Triple Expansion Engine - Elliott Bay

A special section just for steam engines and boilers, as without these you may as well fit a sail.
stevey_frac
Full Steam Ahead
Full Steam Ahead
Posts: 105
Joined: Sat Nov 21, 2009 3:47 pm

Re: Triple Expansion Engine - Elliott Bay

Post by stevey_frac » Mon Mar 01, 2010 10:50 pm

She is beautiful. Can't wait to see video of her in the boat she eventually powers.
User avatar
Aheadslow
Warming the Engine
Warming the Engine
Posts: 62
Joined: Fri May 14, 2010 3:04 pm
Boat Name: No Boat Yet
Location: In The Box With Schrodinger's Cat

Re: Triple Expansion Engine - Elliott Bay

Post by Aheadslow » Sun May 23, 2010 2:47 am

Very impressive engine,,great videos. I fear the Boat will have to be very nice indeed :so as not to look tacky compared to that lovely engine. :D
Human beings have an inalienable right to invent themselves.
User avatar
Maltelec
Master of the Forum
Master of the Forum
Posts: 268
Joined: Sat Nov 14, 2009 7:01 pm
Boat Name: No Boat Yet
Location: Cumbria, UK
Contact:

Re: Triple Expansion Engine - Elliott Bay

Post by Maltelec » Mon Dec 05, 2011 11:41 pm

Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
I've got the vehicle, just need the boat.
User avatar
Aheadslow
Warming the Engine
Warming the Engine
Posts: 62
Joined: Fri May 14, 2010 3:04 pm
Boat Name: No Boat Yet
Location: In The Box With Schrodinger's Cat

Re: Triple Expansion Engine - Elliott Bay

Post by Aheadslow » Fri Dec 09, 2011 10:43 pm

Please tell me you put a nice brass makers plate on that beautiful engine . The world deserves to know who built it. It's going to look truly great in a nice boat.
Congratulations ,,
Human beings have an inalienable right to invent themselves.
S. Weaver
Full Steam Ahead
Full Steam Ahead
Posts: 353
Joined: Mon Sep 26, 2011 4:23 pm
Boat Name: SL Iona

Re: Triple Expansion Engine - Elliott Bay

Post by S. Weaver » Sat Dec 10, 2011 3:30 am

Oh my! :o
Steve
steamboatjack
Full Steam Ahead
Full Steam Ahead
Posts: 283
Joined: Fri Nov 20, 2009 8:02 am
Boat Name: grayling
Location: Cumbria U.K.

Re: Triple Expansion Engine - Elliott Bay

Post by steamboatjack » Sat Dec 10, 2011 6:39 pm

Here is the builders plate, What I really need now is some one who wants an engine built as I have nearly finished number 2.
Regards Jack
Image
87gn@tahoe

Re: Triple Expansion Engine - Elliott Bay

Post by 87gn@tahoe » Sun Dec 11, 2011 6:40 pm

Beautifully done.

I really like the indicator diagram on the builders plate as well, very clever
User avatar
DetroiTug
Full Steam Ahead
Full Steam Ahead
Posts: 1863
Joined: Fri Nov 27, 2009 5:56 pm
Boat Name: Iron Chief
Location: Northwest Detroit

Re: Triple Expansion Engine - Elliott Bay

Post by DetroiTug » Mon Dec 12, 2011 8:17 pm

Beautiful engine for sure.

Wes, I'm not understanding the "indicator diagram" ?? What does it represent? Some sort of steam engine indicator?

-Ron
User avatar
marinesteam
Full Steam Ahead
Full Steam Ahead
Posts: 309
Joined: Thu Nov 19, 2009 2:51 am
Boat Name: TBD
Location: Colorado USA

Re: Triple Expansion Engine - Elliott Bay

Post by marinesteam » Tue Dec 13, 2011 7:36 pm

From Wikipedia, the free encyclopedia
A pressure volume diagram (or PV diagram, or volume-pressure loop)[1] is used to describe corresponding changes in volume and pressure in a system. They are commonly used in thermodynamics and cardiovascular physiology.

PV diagrams, originally called indicator diagrams, were developed in the 18th century as tools for understanding the efficiency of steam engines.

http://en.wikipedia.org/wiki/File:Schem ... iagram.png


Cheers

Ken
Edward
Full Steam Ahead
Full Steam Ahead
Posts: 138
Joined: Tue Nov 17, 2009 9:25 pm
Boat Name: No Boat Yet
Location: Ambleside , Cumbria , UK.

Re: Triple Expansion Engine - Elliott Bay

Post by Edward » Wed Dec 14, 2011 12:14 am

On large engines there was often a blanked off port to which the indicator could be connected to register pressure in the cylinder . On smaller engines it was usually connectd to the cylinder through one of the drain-cock ports .
A cord connected to the crosshead turned a cylinder on the indicator against a spring so that this cylinder would rotate just under one full rotation per stroke , the spring would rotate the cylinder back to its starting position as the crosshead returned . Attached to this rotating cylinder was a paper card .
Pressure from the steam engines' cylinder moved a marker (ink or pencil) up and down on the paper card whilst the fall of the crosshead and the subsequent rewinding of the cord by the spring rotated the paper card mounted on the indicators' cylinder backward and forward .

So by looking at the line drawn on the paper card (having removed it from its cylinder) you can see what the pressure is in the engines' cylinder throughout the cycle .
By measuring the area enclosed by the line on this diagram the average pressure can be worked out . To measure the area you need either a planometer (I think I've spelled that correctly) or a pair of scissors and a delicate pair of scales .

By using the indicator a moderately skilled operator could see if his valve events were correct and could work out the power being produced , this information together with the coal consumption would tell the Chief Engineer or owner whether his engineers and stokers were doing their jobs efficiently or were wasting the company's money .

Indicators of this sort were also used on marine diesel engines but have now been replaced by lasers and other electronic trickery which does the same thing for only 10 or 20 times the cost . It can however do it continuously and electronically instantly adjust injector and valve timings several hundred times each second !

Regards Edward
Post Reply