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[DBS88]

About three years ago I was new to radio control, model boats and steam plants. I wanted to introduce my Grandchildren to steam so thought a steam boat would be an interesting way to do that. Thats how I came to purchase my first Steam Tug, it was fitted with a Cheddar boiler and cheddar automatic boiler control (ABC) system, and in my ignorance, assumed that was normal radio controlled steam boats. I joined a club and started to learn more about both model boats and steam plant. What I came to realise was that the system I had was about twenty years old, it was no longer made, and worse, there didn't appear to be any other similar systems available.
As many of you know, my steam journey is leading towards building a twin engined, steam powered, Black Swan Sloop. Well this installation of a steam plant and electronic controls is my first installation and will include all the items I want to be in my new build, so its a practice run and I will share with you the mistakes as well as the success as it comes together. After the beast part of three years research, I am now ready to experiment and learn by actually having a go at this. The opportunity has arisen from two purchases made last year, the first was a hull and the second was a team plant.
Last year I purchased an all metal hull and superstructure of at that time an unknown tug. It was a barn find, covered in dust, dirt and pigeon mess, I bought it because it was all metal, it was large and had the potential to have a steam plant installed in it. I have repaired and waterproofed the hull - the story of which can be read on another thread here on Mayhem, so thank you to everyone that helped get that job done. https://www.modelboatmayhem.co.uk/forum/index.php/topic,67980.0.html
So the job now is to install a steam plant and to install electronic controls for the engine, boiler, gas and water with a target of enabling the Tug to run for approximately one hour.

[rhavrane]

Bonjour David,
Great project for a great boat 
I can't wait to see your progress especially because I have no experience with electronic stuff mixed with steam.

[DBS88]

Hi here is some further information about this project.
The Hull is constructed from small individual steel plates that have been soldered together, its a work of art that has been carried out by a very skilfull model engineer. It measures 54 inches long by 10 inches wide and requires an additional 11kg  of weight to get it down to the waterline.
The baseline for the the electronic controls to be installed is the Cheddar ABC with the aim of achieving this or better. For anyone who has wondered what these systems do I will try to offer an explanation of what it does. It controls the flow of additional water into the boiler and the flow of gas to heat the boiler.
It controls the flow of additional water into the boiler to achieve longer run times. Water is supplied from either an engine driven or an electric pump. There are two loops where the pump can circulate water to. A) it draws water from the on board water tanks or from the lake and pumps the water round in a circle at a high flow and low pressure back to the water tank or lake, so if an engine driven pump is being used it is always pumping. B) the boiler filling loop.

On the boilers sight glass, is a sensor that detects the water level in the boiler, when the water level drops in the boiler the sensor controlled by electronics tells a valve to close the water loop A, which forces water to go round loop B where it then fills the boiler. When the sight glass sensor says the boiler has water, it waits a few seconds, so the boilers water level rises above the level of the sight glass sensor, the electronics then tells the water valve to open so that water then continues to flow round loop A and not into the boiler. It keeps doing this until the water level in the onboard water tanks drop to a low level, the sensor in the on board water tank then sends an alert to the electronics to say the water level is low.


The electronics also monitor the boiler pressure, for example 3 bar 45 psi, if the pressure is lower a servo controlled gas valve(similar to the water valve) is opened to heat the boiler, at 3 bar the valve moves to reduce the flame to a low setting, when the pressure drops the flame is increased until the desired boiler pressure is achieved again. It does this continuously.
 

[DBS88]

Whilst preparing to build my Black Swan Sloop I have been buying bits and pieces so when I was offered a Cheddar Proteus Boiler, Proteus Engine and Cheddar Automatic Boiler Control System I didn't think twice. It had only been test run and had never been installed in boat or anywhere else and it was from a friend at the boat club. Now I have had the set up for some time, my intention was to use the ABC system for my new build, but I have been reluctant to separate it from the the boiler and engine, so have continued to search for automatic boiler controls. The Proteus Engine is a 7/16 inch bore and stroke, twin cylinder, double acting slide valve engine, with a Maudsley Reversing gear mechanism. The engine has a reputation for being very powerful for its size. The photos show the steam plant as I received it, it had been sat around in a workshop for a few years, and then on a shelf in my basement for a while, I had never seen one run, so looked forward to setting it up on the bench to test run. So I decided to test the Proteus Engine and Boiler together with the Automatic Boiler Controls with a view to installing it in the Bustler Tug.

[rhavrane]

Bonjour David,
I confirm, Proteus is quite powerful. Just a detail, I see a water pump on the left side of the machine, don't you plan to use it ?

[DBS88]

Raphael, yes, thank you, the Proteus setup includes an engine driven pump which I will use to supply additional water to the boiler to achieve longer run times. What I have found out out is that its vital with this pump to ensure its never run dry, to make sure that it is always pumping water, to prevent damaging the pump. The pump and controlling the flow of water to the boiler is a fundamental part of the electronic controls.
Electronic controls are not new, Malcolm Beak and Fraser Hislop led the way with this many years ago, publishing drawings so that home engineers could build their own controls. In fact both Malcolm and Fraser have been incredibly helpful and supportive, they are both talented engineers who have taken the time to share their knowledge, which is very much appreciated.
Cheddar introduced an Automatic Boiler Control System which works well most of the time, and there were some other manufacturers that made some partial controls, but as far as I know, no one did it as well as Cheddar. Then with the demise of Cheddar, the  only controls that appear to have been available was an Automatic Gas Control Valve from Stuart's. Having started out by using these controls, they seem to make perfect sense to me, however I fully accept that it is possible to achieve a good level of control over water flow into the boiler and also with controlling the gas usage by using mechanical controls, such as bypass valves and gas attenuators, with your help I installed such as item on the Lady Sarah steam launch, details of which are on this forum.
With that in mind the idea is to share with you the installation a Cheddar Proteus Steam Plant together with automatic controls and to learn from the process.

[KNO3]

Very interesting, David! Please continue and share some pictures of the steam plant and control system installed in the boat.

[KBIO]

Hello David !
Always interesting to read your posts ! 

I have a question though:
- What is the point to have a water controller level if the pump is driven by the engine? As long as the engine runs, the pump supplies H20 whatever the level in the boiler , no ? Maybe that you are planning to install a controlled by pass valve to pump out of the boat when the boiler level is satisfying ? Generally Cheddar controller are controlling and independent pump .
Also, letting running the pump dry will not tramage anything as , in any case the sealing ring is not lubricated and the volume displaced does not cool down this ring. Instead, loosing prime is an issue to get it back with those small volumes.


I do not have enough back up with my plant , but I imagine that the pump displacement is rated to compensate the water that engine consumes.
Thanks for sharing ! Time to hide the Eastern eggs for the grand kids !
Regards.

[DBS88]

Before responding to the questions asked for completeness I would like to add further information to the previous post.
Malcolm Beak wrote at least two articles for Model Boats Magazine in the late 1980's, one was called "In Control" which described how to build a gas control valve and another was called "We Have Control" which described how to build an electronic water level control with a circuit board and all the components needed for you build one at home.
The next thing was to show you the Stuart Gas Control system which comprises of the electronics box, a pressure(temperature) sensor that in the photo is installed in the top of the boiler, a gas valve that has an adjustment for the pilot light and a servo controlled arm that opens the gas valve fully when the pressure in the boiler is lower than the set level, for example 45 psi, and then closes at the set level, 45 psi so the boiler is just running  on the pilot light setting. This is installed in one of my steam boats and operates well.

[DBS88]

To answer the query about the engine driven pump being matched to the engine and delivering enough water in relation to the rpm, what I have found is that the pump is powerful and is capable of delivering more water than the engine is consuming at any rpm. This makes sense if you are using automatic controls for the water level, since the sensor will call for water at a predetermined level, the pump will then deliver the water to the boiler, which it must do at a rate faster than the water is being consumed or else the water level would fail to increase in the boiler, to a level above the sensor.
The Proteus pump is fitted with a bypass valve, so if the pump is set up to run without the automatic controls, the bypass is adjusted through trial and error so that some water continually flows into the boiler, with the excess water being returned to the inboard tanks or overboard into the lake. If the valve is fully closed all the water enters the boiler, if its wide open, no water enters the boiler.
Where the proteus pump is part of an automatic boiler control system, the pumps bypass valve is left wide open on maximum flow. The water either from the lake or the onboard water tanks continues to be pumped at all times, this is because this is a physical displacement pump and cannot slip water like a centrifugal pump does. The water either flows from the lake back to the lake or from the onboard tank back to the onboard tank until the boiler controls tell a servo controlled valve to close, preventing the water circulating in the by pass circuit. With the valve closed the pressure builds up to a level that overcomes the boilers internal pressure, for example 45 psi, then the water enters the boiler until the water level rises above the sensor and the valve is again opened to circulate water once more round the by pass circuit.
Here is photo of the proteus pumps bypass valve, the second photo shows the clack valve that allows water to enter the boiler and also the servo controlled valve that opens and closes to direct the water to the boiler or round a bypass circuit.

[DBS88]

I put the Proteus steam plant on my work bench and prepared it to run. I checked the inside of the fire flue and the burner, as you can see from the photos this boiler had barely been run. I set the gas jet to the correct spacing of 4.5mm in the burner tube  and then turned on the electronics. The unit goes through a series of checks, and operates the servos so I knew it was all working. I slide the sight glass sensor up the sight glass to check that the valve operated in the no water condition which it did, so returned the sensor back to where there was water in the sight glass and the valve operated as it should. So I fired up the boiler, set the pilot light and waited for the pressure to build. On the ABC you are able to set the pressure at which you want the gas to be turned down to the pilot setting, I set this to the minimum, then when the gas valve closed at 15psi increased the setting gradually til 30 psi and then opened the steam valve and throttle to start the engine. The engine burst into life at an alarming number of revs and sounded glorious, I closed the throttle a little and marvelled at how responsive the engine was from just a few revs to really quite high revs in an instant. The engine was then left to run at moderate speed. The pump was pumping water round the bypass and all appeared to be fine. I waited for the water level to drop in the boiler so I could see the servo operate the water valve and for the water to rise in the boiler. However nothing happened, the water level dropped, below the sensor and the valve didn't operate. I moved the sensor up and down on the sight glass and still nothing happened. Disappointed, I turned off the boiler and let it cool down. I checked all the electric connections and with everything cold, turn on the ABC again, I moved the sensor up and down on the sight glass and it worked as it should opening and closing the water valve. Happy days, so I thought. I turned on the boiler for another test run and waited, with the boiler up to pressure I moved the sensor up and down the sight glass, nothing happened. It appeared the sight glass sensor was faulty and would not detect the water level once it got hot.

[derekwarner]

Australia Post is pretty good Dave..........you should receive the paragraph key within a week or so 




Derek

[DBS88]

To avoid confusion, I need to be clear that this project was started sometime ago and these early updates are to catch up with the current position. Sometimes in life you work really hard and nothing seems to happen, then all of a sudden the wall breaks and everything comes together. Well thats what happened next, like buses several things all came at once, the first of which was a chance conversation with a fellow club member who was sailing his very clever submarine for the first time.  As it happens he is skilled in electronics and he offered to have a look at the sight glass sensor, now I have nothing but admiration for those that understand the dark arts of electronics, as far as I can see it works by magic.
Here are some photos of the inside of the sensor.

What I have managed to work out from looking at it is that there is a light source and there is a receiver upon which the light falls. First the light passes through the sight glass, then it passes through a small slot in a metal plate, then the light falls onto the sensor. Now one of two things happens, I am not clever enough to know which one it is. From school we all know that when light passes through water it bends, so when there is water in the sight glass the light passes through the water and then through the metal slot to reach the sensor, when there's no water the light is not bent and fails to reach the sensor, or it might be the other way round. Any way to cut a long story short, a couple of weeks later I had a working sensor.

The next things happened in fairly quick succession, two adverts appeared on an auction site, the first was for a Cheddar ABC and the second was for a brand new set of boiler controls by a new company, then around the same time I was also offered another complete Cheddar Proteus Engine, Boiler and ABC plus a number of other items, all of which I will expand upon in further updates.

[DBS88]

Some of this background info is complicated and maybe unnecessary, but hopefully its helpful. I watched the advert on the auction website for the Cheddar ABC and prepared to bid for it and was fortunate enough to win. The set was not quite complete, the black shield that fits over the light sensor was missing, the shield keeps out the day light, I believe the sensor won't work with out being covered. Anyway I figured it would be easy enough to make something, but at least I now had another ABC and didn't have to split up the Proteus Steam Plant. Photo 1


The next advert was from a new company that had started to make electronic boiler controls, so I went ahead and purchased the Dénes Designs Automatic Boiler Control unit so that I could use the Cheddar ABC just purchased as spares and use the Dénes ABC for the Black Swan Sloop that I would be building as soon as the boiler that I had ordered arrived. The ABC duly arrived and I put it in the box with the other bits that I was collecting for the Black Swan Sloop. Photo 2


Now a thought occurred to me, that perhaps the new Dénes sight glass sensor could be used with the Cheddar ABC and solve any future worries about finding spares, so I had a look at the Dénes ABC sight glass sensor, and found it had four wires, the Cheddar ABC sight glass sensor only has three wires. So I emailed the company and asked if they made or could make a replacement sensor for the Cheddar Unit? The reason for asking was that I have more than one Cheddar ABC and having found that the sensor could fail I wanted to have a spares. A prompt reply was received that yes the sensor could be supplied, that it was different to the original, in that it had more clever electronics on it, it compensated for temperature and it had something called water debouncing on it. Debouncing helps prevent false alarms with the sensor, when no water is detected, the unit waits a period of time, it then checks to see whether or not water is present, if no water is detected it then operates the servo. The false alarms occur when the water moves up and down the sight glass due movement of the boat or from bubbling in the sight glass. These additions to the sight glass sensor were a step forward and so I agreed to purchase the new replacement sensors from Dénes Designs for the Cheddar ABC which arrived promptly. Photo 3.

[DBS88]

The next step was to remove the old sight glass sensor which due to the design of these sensors means that the sight glass has to be undone and slid up so the sensor can be slid off the bottom of the sight glass. The new sensor was then slid onto the sight glass and the sight glass slid back into position and the nuts tightened. Care is needed to ensure that the sight glass is not damaged or the sensor during the installation.


Next the boiler was 2/3rds filled with water, the engine lubricated and the displacement oiler filled. Also a bottle was filled with water to simulate the onboard tank, into which pipes were placed to take water to the pump and for the pump to return water to the bottle. Also the low level water sensor for the onboard water tanks was placed into the bottle. The gas supply and gas valve were connected and the boiler was then lit. Turning on the ABC it goes through a series of checks, and operates the water and gas valves, then the gas gas comes full on until the set pressure is reached.  The link to the video shows the engine running and the sight glass sensor being tested by sliding it up and down the sight glass. https://youtu.be/iLoyLBfm9dg
The last photo shows the issue with bubbles forming in the sight glass, which with the old Cheddar sensor did lead to false alarms, with the addition of the debouncing in the new sensor this issue should be reduced if not eliminated. Cheddar tried to reduce the problem, on the Mk1 Proteus Boiler the sight glass was at the same end as the burner. On the Mk2 the sight glass is positioned at the other end of the boiler, this I believe was to eliminate the heat from the burner that may have caused the water to boil in the sight glass and also minimise the heat transfer to the sensor leading to premature failure of the sensors.

[Dainesh]

Dear David,


Thank you for the nice words about the Denes Design ABC.
I got many feedbacks from him, and I could improve my products by David's help.


If you interested in any of my products please check my website and my videos.


http://www.denesdesign.co.uk


I will create some new videos, please visit the website regularly if you interested in.
I will place the products on the ebay soon.


Denes Design

[KNO3]

Hello David and Denes,
One very useful trick to remove bubbles from a water gauge is to insert a thin wire inside, which helps the bubbles raise and allowes a true water level reading.
Now I wonder if the new Denes sensor or the original Cheddar sensor work if a wire is present inside the glass tube?

[Dainesh]

That is a good question.
If the wire is not thicker than 0.4 or 0.3 mm should work, but without a test I can't tell.

[rhavrane]

Bonjour,
Oups, I use 0,5 - 1mm copper wires in my water levels : https://www.youtube.com/watch?v=RkK82YE44XI&t=2s

[Dainesh]

Ok.
I will check it this evening.
I have to modify one of my "sight" glass tube.
I think I have a 1mm brass wire somewhere.

[DBS88]

A couple of people have asked about the sensor made by a fellow club member. I do not want you to think that the Cheddar sensor was repairable, it was not. To cut a long story short, the Cheddar sensor worked when cold, failed when hot, then worked when cold again. The parts had little in the way of identification marks, so it was not possible to source replacements. He spent a while researching and purchased new parts, a circuit board and various other components. There was difficulty with the metal shield with the slot in it, its positioning is critical, also a problem shielding the sensors from the daylight. Any way he suceeded, but its not a job for the faint hearted, he did say he enjoyed the challenge, in fact I saw him today and he is still talking to me, so I guess its true. Here are a couple of photos of what he achieved and how he tested it. The first shows the original Cheddar sensor alongside the replacement sensor that he made, the second photo shows the sensor being tested.

[rhavrane]

Bonjour,
Impressive ! As usual, passionates realize miracles 

About copper, I think 1 mm is too much, I used it because I had it. One 5 mm wire should be a good compromise...

[rhavrane]

Bonjour,
We also have good electronic steam passionates in France

My friends Francis and Pascal have produced a gas detection printed circuit that works independently and can be positioned in parallel with any manual gas cut-off system already installed elsewhere 

https://www.youtube.com/watch?v=sqO4eUZjJ-o&t=43s

[Dainesh]

Dear Gents,


Yesterday evening I put a piece of 1mm wire into the sight glass.


I know it is a bit thick but this was the maximum thickness which you gave me.


The result: I can't prove that the sight glass sensor it working as it should.
It was working for half a minute after than it had some miss readings, and then working OK again.


I can't recommed to use a 1mm wire together with the Denes Design sikght glass sensor.

The issue: The sensor is using a IR light to detect the water in the sight glass if I put a piece of wire in it that is putting an extra shade on the sensor and reduce the resolution of the sensor.
Simple explanation: The sensor can't get enough light, like when you put your hand above your eyes to protect your eyes from the sunshine.


I know this is not that news what you expected, but I think the water debouncing can reduce this effect drastically. 


Dave and Bunkerbarge[size=78%] [/size]has many many test with my sight glasses and they are pretty happy with the performance (I hope ).

[Dainesh]

This is really interesting, I will check it later :)

Bonjour,
We also have good electronic steam passionates in France

My friends Francis and Pascal have produced a gas detection printed circuit that works independently and can be positioned in parallel with any manual gas cut-off system already installed elsewhere 

https://www.youtube.com/watch?v=sqO4eUZjJ-o&t=43s