Steam for the PS Pevensey

[Peter Webster]

I am looking at building my own engine for the P.S. Pevensey and would like some help in determining the size such as bore, stroke and boiler size. As this will be my first operable steam engine I have decided on a simple twin cylinder oscillator type, twin cylinder due to the self starting capability. The boat is approx 55" loa and the scale is 1/24.it will be built to repesent the period when it was used to transport wool bales, not the current tourist fitting out. the only other engine I have is a Stuart V10 which I have half built but this would be far to powerful for this boat. I have decided to have a butane fired burner with a simple boiler, but am open to suggestions on these also
thanks
Peter Webster

[steamboatmodel]

Hi Peter,
Stuart has a nice set of castings for a twin V, or Sandy could probably set you up with a ready to run unit.
Regards,
Gerald

[derekwarner_decoy]

Hi PD's ..... I greatly admire your thought of a self build Peter....  & naturally suggest it best to talk W .... :gather others experienced with a completed steam engine build....


With respect to engine size [displacement] to hull size, we must acknowledge one of the French  :rant WEB sites with links via our PD links does reference this issue via a table of recommened engine CC's >>  hull Kg>>prop diameter & even yes a limited recommendation of speed ratio/reduction for paddle wheel selection


You may need to have the computer model of "Babble Fish Language Translations" via Google :computer up & running  :mrgreen:


Only other "scientific or technical" suggestion is to have a cup of TEA.... [no not   ]  & a few Vegemite sangas awaiting your path when attempting the understanding of FROG translations .............  ....regards Derek

[sandy_ACS]

   

Hi Pd's,

Posted: Wed Oct 2006    Post subject: Steam for the PS Pevensey

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I am looking at building my own engine for the P.S. Pevensey and would like some help in determining the size such as bore, stroke and boiler size. As this will be my first operable steam engine I have decided on a simple twin cylinder oscillator type, twin cylinder due to the self starting capability. The boat is approx 55" loa and the scale is 1/24.it will be built to repesent the period when it was used to transport wool bales, not the current tourist fitting out. the only other engine I have is a Stuart V10 which I have half built but this would be far to powerful for this boat. I have decided to have a butane fired burner with a simple boiler, but am open to suggestions on these also
thanks
Peter Webster  

Bravo Peter,

I agree the Stuart V10 would be far to powerful, I would suggest a twin oscillator with something like 7/16" bore X 7/16" or 1/2" stroke, double acting would be about right.
This size of engine would be more than capable as a paddle engine, especially as you will almost certainly need to gear the output down by 2 or 3 : 1 in order to get the paddle rpm correct, this will naturally multiply the available torque by the same ratio.

Such an engine could easily be made from stock materials without the need for castings..I would suggest using leaded bronze (gunmetal) for the cylinders and moving port blocks. The fixed engine standard could be made from Brass (Silicone loaded if you can get it), crankshaft, crankpins, piston pivots, pistons piston rods should be Stainless steel (use Viton O-rings for piston rings) and big ends should be bronze (either phosphor bronze or better still Colphos 90, which is much easier to machine and tap.   You could also make the crankshaft bearings from these materials if you feel it neccessary, but the brass would be just as durable in this instance. (don't forget to add oil ways to the crankshaft bearings).

From a boiler point of view, I would suggest a horizontal centre flue type with crossed water tubes inside the flue and a suitable size would be around 3 1/2" - 4"  outside dia x 6" or 7"  in length. The centre flue should be around 1 5/8" OD (42mm)...oscillating engines are quite steam hungry.


If it would help, I could sketch something out and e-mail, or post it by Mail. Let me know.

Don't forget, the PD's gang are all very willing and helpful, and there is a lot of knowledge amonst the group so don't be afraid to ask.

Good luck with your project.

Best regards.

Sandy.    

[Peter Webster]

Thanks all for your replies to my query re a suitable engine. Derek I have the vegemite sangas nearby at all times and I only drink tea not coffee, can't stand the stuff, .Sandy, I have been looking at the Graham Industries "VRIA" dbl acting single cylinder with a 1/2" bore and 5/8" stroke I have been told it will be enough to power this model and although I would have preferred a twin cylinder engine the person who built the P.S. Oscar W shown on our heading page ocassionally also uses a single cylinder and if the engine stalls and stops he has an electric motor which is hooked up to a centrifigal clutch which he uses to retrieve the model with (he designed and built the clutch himself). I would appreciate any suggestion and sketches re a suitable boiler. Gerald I have checked out the Stuart twin cylinder unit but too expensive at the present time although it would be lovely to use this type.
once again thanks for your responses
Peter ( on 3 weeks leave and the weather is cold)

[kiwimodeller]

Peter, I saw several years ago a single cylinder steam powered ship which had an electric motor coupled to the steam engine. There was no clutch of any sort, just a small chain. The electric motor was operated by pushing the steam control to full ahead then shifting the trim on the transmitter so the servo went a little further and operated a micro switch to make the connection to the motor. I think it had some sort of spring overide on the steam throttle linkage. There was no speed control on the electric motor, just full speed to kick the steam engine back in to life. The other interesting little trick was that when the micro switch was open and the steam engine was running the electric motor it operated like a generator and was somehow connected to a mast head light so you could tell that the steam engine was running. As I said it was many years ago and I believe the gentleman is now deceased so I cannot get you the details but I am sure with a bit of experimenting it could be made to work. Off course an extra radio channel would be easier but in those days two channel was all that most of us could afford. Hope this gives food for thought, don't forget to keep us posted. Cheers, Ian.

[derekwarner_decoy]

Goodness PD's - Karina & [Sandy + Kate] would suggest   , the people in 'white coats'  may be required if I cannot explain why PS Decoy really needs four fluid isolation valves :idea:  :arrow:     :

1) boiler steam isolation to the JMC3H engine
2) boiler water pressure isolation for the pilot for the GAZ regulator
3) lubricator dump isolation to de-oiler/condensor
4) GAZ isolation

.......but I would not be game :roll: to suggest  :? that I needed an additional internal infernal machine to   capture spent  :rant steam & convert  this into VOLTZ for a 'come home motor', complete with  :boom a lighted becon on the mast........  :music - Derek

Oh PS, stick with those Vegemite sangas on your holiday Peter, I agree -  they are 100%  :no1  &

[derekwarner_decoy]

- sorry Ian - I had beeeeeeeeeeeeeeeeen celebrating   the  Australian V8 Supercar race & may have had one too many cups of & mis :  :  understood your posting

Clearly your note is not about a 'come home motor' buy a 'gigger or starter motor'  

apologies :bow - Derek

[sandy_ACS]

     

Hi PD's....

Well Eddy, I suppose it had to happen at some time.....I blame the new server....it obviously has a weekness since it has allowed all these OZZIES to infiltrate the domain... :nose      :nah  :music    
Having said this, I feel that having a name James McDougal...I suspect a Scottish link...so perhaps all is not lost.....
     

Welcome to all new PD's, and I trust you will find lots to interest you in the posts...and yes, there is also the good natured banter to contend with.

It sort of goes with the terratory... :yeah    :computer

Peter...I think the Gage (Graham industries) VR1A would be large enough, however, I agree with the other guy's that the problem of it not being self starting will present you with a few issues to sort out.
The electric motor method, referred to by Kiwimodeller, can be made to work quite successfully, but the required switching is not that simple, especially if you choose to use the motor in generator mode when the steam engine is running. This would require the electric motor to be isolated from the normal motor electrical feed when the steam engine started, otherwise you would get the situation of the motor being fed with current from your battery, via the throttle switch, and the motor trying to generate (in the opposite polarity) which would then feed back to the battery, not a good situation...this, at best, would overheat, or stall the electric motor, and at worst, could damage both the motor and the battery. The type of spring overide linkage he mentioned is, I believe, a type of servo saver linkage which will allow the servo to overtravel when the engine throttle lever hits its stop. I posted details of such a device some posts ago.


As for a suitable boiler, well I attach a set of PDF files for a horizontal centre flue boiler, this is based on my HB-1 boiler and should be more than adequate for the job. This design is capable of 60psi max, but the more usual pressure for the Gage range of engines is 45psi max. The funnel height for this boiler should be at least 5" and can be made from 28mm OD copper or brass tube.    


Ky Paddlewheeler ......hey, no worries my friend..I can appreciate your problems and I am sure you will get the B of L trip at some point in the future when your family problems have been resolved.


OK PD's, keep happy.

Best regards.

Sandy :computer      :vacat

[Bill Hudson]

Hi Sandy and all.  

Been away from the puter for some time. Spent a week dong lots of golf before the weather turns sour. started raining last night.  Now getting caught up on other stuff.  Hopefully with the rain and winter I can get some shop time .

Sandy said "Well Eddy, I suppose it had to happen at some time.....I blame the new server....it obviously has a weekness since it has allowed all these OZZIES to infiltrate the domain...            
Having said this, I feel that having a name James McDougal...I suspect a Scottish link...so perhaps all is not lost..... "

I too have felt out of place here. Most of the time I don't understand what every one is saying.  However I feel better now as I was watching our local public TV station.  There was a Brit program on and some one mentioned " I watch them but usually don't under stand what they are saying"  The Brit. replied... "That is OK. we usually don't understand what we are saying most of the time either."  Makes me feel a little better.
what the heck is vegemite sangas??  

Speaking of Scott decent, does a third generation descendant  from McClung  and McClure count for any thing???  Tea? yeah I drink it in the winter or with Chinese food.      But I prefer  : coffee It wakes me up.  But if I had a real choice it would be       I drink my jackie D because I can not find any decent Scotch locally.  But I still son't under stand what your are talking about most of the time.      
     


"As for a suitable boiler, well I attach a set of PDF files for a horizontal centre flue boiler, this is based on my HB-1 boiler and should be more than adequate for the job. This design is capable of 60psi max, but the more usual pressure for the Gage range of engines is 45psi max. The funnel height for this boiler should be at least 5" and can be made from 28mm OD copper or brass tube. "

Sandy this boiler is similar to the boiler I was planning on using on my stern wheeler   (2) 1/2" bore X 1 1/2" stroke.  I like your boiler better in that the flue is internal and will add to the heating of the water.    Will this boiler work for my engines?




Bill


 

[Peter Webster]

Bill, a vegemite sanger is an Ozzie delicacy that only Ozzies fully appreciate.
Sandy, thanks for the boilers details, I will study them closely and see how they fit in the available space. The lektrik motor ( as Derek calls it) is switch on when a servo moves it into position I will draw a sketch when I build the unit further down the track.
Peter Webster

[Dave_Sohlstrom]

Sandy

Very nice plans. One question. Drawing 3 Main plates shows a 42mm hole for the flue tube on the burner side and a 45mm hole on the funnel end am I not understanding something ? I do not see why they should be different.

Thanks

Dave

[paddlesteamerman1]

Hi PD's

Yes the name does have a rich Sco'ish history, but I am very Ozzie!! Hehehe... and everyone gets it wrong, usually putting only one 'l' not 2...

But it is all good mate!!

And Ozzies aren't that hard to understand! Are We??

Cheers Mate!

[sandy_ACS]

     :computer    

Hi PD's

Hey Bill....Nothing wrong with a drop of Jack D, I got quite hooked on it myself during my many visits to the US....Distinct lack of the Scottish preferred liquid in most places.        

I would suggest you would need a somewaht larger boiler for you 2 off engines (1/2" bore x 1 1/2" stroke) which are much the same size as the engines I am working on for the Bof L.
The boiler I am proposing for mine is the same style, but has a 4" OD barrel x 7-8" length and has a 2" OD centre flue with 2 rows of 10 water tubes (2 side by side with a 1/8" gap). The burner will be larger, having a ceramic element of 35mm OD, other than that the design is the same.

Dave....no you are not going mad, or missing something...I own up to a typo    : ...the correct size should read 42mm for both plates.  

Peter....Ok , glad to help and I look forward to the circuit diagram (for the LEKTRIK MOTOR ) when you get it sorted.......just thought I would highlight one or two possible issues.

   :sob  :nose
Drat..... James.....you spotted my deliberate smelling miss-steak....but I thought there must be a Scottish link/history somewhere along the line.
As for understanding....well I have both family and some very good friends over in OZ so I generally get the drift of most things...other than DEREK's...but he's another story.... :twisted:  :      


OK guys....more later.

Best regards to all.


Sandy :computer    

[derekwarner_decoy]

Hi PD's & an interesting set of plans courtesy from that Scotts place  :vacat  .......

Sandy, but are they not the same as the brillant ACS VB-1  :?:  :!:  :idea:  :arrow:  - the only item I cannot resolve from the Dave_Gallagher snap are the 3/16" diameter horizontal end stays

I am certainly not qualified to comment on 0.059" a side difference [45-43=2 X 0.5 / 25.4 = 0.059"]

Peter W - irrespective of your boiler design or manufacturer, be careful of thermal gradients {& bits of decking getting TOO hot}

With my ACS VB-1 boiler, the shell temperature & criticals reach 150 degrees C - my initial boiler selection to PS Decoys original design I have been able to maintain the status without gross insulation

Would seem a big pitty to bury your boiler & all in 3" of NON- asbestos insulation
Would seem a crying shame to hide your proposed engine & all the brass shiny bits like wise - Derek