The Steamboating Forum

She is beautiful. Can't wait to see video of her in the boat she eventually powers.

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.

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 ,,

Oh my!

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

Beautifully done.

I really like the indicator diagram on the builders plate as well, very clever

Beautiful engine for sure.

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

-Ron

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

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