Twin Horizontal and boiler build

[granath]

Hello, this i my first build and i have Choose the MVh TC 14x18 twin horizontal steam engine



here is my progress at the moment so it isn't that much left, so i started planning on the boiler and here i'm a bit lost since this is my first build.

could somebody help me with size and dimension, of the boiler, i got hold of a copper pipe 70x3x300mm so if i could use that it would be fantastic!
i'm thinking i will build a "porky" style of boiler, or are there some better suggestions?

also i have som questions an the boat, i would like to build it as small as possible (good choice of engine i know) but i really woulden like to go over 1m i hull length could i go smaller without have tons of balance and instabillity problems? (i have looked at the strongbow's hull and i think i will use that)

so i hope i can get som help with this

Best regards // Victor Granath
sorry for the bad English but i'm from sweden hehe

[bogstandard]

Hi Victor,

Sorry I didn't get back to you by email, I have had an overly large quantity over the last week or so, and I must have put yours to the back of the pile.

Your engine is certainly looking good, you are making a nice job of it.

This engine isn't really for a small model. It has been discussed previously and it should really be in a model of about 1.5 metres length.

With reference to the boiler size, I would personally envisage one at 80mm to 85mm diameter by 150 to 175mm long. I suppose you could use your 70mm diameter, but it would have to be fairly long to get the volume of steam required.

As for copper tubing, you would need to consult your national boiler regulations to obtain the correct grade of materials and relevent dimensions as these vary from country to country. Also for testing purposes, in the UK, the boiler should be made to a 'recognised' design. Who makes the decision as to what qualifies as a recognised design, can only be guessed at.

I have certain feelings now about making boilers. I used to make them, but now, if I was going to run steam engines again as a hobby, I would just buy a commercial one. Then you know you will have no trouble (hopefully) getting insurance

As I told you, I was due to make a batch of these engines, but ill health has forced me to cut my workshop time down dramatically. So only essential parts are being made at the moment, just to keep the workshop ticking over. Maybe later I can get back into production.

I am sorry to be the bearer of bad news as to model and boiler size, but at least you now know what it is all about.

John

[granath]

No worry's John! i just hope you get better soon!

thanks for the nice comment's i have some bits that I'm not that proud of but it is my first build and I'm quiet sure it will do it's job, otherwise i will upgrade them after testing

about the size yeah i read the thread but is it that seriously about size? there must be some kind of margin?

i looked at the saito Ty-2 Dr 2-cyl 12mm bore 20mm stroke and they recommend 1000mm-1500mm length so 1m hull should be no problem for this engine or have i got it wrong?

the suggested boiler for the saito Ty-2 Dr is xb-2f 75mm width 300mm length inc burner and i think the burner stands for 1/3 of the length then i look at pictures of it

i will check for regulations about the boiler

Best regards// Victor

[granath]

i now have done some reading and as i understand boiler and engines witch is made in a non commercial use and for "self-use" do not need to follow the restrictions but i would be wise

Machinery must be designed and constructed to avoid any risk of explosion posed by the machinery itself or by gases, liquids, dust, vapours or other substances produced or used by the machinery.

restrictions, suitable material, suitable dimensions

Boilers was constructed by model engineers, not in connection with business, and put into use for his own use, not subject to the requirements of Pressure Equipment Regulations 1999 (PER)

use of saftey valve

A competent person shall examine, test and report on all parts of the system covered by the forgoing written system for review. This person should be someone other than the designer, owner or seller of the unit. An independent witness must verify the results of its deliberations.

i will digg some deeper into it and try to call someone involved with it to get verification of what i come across so far.

[kno3]

Hello, if you understand German, I have a spreadsheet that allows you to calculate both the steam consumption of the engine and the steam production capacity of the boiler.
It can help you understanding what kind of boiler you need to run your engine.

[malcolmbeak]

So let us into the secret – what is an "approved / recognised" design, and where can we find details of them? Who classes as an approved designer?
I have been designing and making my own boilers for over 25 years. All have been tested by the society's boiler tester. None have ever failed during the test or subsequently. Usually the design has been for a specific model. Some were experimental and some didn't work too well.
In general, the thickness of the copper tube and sheet used is much more than is needed. I fancy that the reason most folk shy away from making their own boilers is that they are worried by the silver soldering process. After some practice, it really isn't that difficult.  It seems to me that any capable model engineer should be quite able to make a decent boiler.
If anyone is interested in designing their own boiler, "Model Boilers and Boilermaking" by K.N.Harris is an excellent book.
I now wait to be shot down in flames!
Malcolm

[granath]

Hello, if you understand German, I have a spreadsheet that allows you to calculate both the steam consumption of the engine and the steam production capacity of the boiler.
It can help you understanding what kind of boiler you need to run your engine.

no German isn't my strongest subject but i could probably get it translated so if it isn't that much problem i would gladly take a look at it

what would be the most effective one of a Porky style boiler or a water style boiler, what is the good and bad of the diffrent ones? any diffrent in size between them on the same pressure and torrent of steam.

some pics from today's work



got the other piston fitted and the other piston shaft done, and also i fitted the helpguides for the connection between the pistonrod and the crankshaftrods or what i sould call it
so now it's on to make the pushrods between the crankshaft and pistons and the pushrods for the valves.

// Victor

[kno3]

What's a Porky boiler?

For the spreadsheet, send me your email address.

[granath]

http://www.homemodelenginemachinist.com/index.php?topic=2092.0

if you look at page 5 and 6 you can see what i mean

email on the way

//Victor

[poodge]

Beautiful work,Victor.makes me feel ashamed of my meagre efforts.
You may find a bit of useful info on this page:
http://home.claranet.nl/users/summer/16mmngm/Articles_htms/porky.htm
Hans

[steamboatmodel]

http://www.homemodelenginemachinist.com/index.php?topic=2092.0

if you look at page 5 and 6 you can see what i mean

email on the way

//Victor

If you are going to drill all those holes you would do better to go with a Scott boiler.
You could also try one of Sandy C design form the download section.
But as Malcolm says, and I could not agree more,
"If anyone is interested in designing their own boiler, "Model Boilers and Boilermaking" by K.N.Harris is an excellent book."
Also check in the back posts for information.
Regards,
Gerald

[bogstandard]

Malcolm,

So let us into the secret – what is an "approved / recognised" design, and where can we find details of them?

I asked the same question as yourself.

Also for testing purposes, in the UK, the boiler should be made to a 'recognised' design. Who makes the decision as to what qualifies as a recognised design, can only be guessed at.

It was only two weeks ago that I was asked the question. 'Who's design was it' with reference to a boiler I had made. Luckily I gave him a set of plans and the designers name for the boiler. Hoping that would satisfy their request.

It seems, that under boiler testers rules, it states that it must be made to a 'recognised design'. This is from a pair of boiler testers (one a professional boiler tester) that are starting to test boilers for my local model boating club.

I have no further info other than that, and don't need to, as I will not be making any more boilers.

I am in the same frame of mind as yourself, but I can only relay information that has been asked of me.

I also designed and made my own boilers for many years, does that mean, just because I haven't catalogued them or drawn up plans, they are not a valid design? Or are they referring to say Yarrow, Scotch or centre flue etc?

John

[granath]

Thanks for the fine words! really appreciated! i feel the same way then i look at John build! no ugly spots there!

i looked at the Scott boiler that sandy build and redrawn and I'm really excited it feels like that would be the way to go and as far as Sandy's post about the boiler it looks like it shouldn't have any trouble providing my engine with the required steam..

but i must say I'm no fan of gas. could it be converted to alcohol? will i suffer a loss in performance? i know it will be harder to controll with alcohol then with gas.

are there anything else that is good or no good then trying to run it on alcohol rather then steam..

[derekwarner_decoy]

Hi PD's........& Granath ...we have one member who has correcetd me that a posted message with photograph from outside PD's has a coal fired model vertical boiler & was a supurb build

From memory it was Engineman....or Andreas .....could the responsible person please explain & repost the snaps.... ....................Derek

[steamboatmodel]

Thanks for the fine words! really appreciated! i feel the same way then i look at John build! no ugly spots there!

i looked at the Scott boiler that sandy build and redrawn and I'm really excited it feels like that would be the way to go and as far as Sandy's post about the boiler it looks like it shouldn't have any trouble providing my engine with the required steam..

but i must say I'm no fan of gas. could it be converted to alcohol? will i suffer a loss in performance? i know it will be harder to controll with alcohol then with gas.

are there anything else that is good or no good then trying to run it on alcohol rather then steam..

I looked up Heat of Combustion in Wikipedia;
http://en.wikipedia.org/wiki/Heat_of_combustion
Methanol 9,800 BTU/lb
Ethanol 12,800 BTU/lb
Propane 21,700 BTU/lb
Butane 20,900 BTU/lb
Paraffin 19,900 BTU/lb
Coal (Anthracite) 14,000   
Coal (Lignite) 8,000 BTU/lb
Gasoline 20,400 BTU/lb

From looking at the above you would have to run almost twice the amount of alcohol as you would with Gas. Having said that I think you could still run alcohol, after all they ran most model steam engines on it or coal long before we has the gas. I have a camp stove that runs on alcohol and it boils the water in about the same time as my Butane/propane one does, even faster when the temperature drops.
Regards,
Gerald.