the paddle steamers had geared chain/rope drives, it would be too much mucking around to change the gears wouldn't be?
...And I have also heard of the tragic outcomes of extremely taught wire roping snapping causing a lot of trouble

Offline derekwarner_decoy

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Rope Geared Paddle Engines
« Reply #10 on: October 17, 2006, 08:34:09 PM »
Hi PD's   :D - chain drives as we know them [Renold Chain UK] is actually a  kick back from Monsieur RENOLD who was naturally an engineer from France :shhh

I had the pleasure of post apprenticeship working for the same Renold Chain Australia as a trainee mechanical engineer

1 1/4" to 2" pitch BS or ASA single, duplex or triplex chains were not designed or installed & used with 'quick change pinion sets' - result would have been death to the chain or any person in near contact :cry:

The case that Rodderick mentions re chain shudder or fall off can only be the result of GROSS mis-allignment or a mounting/ tensioning issue

Chain drives when engineered & installed correctly offer great power transmission  scenarios & I understand that many OZ paddlers utilized chain drives

The issue of contamination between chain or spur gear was also a non event as they just poured more black GOOP  :beer  when the chain or gears SQUEEKED a bit - Derek  :)
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

Offline steamboatmodel

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Rope Geared Paddle Engines
« Reply #11 on: October 19, 2006, 02:04:53 AM »
Do you think if we gave them enough rope ?
Regards,
Gerald
Be wary of strong drink. It can make you shoot at tax collectors--and miss. Lazarus Long

 

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