Interesting engine question

[crueby]

Hey all,
Came across this engine on the National Archives website, its from the USS Monadnock, a twin turret monitor type warship. This engine was designed to rotate the gun turret. It has two cylinders, 90 degrees from each other, with a single crankpin. The part I've never seen before is the valve linkage, keys off the crankpin, with levers going out to either valve. Anyone ever see this before? Know who invented this type of linkage? I've attached a copy of the plan, scaled way down to fit - too small to read the dimensions, but you can still see the part outlines fine.
Chris

[Sanjay F]

No idea of the answer but am interested by what you say about the linkage and what it does; is that there to keep both cylinders synchronised with each other mechanically rather than timed 'by measurement or by eye'?

[crueby]

No idea of the answer but am interested by what you say about the linkage and what it does; is that there to keep both cylinders synchronised with each other mechanically rather than timed 'by measurement or by eye'?

The pistons themselves are connected to one crankpin, so that keeps them synchronized. Its the valve linkages that I've never seen before. They both work off the same crankpin as the pistons, which maybe could be adapted to a single cylinder engine?

[crueby]

Actually, I'm describing it wrong - the valves both get driven off the lower left crosshead movement, not directly from the crankpin.

[steamer]

Walschaert-ISH

[crueby]

Walschaert-ISH

    Don't think the patent office search engine has an '-ish' checkbox! 
 

[Charles Lamont]

Joy-ISH too. Each of the curved 'expansion' links is worked by the crosshead of the other cylinder. So each valve is phased at 90° to its piston. So there will be no lap and no expansive use of steam. Reversing both sets of gear is done by the bell-crank. Note that the die block for one valve is 'up' and the other 'down'. This cleverly provides the asymmetry necessary for coordination, just as with cross drive in duplex pumps.

[crueby]

Yeah, the use for the engine would have been for short stop/start runs moving the turret, so no need for changing cutoff, I'd say. It does seem to have elements of Joys and Walschaerts, but then so do any of the other 3 dozen railroad linkages. This one is a bit odd in that the cylinders are offset 90 degrees to each other, which would make sense for fitting in or around the perimeter of the turret.

Might CAD this one up to animate just to watch it go!

[Fj45]

 Hi Chris
   Not much for crime story "who dunnits", but love a good mechanical "what dunnit".
 It looks to me that the "lower left" crosshead only runs the "upper right" valve & the U.R crosshead runs L.L. valve.
 Starting at lower left crosshead there's a link parallel to conrod, pinned to a link with a tee shape. I assume the tee piece is the expansion link. It appears to simply pivot about a point dead center of its slot. Die block positioned in slot by links and arm from weigh shaft as usual. (weigh shaft sitting where camshaft would sit in .I.C. V8).
 Interesting setup l to have not seen before (doubt having studied half so many of these as you but).
 This one confirms my general opinion of US heavy engineering back in the day ..deceptively, ingeniously, simple.. once you get your head round it & (in my case) stop trying to solve imaginary complications that ain't there.
 edit .. couple of replies whist typing

[crueby]

Hi Chris
   Not much for crime story "who dunnits", but love a good mechanical "what dunnit".
 It looks to me that the "lower left" crosshead only runs the "upper right" valve & the U.R crosshead runs L.L. valve.
 Starting at lower left crosshead there's a link parallel to conrod, pinned to a link with a tee shape. I assume the tee piece is the expansion link. It appears to simply pivot about a point dead center of its slot. Die block positioned in slot by links and arm from weigh shaft as usual. (weigh shaft sitting where camshaft would sit in .I.C. V8).
 Interesting setup l to have not seen before (doubt having studied half so many of these as you but).
 This one confirms my general opinion of US heavy engineering back in the day ..deceptively, ingeniously, simple.. once you get your head round it & (in my case) stop trying to solve imaginary complications that ain't there.
 edit .. couple of replies whist typing

"What Dunnit" - great phrase!  I've had 'why-don-it-work' sometimes...

I love looking at old machinery and figuring out how it works. Often linkages got over-complex to get around someone else's patent, sometimes just since the designer didn't really understand the problem!   

[Fj45]

 "I've had 'why-don-it-work' sometimes"  yarrp..
 Thanks for an enjoyable hour, Chris, got any more?

[crueby]

"I've had 'why-don-it-work' sometimes"  yarrp..
 Thanks for an enjoyable hour, Chris, got any more?

No other ones at the moment since I  got that faulty dematerialization circuit  on my Tardis fixed...   




Might have one soon, am figuring out the paddlewheel engine from the Great Eastern. Last mechanism is  the  friction clutch setup for disengaging the  wheels.  Waiting on  some info from the science museum and an old book that may solve it...

[Fj45]

 Speaking of Tardis, I just realized what time it must be over there. I'll stop asking questions from New Zealand, where it's currently lunch time tomorrow.

[crueby]

Speaking of Tardis, I just realized what time it must be over there. I'll stop asking questions from New Zealand, where it's currently lunch time tomorrow.

Its only early evening yesterday here. Still time to buy a lottery ticket if you can tell me tomorrow's  numbers!   

[steamer]

Is there a title block with a name on that print?    Might be a good patent search if you have a name

Dave

[crueby]

Is there a title block with a name on that print?    Might be a good patent search if you have a name

Dave

The only name on it is "Atlantic Works Boston 1864". I tried searchin with that name, but only two patents that are unrelated to this engine. Apparently there were a couple companies by that name over the years, but at least one was a major ship engine manufacturer.

There is quite a bit of detail in the high res version of the drawing, some of the views work a lot like the ones on your Ohio engine drawings, where they mix angles of view and have projection lines going across to show which parts are being shown. I am thinking it will be a good CAD excercise to draw and animate this one. Right now I am in the middle of drawing up the steering engine from the Great Eastern, so maybe after that is done.

[steamer]

Joy-ISH too. Each of the curved 'expansion' links is worked by the crosshead of the other cylinder. So each valve is phased at 90° to its piston. So there will be no lap and no expansive use of steam. Reversing both sets of gear is done by the bell-crank. Note that the die block for one valve is 'up' and the other 'down'. This cleverly provides the asymmetry necessary for coordination, just as with cross drive in duplex pumps.

Yeah   I can see the radial part too.    There have been so many perturbations of valve gear.....well.   

[CI]

Looks to be somewhat of a mirror image across the 45 degree axis.

.

[crueby]

Looks to be somewhat of a mirror image across the 45 degree axis.

.

Yeah, I  think you are right. The more times I  go back to look at it the more it makes sense. Can now see how the motion of one crosshead rocks the lever for the other, giving a shorter motion and offset the 90 degrees. At first I  had thought the crank arm on the bracket to upper left of the crankshaft was part of the valve movement,  now I  see that its the control for fwd and reverse, moving the short arcs from one end to the other. That could also effect cutoff like a Stephenson  link normally does.  As Fj45 said, elegantly simple, but deceptive when first seen. Should have a nice eye candy motion when running.

[paul gough]

Late in catching up, but it occurred to me that it is more Gooch like than Walschaertish as the former predates the latter and US did not use Walshaert until 1870s and mostly later. In any case not really applicable or accurate to use these as descriptors. I seem to recollect John Ericsson designing an engine driven gun turret for a ship, maybe it was the Monitor, he was rather active designing marine stuff for US navy including a hot air engined ship. Might be worth chasing up his doings if there is any likelihood of a connection to him. Regards, Paul Gough.

[steamer]

Good point Paul.   Ericson was pretty prolific!

[AVTUR]

Just looked up Ericsson in Wikipedia since I thought I recognised the name in association with the Rainhill Trials. Yes, an interesting engineer but one of very many that falls short of greatness.

I think the reversing gear is of its own and not related to the conventional gears since it relies on the geometry between the two cylinders. The engine would make a good model, though.

 
still

AVTUR

[crueby]

Also just looked up Ericsson on the patent sites, had no idea he had so many inventions, I only knew of his Monitor engine. Lots of stuff, steam engines, compound steam engines, air engines, gun carriages, torpedos...  This particular arrangement does not show up though.

And on the Gooch gear, that still relied on eccentrics from what I see. This one uses levers from the other cylinder at 90 degrees to get the equivelant motion.

Agreed, this would make a good model! Yet another one to add to the list... 

[crueby]

More searching, and seeing conflicting info on who designed the engines in that ship. Some say Ericsson, others list Benjamin Isherwood actually designing them, based off Ericsson's earlier work. The ship had two of the Ericsson style 'vibrating' engines like the one that Rich Carlstedt built the amazing model of from the Monitor. Also found a plan showing the steam piping in the ship, no real details on the engines, but it does show the turret engine hanging upside down from the deck beams underneath the turret.

[paul gough]

The Original Monadnock seems to be a near contemporary of Monitor so maybe the turret engine was just a copy/adaptation of Ericsson’s Monitor turret engine. Maybe no patent taken out by Ericsson for the engine therefore no record. I believe the Monitor was raised and preserved somewhere. Was there any remains of its turret engine so as to make a comparison with the drawing of the Monadnock’s.

[crueby]

The Original Monadnock seems to be a near contemporary of Monitor so maybe the turret engine was just a copy/adaptation of Ericsson’s Monitor turret engine. Maybe no patent taken out by Ericsson for the engine therefore no record. I believe the Monitor was raised and preserved somewhere. Was there any remains of its turret engine so as to make a comparison with the drawing of the Monadnock’s.

Didn't know the  Monitor had a turret engine. Do you know if details about it are known?

[steamer]

There is a whole museum on the subject of the monitor which much of the wreck recoverd and being conserved.

[steamer]

https://www.marinersmuseum.org/exhibit/uss-monitor-center/

[crueby]

Dave - treasure trove there! They have tons of stuff online, am going through things now...   

[crueby]

Bingo!  They have a great model of the turret engine, pictures here:
https://catalogs.marinersmuseum.org/object/CL29202

[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.

[Rich Carlstedt]

3 months late to the party, but maybe can answer the "Why"
John Ericsson was a master of Kinematic  motion
He  started with hot Air Engine designs as a youngster in Sweden  and
moved to England to pedal his designs , but England in 1820-30 era was all " Steam Driven" and so he designed steam,
but his heart was his Caloric engines (hot air)
Linkages came to him like magic and complexity did not deter him from design.
In order to build the USS Monitors engine, I studied his earlier works  and he was not dismayed at linkage issues.
The Turret Engine design was not patented  as he gave all the designs  ( 40 + ) of the Monitor to the USA Gov. as he was proud to be an American
Look at the Reversing Gear for the Monitor --truly a terrific idea  using what later was  called a "Phase Changing Mechanism"
Never used on any other engine
He was a Kinematic Master

Rich