Posted by: bleedingartindustries | August 26, 2010

Weekend running the Case 80 hp Steam traction Engine

Case Steam Traction Engine

Case Steam Engine

My loving engine widow partner again lost me to “my favorite obsession” this weekend.  As some might remember, I had blogged about a friend of mine who could not find anyone to teach how to run and maintain a steam traction engine.  This weekend I finally put my money where my mouth was and did the near three-hour drive to Camrose, Alberta to train and learn how to start and run his 1912 80 hp Steam Traction Engine.  The idea is that eventually I can use these hours towards my fourth class engineers papers.  I will also have to challenge a test.   Southern Alberta Institute of Technology (SAIT) has an online course that I can take as well, although not many of the new courses have a lot of information dealing with historic boilers such as these.

I spent the weekend with Dave Fitche of the Camrose Museum in Camrose, Alberta.  Anyone who is watching my youtube and engineutopia pages will know that Dave appears in the background of a few of them.  The first year I showed at the Reynolds Museum, Dave was pictured driving the very unique John Bull Tractor.  Dave was initially instructed by the legendary historic steam expert, John Quill.  Dave has worked on steam and traction engines for many years.  He does most of the UT (Ultrasonic) testing here for the historic boilers.  He has worked for the Prairie Steam excursions restoring the 6060 and the 41, as well as at the Camrose and Reynolds Museums.  Dave is a tireless advocate of teaching the young the ways of the older technologies.

Dave and the Case

Dave and the Case engine

The Case is a large engine second largest in size built by the company, but here in Alberta given the mysterious rules of our local brain trust inspections branch (ABSA), the boiler is set to a maximum pressure of 65 PSI steam.  It is reduced every year by a factor of .01.  This would mean in a very few years it would not have enough pressure to run at all.  This is because of bad transcription on the rule book where a word was dropped in the 1950’s.  Hopefully, with the CSA stepping in, as well as the formation of historic boiler associations from across the country, this silliness can be resolved and still keep a safe boiler.

Some things I learned about:

Case Steam Traction Engine Control

Johnson Bar control

Johnson Bar:  This is the control which starts and stops the engine.  It also changes the amount of steam which is effecting on the piston.  At the furthest out notch, the steam is contacting the piston 80 percent of the time.  The furthest in notch the contact is closer to 10 percent.  Not only does this change the power of the engine when first starting and stopping, this will affect the efficiency of the engine.  Dave can reduce his steam (and thus water consumption of the engine) by up to 50 percent just by proper working of this control.  This control also controls the stop of the engine as well as reverse.

Throttle and Clutch

Throttle and Clutch controls

Throttle:  This control changes the amount of steam allowed into the steam chest for operation of the engine.  The more steam, the harder the push, the faster the engine will go

.  This lever precedes the steam governor.  The governor limits the amount of steam which limits the speed that the flywheel will travel.  This engine runs about 250 to 300 RPMmaximum.  Any faster and the engine can run the risk of pulling itself apart.  As the flywheels are made of  cast iron, grenading can become an issue with over speeding of the wheels.  Cast iron is very good with compressive strength but not good with elongation and especially not with fracture.

Clutch:  On this engine the large lever is the clutch to engage the wheels.  When motion is not needed for the engine and only power is needed via the pulley, the clutch is disengaged to allow free motion on the pulley.  The clutch lever is a bit of a beast and one has to be careful when near it.  If not properly engaged, the lever can jump out of position, striking anyone standing near it.  It can kill.

Case traction engine sight glass

Sight Glass

Sight Glass:  This is the thing you really want to watch.  This lets you know the level of the water in the boiler.  This is important to keep well maintained by following a sequence of opening stop cocks and closing valves to blow out the system.  The two taps seen on the side of the sight glass are the tricocks which in case of a glass breakage can prove the water level by opening the taps in order and seeing what comes out.  The water level in this engine should be kept at the triangular pin or higher.  If the water reaches 3 inches below the bottom nut of the sight glass then that would mean the crown sheet of the boiler / firebox would be exposed and creates a dangerous situation which can cause a violent explosion if water were to touch the sheet.  This is called flashover where the water touching the red hot sheet flashes to steam causing a pressure surge that the boiler simply could not handle.

On the other side of things, the water level should be kept from being to full as when water hammers through the steam dome into the engine, the engine takes unusual stress (water hammering) and can also simply just lock up.

It is very challenging to keep the water level even when the tractor is in motion.  Pitch and yaw of the engine changes the visual in the sight glass as the water sloshes back and forth.  Sometimes the water will disappear completely when going downhill and pitched to one side, only to appear overly full once the engine changes position.  As with all the controls, the engine reacts very slowly to change and the control of it is through gentle tugs and shifts as opposed to “flooring” it.

Boiler control was the hardest thing to keep track of.  One wants to keep a full head of steam which needs to keep a good fire going.  At the same time, the water level needs to stay in a certain zone on the sight glass  and there are varying levels of steam use.  Juggling all three so as not to pop the pressure valve but keep a useful head of steam and not allowing the water levels to get too low can be quite taxing. I tried to keep the pressure around 50 PSI but wasn’t as skillful as I could have been.

Case Heat Exchanger

Case Heat Exchanger

Pictured here is the heat exchanger.  It is used when the injector or water pumps add water to the boiler.  It takes waste steam and heats a series of tubes through which the fresh feed water is heated before entering the boiler.

The injector is a crazy smart system which uses steam blown through venturi tubes to suck water into the boiler.  This is truly an amazing invention as it works so exceedingly well.

The boiler holds approximately 300 gal of water and the water tanks in the back hold another 280.  This makes a total weight of nearly 6000 pounds of water alone.  This engine will also use approximately 300 gal of water in an hour under full steam.  Consider this: when threshing in the old times, there would be a team or two of horses and men hauling water as well as a team fetching and delivering coal.  A threshing team would likely consist of up to 15 or 20 people just to do a day’s work.

All in all, it was a great weekend.  I hope to go up again really soon and give a hand.  This engine will be at the Reynolds show this Labour Day weekend, and will be loading for the trip to Wetaskiwin next Monday.  If  I am lucky I can get video to post.

The engine and I

The Case engine and I

Advertisements

Responses

  1. hello Leo, great article. your small steaming friend Ethan Harty


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: