Lorbas by Mirabell61 - FINISHED - Steam powered river tug

[Mirabell61]

Introduction :

 

This project has been completed already in the years 1984 / 1985, when I was still a young man. I had the intension of building my own designed steam engine for a model ship. A regular steam engine with crosshead-guides and Stephenson reversing  control device, was too complicated to build, in lack of neighther lathe nor milling machine (still do`nt have….). So I decided to design a steam-motor with a minimum on moving parts, and yet powerful enough to propell an appr.  1100 mm long RC controlled ship model. And the driving challenge was also to see if I could do it anyway……

 

 

Current status :  After some years of perfect performance, the boiler became a hair crack leakage in one or two of the inner heating tubes solderings, that unfortunately could not be mended without destroying the boiler. So neighther ship nor motor had been moved since. I wanted to rotate the motor the other day by trying to rotate the crankshaft  but all was blocked somewhere, probably the pistons are sticking to the cylinder walls. Shall have to dismantle everything completely for overhaul, and build a new boiler if I want to have fun on that behalf again. Fortunately the was a raghther short little super 8 Kodak film made of the model travelling on the lake at full steam in those wayback years, the film in miserable quality, but at least a document of a successfully completed project. I`ll try to put that film in a little video here on MSW in this log later on. Some of the pictures I found fortunately  in my photo-archive and scaned them in, and was myself surprised that I even had pics of motor complete, and boiler in the building stage. I thought this may be of interest for the one or other fellow builder here at MSW. The ship itself is still ready to be launched at any time, only the prop has a bit patina on it

 

 

 

 

 

The ship

Model-length       1090 mm

Steam powered, gas fired, RC controlled, fictional version  river tug “Lorbas” in nostalgic look

Model Build year : 1984 / 1985

Ship is POB scratch design, self drawn lines, ply frames and diagonal planked with balsa stripes,

Hull coated with glass-fibre rowing cloth and epoxy resin

Removable deck housings and many maintenance opening hatches and doors, and

ventillation openings for the boiler- and machine room

large self made 80 mm 4-blade brass propeller

 

RC control

Simple oldtimer 2-channel radio-controller, Make “Robbe” and on the ship two-channel

receiver and two servos (one for steam reverse valve, stop, foreward, aft) one for rudder

port / stb. One power pack comprising  4 x 1,5 V mignon Batteries. I`m not allowed to use

this RC equipment any more  due to national postal radio frequency regulations

 

The Engine

Self designed Six cylinder Steam motor in Vee-6 design, for superheated steamflow, with direct piston rods to crankshaft, ball bearing crankrod head-bearings,  each cylinderhead  with common, horizontal working slide cam control bars, manifolds for steam inlet and steam outlet (reversible)

Steam reverse valve (for swapping inlet / outlet channels with RC servo function.

Motor designed for 2 bar constant steam backpressure when running at 200 RPM in direct

(quick disconnectable) coupling to propshaft

Idle unbreaked motor runs up to 3000 RPM, if control cam positions are set correct

Model speed like modest walking pedestrian

Lubrication by means of oiler-device in live steam line (high viscosity steam engine oil)

Piston rings made of Teflon in circumferential pistenring grooves

Manifold gaskets made from Viton O-rings (heat resistant)

Elbow- and t-fittings and flanges silver soldered, tubes soft soldered in

Materials:  brass and stainless steel and commercial available bearings

Six Cylinders 10 mm diam.  X 10 mm strokelength

Due to the six cylinder arrangement the motor is capable of starting rotation at any crank position

 

The boiler

It was my aim to create a powerful lightweight design for firing with butan gas burner and gas from commercial, exchangeable  cylindrical cartridges that fit into the boat (like used for refueling cigarette lighters).

 

Function:

 

The boiler has one central flame-tube cross-spicked through with 6  smaller instant steam tubes that mount into the area of the upper steam collector dome. The hot gas of the flametube then reverses direction in the outer end-camber, that also contains the superheater tube coil and from there 13 heating air tubes lead back through the boiler, into the opposite chamber that takes up the chimney tube (inner liner of the ships funnel)

The waste steam tube is connected to the inner chimney liner in order to burn out the micro-oil-fume of the exhaust steam in the upstreaming hot air together with the firing exhaust. (avoid lakewater pollution !)

The safe running time with one distilled boiler-water filling is 20 minutes

The boiler is capable of providing constantly 2 bar backpressure at ships full speed

The boiler is equipped with a stand, wooden plank cladding, a blow off safety valve, a pressure gauge, a main steam valve, an oiling device, a water level indicator, a draining  point, and a heat exchanger for pre-heating  the expanding butan gas from the gas cartridge

The boiler is mounted to a common aluminium baseplate that also takes up the motor mounting bracket and the burner mounting bracket.

To fire up the boiler, the flame tube is heated with a external (more powerful) gas tourch outside the ship. When reaching 2 bar steam pressure the complete baseplate is set into the ship from above

Materials:

Boiler complete from stainless steel, silver soldered, pressure tested with 4 bar

 

Enjoy......

 

Nils

 

 

 

 

 

 

 

 

[Omega1234]

Nils, once again you marvel me! Beautiful model and the fact that she was RC...even better.

 

Have you been able to fit a new RC unit and get her underway recently?

 

Cheers

 

Patrick

[Mirabell61]

unfortunately no Patrick,

 

the boiler still is unreparable (must be new built), and the motor needs complete overhauling

 

Nils

 

 

 

 

I ripped open the boiler outer skin to see where the leakage is (Unreparable)

 

 

 

here a view into the firing tube, there the smaller cross spicked instant steam tubes can bee seen inside

 

 

 

this is how the motor fits into the engine room

 

 

 

here the boiler with removed wooden cladding insulation

[Mirabell61]

G'day Nils, beautiful work, I have just looked at your models in the gallery, amazing work, you really have a talent for model building,

 

  best regards John.

 

Thank you very much John,

it was so far possible to gather some experience over the years and the hobby is still providing fun.....

 

Nils

[cwboland]

Wow Nils, Very nicely built engine and steam plant. I'm sure many people would aspire to such fine detail at this scale. I know I do

[Mirabell61]

Wow Nils, Very nicely built engine and steam plant. I'm sure many people would aspire to such fine detail at this scale. I know I do

 

 

thank you Carl,

I know Carl, its such a long time ago that this project had its high point, but at the tme of build I could hardly wait to simulate steam flow by compressed air and was totally pleased that it worked as designed and planed, after a few minor cam position adjustments

 

Nils

[jbelwood]

Hi Nils,

 

After looking through this thread it dawned on me that you were one of the

few who commented on my CR Lamb stern wheeler. Now that I know of your

accomplishments, as listed above, I really feel humbled. Thank you.

 

I have thought about building the Bohuslan but doubt if I have the skills or

patience to put years into a build. Understand the current version has it's

own issues.

 

Here's a little number I scratch built, 1/87 scale, a few years ago. An extended

and modified version of SS Sabino in Mystic Seaport (CT).

 

 

 

John Elwood

[Mirabell61]

Hi John,

 

thanks for dropping in

I like your Islander model in 1:87, it Looks like a waterline model for arranging with H0 Train scenery, and very well done.

 

I remember the Billing Boat Bohuslän build and at the time of build I unfortunately could`nt afford to by the Fittings kit as well, so all that was self made and there was some bashing to the kit anyhow, but I had fallen in love with the lines of that old Lady as well as the nostalgic 1914 look,

For what I recognised from the new Bohuslän kit (here on MSW), trust you are right, building from kit would probably  turn out as a real "kit bashing Party"

 

Nils

[Omega1234]

Hi Nils.

 

With your Pegasus coming to an end soon, maybe this would be right time to fix the boiler and overhaul the engine???

 

Hint?

 

Cheers

 

Patrick

[jbelwood]

Nils,

 

Here she is "arranged" with HO gauge scenery.

 

John

[michael mott]

 

With your Pegasus coming to an end soon, maybe this would be right time to fix the boiler and overhaul the engine???

I completely agree with Patrick Nils. It would be great to see what you did in detail as you strip down the engine for the overhaul, Steam engines are a lot of fun. A  steam launch is on my list of things to get done in the next few years. I already have a couple of different boilers half built.

this one would work well.

 

 

 

Michael

 

[Mirabell61]

Oh, thats lovely John,

 ist a place I could spend a Holiday......

beautiful work

 

Nils

[Mirabell61]

I completely agree with Patrick Nils. It would be great to see what you did in detail as you strip down the engine for the overhaul, Steam engines are a lot of fun. A  steam launch is on my list of things to get done in the next few years. I already have a couple of different boilers half built.

this one would work well.

 

IMG_6366x800.jpg

 

IMG_6367x800.jpg

 

Michael

 

 

Michael,

 

great to know you are a steam engine freak as well, looks like there will be much thoughts on details to check and exchange in the future. I am including some pics I made whilst building the (now leaking) boiler

 

Nils

 

 

 

 

 

here outer skin (shell) and inner "gutts" with tubes and chambers

 

 

 

 

during assembly, still without fore- and aft drums

 

 

 

 

final assembly, with wooden cladding. Waterlevel indicater to be exchanged. The tube from the steam dome leads into the superheating coil

 

 

[michael mott]

Wow Nils that is a complex boiler, I am curious about how the tubing is wrapping around inside the main outer tube. I have K.N Harris book Model Boilers ans Boilermaking published in 1972 A Model and Allied Publication your boiler reminds me of a "Cornish" or "Scot"  marine  boiler.

 

John that is a beautiful model and the boat looks fantastic

 

Michael

[Mirabell61]

Michael,

at time of build I did`nt have any boiler-book plans or so, my thoughts were around what would be a goog heat efficiency in compact size to fit in to the boat and not being too heavy. The complexity is necessary for continuously holding 2 bars at discharge at that small size.

 

I just looked up a scots boiler now after reading your comment, and yes yòu`re right, I found a cutaway picture of a "Hurst series 200" scots boiler on the web , which I think may be copywrighted. Therefore no pic here. Difference to my boiler are the missing extra "instant steam tubes" , as you say I wrapped around the other tubes and the super heater device I have installed

 

Nils

[Mirabell61]

Michael,

 I have found this humble boiler design drawing in my old files, it shows the position of the six wrapping  8 x 1mm tubes wich cross (silver soldered) through the large 28 x 1 mm flame tube

 

Nils

 

[michael mott]

Thanks Nils for taking the time to show us your drawing.

 

Michael

[captainbob]

What a beautiful six cylinder steamer, I love it.  Don't know much about internal combustion but just say steam and I'm there.

 

Thanks for showing your work.

 

Bob

[Mirabell61]

Hi Nils.

 

With your Pegasus coming to an end soon, maybe this would be right time to fix the boiler and overhaul the engine???

 

Hint?

 

Cheers

 

Patrick

 

Thats a good idea Patrick,

but the boiler cant be fixed, it must be completely new built and I`m not in the mood for that right now, maybe later on.....

 

If I can get at least the motor overhauled and in rotation again after prior strip down, that would be fine

 

Nils

[Piet]

Great looking tug Nils and fantastic bit of engineering on the boiler and engine.

 

Cheers,

[Omega1234]

Thanks Nils.

 

I understand what you're saying...if only there was enough time in our lives to do everything that we want....

 

Fixing the boiler and getting the 'ole girl" going would be marvellous, but there's always other priorities.

 

Stay well and I look forward to more updates.

 

Cheers

 

Patrick

[Mirabell61]

Thanks Patrick,

 

at time of design and build the boat was taylored around the steam plant, and more a functional platform to experience the Performance of Boiler and engine.

Thats why it was rather concidered a functional model than a detailed scale model.

I am including some Pictures a had taken a couple of days ago of the deckhousings (a bit dusty though), you may notice the amount of necessary openings and hatches required for burner air and Ventilation of the machine room......

 

Build log part 2

 

 

 

"Lorbas" was chartered to a diving company

 

 

 

 

machine room has six moveable skylight openings

 

 

 

open wheelstand rain wind and weather (for old seabears)

 

 

 

foremast can be flapped down for passing river bridges (but watch out for funnel...)

 

 

 

anchor winch (used old toothwheels)

 

 

 

anchor fishing davit only on stb. side

 

 

 

entrance to machine room

 

 

 

at righthand, slide vent hatch for boilerroom

 

 

 

funnel enblem ( my own initials...)

the name "Lorbas" I adopted from the former East-Prussian nomination word for smart, sly little kids, like Huck Finn or Tom Sawer were

 

 

 

 

 

 

 

 

 

 

 

Edited January 25, 2015 by Mirabell61

[Omega1234]

 

Thats why it was rather concidered a functional model than a detailed scale model.

 

Hi Nils.

 

I think in anyone's books, your wonderful tug would be considered more than just a "Functional model".... The level of detail and its complexity, the realism of the fixtures and fittings, plus the quality of the finish and overall workmanship means that it's Truly a scale marvel.

 

Damn good stuff!

 

Cheers

 

Patrick

Edited January 25, 2015 by Omega1234

[Mirabell61]

 

Thats why it was rather concidered a functional model than a detailed scale model.

 

Hi Nils.

 

I think in anyone's books, your wonderful tug would be considered more than just a "Functional model".... The level of detail and its complexity, the realism of the fixtures and fittings, plus the quality of the finish and overall workmanship means that it's Truly a scale marvel.

 

Damn good stuff!

 

Cheers

 

Patrick

 

 

Thank you Patrick,

 

I thought that this model would be worth showing at MSW, before it sits idle around collecting dust, like it was appr. 29 years long

 

Nils

[Mirabell61]

Great looking tug Nils and fantastic bit of engineering on the boiler and engine.

 

Cheers,

 

 

Thanks for your fine comment Piet,

 

I`m happy that you like it....

 

Nils

[captainbob]

Thanks for the pictures.  I'm sure Lorbas gave you many hours of pleasure.

 

Bob

[Mirabell61]

thats right Bob,

 

it was fun, going to the lake, firing up the Boiler, to Launch her, and watch the smoke / steam track from her funnel whilst steaming her rounds and manouvers.

It realy puts me down a bit, that a new Boiler will have to be made, before the revival of this performance can take place.

Think I`ll start with dismantling the V-6 engine for General overhaul when my Pegusus is completed

 

Nils

[captainbob]

 

Think I`ll start with dismantling the V-6 engine for General overhaul when my Pegusus is completed

 

Nils

Would sure like to see the dismantling and all the parts.

 

Bob

[Mirabell61]

Sure Bob,

 

I can Show all the parts, in fact I am curious myself to see how they did, (wear, tolerances, etc, and condition of the Pistons and cylinders and glide bearings)

 

For the crankhousing, cylinderhead, and anchor bolts of a number larger engine housing, here is a sample in advance, (same principle as the smaller engine).

this one was I started for a even more powerful Motor, but its on hold. For weight reasons it is made from Aluminium (six cylinders from 18 x 1,5 mm tube, 15 mm boring and 20 mm strokelength)

 

Nils

 

 

 

 

[chevygrunt]

Hi, What a lovely Tug you have built! The standards have just been raised and I hope I can achieve something half as good as yours(I'm building a little Steam Tug named "Sanson"). Your boiler is quite interesting and a V6 says it all.

Please remember all the joy she has given, and really consider rebuilding the boiler in the future.

Cheer, Scott.