Greetings! From a theoretical perspective, firebox is the most heat-intense part of any steam locomotive. Designers always aimed to maximise it's heating surface to increase the steam generation rate and put a good use to all the heat created by fire. How feasible is the decision to go against it and make firebox thermally insulated? (firebox usually generated around 40% of all steam). If thermally insulated firebox preserves heat, what ensures that this preserved heat is transferred to water and is not lost with gases exiting to firebox? Exiting gases have a very high speed and were usually unable to transfer heat completely even with long tubes. Temperatures in smokeboxes of conventional locomotives raised all the way up to 400 degrees Celsium with intense combustion rates. Thirdly, how necessary is combustion chamber? On conventional locomotives it was mostly used to evade using long tubes and flues, not for any efficiency purposes. The final question, will you measure the work of finalized locomotive in relative units, such as: steam consumption per drawbar horsepower; power output relative to firegrate area; steam generation rate plotted against fuel combustion rate etc. just so it could be compared to conventional locomotives? Sources I'm using are: - Ralph Johnson. "The steam locomotive,: Its theory, operation and economics, including comparisons with Diesel-electric locomotives" - 1938 American Locomotive Cyclopedia - Soviet 1928, 1929 and 1936 manuals for steam locomotive design including manuals for boiler heat balance calculations - Soviet 1935 and 1956 handbooks with steam locomotive performance diagrams
Hello! Excellent question, this is a very important subject and deserves a much more detailed explanation that I can give it here. Briefly, for a conventional boiler, radiant heat transfer in the firebox is a function of firing temperature. As firing temperature reaches a maximum quite early on, the firebox generates a roughly constant quantity of steam independent of evaporation rate. This means that as evaporation rate increases, the tube bank is responsible for generating a progressively greater fraction of the boiler's steam output via convective heat transfer. This causes superheat to increase with increasing evaporation rate, reducing loco efficiency at part loads due to less than optimal steam temperatures. The convective heat transfer/absorption efficiency in the tube bank is independent of the combustion gas mass flow rate, the faster the gas flows, the more heat is transferred. The reason that smokebox gas temperature increases (to 400 deg.C) with intense combustion rates is not due to the limitations of the tube bank, rather it is due to the firebox's limited capacity to absorb the combustion heat output resulting in an increasing combustion gas temperature at the tube plate. The tube bank continues to absorb the same fraction of heat per unit of combustion gas that flows through it, but the inlet temp. is higher so it follows that the outlet temp. at the smokebox must also be higher. The new boiler employs convective heat transfer only, for equilibrium steaming, the inlet temperature at the heat exchanger is largely fixed at all evaporation rates, this means that the superheat remains constant and combustion efficiency is always at a maximum. The absorption efficiency of the boiler is also nearly constant. In simple terms, the combustion chamber in this boiler prevents the flames from being quenched by impingement on the relatively cold surfaces of the heat exchanger, which would result in incomplete combustion. A big yes to your final question, absolutely essential. I'd love to get my hands on some of the sources you reference!
@@Mackwell-Co Thank you for your response! I will adress sources first. Most of them are Russian language manuals of Soviet Union that were used for locomotive design. They are: - 1928 brief manual - 1929 brief manual - 1935 "Steam locomotive series FD" which is one of the greatest books I have, explaining the calculation of actual locomotive which was mass-produced, including comparison of theoretical performance with actual test data. - 1936 extensive manual with a hevay emphasis on boiler heat balance calculations - 1952 extensive manual with even heavier emphasis on thermodynamics. As for English-language sources, those are American Locomotive Cyclopedias of 1938 and 1916 and R. Johnson's "Steam locomotive" which has data on American locomotive pefrormance tests. [in fact, only 1916 Cyclopedia is actually in English, other two are in Russian translation]. I'd like to comment some of your sentences from the point of knowledge I posses. > "As firing temperature reaches a maximum quite early on, the firebox generates a relatively constant quantity of steam independent of evaporation rate." I would like to respectfully disagree here. Conventional firebox transfers heat in two ways - via convection (through it's heating surface) and radiation. While radiative heat transfer is indeed a function of combustion temperature which is barely dependent on combustion rate, there is also a convection process with the following formula: Q = K×H×(t-tₒ), where: Q is the amount of heat transferred K is heat transfer coefficient H is heating surface of firebox t and tₒ are temperatures of heating and heated body. Now, K here is a function of mass flow and is proportional to it and is a function of combustion intensity, excess air coefficient firebox parameters. So, while radiant heat transfer remains mostly constant, convection heat transfer grows with combustion intensity and therefore firebox generates progressively larger amount of steam. If you manage to get your hands on Ralph Johnson's (amazing) book, there's 1912 test data on unique tests performed in Coatsville, Pennsylvania, where evaporation rate was determined independently for firebox and tubes/flues. The table given under paragraph VII "Steam generation" shows firebox generating different amounts of steam depending on combustion rates and it keeps up in proportion with overall steam generation rate. So amount of steam generated in conventional firebox is definitely not constant and is a function of amount of fuel combusted with evaporation rates from firebox surface reaching more than 200 kilograms of steam per meter squared per hour. This is why I asked about your locomotive completely (as far as I understood) eliminating firebox heating surface per se and the feasibility of such decision. >"This means that as evaporation rate increases, the tube bank is responsible for generating a progressively greater fraction of the boiler's steam output via convective heat transfer. This causes superheat to increase with increasing evaporation rate, reducing loco efficiency at part loads due to less than optimal steam temperatures." I can agree here, though firebox still generates a sufficient amount of steam. Again, referring to tests in Coatsville, when boiler in total was generating 20000 kg of steam per hour, firebox was generating around 6000 kg. Heating surface of firebox was 12 times smaller than that of tubes (22.8 m² against 279 m²) meaning that firebox evaporated 263 kg of steam per m² per hour while tubes - only 50 kg. >"The convective heat transfer/absorption efficiency in the tube bank is independent of the combustion gas mass flow rate, the faster the gas flows, the more heat is transferred." The heat transfer in tubes is found via a cumbersome logarithmic equation which I find a bit complicated to post here... The left part of the equation has temperatures in it which have to be equal to the right part of the equation, which is K×H (coeffient of heat transfer and heating surface of tubes). The thing here is, K is actually a function of two values, one of them being tube diameter and other - gas flow rate. Amount of heat transferred then is: Q = K×H×t Where t is the average gas temperature in tubes. While the text above does not disagree with the point of heat transfer efficiency being independent of mass flow rate, this raises another important question for me. K is not directly proportional to mass flow rate; in fact, different formulas show K being proportional to mass flow rate to the powers of 0.5...0.8. That means that gain from raising mass flow rate is progressively smaller; so while the more heat is transferred with larger rate, what is the ratio of transferred heat to the total heat available in gases? I think this is a very important thing to consider. >"The reason that smokebox gas temperature increases (to 400 deg.C) with intense combustion rates is not due to the limitations of the tube bank, rather it is due to the firebox's limited capacity to absorb the combustion heat output resulting in an increasing combustion gas temperature at the tube plate. The tube bank continues to absorb the same fraction of heat per unit of combustion gas that flows through it, but the inlet temp. is higher so it follows that the outlet temp. at the smokebox must also be higher." In your locomotive, where all the firebox heat is preserved, does that mean that outlet temperature will be higher than that of conventional locomotives? This was the largest concern to me when I was listening to boiler design. The way I imagine it, there will be more heat with heating surfaces (which allow this heat to be transferred to water) being smaller (with elimination of heat-intense firebox surface), which will limit the possibility of heat to be transferred leading to a lot of heat remaining untransferred. Anyways, I would like for you to clarify this moment to me. As for final sentences, it is honestly a bit complicated to me to imagine how all this works without some sort of internal elements diagram of the boiler. Though what you say sounds interesting and may actually neglect something of aforementioned concerns.
Thanks for this detailed replied. As mentioned, in no way did I intend to address this subject exhaustively here. My comments were greatly simplified and very approximate, intended to convey a basic theme. Briefly and slightly less approximately: You are correct regarding firebox heat transfer. The Hudson-Orrok firebox heat transfer equation as modified by Porta is useful for quantifying this, given as: n = 1/(1+((A ÷ 0.46) x (Q ÷ (10^6 x H))^0.5)) Where: n = Fraction of firebox heat release rate absorbed by the firebox heat transfer surfaces. A = Combustion excess air coefficient. Q = Total heat release rate in the firebox in kcal/h H = Inner firebox heat transfer surface in m^2 (including refractory arch factor) Taking the data for the oil fired 5AT as an example, using this equation it can be approximately shown that at rated evaporation, n = 0.27, and at 10% evaporation, n = 0.54 Therefore a 10 fold increase in heat release rate in the firebox results in a 5 fold increase in firebox heat absorption. Again you are correct about the convective heat transfer coefficient in the tube bank not being in proportion to the combustion gas mass velocity. Your figures showing it to be proportional to the power of 0.5 to 0.8 agrees with the figures I have here (on the face of it approx. similar to the heat absorption relationship in the firebox). However, as the heat transfer coefficient falls, the log mean temperature difference between the combustion gas and the tube surfaces rises due to the outlet temperature of the tube bank increasing. This attenuates the effect of the falling heat transfer coefficient, which also varies in relation to temperature and rises with temperature, offering further attenuation. Taking the worst case scenario here where the heat transfer coefficient falls in proportion to the square root of the mass velocity. If the mass velocity increases 5 fold, the heat transfer coefficient will increase only 2.24 fold. Then, to transfer the same quantity of heat, the log mean temperature difference must be 2.23 times higher. At a tube bank inlet temperature of 900 deg.C and a saturated steam temperature of 186 deg.C with an absorption efficiency initially 98%, the fall in absorption efficiency to maintain the heat transfer rate is only 25% as against a 55% fall in the heat transfer coefficient, and this is the worst case. There are a number of factors not considered here, but the result is that in practical terms, tube bank absorption efficiency may be considered approximately independent of mass velocity. The new boiler has a carefully designed heat exchanger to compensate for the loss of firebox heating surface, which includes both a large heating surface within a compact unit and a high free gas area to ensure acceptable draughting power. The smokebox gas temperature is expected to reach not more than 300 deg.C without a smokebox economiser. R. Johnson's book sounds particularly interesting, especially the test data you mention. I will keep a look out for a copy.
Water cooled combustion chambers on small boilers are pretty much a no-no now adays. It quenches the partially burned gases and results in very high ubburned hydrocarbons and carbon monoxide. These crappy wood fired outdoors hot water boilers you see in the USA all have chilled combustion chambers and produce huge amounts of smoke for this reason. They have given wood boilers a horrible name and have even resulted in bans. The gassification hydronic boilers use ceramic lined fireboxes and often preheated combustion air and burn very clean.
There better not be anything in this documentary about my wife!! She’s a 21st century boiler, to say the very least of it, and I don’t need any more people knowing even more about her ways and our private life than they already do. It’s a miracle she’s not in the national news spread about that visit to La Chambre. Caught a right dose.
Something I just found out about is that conventional steam locomotive boilers have to be warmed up slowly. If a roaring fire is started in a cold boiler, it could cause serious damage as the pieces of the boiler expand at different points as it is heated. I think your idea is amazing just by simplifying everything essentially down to a single tube. I can also imagine that replacing any internal piping would be 100 times easier than taking the engine out of commission for who knows how long to put new fire tubes in, stays, clean out for scale buildup, repairing and inspecting for leaks in the fiber box or the barrel, etc. I'm excited to see what you have next!
Yes i think too that building a water tube boiler with common moderns methodes of welding is far easier and faster, and so cheaper than making a traditionnal fire tube loco style boiler with great thickness of steel and many stays, weight, time to raise steam, exploding issues ... etc What a hard and heavy cost work to building a riveted boiler in the 19 th / early 20 century ! Water tubes boiler is the way for the future for many good reasons !
Water tube boiler have worked successfully look up a company called sentinel there was a 0-6-0+0-6-0 loco built by them that had a water tube boiler and that was able to move loads of 1000+ tons. Their railcars also did use water tube boilers in some cases.
Quite true, Sentinel developed some innovative designs. Their staple boilers were an interesting mix of vertical fire tube with horizontal water tubes. Do you have any links to info on their 0-6-0+0-6-0?
@@Mackwell-Co there isn’t much about it on the Internet there is a photo of it here www.national-preservation.com/threads/what-ifs-and-locos-that-never-were.444966/page-10 but the quoted tractive effort is not right as the loco was never pushed to the point it couldn’t pull a train and it was closer to 100t rather than the 90t. It had 4 2cylinder engines producing 400 hp in total with poppet valves and cam valve gear rotating at half engine speed it also had low and high gear but it was so powerful that low gear was rarely used. Sadly there are no designs for the boiler it had although it was very similar to the ones in the rail cars sent to Egypt also made by sentinel but with a psi of 335 it was also fitted with feed water heaters. As this loco was a one off not much is known about it there isn’t a date given for its build date but the it’s works number of 9603 would but it around 1957. The chassis were considered for parts converting to two diesel locos but that didn’t end up happening and it was scrapped at Dorman Long where it worked in 1966. I got most of this information from a book available from the industrial railway society about the sentinel locos and railcars
A question popped into my head while watching this: Do you reckon this boiler design could be adapted to new-build steam projects, in essence taking an existing but extinct design (i.e. we have the blueprints/shop drawings for this class, but none survived into preservation) and swapping out the original fire tube boiler for one of your design? Thus getting a locomotive that aesthetically and functionally resembles a grand old Victorian lady (for example, just for visualization, the Great Central Railway's Class 2 No. 567, or the SECR E Class planned by the Brighton Atlantic Group once the current H2 Atlantic is finished), but steams up in just an hour as opposed to 3-6 hours for a normal steam engine, and operates more efficiently and cleanly than the original? I suppose a related question (most likely already answered, so apologies if I haven't seen it): You show this boiler being test fired with wood, but how would it behave when fired with coal?
Yes definitely, it is designed so that it can be built to match exactly the external dimensions of an original boiler, but with improved performance i.e. zero spark emissions, quick steaming etc. Coal isn't consistent with the environmental focus of the project and would require a more complex grate to manage the higher ash content. However, if cord wood wasn't an option then biocoal such as that being developed by CSRail in conjunction with the NRRI in the United States will work well, as will wood pellets or compressed briquettes (the latter two were tested in EP2). Straight vegetable oil is an option too.
You need to watch a video titled "Dan Gelbart's uniflow steam engine". It's a model engine of his own design. It is a uniflow engine, which was the most efficient reciprocating steam engine as of the 1940s when research on steam engines mostly stopped. It uses an Invar piston to avoid differential thermal expansion and seizing(more common in uniflow engines), it uses a Vespel (15 percent graphite impregnated polyamide (nylon)) cylinder liner for low friction and operation without steam side lubrication. He has made provision for a Teflon or Vespel piston ring. Vespel probably retains its mechanical strength to higher temperatures. The polymer cylinder liner also serves to prevent heat loss and condensation. It uses a bash valve admission, computer controlled, electromagnetically actuated admission valve closure, and an innovative exhaust valve in the piston that prevents the need for auxiliary exhaust valves that unuflow engines need if they lose condenser vacuum. He reports 10% thermal efficiency, which for a model size engine is God damn incredible. I would really love to see some of these principles implemented in this engine, particularly the Vespel cylinder liner. My vision of a reasonably efficient steam engine would be a water tube boiler with superheater, economizer, air heater, and exhaust heater, coupled to a high speed, internally located, fully enclosed, geared, and force-lubricated uniflow steam engine and possibly a condenser. It wouldn't look much like a stereotypical steam engine, because of the lack of a water tube boiler, but more like a LNER J70. To be perfectly honest, reciprocating steam engines do have a place, but transportation really isn't one of them. Places where waste fuels and steam are available, namely sewage treatment plants, waste incinerators, chemical plants, oil refineries (have a large steam supply), and perhaps for auxiliaries of full size power plants. Below 1,000 horsepower, the reciprocating steam engine is clearly the superior in efficiency. Between 1,000 and 5,000 it's a toss up, and above 5,000, the turbine is the clear winner. The requirement for clean, oil-free exhaust steam/condensate has probably been a big limiting factor, which is why I think Vespel cylinder liners, vespel/Teflon piston rings, and Vespel/Teflon rope packings and no internal lubrication could help make reciprocating steam more competitive in smaller sizes. The idea of building a more modern, up to date steam engine has fascinated me for a long time, and it's really great someone is trying to put it into practice. I subscribed.
Was going to ask about the boiler design. Could you show the drawings of the water tubes? Also where does the water circulation pump pump from? I’m probably one of the few fans wanting even more detail!
One day! There are inlet/outlet connections that pass through the underside of the smokebox wrapper just behind the door plate (and ahead of the saddle when fitted to the loco chassis). But otherwise the connections are located wherever suitable. Thanks for your interest!
Regarding piston a rod fiction attachment. Is it possible to machine rod with a shallow spool shape say 5mm rims with diameter of 25mm and the centre 14mm with a diameter of say 24.9mm and the piston the opposite. You would probably need to freeze the rod and make the piston quite hot to fit. If thought needed you could pein the rod with centre punch on either side. No idea how practical this is!
Hello - very interesting project you have! With an insulated firebox, could you make use of a Stirling engine to circulate water for initial steam generation, and then run a steam-driven pump for normal operations?
You could probably increase the strength of the friction fit piston head by placing a clip ring retainer on the lower side. Also, a 1928-1932 Bryan (Bryant) steam tractor would prob ably be light enough to do the seeder work. And their 600 psi water tube boiler design is still being built for other purposes
Very interesting project, can't wait to hear more detail on boiler internals and water and steam temp./pressure control. Lamont style boilers usually feature a steam separating drum that also takes care of easy water level control and water make up. Super heat temp. has to be carefully monitored esp. because the firebox temp cannot be controlled within seconds. Maybe you are employing some sort of super heater water injection?
I always felt steam power could still be in use today if research and experimentation had continued since the switch to Diesel electric. Power plants still use steam turbines to turn the generators. The same is possible for a steam electric train. Keep up the good work.
My brother from another mother except my idea and planning is for a 15 inch gauge farm railroad I have been saving up for kozo hiraoka's books on the Pennsylvania A3 and Shay locomotive I'm also getting a creality CR10 3D printer for master casting molds I might actually want to keep in touch with you this is right up my alley
Very interesting boiler design, I’ve actually proposed similar with fire tube boilers for a water circulator similar in design to a single row superheater fed from below. Though I have to ask: is this boiler cheaper and easier to build than an actual fire tube boiler? The only reason I ask is because the 5AT project was turned down because it was more expensive to build overall than the new build P2
Good on ya mate, I take it you are a fitter turner or similar. Have you ever come across a Dave Collins from up in Keri Keri he had a sawmill running on Steam a few years back. Keep up the good work, steams very interesting aye.
Maybe the circulating pump could be just a lenght of pipe through the hottest combustion gasses with a couple of clack-valves, functioning along the lines of a coffee-maker or a pop-pop boat.
Great work. Love it!!! I think that wasted heat you mention at the beginning is call 'Sensible Heat'!... How much will valve chest and cylinder temperatures affect how tightly the piston grips the piston rod?
Thanks! Yes as the pump's piston - rod assembly heats up, the slightly higher coefficient of expansion for the 1045 piston compared with the 420 stainless steel rod means a slight loss of grip so I have made a small allowance in the fit tolerance. The strength of steel (generally) tends to increase up to about 200 deg.C which is perfect for a saturated steam temp of 218 deg.C.
Fascinating project! Have you any plans for the boiler to be closed loop? Given the greenhouse effect of water vapour and the limited global supply of fresh water?
When you described piston and rod connection method. Does not look like those numbers are take into the working temperatures (the rod and piston are made from different metal and might expand a little bit differently (and the numbers would be less good). Doesn't this introduce an additional stress to piston that would lead to deterioration (metal fatigue)?
Yes you're right. 420 Stainless steel and 1045 carbon steel have very similar expansion coefficients, but they are different, the 420 SS having a slightly lower coefficient. For simplicity I didn't include the check on this in the video but at working temperature the slight reduction in grip is within limits, the loss of interference is 0.008 mm. Because the stresses in the piston and rod due to the shrink fit are constant and only cycle a small amount with temperature, this will not introduce fatigue.
Something else poked into my mind over the week - how are the water gauge and manifold going to be hooked up, seeing as the boiler doesn't extend into the cab? Are they just going to be piped outside the casing and insulated?
In a low water volume, highly dynamic water tube boiler like this one (probably) is, a water gauge is not as dependable as you might think. Waterlevels can vary very quickly and drastically under changing load conditions and would be impossible to manage manually. Pressure and waterlevel are rather temperature controlled to keep steam properties as uniform as possible. Since Sam is already monitoring various temperatures electronically, it will be likely that he will also measure waterlevels in this way. In the usual Lamont boiler, waterlevels can be easily measured, in some cases by means of a couple of ordinary spark plugs!
Basically yes (have a look at the manifold steam supply on SAR 25 class locos). The boiler doesn't need conventional gauge glasses which makes it a bit simpler!
Greetings actually they didnt use water around firebox to make more heat they did it to prevent fire from melting firebox and exploding the boiler. ps I really like the idea I'll take your entire stock jk but srsly nice loco I'll consider it at some point maybe a few years from now .
Wow you're a lucky man you're doing something I always wanted to do and never got a chance to I always wanted steam locomotives to come back into the world. To I have to admit your design is a lot more simplified than mine I had an idea for a hydrogen-fueled hybrid steam locomotive that had a hexagon steel lattice insert into basically a modified fire tube boiler so it would link the inside structure friction stir welding to the outside structure of the boiler shell making it an extremely strong design using thermoelectric effects diesel electric locomotive trucks on the tender for dynamic braking also battery packs on the tender and condensers cuz when you burn hydrogen it combines with oxygen to burn and turns into water vapor you could convince that then the exhaust from the engine you could condense the exhaust from the engine it was literally not even going to need a fireman that was going to be computer-controlled with a backup battery and a backup computer for redundancy it would have been one hell of a machine my boiler is a trip along the hexagon plate perforated so the water can percolate into steam and the fire tubes go through the center of the hexagons my major problem was the Firebox I could never figure out a better fire box design I know that water tube boiler is never quite worked for locomotives they failed one way or another that's why I tried to redesign the fire tube boiler and I know you're probably thinking where where do I get the hydrogen that's a whole nother invention I have that I'm not really going to talk about here very interesting design good luck in your endeavors
there is one problem I can think of with not having water near the firebox. when the locomotive is in heavy operation, it creates a very strong draft which could melt the firebox from the heat generated .
Really dumb question but does the firebox have a square hole inside the door mounting or is it rounded to help with stress underneath the square insert?
mackwelloco.com/locomotives/ 2-6-0 tender locomotive. It is designed for passenger service - 150 tonnes (trailing) on a 1 in 50 gradient. It will do just fine for freight too, just small. There is a spec sheet available at the link above.
i was expecting a completely different kind of fuel, but with modern materials, even dirty fuels can be used way more effectively. i wonder what a completely carbon fibre or other new material manufactured FB and Boiler, could do
Will this type of boiler be able to handle the sudenchanges in power output that are a characteristic of a railway locomotive? (Marine boilers tend to run at a constant rate for long periods of time.) Also, I would have thought that the smaller boiler water volume would have made it less likely to be able to deal with suden changes in output. Don't get me wrong, I'm interested and not being critical... But it's so very different from the tried and tested Stevenson boiler which was able to cope with sudden changes in output precisely because it had a large water volume.
Yes it does, particularly well, if not better than a fire tube boiler. We have testing this feature extensively and because the boiler is basically supplying steam to an open pipe pointing up the funnel, the sudden steam draw is more severe than a loco slipping uncontrollably. Even the conventional Stephenson type loco boiler's ability to cope with sudden increases in load has almost nothing to do with the large volume of water it contains, what counts is that the fire must instantly supply more heat to match the load - which it typically does very well. Upon decreasing load, the absence of radiant heat transfer in the new boiler means that a hot fire bed doesn't keep generating steam uncontrollably i.e. when draught stops, so does steam production.
@@Nick-xm1ux that's why I'm thinking this one doesn't have a sight glass since it has no crown sheet, it's water tube not fire tube, more than that it's forced circulation so the water is constantly pumped around , so I would guess it's like a doble steam car boiler in that it's almost always all the way full
@@Mackwell-Co Indeed! I was reading the link you added in the description about the H45 and I read that one of it's problems was that it was impossible to raise steam unless you already had steam available kinda like charging a fireless, will your locomotive be like this or will you be able to raise steam more conventionally?
The boiler will raise steam conventionally (but much faster), as we did in this video. The link included some other types of German high pressure locos and I think the problem you mention above refers to H02, which was fitted with a Loeffler boiler.
@@Mackwell-Co Well that definitely gives it a better edge, have you ever considered an oil fired version? Using biodiesel and recycled oil from plastics or even (I know it's probably not legal where you're located) hemp seed oil could be a good renewable fuel for a boiler.
@@boxcarthehusky420 Yes, the primary focus is on using solid wood fuel as it is not sufficiently viable to produce liquid biofuels. But, if there was a waste stream available such as used cooking oil, the boiler will work just fine with any type of liquid biofuel. I expect it to be less sensitive to burner design with the dry firebox. No doubt hemp seed oil would burn well and if it was otherwise going to waste then why not! Under certain circumstances, locos may be set up for both solid and liquid biofuel firing with no alterations required - true multi-fuel capability!
Do you know also one of the reasons why water tube boilers were a failure on steam locomotives is that locomotives go through a lot of rough riding on the track specially at high speed you get lots of vibration and harmonics vibrations over time those water tubes will vibrate and start to metal fatigue over time and then the tubes would rupture and send that pressure back into the firebox if you have a tube rupture how are you going to prevent the fire blowing out the firebox door metal fatigue is a real issue with water to boilers I have an invention for you to solve that problem if you're interested peace out into the world have a great day
Is this a water tube boiler or a hybrid boiler also do u have pictures of what the boiler looks like inside , like building progress pictures like drawings , blueprints., is this what the boiler is www.hurstboiler.com/boiler-images/hybrid_boilers
It is a pure watertube. Not like those in your link. A number of factors limit how much I can reveal about the internal design at present, but all will be revealed in due course!
Yes, injectors are very efficient on their own, but they limit the quantity of energy that can be recovered from the exhaust steam and so reduce the efficiency and power of the loco. The (eventual) boiler pressure of 310 psig is nearing the limit for injectors too.
Did you consider other alternative fuels? Although wood is sustainable, it does produce Carbon Dioxide. I have always theorised using Hydrogen Gas for High Heat output and Zero Carbon Footprint. All the same, a great project. Do you plan to manufacture more than the boiler?
The carbon dioxide released by wood fuel doesn't add carbon to the carbon cycle, just as you and I consume food and breath carbon dioxide out - so no contribution is made to climate change. Long ago I explored hydrogen in depth, but my understanding is the bulk of hydrogen produced today is done so by steam reforming natural gas, thereby adding carbon to the carbon cycle! The alternative, electrolysis generated hydrogen, is taking high value electrical energy (generated somehow) and converting it into low value heat energy unless the hydrogen is employed in a fuel cell - which then makes for a relatively inefficient (but higher capacity) battery. Thank you for raising this point as it is a good question! Yes the whole locomotive is to be built i.e. chassis, tender etc. A boiler on a static test frame is great for scientific type tests but not much of a demonstration.
To make transport sustainable using the power of steam! Building a head of steam faster makes steam more practical to use, but this is just one of many advancements.
We don't know much about the boiler set up yet, but what we know indicates some sort of mono tube type of setup, that has no problem at all with fast steaming up. If the circulating pump was electrically driven, instead of steam powered, this system could be operational well within half an hour!
Then you have the large articulated locomotives. Locomotives like UP's 4000 class took over a day from a cold boiler (more to avoid stress due to thermal expansion).
I'm using an advanced combustion system to eliminate spark emissions instead of a spark arrestor, the latter is liable to block and will not always arrest 100% of the sparks.
Diesel engines are impressive, turn the key and off you go in less than a minute. When it comes to transitioning from fossil fuel to sunlight, what options do we have?
Check out the EROI of nuclear and its cost trends. A nuclear future seems unlikely. Advanced steam locomotion is simply the most efficient way to turn sunlight into traction.
@@Mackwell-Co what about a steam electric turbine? Steam to generate electricity, electricity could be stored in a battery for when there is no water and to preheat water for quicker start ups?
this kind of work needs to be done by adults not children, messing not with what they don't understand, listening to dreadful annoying irritating repetitive thumping pounding brainless dumbed down noise, unwatchable and unlistenable. try again in 20 years time
Greetings!
From a theoretical perspective, firebox is the most heat-intense part of any steam locomotive. Designers always aimed to maximise it's heating surface to increase the steam generation rate and put a good use to all the heat created by fire. How feasible is the decision to go against it and make firebox thermally insulated? (firebox usually generated around 40% of all steam).
If thermally insulated firebox preserves heat, what ensures that this preserved heat is transferred to water and is not lost with gases exiting to firebox? Exiting gases have a very high speed and were usually unable to transfer heat completely even with long tubes. Temperatures in smokeboxes of conventional locomotives raised all the way up to 400 degrees Celsium with intense combustion rates.
Thirdly, how necessary is combustion chamber? On conventional locomotives it was mostly used to evade using long tubes and flues, not for any efficiency purposes.
The final question, will you measure the work of finalized locomotive in relative units, such as: steam consumption per drawbar horsepower; power output relative to firegrate area; steam generation rate plotted against fuel combustion rate etc. just so it could be compared to conventional locomotives?
Sources I'm using are:
- Ralph Johnson. "The steam locomotive,: Its theory, operation and economics, including comparisons with Diesel-electric locomotives"
- 1938 American Locomotive Cyclopedia
- Soviet 1928, 1929 and 1936 manuals for steam locomotive design including manuals for boiler heat balance calculations
- Soviet 1935 and 1956 handbooks with steam locomotive performance diagrams
Hello! Excellent question, this is a very important subject and deserves a much more detailed explanation that I can give it here. Briefly, for a conventional boiler, radiant heat transfer in the firebox is a function of firing temperature. As firing temperature reaches a maximum quite early on, the firebox generates a roughly constant quantity of steam independent of evaporation rate. This means that as evaporation rate increases, the tube bank is responsible for generating a progressively greater fraction of the boiler's steam output via convective heat transfer. This causes superheat to increase with increasing evaporation rate, reducing loco efficiency at part loads due to less than optimal steam temperatures. The convective heat transfer/absorption efficiency in the tube bank is independent of the combustion gas mass flow rate, the faster the gas flows, the more heat is transferred. The reason that smokebox gas temperature increases (to 400 deg.C) with intense combustion rates is not due to the limitations of the tube bank, rather it is due to the firebox's limited capacity to absorb the combustion heat output resulting in an increasing combustion gas temperature at the tube plate. The tube bank continues to absorb the same fraction of heat per unit of combustion gas that flows through it, but the inlet temp. is higher so it follows that the outlet temp. at the smokebox must also be higher.
The new boiler employs convective heat transfer only, for equilibrium steaming, the inlet temperature at the heat exchanger is largely fixed at all evaporation rates, this means that the superheat remains constant and combustion efficiency is always at a maximum. The absorption efficiency of the boiler is also nearly constant.
In simple terms, the combustion chamber in this boiler prevents the flames from being quenched by impingement on the relatively cold surfaces of the heat exchanger, which would result in incomplete combustion.
A big yes to your final question, absolutely essential.
I'd love to get my hands on some of the sources you reference!
@@Mackwell-Co Thank you for your response!
I will adress sources first. Most of them are Russian language manuals of Soviet Union that were used for locomotive design. They are:
- 1928 brief manual
- 1929 brief manual
- 1935 "Steam locomotive series FD" which is one of the greatest books I have, explaining the calculation of actual locomotive which was mass-produced, including comparison of theoretical performance with actual test data.
- 1936 extensive manual with a hevay emphasis on boiler heat balance calculations
- 1952 extensive manual with even heavier emphasis on thermodynamics.
As for English-language sources, those are American Locomotive Cyclopedias of 1938 and 1916 and R. Johnson's "Steam locomotive" which has data on American locomotive pefrormance tests. [in fact, only 1916 Cyclopedia is actually in English, other two are in Russian translation].
I'd like to comment some of your sentences from the point of knowledge I posses.
> "As firing temperature reaches a maximum quite early on, the firebox generates a relatively constant quantity of steam independent of evaporation rate."
I would like to respectfully disagree here. Conventional firebox transfers heat in two ways - via convection (through it's heating surface) and radiation. While radiative heat transfer is indeed a function of combustion temperature which is barely dependent on combustion rate, there is also a convection process with the following formula:
Q = K×H×(t-tₒ), where:
Q is the amount of heat transferred
K is heat transfer coefficient
H is heating surface of firebox
t and tₒ are temperatures of heating and heated body.
Now, K here is a function of mass flow and is proportional to it and is a function of combustion intensity, excess air coefficient firebox parameters.
So, while radiant heat transfer remains mostly constant, convection heat transfer grows with combustion intensity and therefore firebox generates progressively larger amount of steam. If you manage to get your hands on Ralph Johnson's (amazing) book, there's 1912 test data on unique tests performed in Coatsville, Pennsylvania, where evaporation rate was determined independently for firebox and tubes/flues. The table given under paragraph VII "Steam generation" shows firebox generating different amounts of steam depending on combustion rates and it keeps up in proportion with overall steam generation rate. So amount of steam generated in conventional firebox is definitely not constant and is a function of amount of fuel combusted with evaporation rates from firebox surface reaching more than 200 kilograms of steam per meter squared per hour.
This is why I asked about your locomotive completely (as far as I understood) eliminating firebox heating surface per se and the feasibility of such decision.
>"This means that as evaporation rate increases, the tube bank is responsible for generating a progressively greater fraction of the boiler's steam output via convective heat transfer. This causes superheat to increase with increasing evaporation rate, reducing loco efficiency at part loads due to less than optimal steam temperatures."
I can agree here, though firebox still generates a sufficient amount of steam. Again, referring to tests in Coatsville, when boiler in total was generating 20000 kg of steam per hour, firebox was generating around 6000 kg. Heating surface of firebox was 12 times smaller than that of tubes (22.8 m² against 279 m²) meaning that firebox evaporated 263 kg of steam per m² per hour while tubes - only 50 kg.
>"The convective heat transfer/absorption efficiency in the tube bank is independent of the combustion gas mass flow rate, the faster the gas flows, the more heat is transferred."
The heat transfer in tubes is found via a cumbersome logarithmic equation which I find a bit complicated to post here... The left part of the equation has temperatures in it which have to be equal to the right part of the equation, which is K×H (coeffient of heat transfer and heating surface of tubes).
The thing here is, K is actually a function of two values, one of them being tube diameter and other - gas flow rate. Amount of heat transferred then is:
Q = K×H×t
Where t is the average gas temperature in tubes. While the text above does not disagree with the point of heat transfer efficiency being independent of mass flow rate, this raises another important question for me. K is not directly proportional to mass flow rate; in fact, different formulas show K being proportional to mass flow rate to the powers of 0.5...0.8. That means that gain from raising mass flow rate is progressively smaller; so while the more heat is transferred with larger rate, what is the ratio of transferred heat to the total heat available in gases? I think this is a very important thing to consider.
>"The reason that smokebox gas temperature increases (to 400 deg.C) with intense combustion rates is not due to the limitations of the tube bank, rather it is due to the firebox's limited capacity to absorb the combustion heat output resulting in an increasing combustion gas temperature at the tube plate. The tube bank continues to absorb the same fraction of heat per unit of combustion gas that flows through it, but the inlet temp. is higher so it follows that the outlet temp. at the smokebox must also be higher."
In your locomotive, where all the firebox heat is preserved, does that mean that outlet temperature will be higher than that of conventional locomotives? This was the largest concern to me when I was listening to boiler design. The way I imagine it, there will be more heat with heating surfaces (which allow this heat to be transferred to water) being smaller (with elimination of heat-intense firebox surface), which will limit the possibility of heat to be transferred leading to a lot of heat remaining untransferred. Anyways, I would like for you to clarify this moment to me.
As for final sentences, it is honestly a bit complicated to me to imagine how all this works without some sort of internal elements diagram of the boiler. Though what you say sounds interesting and may actually neglect something of aforementioned concerns.
Thanks for this detailed replied. As mentioned, in no way did I intend to address this subject exhaustively here. My comments were greatly simplified and very approximate, intended to convey a basic theme.
Briefly and slightly less approximately: You are correct regarding firebox heat transfer. The Hudson-Orrok firebox heat transfer equation as modified by Porta is useful for quantifying this, given as:
n = 1/(1+((A ÷ 0.46) x (Q ÷ (10^6 x H))^0.5))
Where:
n = Fraction of firebox heat release rate absorbed by the firebox heat transfer surfaces.
A = Combustion excess air coefficient.
Q = Total heat release rate in the firebox in kcal/h
H = Inner firebox heat transfer surface in m^2 (including refractory arch factor)
Taking the data for the oil fired 5AT as an example, using this equation it can be approximately shown that at rated evaporation, n = 0.27, and at 10% evaporation, n = 0.54
Therefore a 10 fold increase in heat release rate in the firebox results in a 5 fold increase in firebox heat absorption.
Again you are correct about the convective heat transfer coefficient in the tube bank not being in proportion to the combustion gas mass velocity. Your figures showing it to be proportional to the power of 0.5 to 0.8 agrees with the figures I have here (on the face of it approx. similar to the heat absorption relationship in the firebox). However, as the heat transfer coefficient falls, the log mean temperature difference between the combustion gas and the tube surfaces rises due to the outlet temperature of the tube bank increasing. This attenuates the effect of the falling heat transfer coefficient, which also varies in relation to temperature and rises with temperature, offering further attenuation.
Taking the worst case scenario here where the heat transfer coefficient falls in proportion to the square root of the mass velocity. If the mass velocity increases 5 fold, the heat transfer coefficient will increase only 2.24 fold. Then, to transfer the same quantity of heat, the log mean temperature difference must be 2.23 times higher. At a tube bank inlet temperature of 900 deg.C and a saturated steam temperature of 186 deg.C with an absorption efficiency initially 98%, the fall in absorption efficiency to maintain the heat transfer rate is only 25% as against a 55% fall in the heat transfer coefficient, and this is the worst case. There are a number of factors not considered here, but the result is that in practical terms, tube bank absorption efficiency may be considered approximately independent of mass velocity.
The new boiler has a carefully designed heat exchanger to compensate for the loss of firebox heating surface, which includes both a large heating surface within a compact unit and a high free gas area to ensure acceptable draughting power. The smokebox gas temperature is expected to reach not more than 300 deg.C without a smokebox economiser.
R. Johnson's book sounds particularly interesting, especially the test data you mention. I will keep a look out for a copy.
@@Mackwell-Co Thank you for this detailed reply! I wish you good luck with your project.
Water cooled combustion chambers on small boilers are pretty much a no-no now adays. It quenches the partially burned gases and results in very high ubburned hydrocarbons and carbon monoxide. These crappy wood fired outdoors hot water boilers you see in the USA all have chilled combustion chambers and produce huge amounts of smoke for this reason. They have given wood boilers a horrible name and have even resulted in bans. The gassification hydronic boilers use ceramic lined fireboxes and often preheated combustion air and burn very clean.
There better not be anything in this documentary about my wife!! She’s a 21st century boiler, to say the very least of it, and I don’t need any more people knowing even more about her ways and our private life than they already do. It’s a miracle she’s not in the national news spread about that visit to La Chambre. Caught a right dose.
Its amazing to see someone working on different ideas for modern engines. Thank you for indulging your interest.
Something I just found out about is that conventional steam locomotive boilers have to be warmed up slowly. If a roaring fire is started in a cold boiler, it could cause serious damage as the pieces of the boiler expand at different points as it is heated.
I think your idea is amazing just by simplifying everything essentially down to a single tube. I can also imagine that replacing any internal piping would be 100 times easier than taking the engine out of commission for who knows how long to put new fire tubes in, stays, clean out for scale buildup, repairing and inspecting for leaks in the fiber box or the barrel, etc.
I'm excited to see what you have next!
Yes i think too that building a water tube boiler with common moderns methodes of welding is far easier and faster, and so cheaper than making a traditionnal fire tube loco style boiler with great thickness of steel and many stays, weight, time to raise steam, exploding issues ... etc What a hard and heavy cost work to building a riveted boiler in the 19 th / early 20 century !
Water tubes boiler is the way for the future for many good reasons !
I like this project. Can't wait to see the locomotive in action some day.
Excellent. Watched half the video and then subscribed. Thank you for sharing this.
Your technology is solid. I will be following this build. Keep up the excellent work.
Thank you!
@@Mackwell-Co I have some relevant texts from old reference books. Can I email? My channel has contact info.
@@EngineersWorkshop Yes please! I have sent my contact details via your email address.
I will anxiously be awaiting a bicycle steam engine design so I no longer need lithium batteries!
YOUR STILL Killing th planet
SOLAR/Nuclear and batterys are better
Water tube boiler have worked successfully look up a company called sentinel there was a 0-6-0+0-6-0 loco built by them that had a water tube boiler and that was able to move loads of 1000+ tons. Their railcars also did use water tube boilers in some cases.
Quite true, Sentinel developed some innovative designs. Their staple boilers were an interesting mix of vertical fire tube with horizontal water tubes. Do you have any links to info on their 0-6-0+0-6-0?
@@Mackwell-Co there isn’t much about it on the Internet there is a photo of it here www.national-preservation.com/threads/what-ifs-and-locos-that-never-were.444966/page-10 but the quoted tractive effort is not right as the loco was never pushed to the point it couldn’t pull a train and it was closer to 100t rather than the 90t. It had 4 2cylinder engines producing 400 hp in total with poppet valves and cam valve gear rotating at half engine speed it also had low and high gear but it was so powerful that low gear was rarely used. Sadly there are no designs for the boiler it had although it was very similar to the ones in the rail cars sent to Egypt also made by sentinel but with a psi of 335 it was also fitted with feed water heaters. As this loco was a one off not much is known about it there isn’t a date given for its build date but the it’s works number of 9603 would but it around 1957. The chassis were considered for parts converting to two diesel locos but that didn’t end up happening and it was scrapped at Dorman Long where it worked in 1966. I got most of this information from a book available from the industrial railway society about the sentinel locos and railcars
Thanks for this info!
@@Mackwell-Co douglas-self.com/MUSEUM/LOCOLOCO/colombia/colombia.htm here is a link to the Sentinel railmotor which worked at 550psi
Very interesting - Cheers!
A question popped into my head while watching this: Do you reckon this boiler design could be adapted to new-build steam projects, in essence taking an existing but extinct design (i.e. we have the blueprints/shop drawings for this class, but none survived into preservation) and swapping out the original fire tube boiler for one of your design? Thus getting a locomotive that aesthetically and functionally resembles a grand old Victorian lady (for example, just for visualization, the Great Central Railway's Class 2 No. 567, or the SECR E Class planned by the Brighton Atlantic Group once the current H2 Atlantic is finished), but steams up in just an hour as opposed to 3-6 hours for a normal steam engine, and operates more efficiently and cleanly than the original?
I suppose a related question (most likely already answered, so apologies if I haven't seen it): You show this boiler being test fired with wood, but how would it behave when fired with coal?
Yes definitely, it is designed so that it can be built to match exactly the external dimensions of an original boiler, but with improved performance i.e. zero spark emissions, quick steaming etc.
Coal isn't consistent with the environmental focus of the project and would require a more complex grate to manage the higher ash content. However, if cord wood wasn't an option then biocoal such as that being developed by CSRail in conjunction with the NRRI in the United States will work well, as will wood pellets or compressed briquettes (the latter two were tested in EP2). Straight vegetable oil is an option too.
You need to watch a video titled "Dan Gelbart's uniflow steam engine". It's a model engine of his own design. It is a uniflow engine, which was the most efficient reciprocating steam engine as of the 1940s when research on steam engines mostly stopped. It uses an Invar piston to avoid differential thermal expansion and seizing(more common in uniflow engines), it uses a Vespel (15 percent graphite impregnated polyamide (nylon)) cylinder liner for low friction and operation without steam side lubrication. He has made provision for a Teflon or Vespel piston ring. Vespel probably retains its mechanical strength to higher temperatures. The polymer cylinder liner also serves to prevent heat loss and condensation. It uses a bash valve admission, computer controlled, electromagnetically actuated admission valve closure, and an innovative exhaust valve in the piston that prevents the need for auxiliary exhaust valves that unuflow engines need if they lose condenser vacuum. He reports 10% thermal efficiency, which for a model size engine is God damn incredible. I would really love to see some of these principles implemented in this engine, particularly the Vespel cylinder liner.
My vision of a reasonably efficient steam engine would be a water tube boiler with superheater, economizer, air heater, and exhaust heater, coupled to a high speed, internally located, fully enclosed, geared, and force-lubricated uniflow steam engine and possibly a condenser. It wouldn't look much like a stereotypical steam engine, because of the lack of a water tube boiler, but more like a LNER J70.
To be perfectly honest, reciprocating steam engines do have a place, but transportation really isn't one of them. Places where waste fuels and steam are available, namely sewage treatment plants, waste incinerators, chemical plants, oil refineries (have a large steam supply), and perhaps for auxiliaries of full size power plants. Below 1,000 horsepower, the reciprocating steam engine is clearly the superior in efficiency. Between 1,000 and 5,000 it's a toss up, and above 5,000, the turbine is the clear winner. The requirement for clean, oil-free exhaust steam/condensate has probably been a big limiting factor, which is why I think Vespel cylinder liners, vespel/Teflon piston rings, and Vespel/Teflon rope packings and no internal lubrication could help make reciprocating steam more competitive in smaller sizes.
The idea of building a more modern, up to date steam engine has fascinated me for a long time, and it's really great someone is trying to put it into practice. I subscribed.
Was going to ask about the boiler design. Could you show the drawings of the water tubes? Also where does the water circulation pump pump from? I’m probably one of the few fans wanting even more detail!
One day! There are inlet/outlet connections that pass through the underside of the smokebox wrapper just behind the door plate (and ahead of the saddle when fitted to the loco chassis). But otherwise the connections are located wherever suitable. Thanks for your interest!
@@Mackwell-Co
Is it a forced circulation boiler? Or are you just talking about the boiler feed pump?
Regarding piston a rod fiction attachment. Is it possible to machine rod with a shallow spool shape say 5mm rims with diameter of 25mm and the centre 14mm with a diameter of say 24.9mm and the piston the opposite. You would probably need to freeze the rod and make the piston quite hot to fit. If thought needed you could pein the rod with centre punch on either side.
No idea how practical this is!
Hello - very interesting project you have! With an insulated firebox, could you make use of a Stirling engine to circulate water for initial steam generation, and then run a steam-driven pump for normal operations?
You could probably increase the strength of the friction fit piston head by placing a clip ring retainer on the lower side. Also, a 1928-1932 Bryan (Bryant) steam tractor would prob ably be light enough to do the seeder work. And their 600 psi water tube boiler design is still being built for other purposes
Ahh the enthusiasm of youth...best of luck lad, I mean that.
Very interesting project, can't wait to hear more detail on boiler internals and water and steam temp./pressure control.
Lamont style boilers usually feature a steam separating drum that also takes care of easy water level control and water make up. Super heat temp. has to be carefully monitored esp. because the firebox temp cannot be controlled within seconds. Maybe you are employing some sort of super heater water injection?
Thank you! I will need to explain just how all this works in some future videos.
Also are you going to use this in tropical turbine pump that would be the most efficient type
I always felt steam power could still be in use today if research and experimentation had continued since the switch to Diesel electric. Power plants still use steam turbines to turn the generators. The same is possible for a steam electric train. Keep up the good work.
My brother from another mother except my idea and planning is for a 15 inch gauge farm railroad I have been saving up for kozo hiraoka's books on the Pennsylvania A3 and Shay locomotive I'm also getting a creality CR10 3D printer for master casting molds I might actually want to keep in touch with you this is right up my alley
can you show us a drawing of how the boiler is laid out? im not understanding how you have it set up..
Very interesting boiler design, I’ve actually proposed similar with fire tube boilers for a water circulator similar in design to a single row superheater fed from below.
Though I have to ask: is this boiler cheaper and easier to build than an actual fire tube boiler? The only reason I ask is because the 5AT project was turned down because it was more expensive to build overall than the new build P2
Yes it is both easier to build and cheaper. No stays saves a bit of time!
Isn't using a pulverizer to burn the wood as dust better?
Good on ya mate, I take it you are a fitter turner or similar. Have you ever come across a Dave Collins from up in Keri Keri he had a sawmill running on Steam a few years back. Keep up the good work, steams very interesting aye.
Also in the asked questions, you said it wouldn’t run on coal, but what’ll happen if you try run it on coal?
would be cool to see it bolted a steam engine like atractor or on Rails to demonsrate its power
You mentioned lightweight; how much lighter than a regular locomotive is it going to weigh?
Maybe the circulating pump could be just a lenght of pipe through the hottest combustion gasses with a couple of clack-valves, functioning along the lines of a coffee-maker or a pop-pop boat.
Amazing! Wonderful! Thank you for your consideration of humanity. i am basking in the glow of your good karma :)
Great work. Love it!!! I think that wasted heat you mention at the beginning is call 'Sensible Heat'!... How much will valve chest and cylinder temperatures affect how tightly the piston grips the piston rod?
Thanks! Yes as the pump's piston - rod assembly heats up, the slightly higher coefficient of expansion for the 1045 piston compared with the 420 stainless steel rod means a slight loss of grip so I have made a small allowance in the fit tolerance. The strength of steel (generally) tends to increase up to about 200 deg.C which is perfect for a saturated steam temp of 218 deg.C.
Fascinating project! Have you any plans for the boiler to be closed loop? Given the greenhouse effect of water vapour and the limited global supply of fresh water?
When you described piston and rod connection method. Does not look like those numbers are take into the working temperatures (the rod and piston are made from different metal and might expand a little bit differently (and the numbers would be less good). Doesn't this introduce an additional stress to piston that would lead to deterioration (metal fatigue)?
Yes you're right. 420 Stainless steel and 1045 carbon steel have very similar expansion coefficients, but they are different, the 420 SS having a slightly lower coefficient. For simplicity I didn't include the check on this in the video but at working temperature the slight reduction in grip is within limits, the loss of interference is 0.008 mm. Because the stresses in the piston and rod due to the shrink fit are constant and only cycle a small amount with temperature, this will not introduce fatigue.
Instead of shrink fitting, why not use a C-clip on the piston?
Something else poked into my mind over the week - how are the water gauge and manifold going to be hooked up, seeing as the boiler doesn't extend into the cab? Are they just going to be piped outside the casing and insulated?
In a low water volume, highly dynamic water tube boiler like this one (probably) is, a water gauge is not as dependable as you might think. Waterlevels can vary very quickly and drastically under changing load conditions and would be impossible to manage manually. Pressure and waterlevel are rather temperature controlled to keep steam properties as uniform as possible. Since Sam is already monitoring various temperatures electronically, it will be likely that he will also measure waterlevels in this way. In the usual Lamont boiler, waterlevels can be easily measured, in some cases by means of a couple of ordinary spark plugs!
Basically yes (have a look at the manifold steam supply on SAR 25 class locos). The boiler doesn't need conventional gauge glasses which makes it a bit simpler!
Greetings actually they didnt use water around firebox to make more heat they did it to prevent fire from melting firebox and exploding the boiler. ps I really like the idea I'll take your entire stock jk but srsly nice loco I'll consider it at some point maybe a few years from now .
Is this a giant Briggs boiler?
Is this a boiler or a steam generator? Many steam-powered automobiles used steam generators.
Wow you're a lucky man you're doing something I always wanted to do and never got a chance to I always wanted steam locomotives to come back into the world. To I have to admit your design is a lot more simplified than mine I had an idea for a hydrogen-fueled hybrid steam locomotive that had a hexagon steel lattice insert into basically a modified fire tube boiler so it would link the inside structure friction stir welding to the outside structure of the boiler shell making it an extremely strong design using thermoelectric effects diesel electric locomotive trucks on the tender for dynamic braking also battery packs on the tender and condensers cuz when you burn hydrogen it combines with oxygen to burn and turns into water vapor you could convince that then the exhaust from the engine you could condense the exhaust from the engine it was literally not even going to need a fireman that was going to be computer-controlled with a backup battery and a backup computer for redundancy it would have been one hell of a machine my boiler is a trip along the hexagon plate perforated so the water can percolate into steam and the fire tubes go through the center of the hexagons my major problem was the Firebox I could never figure out a better fire box design I know that water tube boiler is never quite worked for locomotives they failed one way or another that's why I tried to redesign the fire tube boiler and I know you're probably thinking where where do I get the hydrogen that's a whole nother invention I have that I'm not really going to talk about here very interesting design good luck in your endeavors
Will there be backup pumps?
Certainly will, dual circulating pumps and dual feed pumps.
there is one problem I can think of with not having water near the firebox. when the locomotive is in heavy operation, it creates a very strong draft which could melt the firebox from the heat generated .
Really dumb question but does the firebox have a square hole inside the door mounting or is it rounded to help with stress underneath the square insert?
Nevermind just finished watching the video. Having square corners wont cause problems if theres no pressure in the firebox!
Good question all the same!
imagine making the back of the firebox white
would heat be reflected through to the front?
Probably been asked before but what wheel arrangement are you planning on useing and what kind of service will then complete loco be expected to do
mackwelloco.com/locomotives/
2-6-0 tender locomotive. It is designed for passenger service - 150 tonnes (trailing) on a 1 in 50 gradient. It will do just fine for freight too, just small. There is a spec sheet available at the link above.
@@Mackwell-Co thank you for your reply cant wait to see it complete think will need to make a trip from UK
neighbor probly keeps hiving "being chased by train but cant seem to leave tracks" nightmare
i was expecting a completely different kind of fuel, but with modern materials, even dirty fuels can be used way more effectively. i wonder what a completely carbon fibre or other new material manufactured FB and Boiler, could do
Will this type of boiler be able to handle the sudenchanges in power output that are a characteristic of a railway locomotive? (Marine boilers tend to run at a constant rate for long periods of time.) Also, I would have thought that the smaller boiler water volume would have made it less likely to be able to deal with suden changes in output.
Don't get me wrong, I'm interested and not being critical... But it's so very different from the tried and tested Stevenson boiler which was able to cope with sudden changes in output precisely because it had a large water volume.
Yes it does, particularly well, if not better than a fire tube boiler. We have testing this feature extensively and because the boiler is basically supplying steam to an open pipe pointing up the funnel, the sudden steam draw is more severe than a loco slipping uncontrollably. Even the conventional Stephenson type loco boiler's ability to cope with sudden increases in load has almost nothing to do with the large volume of water it contains, what counts is that the fire must instantly supply more heat to match the load - which it typically does very well. Upon decreasing load, the absence of radiant heat transfer in the new boiler means that a hot fire bed doesn't keep generating steam uncontrollably i.e. when draught stops, so does steam production.
@@Mackwell-Co Thank you for explaining this... I understand now and am looking forward to future developments.
how do you tell water level (having thought about it i guess a water tube boiler doesn't need a sight glass)
@@Nick-xm1ux that's why I'm thinking this one doesn't have a sight glass since it has no crown sheet, it's water tube not fire tube, more than that it's forced circulation so the water is constantly pumped around , so I would guess it's like a doble steam car boiler in that it's almost always all the way full
Yes a little bit like a Doble, but the contrary, almost always all the way empty!
I know you from Leokimvideos, I think that’s the name
do you have any other ways to receive money other than patreon?
Yes I have just added two alternative ways to support the project on the website here: mackwelloco.com
@@Mackwell-Co I have made my self a supporter, may the iron horse rise again
Thank you!!
@@The_New_IKB all hail the iron horse
Have you ever talked to anyone from DLM? Modern Steam is a goal for them.
Not yet but very interesting work they are doing!
@@Mackwell-Co Indeed!
I was reading the link you added in the description about the H45 and I read that one of it's problems was that it was impossible to raise steam unless you already had steam available kinda like charging a fireless, will your locomotive be like this or will you be able to raise steam more conventionally?
The boiler will raise steam conventionally (but much faster), as we did in this video. The link included some other types of German high pressure locos and I think the problem you mention above refers to H02, which was fitted with a Loeffler boiler.
@@Mackwell-Co Well that definitely gives it a better edge, have you ever considered an oil fired version? Using biodiesel and recycled oil from plastics or even (I know it's probably not legal where you're located) hemp seed oil could be a good renewable fuel for a boiler.
@@boxcarthehusky420 Yes, the primary focus is on using solid wood fuel as it is not sufficiently viable to produce liquid biofuels. But, if there was a waste stream available such as used cooking oil, the boiler will work just fine with any type of liquid biofuel. I expect it to be less sensitive to burner design with the dry firebox. No doubt hemp seed oil would burn well and if it was otherwise going to waste then why not! Under certain circumstances, locos may be set up for both solid and liquid biofuel firing with no alterations required - true multi-fuel capability!
Do you know also one of the reasons why water tube boilers were a failure on steam locomotives is that locomotives go through a lot of rough riding on the track specially at high speed you get lots of vibration and harmonics vibrations over time those water tubes will vibrate and start to metal fatigue over time and then the tubes would rupture and send that pressure back into the firebox if you have a tube rupture how are you going to prevent the fire blowing out the firebox door metal fatigue is a real issue with water to boilers I have an invention for you to solve that problem if you're interested peace out into the world have a great day
Is this a water tube boiler or a hybrid boiler also do u have pictures of what the boiler looks like inside , like building progress pictures like drawings , blueprints., is this what the boiler is www.hurstboiler.com/boiler-images/hybrid_boilers
It is a pure watertube. Not like those in your link. A number of factors limit how much I can reveal about the internal design at present, but all will be revealed in due course!
@@Mackwell-Co okay interesting cool,
Why do you not use injectors to feed water into the boiler? Injectors are 90% efficient.
Yes, injectors are very efficient on their own, but they limit the quantity of energy that can be recovered from the exhaust steam and so reduce the efficiency and power of the loco. The (eventual) boiler pressure of 310 psig is nearing the limit for injectors too.
Did you consider other alternative fuels? Although wood is sustainable, it does produce Carbon Dioxide. I have always theorised using Hydrogen Gas for High Heat output and Zero Carbon Footprint. All the same, a great project. Do you plan to manufacture more than the boiler?
The carbon dioxide released by wood fuel doesn't add carbon to the carbon cycle, just as you and I consume food and breath carbon dioxide out - so no contribution is made to climate change. Long ago I explored hydrogen in depth, but my understanding is the bulk of hydrogen produced today is done so by steam reforming natural gas, thereby adding carbon to the carbon cycle! The alternative, electrolysis generated hydrogen, is taking high value electrical energy (generated somehow) and converting it into low value heat energy unless the hydrogen is employed in a fuel cell - which then makes for a relatively inefficient (but higher capacity) battery. Thank you for raising this point as it is a good question! Yes the whole locomotive is to be built i.e. chassis, tender etc. A boiler on a static test frame is great for scientific type tests but not much of a demonstration.
Hi is that you nico regards Robbie
But what’s the point of the project? Is this to like build a head of steam faster or something?
To make transport sustainable using the power of steam! Building a head of steam faster makes steam more practical to use, but this is just one of many advancements.
Oh well what are the others?
how does one make a boiler that wont kill them? a video on that would be nice as i am into steam but have no idea on how to produce it lol
Be careful
If you make steam too fast you can stress the boiler that can cause boiler failures or problems
We don't know much about the boiler set up yet, but what we know indicates some sort of mono tube type of setup, that has no problem at all with fast steaming up. If the circulating pump was electrically driven, instead of steam powered, this system could be operational well within half an hour!
@@chamagical just be careful
It might not be a wet fire box but boiler failures can take place.
Jou should take your time with fireingup.
pere marpuette 1225 howell🔔
melon festival 2018🚂🚃🛤
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come on really we need LESS of this shit and more renewable NON BURNING ones
LOL 3 hrs to raise steam in a loco? you wont be doing that too many times i promise you that.
3 hrs?
Then you have the large articulated locomotives. Locomotives like UP's 4000 class took over a day from a cold boiler (more to avoid stress due to thermal expansion).
Im no exspert but thats the rong type of pump
That is a boiler test pump
Both pumps are temporary only, I'll be building the new pumps in upcoming episodes.
@@Mackwell-Co
O okay
I recommend steam injectors
How did you make not emit soparks.?
Did you use spark arestors
I'm using an advanced combustion system to eliminate spark emissions instead of a spark arrestor, the latter is liable to block and will not always arrest 100% of the sparks.
@@Mackwell-Co
Are you guys gonna use coal?
Nope!
This is lovely BUT. A diesel engine can start up immediately. There isn't any point in this.
Diesel engines are impressive, turn the key and off you go in less than a minute. When it comes to transitioning from fossil fuel to sunlight, what options do we have?
@@Mackwell-Co Nothing at the moment. Solar power isn't effective enough on a wide scale. Atomic energy is the future. Remember: The Future Is Nuclear!
Check out the EROI of nuclear and its cost trends. A nuclear future seems unlikely. Advanced steam locomotion is simply the most efficient way to turn sunlight into traction.
@@Mackwell-Co what about a steam electric turbine? Steam to generate electricity, electricity could be stored in a battery for when there is no water and to preheat water for quicker start ups?
@@Nundevwizer might as well just build a gasifier ?
You cant do much with steam unless you Supper Heat it lol
this kind of work needs to be done by adults not children, messing not with what they don't understand, listening to dreadful annoying irritating repetitive thumping pounding brainless dumbed down noise, unwatchable and unlistenable.
try again in 20 years time