[modeleng] Re: Thoughts on future projects....
- From: stepney <alan@xxxxxxxxxxxxxxxx>
- To: modeleng@xxxxxxxxxxxxx
- Date: Sat, 17 Mar 2012 17:47:38 +0000
Fitting the feathering to a small boat, with the complexity it entails,
would be a major task.
Plus the added width might make life difficult, not least for
transporting the boat on land.
Hence I assumed (perhaps wrongly) that it wouldnt have feathering paddle
wheels.
I wouldnt be in favour of electrical powered boiler. If it is going to
be used, may as well fit an electic motor!
Alan
On 17/03/2012 12:54, Clifton wrote:
> Hi All,
>
> For the best efficiency of paddles they need to feather. This means that
> each paddle enters the water vertically, travels backwards through the water
> then exits again vertically. This avoids the loss of efficiency by the
> paddles first slapping the water then trying to lift a load of water
>
> To achieve this it means that each paddle has to pivot individually with a
> linkage to a fixed offset point. Rather like a loco eccentric.
> The biggest snag is that you need a set of sponsons outboard of the paddles
> to carry the fixed eccentric point.
>
> Just recently I think in EIM there was a article on a model boat with a
> electronically controlled Flash steam boiler. I see no reason why it could
> not be scaled up.
>
> Regards
>
> Clif
> ----- Original Message -----
> From: "stepney"<alan@xxxxxxxxxxxxxxxx>
> To:<modeleng@xxxxxxxxxxxxx>
> Sent: Saturday, March 17, 2012 11:11 AM
> Subject: [modeleng] Re: Thoughts on future projects....
>
>
>> Coming back to the steam options that Chris mentioned,
>>
>> I know someone who has done a lot of research on steam bikes. An
>> ex-university lecturer, he has written an interesting paper on them plus
>> a comprehensive survey. There was one running at the St Agnes rally a
>> few years ago.
>>
>> Generally, they werent too successful as motorbikes, but could be good
>> fun.
>>
>>
>> As for steam boats, there was an interesting flash steam boiler at... I
>> think it was Donnington, a few years ago. I have photos and details
>> somewhere.
>> It made a compact unit that provided lots of steam.
>> Plus, of course, no actual pressure vessel to test.
>> That would be my choice for such a vessel. The other option is a
>> vertical boiler, which is common and for which there are numerous
>> designs available.
>>
>> For the engine, and without doing any calculations, I would guess that 3
>> or 4hp, would suffice.
>> (Paddles being less efficient than a screw, and to raise the efficiency
>> of paddles means quite complex paddle design, so I assume they would be
>> fairly basic=less efficient.)
>> There are lots of engines that would provide that power. Some of the
>> Leak designs would do, but for a paddle steamer, I would go with an
>> inverted V, much like the model that Tel built last year (or was it the
>> year before?).
>> An enlarged version of that would give a low CofG, and take up little
>> space.
>>
>> Alan
>>
MODEL ENGINEERING DISCUSSION LIST.
To UNSUBSCRIBE from this list, send a blank email to,
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.
Other related posts:
