I came here trying to learn how this all times out for some models I got, and now im just fascinated a bunch of guy in the 1800's could figure this out and then perfect it.
The best demonstration of Walschaerts gear I've seen on RUclips, explaining the basics an the nuances clearly and concisely with well presented graphics. Well Done.
What a wonderful explanation! The modeling is superb, and the build-up of the different parts of the system makes this very complex setup understandable. Bravo!
Wow! An amazing exposition on how to create a mechanical computer to for complex, adjustable relative motion. Starting from the first eccentric through successive refinements to tweak the model is beautifully explained, thank you.
This has been the best demo/explanation of the function of the combination lever that I've ever seen. Reading about it has never clicked for me. Thanks
Blondiehacks brought me here. Wow, I'm impressed. I did build small model IC and Stirling engines, maintained a small stationary steam engine, and do theoretically understand the Stephenson valve gear. Stephenson was a genius, but Walschaert definitevly exeeds that level. Thanks a lot, learned very much, exceptional tutorial and animations! Need to have a closer look onto the valve gear next time I'll came across a steam locomotive...
When I saw this video was over 45 mins. I wasn't sure I could sit through it. After viewing, I'm prepared to watch it over and over now. Fantasic naration, 3D and animation and above all insight into valve gear motion. Thanks a lot.
This is a magnificent explanation that is easily the most comprehensive and clear description of an otherwise mind boggling mechanism. I have been in awe of the Walschaerts Valve Gear (like many) with its almost hypnotic motion on a running loco; it speaks volumes of the brilliance of its inventor. I've often wondered how long it took to work out the entire design from inception, and the progression of development must have been an enlightening experience. Many thanks for the hours of work in developing this fantastic tutorial.
Trial and error or calculus. Calculus has been around for a while, but most people I meet these days wouldn't want to work through all those calculations by hand.
I like how you showed an intuitive way to come up with the walschaerts valve gear, maybe even close to the inventor's thought process? The video then proceeds to deeply examine how each component it the mechanism we came up with moves, and what that movement entails for the operation of our engine.
Ever since my first toy train set I have been fascinated by the mention of Walschaerts Valve gear but it has never been clearly explained Thanks for enlightening me.
Took me a long time to be in the mood to watch this, but that gave me the opportunity to watch this _and actually learn something._ This is a very well put together presentation with clear explanations of everything, very easy to follow visuals, and a great narrator. Looks like I'll be giving the steam engines in train simulator another try.
Fantastic video! I have always been fascinated by steam engines since I was a little kid, and they were still in operation on a limited basis. I would make drawings of them from the illustrations in the Encyclopedia Britanica (many decades before the internet!). I'm 76 now and yes, I went on the be a mechanical engineer. You could have guessed that when I was seven or eight years old!
I've always been interested in trains and steam locomotives. I assumed the workings of valve gear was beyond my comprehension. This video proves that good teaching can bridge the gap between what we currently understand and the next level. So many of my teachers were not up to scratch. As commented elsewhere, an excellent video.
Your presentation is almost textbook that was used in my Dad's day when he was working as a design engineer in the late 30's & early 40's. He tried to explain all this but didn't possess the communication skill that you have. 'Course the graphics help a lot, but your delivery is clear as can be. Thanks. liked&subbed immediately. P.S. 2-8-4 is my favorite wheel arrangement.
I've been looking forward to this tutorial for some time now. Both this and the previous video have given me a better understanding of steam locomotives. Thank you so much!
Wow, I have been looking and looking for this kind of design analysis and interpretation. This is absolutely fantastic and very clear. Thank you very very much for this animation with detailed explanation. :)
Excellent explanation. Looking forward to the Baker gear. I've been fascinated by these machines since watching them growing up. They seem to be alive, unlike the diesels or electrics. Really enjoying learning the details of how they work.
It's a small thing in railroading, especially in the N. American environment, but the name of the inventor is pronounced 'VAHL-skaretz', sounding like 'scared' but with a 'ts' sound at the end. That aside, I really appreciate this comprehensive description of Walschaerts valve tear. It is most informative, and VERY well done.
I was recently gifted a collection of International Correspondence School books (distributed in the 1930 - 1946 timeframe). Five of the textbooklets addressed valve motions and all were structured exceeding well - as there should be for an instructional book. This video is the moving version of those books; structured almost identically. Really well done - with all of the corner cases covered!
Wow. There's enough information here to make your head spin as much as the wheels! Might take me a few re-watches of this to grasp everything to the fullest extent, but at least it's all here!
That was a verry impressive presentation. It provides so much clarification of the different elements of this system. When I first studied mechanical engineering as a student, it was a topic in a textbook, the teacher had a wooden model to help provide clarity. Again, brilliant presentation.
This was a brilliant example of the mechanics. You hear things,and(start) to pick up on the main idea over the years. But nothing was left out here. I knew what volumetric pressure was,but here’s the precise application of it for a steam locomotive. Thanks for posting this-many thanks!!!
Thanks Dan... a magnificent piece of work. I thought I understood the main ideas of Walschaerts valve gear, but clearly I had missed some key points. Great job! Amazing what those mechanical engineers did without calculators, CAD systems, 3D modeling, etc.
An excellent description. I could imagine the invention, testing, development and refinement stages evolving as the design progressed and the improvement of performance as the whole thing came together. Taking us through the stages as you did was a brilliant idea and beautifully done. Congratulations.
Thankyou for making this excellent video resource. Us Model Engineer folk have many resources available to us for valve gear, the late Don Ashton’s work being one of the best, but for people like me, mathematically heavy! The only explanation of how to find how long the Union link needs to be in relation to the combination lever vertical and piston mid stroke was very interesting. Something I have previously missed. Thankyou again.
Excellant explanation. Doing into the tiny details of how the angles and circular motion are considered. Certainly an ingenious device. And your graphics are great at helping me to understand.
This is a brilliant video. Even if you "know" how the valve gear operates, this addresses the sort of things you don't think about but were crucial when Walschaerts, or Heusinger (which is how we know it here) invented the beautifully simple and effective motion. - Just want to say, there was a lot of locomotives with outside Stephenson's and especially Allan's valve gear in Austria - Hungary. I'm from Czechia and when you said it, I was like, no, this is normal and does fit quite well? :D
Great explanation and animation. I didn't know anything about locomotive valve timing. Next trip to the rail museum, I'll be taking a closer look. Thanks!
Wonderful explanation. It could explain the force of the steam when it enters the piston and how a small piston like that of locomotives can support so much weight.
Just watched the part 1 and part 2 videos, and I loved them! I learned a lot. I can't wait to see part 3 and hope it doesn't take two years! Another video that would be interesting to add to the understanding of steam engine performance would be "indicator diagrams" showing how pressure in the cylinder is affected by differing valve cutoff positions. I am an engineer of internal combustion engines and it is different to think about steam engines, where the cylinder pressure is about equal to boiler pressure, unless the valve event is set to cut off steam admission at different points in the stroke.
Thank you so much for this. I was brought up with steam as we had a steam traction engine and 2ft guage railway at home (UK). I had a pretty free hand in operating them as I grew older but always with some oversight. My uncle told me about the function of the reverse lever and how to 'notch it back' as speed grew because less steam was needed at higher revs. I got it in terms of how and when but never understood the mechanism of valve timings etc. Now thanks to you, 55 years later I do!
Possibly the best video explaining this. Good work, even though I was bored at times because I am familiar with mechanics and designed something simpler about 25 years ago during my mechanical engineer study. EDIT: We call this valve gear Heusinger. It is practically identical, designed independently by a certain Mr. Heusinger.
Because I live in a country that abolished steam locomotives before me born and we as a society do not support such history, it is really my first to see such detailed explanation for the connecting rods between the cylinders and wheels. I would urge and if necessary try to help but I am not any export that you as a community need to make such detailed and yet simple lectures for every aspect of steam locomotives design and maintenance in whatever aspect you think about. Probably at some point we might form a group to design steam locomotives much better and efficient.
Very nicely done! Just stumbled across this 8 days after you released it. Earned ya a subscription! Now I know what to look for when I set up my Pacific!
I loved this, I hope to see the next part soon. I would love to see this done for poppet valves like the type used on the L1 Hudsons, and a full work up on Stevenson valves.
Me too: excellent explanation! Thank you. :-) Slight suggestion: when you say something that amounts to "Here we see...", then I must scan my big screen with the speed of an old cathode ray to find where "here" is. The explanation might benefit from some lead-in "cursor movement" to the place of action.
I had an antique toy steam engine as a kid 60years ago on which both the piston/cylinder and the valve assembly pivoted and always pointed directly at their rotating connection points on the flywheel. Thus, there was not the angular "error" in either the push rod or the connecting rod strokes. Midpoints of the strokes acted concurrently with the piston and valve midpoints. (Actually, the pivoting motion of the piston/cylinder was mechanically linked to the valve actuator in such a way as to provide the necessary 90 degree lead of the valve action over the piston action.) It was brilliantly simple. Sadly, the toy vanished in one of several moves since.
This was awesome! A beautiful explanation of Walschaerts valve gear, well demonstrated at that! The only thing I'd say about your presentation is the fact that I don't think C&O Kanawhas had Walschaerts, but instead Baker, as all Lima-built and most 2-8-4s in general did. Still, this presentation does a great job making the Walschaerts look right at home on this iron horse!
When the video first started, I noticed the same thing. Then @ 1:10 he addressed that elephant! You hit the nail on the head with your comment that the Walschaerts looks at home - a credit to whoever did the graphics for this. Take it easy, @Railman!
These videos have been very helpful. I'd love to see more information on the frame, suspension, pilot and trailing trucks of these more modern steam locomotives (which I know isn't the most interesting or exciting topic 😄). I'm really want to understand more about what the cradle does, and how the rear weight of the cab and firebox is distributed to the trailing truck (it has something to do with "heart rockers" I believe). I recently bought a copy of the 1925 Locomotive Cyclopedia, which has tons of knowledge, but it's still hard making sense from the technical drawings. I'm debating on purchasing UP 844 1.5" scale model drawings to study and understand more about every nut and bolt of these machines. The 7.25" gauge model is so large, the designer even included prototypical frames and suspension. Studying live steam locomotive drawings has been helpful as their designs tend to be simpler.
"MOIN" as we say here in north germany... or as jock spoken south scandinavia. on the one side so interesting to me, how small our hobby world seams to be, that someone like you have entered my chanal. thank you for that. on the other side a lot of respect to your video of explaining professionally steam locomotion technology, says the german vehicle engineer and welding engineer. TO OUR HOBBY, all the best and more please....
I watched both episodes a lot earlier, but never commented on them untill now. These are superb videos when it comes to explaining locomotive valve gear and valves! I am very invested in this subject as of late and can't wait for more installments! Can we expect more valve gears like of the dual eccentric type (Allan & Gooch) or should we look forward to similar valve gears to Walschaerts-Heusinger and Baker? Will poppet/cam valve gears also be discussed? i.e. Caprotti, Franklin, etc.
"it would be impossible to have two separate eccentrics on an outside valve gear". It was done at least once, with a single experimental example of an LMS Stanier Black 5 (en.wikipedia.org/wiki/LMS_Stanier_Class_5_4-6-0_4767). It was preserved and can still be seen.
Some more advance related subjects that would be nice to cover. For compound locomotives (e.g. mallets) is there anything to prevent the condition where the high pressure cylinder is in exhaust stage, while the low pressure cylinder has its intake blocked, or is some kind of buffer/surge chamber used to handle this ??? In the case of of locomotives with 3 steam cylinders, how is the center cylinder power and control linkages connected to the locomotive drive chain ??? Some locomotives had provisions for a 'booster', a low speed steam motor that can be located on the locomotive trailing wheels, or on one of the tender wheels to provide an addition 'boost' to start a heavy train moving from a full stop. I have not seen anything on RUclips on how these 'boosters' operate. Can something be produced to cover this ???
Walschaerts Valve gear, a mechanical analog computer. good 'splainin, too. steam locomotives are some of the most impressive machines ever built . . . everything hasapurpose . . . everything moves!
One more syllable please: Kanawha, years ago I worked in the Capitol of West Virginia in Kanawha County. Had the pleasure of watching these engines pull the fall foliage train.
Makes me wonder too, ALCO setup locomotives this way. Found this really cheesey movie titled Boxcar Bertha, was filmed on the Reader RR in Arkansas. They were running their ex millitary 2-8-0 and the I quickly noted its indirect motion.
Great video! I have one question though - is there any advantage in using indirect motion? If it was used in some locomotives, then their designers must have chosen to do so for some real reason and not just wanting to be different.Were those locomotives expected to run backward more or something else?
Think on switching locomotives, operating in ports, depots and railway triage. They move a lot back and forth, at low speeds (so a breaking linkage won't lead to major damage), but they move backward at least as much as forward (if not more). For them, indirect motion may be a viable option.
I came here trying to learn how this all times out for some models I got, and now im just fascinated a bunch of guy in the 1800's could figure this out and then perfect it.
The best demonstration of Walschaerts gear I've seen on RUclips, explaining the basics an the nuances clearly and concisely with well presented graphics. Well Done.
Best explanation/demonstration of Walschaerts valve gear EVER, not just on RUclips.
After 2 years, they finally made a video. This literally made my day better
We'll meet again in 2025 for the Baker video.
@@reubensandwich9249 ... and then you will do British Capprotti, yes?
What a wonderful explanation! The modeling is superb, and the build-up of the different parts of the system makes this very complex setup understandable. Bravo!
Wow! An amazing exposition on how to create a mechanical computer to for complex, adjustable relative motion. Starting from the first eccentric through successive refinements to tweak the model is beautifully explained, thank you.
This has been the best demo/explanation of the function of the combination lever that I've ever seen. Reading about it has never clicked for me. Thanks
Blondiehacks brought me here. Wow, I'm impressed. I did build small model IC and Stirling engines, maintained a small stationary steam engine, and do theoretically understand the Stephenson valve gear. Stephenson was a genius, but Walschaert definitevly exeeds that level. Thanks a lot, learned very much, exceptional tutorial and animations! Need to have a closer look onto the valve gear next time I'll came across a steam locomotive...
Fantastic video!
When I saw this video was over 45 mins. I wasn't sure I could sit through it.
After viewing, I'm prepared to watch it over and over now.
Fantasic naration, 3D and animation and above all insight into valve gear motion. Thanks a lot.
This is a magnificent explanation that is easily the most comprehensive and clear description of an otherwise mind boggling mechanism. I have been in awe of the Walschaerts Valve Gear (like many) with its almost hypnotic motion on a running loco; it speaks volumes of the brilliance of its inventor. I've often wondered how long it took to work out the entire design from inception, and the progression of development must have been an enlightening experience. Many thanks for the hours of work in developing this fantastic tutorial.
And all of this was worked out and designed without the use of computers. The engineers back then had amazing talent and forethought.
And a lot of trial and error
Back then they were self-taught as well.
They used sliding rules, printed tables and diagrams and a lot of sweating in front of drawing boards.
Trial and error or calculus. Calculus has been around for a while, but most people I meet these days wouldn't want to work through all those calculations by hand.
I like how you showed an intuitive way to come up with the walschaerts valve gear, maybe even close to the inventor's thought process? The video then proceeds to deeply examine how each component it the mechanism we came up with moves, and what that movement entails for the operation of our engine.
Ever since my first toy train set I have been fascinated by the mention of Walschaerts Valve gear but it has never been clearly explained Thanks for enlightening me.
Took me a long time to be in the mood to watch this, but that gave me the opportunity to watch this _and actually learn something._ This is a very well put together presentation with clear explanations of everything, very easy to follow visuals, and a great narrator.
Looks like I'll be giving the steam engines in train simulator another try.
Fantastic video! I have always been fascinated by steam engines since I was a little kid, and they were still in operation on a limited basis. I would make drawings of them from the illustrations in the Encyclopedia Britanica (many decades before the internet!). I'm 76 now and yes, I went on the be a mechanical engineer. You could have guessed that when I was seven or eight years old!
I've always been interested in trains and steam locomotives. I assumed the workings of valve gear was beyond my comprehension. This video proves that good teaching can bridge the gap between what we currently understand and the next level. So many of my teachers were not up to scratch. As commented elsewhere, an excellent video.
Your presentation is almost textbook that was used in my Dad's day when he was working as a design engineer in the late 30's & early 40's. He tried to explain all this but didn't possess the communication skill that you have. 'Course the graphics help a lot, but your delivery is clear as can be. Thanks. liked&subbed immediately. P.S. 2-8-4 is my favorite wheel arrangement.
I've been looking forward to this tutorial for some time now. Both this and the previous video have given me a better understanding of steam locomotives. Thank you so much!
Now I can understand all of the linkages that I have seen on locomotives for years and why they are necessary. Great video!!
Wow, I have been looking and looking for this kind of design analysis and interpretation. This is absolutely fantastic and very clear. Thank you very very much for this animation with detailed explanation. :)
Excellent explanation. Looking forward to the Baker gear.
I've been fascinated by these machines since watching them growing up. They seem to be alive, unlike the diesels or electrics. Really enjoying learning the details of how they work.
I'm waiting for the same thing baker valve gear, always looked the most interesting to me.
WOW! The brilliance of the engineer(s) who designed this integral and differential device.
It's a small thing in railroading, especially in the N. American environment, but the name of the inventor is pronounced 'VAHL-skaretz', sounding like 'scared' but with a 'ts' sound at the end. That aside, I really appreciate this comprehensive description of Walschaerts valve tear. It is most informative, and VERY well done.
This is Sooooo clever! Elegant. Excellent explanation, thank you. The model is lovely too. Congratulations to the person who put it together.
I was recently gifted a collection of International Correspondence School books (distributed in the 1930 - 1946 timeframe). Five of the textbooklets addressed valve motions and all were structured exceeding well - as there should be for an instructional book. This video is the moving version of those books; structured almost identically. Really well done - with all of the corner cases covered!
C&O's 2-8-4's were some of the finest engines ever built, by both American & Lima Locomotive Works.
Joe Bliss C&OHS #72
Wow. There's enough information here to make your head spin as much as the wheels! Might take me a few re-watches of this to grasp everything to the fullest extent, but at least it's all here!
That was a verry impressive presentation. It provides so much clarification of the different elements of this system. When I first studied mechanical engineering as a student, it was a topic in a textbook, the teacher had a wooden model to help provide clarity. Again, brilliant presentation.
I've tried to find a good explanation of this for decades! Thank you for such a clear and detailed video of it.
Brilliant video. Thank you for putting this together.
Thank you! Very nice video! Unbelievable graphics! So great that you used a C&O 2700 too!
This was a brilliant example of the mechanics. You hear things,and(start) to pick up on the main idea over the years. But nothing was left out here. I knew what volumetric pressure was,but here’s the precise application of it for a steam locomotive. Thanks for posting this-many thanks!!!
Thanks Dan... a magnificent piece of work. I thought I understood the main ideas of Walschaerts valve gear, but clearly I had missed some key points. Great job! Amazing what those mechanical engineers did without calculators, CAD systems, 3D modeling, etc.
An excellent description. I could imagine the invention, testing, development and refinement stages evolving as the design progressed and the improvement of performance as the whole thing came together. Taking us through the stages as you did was a brilliant idea and beautifully done. Congratulations.
Thankyou for making this excellent video resource. Us Model Engineer folk have many resources available to us for valve gear, the late Don Ashton’s work being one of the best, but for people like me, mathematically heavy! The only explanation of how to find how long the Union link needs to be in relation to the combination lever vertical and piston mid stroke was very interesting. Something I have previously missed. Thankyou again.
Excellant explanation. Doing into the tiny details of how the angles and circular motion are considered. Certainly an ingenious device. And your graphics are great at helping me to understand.
This is a brilliant video. Even if you "know" how the valve gear operates, this addresses the sort of things you don't think about but were crucial when Walschaerts, or Heusinger (which is how we know it here) invented the beautifully simple and effective motion. - Just want to say, there was a lot of locomotives with outside Stephenson's and especially Allan's valve gear in Austria - Hungary. I'm from Czechia and when you said it, I was like, no, this is normal and does fit quite well? :D
Bravo! The best explanation of valve and control mechanism. I learnt a lot today. Thanks.
thank you for doing this. It's the best I've ever seen. Better than anything in a book for understanding the process.
Great explanation and animation. I didn't know anything about locomotive valve timing. Next trip to the rail museum, I'll be taking a closer look. Thanks!
Wonderful explanation. It could explain the force of the steam when it enters the piston and how a small piston like that of locomotives can support so much weight.
Just watched the part 1 and part 2 videos, and I loved them! I learned a lot. I can't wait to see part 3 and hope it doesn't take two years!
Another video that would be interesting to add to the understanding of steam engine performance would be "indicator diagrams" showing how pressure in the cylinder is affected by differing valve cutoff positions. I am an engineer of internal combustion engines and it is different to think about steam engines, where the cylinder pressure is about equal to boiler pressure, unless the valve event is set to cut off steam admission at different points in the stroke.
Thank you so much for this. I was brought up with steam as we had a steam traction engine and 2ft guage railway at home (UK). I had a pretty free hand in operating them as I grew older but always with some oversight. My uncle told me about the function of the reverse lever and how to 'notch it back' as speed grew because less steam was needed at higher revs. I got it in terms of how and when but never understood the mechanism of valve timings etc. Now thanks to you, 55 years later I do!
Very good video with excellent graphics covering all aspects of this valve motion.
Possibly the best video explaining this. Good work, even though I was bored at times because I am familiar with mechanics and designed something simpler about 25 years ago during my mechanical engineer study. EDIT: We call this valve gear Heusinger. It is practically identical, designed independently by a certain Mr. Heusinger.
Because I live in a country that abolished steam locomotives before me born and we as a society do not support such history, it is really my first to see such detailed explanation for the connecting rods between the cylinders and wheels. I would urge and if necessary try to help but I am not any export that you as a community need to make such detailed and yet simple lectures for every aspect of steam locomotives design and maintenance in whatever aspect you think about. Probably at some point we might form a group to design steam locomotives much better and efficient.
Perfect. Couldn't be shown better. I enjoyed it.
I'm looking forward to the next video in the series
Very nicely done! Just stumbled across this 8 days after you released it. Earned ya a subscription! Now I know what to look for when I set up my Pacific!
Thank you so much! Eventualy I began to understand the details!
Excellent explanation. Finally beginning to understand how this works. Thank you.
I loved this, I hope to see the next part soon.
I would love to see this done for poppet valves like the type used on the L1 Hudsons, and a full work up on Stevenson valves.
Amazing. No longer than a month ago I was looking for exactly this kind of video. Did you read my mind?
Me too: excellent explanation! Thank you. :-)
Slight suggestion: when you say something that amounts to "Here we see...", then I must scan my big screen with the speed of an old cathode ray to find where "here" is. The explanation might benefit from some lead-in "cursor movement" to the place of action.
I had an antique toy steam engine as a kid 60years ago on which both the piston/cylinder and the valve assembly pivoted and always pointed directly at their rotating connection points on the flywheel. Thus, there was not the angular "error" in either the push rod or the connecting rod strokes. Midpoints of the strokes acted concurrently with the piston and valve midpoints.
(Actually, the pivoting motion of the piston/cylinder was mechanically linked to the valve actuator in such a way as to provide the necessary 90 degree lead of the valve action over the piston action.) It was brilliantly simple. Sadly, the toy vanished in one of several moves since.
Very interesting video,thank you for taking the time to explain how it works.
This was awesome! A beautiful explanation of Walschaerts valve gear, well demonstrated at that! The only thing I'd say about your presentation is the fact that I don't think C&O Kanawhas had Walschaerts, but instead Baker, as all Lima-built and most 2-8-4s in general did. Still, this presentation does a great job making the Walschaerts look right at home on this iron horse!
When the video first started, I noticed the same thing. Then @ 1:10 he addressed that elephant! You hit the nail on the head with your comment that the Walschaerts looks at home - a credit to whoever did the graphics for this. Take it easy, @Railman!
These videos have been very helpful.
I'd love to see more information on the frame, suspension, pilot and trailing trucks of these more modern steam locomotives (which I know isn't the most interesting or exciting topic 😄). I'm really want to understand more about what the cradle does, and how the rear weight of the cab and firebox is distributed to the trailing truck (it has something to do with "heart rockers" I believe). I recently bought a copy of the 1925 Locomotive Cyclopedia, which has tons of knowledge, but it's still hard making sense from the technical drawings.
I'm debating on purchasing UP 844 1.5" scale model drawings to study and understand more about every nut and bolt of these machines. The 7.25" gauge model is so large, the designer even included prototypical frames and suspension. Studying live steam locomotive drawings has been helpful as their designs tend to be simpler.
"MOIN" as we say here in north germany... or as jock spoken south scandinavia. on the one side so interesting to me, how small our hobby world seams to be, that someone like you have entered my chanal. thank you for that. on the other side a lot of respect to your video of explaining professionally steam locomotion technology, says the german vehicle engineer and welding engineer.
TO OUR HOBBY, all the best and more please....
I need to watch this when less tired! But excellent graphics!! I'd love to know how you did them. They're fabulous!
Easy to understand, thank you.
cant wait to see the baker video, haven't found a good basic explanation of it anywhere
I've seen deep dives on technical subjects, but this is Marianas Trench deep. fascinating!
Fantastic video. Can’t wait for the Baker video. Also hoping a Stephenson’s valve gear video isn’t out of the question?
Great video. It would be great if you could also do a video of Southern Valve Gear.
Excellent stuff! thanks for such a well done explanation.
Best video ever on this topic !
Great explanation of the valve gear is there one for Stevenson value gear
Any intention to finish this series? The last two videos are so good, if love to see a breakdown of baker and Stephenson valve gear as well.
Excellent lecture. Wow.
I watched both episodes a lot earlier, but never commented on them untill now. These are superb videos when it comes to explaining locomotive valve gear and valves! I am very invested in this subject as of late and can't wait for more installments! Can we expect more valve gears like of the dual eccentric type (Allan & Gooch) or should we look forward to similar valve gears to Walschaerts-Heusinger and Baker? Will poppet/cam valve gears also be discussed? i.e. Caprotti, Franklin, etc.
"it would be impossible to have two separate eccentrics on an outside valve gear". It was done at least once, with a single experimental example of an LMS Stanier Black 5 (en.wikipedia.org/wiki/LMS_Stanier_Class_5_4-6-0_4767). It was preserved and can still be seen.
At 27:22, this set up is used in garratts we're the rear engine is travelling backwards
Good explanation!
Wow-this is an abso;utely brilliant presentation. I will be watching he others with relish as well! :-)
you are one very smart man to no all this
Some more advance related subjects that would be nice to cover.
For compound locomotives (e.g. mallets) is there anything to prevent the condition where the high pressure cylinder is in exhaust stage, while the low pressure cylinder has its intake blocked, or is some kind of buffer/surge chamber used to handle this ???
In the case of of locomotives with 3 steam cylinders, how is the center cylinder power and control linkages connected to the locomotive drive chain ???
Some locomotives had provisions for a 'booster', a low speed steam motor that can be located on the locomotive trailing wheels, or on one of the tender wheels to provide an addition 'boost' to start a heavy train moving from a full stop. I have not seen anything on RUclips on how these 'boosters' operate. Can something be produced to cover this ???
The one loco I can think of that runs "backwards" is the SP Cab Forward - they adjusted the linkages to account for this.
Very useful thanks!
Superb! Thanks a lot.
Going to have to watch that again. . . after I look up some terms, like “Trunnion”
thank you
Very interesting thanks!
Walschaerts Valve gear, a mechanical analog computer.
good 'splainin, too.
steam locomotives are some of the most impressive machines ever built . . . everything hasapurpose . . . everything moves!
One more syllable please: Kanawha, years ago I worked in the Capitol of West Virginia in Kanawha County. Had the pleasure of watching these engines pull the fall foliage train.
Very well done 👍 did you do the animation too?
Are there some plans with measurements or exact proportions available? I'd like to try such a gear in CAD.
Can you try and explain UP #5511's Valve Gear it's very much so different than the one shown here
This was an outstanding video! A question though - why setup for indirect gear at all? What possible benefits are there?
Makes me wonder too, ALCO setup locomotives this way. Found this really cheesey movie titled Boxcar Bertha, was filmed on the Reader RR in Arkansas. They were running their ex millitary 2-8-0 and the I quickly noted its indirect motion.
totally awesome!
PURE GENIUS!!!!!!!!!
My brother-in-law is an eccentric crank!
With every correction link I can hardly wait to see which new correction link requires another correction link. Sincerely, Rube Goldberg.
Damn dude you definitely have a voice for radio lol
I am designing the steam locomotive. What about suspension for drive wheels and crank center distances.. can you please explain
how do you no all this stuff on valve gear
What's the history of these? How long did they operate with sub-optimal designs before somebody got it right?
Good, very good!!!
AWESOME!👍
Great video!
I have one question though - is there any advantage in using indirect motion? If it was used in some locomotives, then their designers must have chosen to do so for some real reason and not just wanting to be different.Were those locomotives expected to run backward more or something else?
Think on switching locomotives, operating in ports, depots and railway triage. They move a lot back and forth, at low speeds (so a breaking linkage won't lead to major damage), but they move backward at least as much as forward (if not more). For them, indirect motion may be a viable option.
Ummmm....I Love this video
Thank you, that is all