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[bill stafford]

dear forum,
 can any one tell me what you drive a D-10 w via boiler design
most out her in au are 100mm single centre flue , and struggle to supply much more than 20/25 psi and about 15 minutes of steam.
i was thinking of a twin centre flue design or a multie flue design of K .N. harrises book (correct name ??)
the multy flue design is supposed to be a much better steamer than a centre flue, and a local steam nut also thinks so.
i was thinking of a twin gas burner set up for either boiler design.
out her in au. we can only get 20/25mm burners , but in Uk you used to be able too get 30 mm versions , any info / ideas appreciated
i set up a tvr-1 in a tug for another guy, w a 100mm centre flue bolier , and it runs well , 25/45 psi +25 minutes duration , drives a 50/75mm prop and gas fired
thanks for any ideas
i am in the design stage  now ,but it will be a while before it is built, and I intend to make a simpler version first , but the above boiler would be 150mm diam , and i will try to get it certified, either AMBSC or au standard, that is a struggle , as its not a loco boiler

[spearfish99]

Not a steam man myself but wonder if these might be of any help

http://www.stationroadsteam.co.uk/Stuart/500%20series%20boilers.htm

http://mainsteam.co.uk/usedmodels.htm

http://www.stuartmodels.com/item/84/stuart-hb4-boiler

[ooyah/2]

dear forum,
 can any one tell me what you drive a D-10 w via boiler design
most out her in au are 100mm single centre flue , and struggle to supply much more than 20/25 psi and about 15 minutes of steam.
i was thinking of a twin centre flue design or a multie flue design of K .N. harrises book (correct name ??)
the multy flue design is supposed to be a much better steamer than a centre flue, and a local steam nut also thinks so.
i was thinking of a twin gas burner set up for either boiler design.
out her in au. we can only get 20/25mm burners , but in Uk you used to be able too get 30 mm versions , any info / ideas appreciated
i set up a tvr-1 in a tug for another guy, w a 100mm centre flue bolier , and it runs well , 25/45 psi +25 minutes duration , drives a 50/75mm prop and gas fired
thanks for any ideas
i am in the design stage  now ,but it will be a while before it is built, and I intend to make a simpler version first , but the above boiler would be 150mm diam , and i will try to get it certified, either AMBSC or au standard, that is a struggle , as its not a loco boiler

Hi Bill
Have a look at this boiler build by the late Patternmaker on this forum, it's a Scotch Marine return flue boiler based on a Boiler by K.N.Harris , it's the very last boiler design in his book on boilers.  ( http://www.modelboatmayhem.co.uk/forum/index.php/topic,28450.0.html )The boiler had a converted burner head from a plumbers blow lamp and steams his Stuart launch engine very well which has a bigger bore than the D10, I designed this modified boiler and it is installed in a 42" long tug called Cervia and it's listed on this forum  (S.T.CERVIA AN OLD LADY), steams a D10 which is fitted using pond water and a boiler feed pump all day as long as you have gas in the tank, Let me know if this is what you want via a P.M. and are you going to build the boiler yourself.
George.

[bill stafford]

yes please george, although bi think i will be going w kn harrises multi tube boiler , only 150mm diam and twin gas burners, but your advise was exactly what i wanted, some one who has built one and used it
i was thinking of twin burners to get enough heat

out of gas.
i intend to build it my self , but a lot of red tape out here in oz but i haven't built any boilers yet , but my friend has made well over 5/6, all certified , and will help in any way possible
thank you for the help

[ooyah/2]

Bill ,
Just remember that a multi tube boiler requires a constant water feed from an engine driven feed pump as there is not a great water volume in them but very fast steamers and with the correct heat source  will steam a D10.
Here is a few pics of a vertical multi tube boiler with a steam dryer fitted on top and you can use the exhaust steam from the engine to pre-heat the water into the boiler by making a combined oil trap com-steam collector.


George.


Just added the D10 which is currently powering S.T. CERVIA.  D 10 on the left and a Launch engine on the right.

[bill stafford]

loverly work, i wish i was as gifted, mine was made by a tool maker ex fords au, it was too good a offer to refuse
multi tube boiler needing a feed pump is a added concern , and  reflects your added experiences, and shows mine is lacking , hence the questions.
 i was hopping that harrises design would allow me not to, but it could be added , even a electric driven one ,, seperate from the crankshaft need a feed pump. i was also going to blow the out side shell up to 6 inch diam , from 4.5 inch, hopping to reduce the need for a feed pump.
 the recomend for the scotch type boiler and single large gas torch burner is another good idea , and 1 that my friend out here was talking about , a single , large burner , rather than twins
thank you

[bill stafford]

very nice slip yoke drive on the feed pump

[ooyah/2]

Bill,
You can make a pump that is electrical driven or an engine driven pump.


I have used MFA-COMO for their small geared motors (  http://www.mfacomodrills.com/gearboxes/918d_series.html ) the 918D series to give about 120 r.p.m. which is the speed that I use to feed the boiler of my D10 before I made it engine driven.
On the first pic yyou can see that the Scotch yoke has a drive disc that has tapped holes in it , that is in order to adjust the stroke.


If you use the MFA-COMO gear box you will need to have a support bracket on the end of the G/Box as it flexes quite a bit, you can see the bracket on the test rig pics.
The 2- pics are of a G/Box that is no longer available , hence I now use the MFA G/Box


Here are 2-picspics of the electric driven pump and 3- pics of a test rig that I use for making feed pumps for TVR engines.


The TVR pumps are 1- Horizontal and the other Vertical.


The gears used are Meccano, cheep and cheerful !!!


Hope this is of help.


George.

[Mark T]

Hi George I hope that this is not a daft question - but    how do you work out if the pump is supplying the correct amount of water to the boiler?  I guess you want to refill what is being evaporated but how would you know if your getting it right?  Is it trial and error or is there a more scientific way of working out the delivery volume?  Thanks Mark

[ooyah/2]

Hi George I hope that this is not a daft question - but    how do you work out if the pump is supplying the correct amount of water to the boiler?  I guess you want to refill what is being evaporated but how would you know if your getting it right?  Is it trial and error or is there a more scientific way of working out the delivery volume?  Thanks Mark

Mark,
No questions are daft if you don't know the answer.
I am not one for calculating a boilers requirement but over the years and quite a few boiler builds I have gained enough to roughly know what my boilers needs are, so it's a little trial and error.
I always make pumps adjustable mainly the stroke and as you can see on my pics there is an adjustable drive disc to the pump, also most important is to have a bypass valve in the delivery line to the boiler which allows you to adjust the boiler requirements and be able to return water to the feed tank or overboard.
For a boiler large enough to drive a D10 I would have it running about 120 r.p.m. to 200 r.p.m. with a 1/4" ram and an adjustable stroke of max 1", this will allow adjust meant via the bypass valve.
For the T.V.R. I would recommend a pump with a 3/16" dia ram x 3/8" stroke with a bypass valve in the delivery line.


Hope this helps.
George

[Mark T]

Thanks George that's really interesting as I'm only just starting to research my first steam build.  You mention a bypass valve which I understand in principle but how do they work and how do you adjust them.  My first thoughts are that when a certain pressure is reached the excess is either sent overboard or as you say to a tank.  Is this assumption right and I guess this valve would work in series with a non return valve too?  Mark

[ooyah/2]

Thanks George that's really interesting as I'm only just starting to research my first steam build.  You mention a bypass valve which I understand in principle but how do they work and how do you adjust them.  My first thoughts are that when a certain pressure is reached the excess is either sent overboard or as you say to a tank.  Is this assumption right and I guess this valve would work in series with a non return valve too?  Mark

Mark, Yes you will need a non return valve ( clack valve ) in the boiler and in the pressure line from the pump to the boiler  clack valve you install a "T" piece and fit a screw down 90Deg  valve, you start by having the valve closed and if there is too much water going to the boiler you open the screw down valve a little , let every thing settle, and if you still have too much going to the boiler continue to open the valve until you get the balance correct.
With the 90 Deg valve you will take a line back to the water tank or overboard.


George.

[Mark T]

Thanks George that all makes complete sense to me now    I've a lot to learn about steam but I'm getting there slowly!

[ooyah/2]

Mark,
Don't be slow at asking questions , even if you think they are daft,  there are lots of members here only to willing to help.


George.

[bill stafford]

thank you all for your help and advise
im now thinking of a horizontal scotch boiler for the D-10, dont know yet if it will have single or twin burners , along the lines of KN Harris`s design+a electric feed pump , although the D-10 should drive a crankcase version.
i havent being happy w the centre flue that are steaming D-10 out here in au, they lack duration and steam volume and pressure , and if we feed the beast , the beast will grunt !!!
i will start to collect copper for build plus s/solder rods , but there has being a change in s/s rods out here , no cadium , still sorting that out , i have a 150mm metre of copper tube , loco suitably , so i need fire tubes and end caps+fittings, so thanks to your help , the design is forming.
I will try to get certified to AMBSC code , and have a good chance , or to au standards , but all this takes time , and it seems i will have to relocate my home and shed

[verithingeoff]

G'day Bill, hello from the Sunshine Coast
I run my D10 from an MSM boiler It's 3"diam x 5" tall. Gas fed centre flue. It's a nice compact boiler and is going into a boat I'm restoring at the moment.


Here's Youtube vid
https://www.youtube.com/watch?v=0GWgZ2MfJnE

[rhavrane]

Bonjour,
For my D10 which has a coupled water feed pump, I have ordered a 120 x 220 x 40 mm horizontal boier (*) with a 250 g/h gas torch and a 4,5'' X4 blade Propshop. Very powerful machine, it pulls a real boat with just about 1 bar, and at 2,or more, it is too fast     
  First test : https://www.youtube.com/watch?v=utYZJDJPBVg
  1 bar pulling : https://www.youtube.com/watch?v=7l_-js-fX_I : :
  2 bars pushing :  https://www.youtube.com/watch?v=BPPux5exRNE
  3 bars running : https://www.youtube.com/watch?v=gbvYKKf8tJE

(*) In France, we have to certify boilers which contain more than 25 liters ==> Our model ones are tested by their manudacturers... or our fiends

[derekwarner]

Bonjour Raphael... your D10 I have seen before however never studied the gas installation

1. is the first image a an overboard gas bleed?
2. you appear to be monitoring actual gas pressure to the burner [after the regulator]. Have you always installed the gauge in this location?
3. I have taken the alternate approach in monitoring gas pressure on the input side of the regulator, however would be interested in your thoughts

Derek

[rhavrane]

Bonjour Derek,
1 - Yes, to avoid having the gas tanks full of liquid gas when we use it with its gas phase, we commonly install a second dedicated valve which is deeper than the main one ==> when the liquid gas reaches its bottom, its lets a "sky" in the tank  and the liquid gas overflows out of the boat, thank to the little pipe you see, instead of going in the hull with the risk you imagine when you light on the torch.
This is more useful for the tanks which are equipped with a Legris type feeding system (silver) :
        https://www.youtube.com/watch?v=VxBGnpX77tA&index=12&list=PLCVcZL8L7sBLTuX-AL3bvPSSS_6ikUc2B

2 - On this gas circuit, I have two accessories, a regulator we call "régulateur" and a "gas expansor" we call "détendeur" but not well translated by Google Traduction (*). You know that the first one slows down the gas flow at a dedicated choosen pressure, the second one maintains a constant output pressure at a choosen value regardless of the pressure in the gas tank which rises especially when the tank heats up.
Too much pressure, even regulated, can blow the burner, this is why it can be useful to use this other "regulator", and, in this case, the interesting gas pressure is the one which is after it.
As it is more complicated and expensive (I buy), I do not install an expansor on all my boats, so the gas gauge remains on the tank.

(*) You can see another "gas expansor" better on this other boat, made with a real house one :
     https://www.youtube.com/watch?v=tSOSj89BY_M

3 - If you have no gas expansor, I think the positionning of the gas gauge has different purposes. Based on my experience, most of my tanks, especially when they are small, cool down, so, as I install just one gas gauge,  I prefer instaling it on the tank to see its inside pressure after a few minutes of navigation. Indeed, sometimes, I think the gas regulator does not work because there is not enough pressure in the tank ! And I control the max flow with the gas valve... at the beginning of the navigation.

When I can maintain the gas pressure at a level of 1 bar, The regulator works well and I am content with what I can buy.
T my opinion, in fact, I think your implementation choice is the most apprpriate because it allows you to measure objectively the gas flow before AND after regulation, at any moment of the navigation. And it is the cheapest alternative to two gauges !
If I could buy more adaptators like this one,, and for 3 mm pipes, https://www.youtube.com/watch?v=o2aWzYf-g9I I would apply your choice