Cordless was a business genius as well. He provided his engines for free or close to it and charged the users half the difference in fuel costs between the slide valve engines and his rotary valve engines. He made a huge amount of money with this scheme. These engines provided mill power until grid based electric power became available and it was possible to put electric motors on each machine. The American Precision Museum in Windsor, Vermont has a small line shaft set up that can be turned by hand. I was amazed by how little force was required. Both of these museums are time well spent for machine freaks like us.
I really enjoyed this video. I build miniature steam engines, all of which have all been the slide valve type. I have my heart set on building a Corliss in the future and the beauty of the mechanism and your fabulous explanation has increased my desire to build one - thank you!!😃
Pulse width modulation. For me, WW2 seems to be the pinnacle of accomplishment by mechanical means what is now done via electronics. Sensors now instead of cams, eccentrics, rod length and grooves/slots. I do appreciate what you are presenting here.
Thank you! Of course this predates WW2 by 90 years! We have another device, a hydraulic governor, that has a technology on it that was used in naval warships for fire control. Another mechanical version of what is now done electronically. You've given us another idea for a video!
I think this is an important omission from this presentation. The slide valves WERE adjustable after the engine was built. Stephenson's slider system controlled the stroke of the slider valve to adjust how much steam entered the cylinder. Having said that the very rapid opening and closing of valves, the separation of inlet from exhaust and independent timing of inlet and exhaust are important contributions of the Corliss system. I was talking today to the operator of a full size (90 foot) steam ship and he did not understand the fact that efficiency of the engine could be controlled with the Stephenson valve. They control their engine simply by adjusting steam pressure/volume provided to the engine.
WIAT a minute. The walschaert and Baker vale gear used on locomotives allow for a variable opening and closing of the valve. The lead and lap is changes by changing the stroke of the steam vale. Engines starting under load receive full boiler pressure, As the speed increases the stroke is shortened and less team admitted to the cylinder allowing expansion of steam to keep the engine running more efficiently. No locomotive ever used corliss valve gear as far as I know. You refer to the action of a D type valve only used on low pressure engines - stationary and in locomotives. The big engines developed in 1930 - 1946 used spool valves or poppet valves.
Thank you very much for all these amazing videos. I've learned a LOT about steam engine & steam valve technology. I look forward to enjoying all your future videos.
Ever heard of lighting. It actually works quite well. It allows one to see what you're actually talking about so we can actually learn something instead of being frustrated and deciding to leave and never again watch one of your videos. Just a thought.
Good video, the point at the end about letting the steam expand is interesting. Intuitively it just seems like you would want as much steam as possible, i guess if you can save steam then ultimately you can save fuel.
they came up with compound expansion where you would have 3 cylinders. the first high pressure the second gets the exhaust from the first so medium pressure , the last gets exhaust from the middle cylinder and expands the steam completely. titanic used that as well as a turbine as the final stage.
Oliver, Modern tech could probably function similarly if that is what you mean. The astounding part is that this variable valve timing is done purely mechanically and was invented 170 years ago.
This is the best video on the whole internet in regards to explaining the Corliss valve. Incredibly well done!
Cordless was a business genius as well. He provided his engines for free or close to it and charged the users half the difference in fuel costs between the slide valve engines and his rotary valve engines. He made a huge amount of money with this scheme.
These engines provided mill power until grid based electric power became available and it was possible to put electric motors on each machine. The American Precision Museum in Windsor, Vermont has a small line shaft set up that can be turned by hand. I was amazed by how little force was required.
Both of these museums are time well spent for machine freaks like us.
Very interesting bit of information. Thanks for posting!
I really enjoyed this video. I build miniature steam engines, all of which have all been the slide valve type. I have my heart set on building a Corliss in the future and the beauty of the mechanism and your fabulous explanation has increased my desire to build one - thank you!!😃
Pulse width modulation. For me, WW2 seems to be the pinnacle of accomplishment by mechanical means what is now done via electronics. Sensors now instead of cams, eccentrics, rod length and grooves/slots. I do appreciate what you are presenting here.
Thank you! Of course this predates WW2 by 90 years! We have another device, a hydraulic governor, that has a technology on it that was used in naval warships for fire control. Another mechanical version of what is now done electronically. You've given us another idea for a video!
Nice explanation & demonstrations of the differences between slide-valves & Corliss-valves!
Thank you! There is always more that can be said but 17 minutes was longer than I had hoped for already! I might have to revise it at some point!
@@newenglandwirelesssteammus4167 There's nothing wrong with long videos, if that what it takes to display or describe something! :)
Slide valve engines with cut off governors also control speed by admission timing much the same as 'linking up' on a locomotive.
I think this is an important omission from this presentation. The slide valves WERE adjustable after the engine was built. Stephenson's slider system controlled the stroke of the slider valve to adjust how much steam entered the cylinder. Having said that the very rapid opening and closing of valves, the separation of inlet from exhaust and independent timing of inlet and exhaust are important contributions of the Corliss system. I was talking today to the operator of a full size (90 foot) steam ship and he did not understand the fact that efficiency of the engine could be controlled with the Stephenson valve. They control their engine simply by adjusting steam pressure/volume provided to the engine.
I am looking forward to another Steam Up after this Covid crisis is over. Thanks for this video.
WIAT a minute. The walschaert and Baker vale gear used on locomotives allow for a variable opening and closing of the valve. The lead and lap is changes by changing the stroke of the steam vale. Engines starting under load receive full boiler pressure, As the speed increases the stroke is shortened and less team admitted to the cylinder allowing expansion of steam to keep the engine running more efficiently.
No locomotive ever used corliss valve gear as far as I know. You refer to the action of a D type valve only used on low pressure engines - stationary and in locomotives. The big engines developed in 1930 - 1946 used spool valves or poppet valves.
and the Stephenson Valve Gear had the same function shame this was glossed over
Brilliant explanation, IMHO. Thanks for posting this!
Thank you so much for making this! You did a great job explaining this rather complex system for the layman!
We're happy to do it.
Thank you very much for all these amazing videos. I've learned a LOT about steam engine & steam valve technology. I look forward to enjoying all your future videos.
Ever heard of lighting. It actually works quite well. It allows one to see what you're actually talking about so we can actually learn something instead of being frustrated and deciding to leave and never again watch one of your videos. Just a thought.
Good video, the point at the end about letting the steam expand is interesting. Intuitively it just seems like you would want as much steam as possible, i guess if you can save steam then ultimately you can save fuel.
they came up with compound expansion where you would have 3 cylinders. the first high pressure the second gets the exhaust from the first so medium pressure , the last gets exhaust from the middle cylinder and expands the steam completely. titanic used that as well as a turbine as the final stage.
Absolute genius!
Great explanation ! could the corliss valves be replaced by modern valves as those used in gas engines ?
Oliver, Modern tech could probably function similarly if that is what you mean. The astounding part is that this variable valve timing is done purely mechanically and was invented 170 years ago.