Interesting engine question

[Sanjay F]

Great detective work everyone - looks like a great model, would be nice to see it in action! 

[steamer]

That looks familiar now do t it!?.    Everyone was trying to come up with a new valve gear..
I'm not at all suprised.

Dave

[Jasonb]

An interesting engine to add to your build list.

I've had a couple of images of a similar layout engine stored for quite a while but doubt I'll ever make it. Standard valve gear on this Rennie pumping engine.

https://commons.wikimedia.org/wiki/File:Brunel_Engine_House,_steam_pumping_engine_-_geograph.org.uk_-_1654054.jpg

[paul gough]

I cannot remember where I read about the Ericsson turret engine. If it was in one of my 19th century publications it is gone as I dispensed with almost all of my library on the move South from Kuranda (Cairns area) in North Queensland to Orbost in Victoria. I did keep a few of these oldies but most are loco books. I will go through the couple that might have something in them. It is also possible I came across discussion on the engine in one of the many “engineering” journals of the time when I had a fit of Ericsson mania some years ago. In any case it seems you have found enough for your needs and maybe more. Good luck with it. Regards, Paul Gough.

[crueby]

An interesting engine to add to your build list.

I've had a couple of images of a similar layout engine stored for quite a while but doubt I'll ever make it. Standard valve gear on this Rennie pumping engine.

https://commons.wikimedia.org/wiki/File:Brunel_Engine_House,_steam_pumping_engine_-_geograph.org.uk_-_1654054.jpg

Oh, I remember seeing a video of that one, or one like it, years ago, it ran a pump under the floor. Not the same valve layout, but still a very neat design.

[crueby]

Thanks for all the detectiv-ing help everyone!!

[Fj45]

 Nice, that was a good read.
 Greeting s from next year!

[Zephyrin]

With the freezing temperatures in my garage, I stayed warm and spent yesterday afternoon creating an animation of this engine based on the first image in the thread, using Solvespace. Just to see all these connecting rods moving together...

It seems to me that there is a lot of slippage in the slide shaft (the sort of expansion link)  and if the positions of the 2 slide valves are constrained, the model freezes and can no longer rotate!
But I only measured the lengths on the drawing with a ruler, so of course adjustments are possible.

the video of the screen capture, I have to turn the crankpin  withe the mouse, hence the shaken movement!

https://ti1ca.com/yyvsf9pq-MEM-capture-MEM-capture.mp4.html

Happy new year !

PS : this engine is clearly the engine of the turret of the USS Monitor, and is visible in some of the engravings

[crueby]

With the freezing temperatures in my garage, I stayed warm and spent yesterday afternoon creating an animation of this engine based on the first image in the thread, using Solvespace. Just to see all these connecting rods moving together...

It seems to me that there is a lot of slippage in the slide shaft (the sort of expansion link)  and if the positions of the 2 slide valves are constrained, the model freezes and can no longer rotate!
But I only measured the lengths on the drawing with a ruler, so of course adjustments are possible.

the video of the screen capture, I have to turn the crankpin  withe the mouse, hence the shaken movement!

https://ti1ca.com/yyvsf9pq-MEM-capture-MEM-capture.mp4.html

Happy new year !

PS : this engine is clearly the engine of the turret of the USS Monitor, and is visible in some of the engravings

Fantastic! Very instructive to see the linkages in motion!   

[Zephyrin]

I forgot the dimensioned pictures used for the animation...
Getting a clearly dimensioned drawing is not that easy with Solvespace...

[crueby]

Neat!   

I bet the dimensions on the valve linkages need to be in a close range for it to function, animating it up would allow experimentation on that. A while back I tried drawing up a Joys valve setup, and found the ratios of lengths on the different parts made a huge difference in how it moved or if it jammed up.

[Fj45]

 Wonderful Zephyrin,
 Those rods and links sure dance a merry jig don't they?

[Zephyrin]

I think this model is a great find among John Ericsson's designs, very appealing, but at my age, I'm not going to say that I'll ever build this model...

By adding a constraint to the angle of the gear shift slide, the eccentric connecting rods no longer slip, and the model runs very smoothly...

[crueby]

Thats fantastic!

[Captain Jerry]

That is a very interesting linkage and would make a great model with all that complicated movement, particularly since it could be handled with a single eccentric so when I see something like this I say "why?"  I would guess that vertical clearance is the problem. To use an eccentric would need a longer crankshaft and probably an additional shaft bearing and the valves would be on the top face of the cylinders adding to the overall height of the engine which would be mounted in the crowded  below deck space.  That is why the obvious similarity to various railroad linkages which have to contend with same valve location issue.  There may be other reasons why but thats my best guess.