I'm eventually going to buy one of these. Perhaps not a Stuart, but the cost of them, and the fact they are so complex, makes it a very scary thing to ''invest' in. I just think they look magnificent, both running and still.
Very nice. I especially liked the last one and the fact it was connected to a propeller and gear box. These engines are so powerful I like seeing them working and running something. Thank you for sharing.
Why in real life, as in triple expansion engines in ships and boats, they all start by them selves ? and the models don't. Thanks very good video. You do such nice work.
Keith...I would like to hear you comment on the efficiency of a triple expansion compared to a single. With the steam being used three times it seems like there would be much more power with less steam used. A second question that is based on the assumption that triple expansion engines were often used in marine applications. How did they restart the engine when reversing the prop direction?
Steam engines can run on air but really like steam. Steam does not have a chance to expand while the inlet valve is open. Close the inlet and it can now expand. But how much it wants to expand versus how much it can actually expand is determined by the increasing cylinder volume as the piston moves. So steam expands from cut off until exhaust. A good part of your power comes from expansion. So when the piston comes thru cushion, the exhaust valve opens. The exhaust is still under pressure and still has more expansion available. Instead of free jetting this to atmosphere, it is now used in the next cylinder. Each successive use of steam is under lower pressure. So the piston area is increased to reflect this. Each time, more of the available expansion is used. Since boats have to carry fuel, it’s important to the most out of your steam.
As I was watching a thought occurred to me; Why are the triple expansion engines not self starting? the three cylinder engines on Shay locomotives are self starting, so what's the difference? So, here's my answer right or wrong. The triple expansion engine admits steam only into the high pressure cylinder at start up and the other two do nothing, thus resisting any motion. The Shay locomotive on the other hand is either three separately operating engines or a system that feeds steam into all three cylinders is used at start up. So, a triple expansion engine is actually a "compound engine". Large compound steam locomotives use a system that allows simple, steam at high pressure is admitted to all cylinders during start up and then switched to compound after reaching a certain speed or motion. Am I right so far? So, can YOU add a system to your triple expansion engines to make them self starting? Now that would be a great model engineering project series. I'd use that engine with the propeller attachment. No change to the actual engine just a simple/compound system added. Then put it all in a radio controlled boat and go sailing. Keith, this video showed me that you teach us more than you think you are. Like anything else in learning, the light suddenly went on in my head, leading to both questions and answers. Love it. ;-)
I'm eventually going to buy one of these. Perhaps not a Stuart, but the cost of them, and the fact they are so complex, makes it a very scary thing to ''invest' in. I just think they look magnificent, both running and still.
Thing of beauty
Very nice. I especially liked the last one and the fact it was connected to a propeller and gear box. These engines are so powerful I like seeing them working and running something. Thank you for sharing.
Thank you for Watching {:-)))
Why in real life, as in triple expansion engines in ships and boats, they all start by them selves ? and the models don't. Thanks very good video. You do such nice work.
Maybe they were fitted with "Simpling valves". (please type simpling valve into Google)
The two steam boats I crewed on Waratah ( 1902 steam tug)Lady Hopetoun (1902 VIP Launch) Both had Triple Expansion engines
Definitely entertaining. Thank you!
Glad you enjoyed it!
Beautiful!
Thank you!
Beautiful. Did expansion engines on ships also need to be rotated to start?
They probably were fitted with "Simpling valves". (please type simpling valve into Google)
Keith...I would like to hear you comment on the efficiency of a triple expansion compared to a single. With the steam being used three times it seems like there would be much more power with less steam used. A second question that is based on the assumption that triple expansion engines were often used in marine applications. How did they restart the engine when reversing the prop direction?
using the same steam 3 times on every cycle makes a Triple Expansion Engine more powerful and more efficient
Triple expansion engines are remarkably efficient. Add Corliss valve gear and the efficiency approaches that of a steam turbine.
Steam engines can run on air but really like steam. Steam does not have a chance to expand while the inlet valve is open. Close the inlet and it can now expand. But how much it wants to expand versus how much it can actually expand is determined by the increasing cylinder volume as the piston moves. So steam expands from cut off until exhaust. A good part of your power comes from expansion. So when the piston comes thru cushion, the exhaust valve opens. The exhaust is still under pressure and still has more expansion available. Instead of free jetting this to atmosphere, it is now used in the next cylinder. Each successive use of steam is under lower pressure. So the piston area is increased to reflect this. Each time, more of the available expansion is used. Since boats have to carry fuel, it’s important to the most out of your steam.
⭐🙂👍
As I was watching a thought occurred to me; Why are the triple expansion engines not self starting? the three cylinder engines on Shay locomotives are self starting, so what's the difference?
So, here's my answer right or wrong. The triple expansion engine admits steam only into the high pressure cylinder at start up and the other two do nothing, thus resisting any motion. The Shay locomotive on the other hand is either three separately operating engines or a system that feeds steam into all three cylinders is used at start up.
So, a triple expansion engine is actually a "compound engine". Large compound steam locomotives use a system that allows simple, steam at high pressure is admitted to all cylinders during start up and then switched to compound after reaching a certain speed or motion.
Am I right so far?
So, can YOU add a system to your triple expansion engines to make them self starting? Now that would be a great model engineering project series. I'd use that engine with the propeller attachment. No change to the actual engine just a simple/compound system added. Then put it all in a radio controlled boat and go sailing.
Keith, this video showed me that you teach us more than you think you are. Like anything else in learning, the light suddenly went on in my head, leading to both questions and answers. Love it. ;-)
Please type simpling valve into Google.