johnsmachines

machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment.

Tag: steam engine

Portsmouth UK. 2 more great museums.

Not strictly museums.  Ships actually, but displayed as museum pieces.  Both incredibly interesting.  And I am not including Nelson’s “Victory”.  I had seen it 40 years ago, and after 5 hours of walking, my knees told me that enough was enough.

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“Victory” as seen today.  Still the biggest crowd pleaser.  Now sitting on props in a dry-dock.

My main targets today were “Warrior” and the “Mary Rose”.

Warrior was built in 1860.  The age of steam was well underway.  But to date, warships were still sailing ships.  However the French were rebuilding their navy after their humiliating defeat at Trafalgar, and they had built the first propeller driven, steam powered, iron clad (wooden ship with steel plate cladding).  The Brits were not going to stand for that, so they built “Warrior”.  The most powerful, fastest battleship afloat, and more than a match for anything else in the world.  By the time it was built, the French and the Brits were allies, for a while.  Warrior was destined to never fire a shot in anger.

Today it sits moored at Portsmouth’s Historic Dockyard, and is a fascinating mixture of steam and sail, muzzle loaders and breech loading guns, Steel and wood.  It is a big ship, 127.5m (418′) long, and 9210 tons.  It looks a little odd to our eyes because it has no superstructure, except 2 funnels, and the foremast and mainmast are widely separated.

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Steel framed, 18″ of oak lined, plus 4.5″ of steel plate.   The masts are steel, with wooden upper sections.  The figure head is a Greco-Roman warrior.   706 crew.

This ship could make 14.4 knots (27.7kph) under steam, 13 knots (24kph) under sail, and 17.2 knots (31.9 kph) with sail plus steam.  Not as fast as a clipper, but much faster than any other warship.

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4.5″ (114mm) armour plating, plus 18″ (460mm) teak planking.

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Traditional spoked steering wheels were duplicated on 3 decks.

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Hundreds of Lee-Enfield percussion cap rifles were available.

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And cutlasses, to repel boarders.  Muzzle loading cannon tools to left.

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And Colt 45’s for the officers.

But the main armament was of course the big guns.

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The gun deck was similar to that of the 120 year older Victory.   except that these are huge 68 pounders.  19 man gun crew for each.  A mixture of 10 x 110lb breech and 26 x 68lb muzzle loaders.

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And the crew still slept in hammocks on the gun deck.  And ate there.

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But they had washing machines  and lavatories (first ever warship with these)

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and baths!

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The steam engine, surprisingly was a relatively primitive, but powerful twin cylinder, single expansion, horizontal trunk engine of 5469hp, driving a single propeller.  The 10 boilers were box shaped, double firebox, no fire tubes.   22 psi only.

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Coal was delivered in small coal trucks on rails, and shovelled into the firebox’s.  No gauges,  except in engine room.   853 ton coal stowage.

I have many more photos of Warrior, but I am down to my last few megs of storage, and I want to show some pics of the Mary Rose, which is probably the most stunning museum display I have ever seen.  I know that I keep saying that, but this really is…..

Mary Rose was a 35 year old warship which sank in 1545 during the battle of the Solent, against a huge French invasion fleet, while Henry 8 was watching.  No-one really knows why it sank, but the most popular theory is that bigger cannons had been installed, requiring low gun-ports to be cut into the the hull, and that after firing a broadside the ship had turned and the open gun-ports shipped a lot of water, which sank the ship.   Whatever, the ship was unable to be raised. Most of the hull gradually rotted and broke away.  But the parts which were under silt did not rot, and were still there when discovered over 3 centuries later.  In 1985 the remains were raised, and painstakingly preserved.  A museum to house the remains was specially built.  And it is stunning!  No other word for it.  Here are a few pics from today.

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Mary Rose.  Pride of the English fleet.

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and you know who.

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About 1/3 of the hull remains, including most of the keel.

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The bronze cannons are in fairly good shape.  Only real remains are displayed.

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This is a breech loading iron cannon, made of strips and hoops of iron.  The ancient wood and iron has been treated for years with PEG (polyethylene glycol) before going on display.

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Hundreds of ewe long bows were found, many still in their storage boxes.

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And many skeletons.  This one was a bowman.  That humerus (upper arm bone) is massive.  There were 35 survivors out of the many hundreds of men on board. 

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And a reconstruction of the bowman.

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And sadly, a dog.

A most remarkable museum.  Add it to your bucket list.  Allow at least 2 hours.

 

 

 

 

 

BT. Before Trevithick.

Before Trevithick were Savery, Newcomen and Watt.  And way before them, Hero of Alexandria (1st century AD)

Thomas Savery, a military engineer from Devon, took out a patent in 1698 for a steam operated pump.  It had no moving parts, except some valves.

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It had 2 low pressure boilers.  Steam from one boiler was introduced into one chamber, and water was then introduced which condensed the steam, forming a partial vacuum, which sucked up water from below.  Steam from the other boiler was then introduced, which pushed the water upwards.  As a pump it was a failure, and it is not known if any were made.  Modern reconstructions have also been unable to pump water successfully. But the patent lasted, and forced Newcomen to involve Savery with his invention in 1712.

Thomas Newcomen was an ironmonger and Baptist lay-preacher from Dartmouth, Devon, and he is the reason that I am currently in this pretty Devon town.  There is an original Newcomen “atmospheric engine” in Dartmouth.

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(taken at an angle to avoid window reflections)

The Newcomen pump, (for pumping water from the mines was its purpose) also used the condensation of steam creating a partial vacuum, as its principle of action, and it was quite successful.   So successful in fact, that more than 600 of them were built, and they continued to be built well after the improvements of Watt and Trevithick, into the nineteenth century.  In the diagram above, the 22″ power cylinder is on the right, and the pump cylinder is on the left.  The genius of this design is that the pump can operate in the depths of the mine (or canal or military trench) while the engine remains above ground.

It is incredibly inefficient in thermal terms, converting only 1:200 of the energy from burning coal into the mechanical energy of the pump, but it was by far, more powerful than any pumps driven by man, horse, wind or water at that time.

The room in which the Dartmouth engine is housed is just bigger than the 15′ high engine, so pictures are difficult.

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All wood, except the power cylinder on the right, and the pump and pipes (not seen).  The curved ends of the big wooden beam keep the piston rod and pump rod vertical.  Cylinder boring had not been introduced yet, so the gap between piston and cylinder was up to 1/4″.

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The valves to admit the steam and water were originally operated by hand, but later some automated simple levers were introduced.  Note the square nuts (original).  It appears that the woodwork is mostly original, albeit repaired in places.

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The pump connection

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This power piston has a bore of 22″ (560mm), but they were built increasingly bigger, up to 80″ (2032mm).

The Newcomen engines were simple, and effective.  Their main problem was that they consumed vast quantities of coal.  They were widely used, but there was/are no coal deposits in Cornwall, and transporting coal from Wales was costly, and taxed.

James Watt‘s big contribution to steam engines was to add a condenser to the engine, which was separated from the power cylinder.  That doubled the efficiency.  He also sealed the top of the cylinder, so both strokes of the piston rather than just the down stroke, were power strokes.  But it was still a vacuum powered engine, and therefore had an absolute limit of working pressure of something less than atmospheric pressure (15psi).

Richard Trevithick‘s main contribution in 1800 was to increase the steam pressure available, by inventing the “Cornish boiler” which produced steam at 50psi, and even up to 145psi.  This more than doubled again the thermal efficiency of the steam engine, and made it much more compact, leading to his applications of steam engines in road vehicles, railway locomotives, ship engines, and industrial stationary engines (like my model dredger engine).

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Watt modified Newcomen engine on the left, Trevithick dredger engine on the right. Size comparison.

Tomorrow I am driving to Portsmouth.  So I will leave the west country inventors of steam engines.  It has been a fascinating journey.

First stop, Fort Nelson.  To renew my acquaintance with the Ottoman bombard, which was the subject of my blogs several years ago.

 

First Steam Locomotive.

In 1802 a Richard Trevithick designed engine was made by the Coalbrookdale company.  Not much is known about it, but is recorded that the steam pressure reached 145psi!  Trevithick had previously operated his road steam locomotive up the Camborne Hill, but this was the first one to run on rails.

The next one was made for the steelworks at Merthyr Tidfil, Wales.  It was a Trevithick engine which ran on rails.  The owner made a 500 guinea bet with a rival (an astronomical figure.  Somewhere I read that it would be equivalent to a million dollars these days), and in Feb 1803 the engine towed 5 wagons, loaded with 10 tons of iron ore (or coal, not sure), and 70 odd bods, a distance of 10 miles.  There was dispute about whether the bet had been won due to some technicalities, and no record of it being paid, but it was a moral victory.  The age of steam had really begun.

The biggest problem was not the locomotive, but the rails.  They were not strong enough, and frequently broke.  It took the genius of George Stephenson to solve that problem, by using forged iron in preference to cast iron.  And his son Robert to increase the efficiency of the engine and boiler in the form of “Rocket”.  But that is another story, for 30 years later.

Unfortunately the original of the Merthyr Tidfil loco has not survived, but several replicas have been made, based on original drawings.  I saw one of them at Swansea, Wales, not far from Merthyr Tidfil.  Not a steaming day.  It does run.

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Not great photos.  The lighting conditions in the National Waterfront Museum were difficult.

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The typical big, skinny Trevithick flywheel, and driver’s wagon.

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Square main shaft.  Hex nuts were not around in 1802.  

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And that is a view that you don’t often see.  The pressure gauge is definitely a modern requirement, as I discovered with my dredger engine.

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Notice the fish belly rails.  Originals were cast iron.  “Fish belly” shape to increase the strength, but alas, not strong enough.  Hex nuts again!  And those gears have modern shaped teeth.  Quite a few compromises in this replica.

And I have now arrived in Camborne, Cornwall, Trevithick’s home, and the site of his famous trial of the steam road loco.

I made a pilgrimage to Fore St (“Camborne hill”), then to his statue, to pay homage.

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Richard Trevithick.  Genius.

 

Bolton Steam Museum

I was a bit unsure about visiting this one.  A smaller museum, and I knew from the web site that it was not a steaming day.  But it was only a half hour drive, so off I went.  I arrived at the address, and there was a supermarket, but in a corner of the supermarket block there was a tall, old,  sizeable red brick building with no windows.  And a sign… “Bolton Steam Museum”.

In I wandered, and a gentleman in overalls approached.  This was a volunteer working day.  But Ian (apologies if I got the name wrong), stopped his task and spent over an hour showing me around, explaining the finer points of his babies, starting some of them on electric motors to demonstrate the movements, then invited me to a cuppa with his mates, where there was further discussion, mainly about rope drives and stone engine bases.

No parking or entry fee on a non steaming day, (but a donation was appreciated).

The machines were not the monsters of Kewbridge or Kempton pumping stations.  They were mostly from the industrial age of the midlands 1840-1930, powering textile mills, sawmills, and factories.  Some were quite big.  All were beautifully restored and presented, and for once, the descriptive labels had lots of information about the physical characteristics and histories of the engines.  A nice aspect was the elevated walkway down the centre of the room, allowing a good view above the engines.

Some photos follow.  Not as many as the museum deserves, because I am nudging my  Wordpress limits.

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The twin beam engine of 1840 is the oldest engine in the museum. It started life as a twin, but when higher pressure steam became available it was converted to a compound twin.  Note the non identical con rods.  That happened during the conversion to compound.  Partly seen is an excellent collection of engine lubricators.

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This is a “non dead centre” engine.  It has 2 con rods, one for each piston, but only one crank.  Watch the video below and see if you can figure it out.  It ran 100 looms in a textile mill.

 

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Two of the barring engines.  These were small steam engines which were used to rotate the flywheel of a much bigger engine, to its correct starting position.

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For the first time ever, I saw rope drives in action.  Rope made of cotton was preferred, but these days sisal is usually used.  Each rope could transmit 54hp if made of cotton, 30hp if sisal.  They worked in V shaped grooves, and hung rather loosely between the pulleys, the weight of the rope wedging the rope into the groove.  The splices, joining the rope into an endless loop were made by specialists, on the engine, and unlike marine splices, barely increased the diameter of the rope.  The splices which I saw extended over about 2 meters of the rope. 

This museum is another gem.  I have described only a few of the 24 major items on display.  There are many more, including engine lubricators, gauges, and valves.  It was well worth the stay in Manchester, and more than made up for my disappointment at the  Museum of Science and Industry.  Try to see it on a steaming day.  The dates are published on the website http://www.nmes.org

Also, the 36 page “Souvenir Museum Guide” is the best guide of its type I have encountered and contains detailed descriptions and colour photographs of the major exhibits.  It is a steal for £2.  The History of the Bolton Steam Museum is 64 pages, crammed with photos, and after a quick browse I am looking forward to reading it.  Also IMO, a steal at £3.

Sincere thanks to the volunteers who shared their enthusiasm for steam engines with me today.  I do hope to return one day to see the engines running on steam.

 

 

Next Project

The Trevithick dredger engine model is almost finished.  Currently applying some paint.  And getting it ready for the final boiler inspection.  I am guessing about 2 weeks.

I have chosen a spot in the house where it will sit, and will post a photo in due course.

A few people have been asking if I have decided what to make next.  In terms of a major build, the answer is no, I have not decided.  I have considered a few possibilities.  Those possibilities include a model of Stephenson’s “Rocket”, Trevithick’s “Catch Me Who Can” or “Pen-y-darren engine”, a Shand-Mason fire engine, or even another cannon.

What I will do, is to complete several unfinished projects, and if a major project becomes obvious, imperative, then anything is possible.

The unfinished projects include…

  1.  An Arduino controlled rotary table.  The mechanicals are made.  Just need to dive into the electronics.
  2. The Southworth steam powered boiler feed pump for the vertical boiler.
  3. The CNC controlled tool post milling attachment for the Boxford CNC lathe.
  4. Paint the Bolton beam engine.  Lag the cylinder.  Install a cylinder oiler.
  5. Finish the triple expansion model marine engine.  The lagging, the piston rings, the gaskets, the oiler and oil pipework, and painting.

Looking at that list, I really do not need to start another major project.

And sometimes it is nice to sit back, and enjoy the glow and satisfaction of previous projects.  It does sound rather self satisfied, no?  So here is a selection of videos, mostly first runs of newly completed projects.  Most are YouTube links, but one or two will run directly.

This was the first model steam engine which I made about 5-6 years ago.  It is a Bolton 7 single cylinder mill engine, and this was the first occasion I had run it on steam.  It was a very exciting moment, seeing it actually running on steam.

Next came the Bolton 12 Beam Engine.  Still a crowd favourite.  The beard was ordered off by SWMBO not long after this.

Then a couple of Stirling engines.  How they work is still a mystery to me.

 

Then the problematic, difficult triple expansion engine, which took 3 years and several extended breaks to get to the working stage.  Still not finished completely.  Stuart Tankard’s boiler.  Since then I made a vertical boiler.

And somewhere in there I made this little reversing engine for the club competition.  Alas, it failed in action.

And 3 cannons came out of left field.  They started as a CNC project, but then took on a consuming interest of their own.  About this time I saw the necessity of learning how to put together a video.  Still learning.

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The 6″ vertical boiler.

And finally the Trevithick dredger engine.  The historical aspects of this engine, the genius of Trevithick, the fact that the engine works…. has been marvellous.  The engine is looking quite different with some paint applied.  And the propane burner is significantly better than appears in this video.

So, if you are still with me after all of those videos, congratulations on your stamina.  It is  therapeutic to take stock sometimes, and to wonder about where making all of these engines is going.  It was not to any plan.  Still no plan.  Just enjoying the moments, the days.

Trevithick Dredger Engine- Valves

No workshop posts for a while because I have been making parts for the internals of the engine, and when installed they are not very photogenic.

Since the last post I have made the piston, piston rod and installed soft packing to seal the piston, made the valves and valve handles..

 

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Stainless steel piston rod, bronze 20mm dia piston, and soft packing inserted into the machined groove.

Also made the throttle valve and steam direction valve.

 

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This was the third attempt at making a steam valve.  I went slightly undersized with the first, totally buggered the O ring groove on the second, but the third one looks OK.

 

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Good one (I hope) on the left, and destroyed one on the right.  The lathe tool bit into the bronze.

 

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From left to right.  The bush, the undersize, the buggered, and the OK I hope.  and the plans.

And after all of that, and also making the throttle valve, I discovered a mistake in the plans.  A 1mm discrepancy, which I suspect was an arithmetic mistake on the part of the plan maker.  I decided to modify the valves, bush and valve block rather than remake the valves.

 

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I machined 1mm off the faces shown in the photo, then spent some time prettying it up.  Then took 1mm off the valve lengths, and the valve bush.

 

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This is what it looks like now.  All fixed.  Waiting for Viton O rings to arrive.  Looks OK IMO.

 

 

 

 

 

 

 

TRIPLE EXPANSION MODEL ENGINE- FIRST RUN (air)

This is a short video of the first run of the Bolton9 Model Triple Expansion Steam Engine, which I have been building on and off over the past 3 years.

The video is a bit shakey, because it is taken on my hand held phone while I am using he other hand to operate the controls.  I really did not expect the engine to work!

It runs a bit roughly, and is still quite tight, but settles down in the final few seconds.

It is not running very smoothly, because it is on air rather than steam, and because it is probably only powered on the high pressure cylinder, and maybe a bit on the intermediate, and not at all on the low pressure cylinder.

The next day it would not run.  Very frustrating.  I suspect that one of the eccentrics slipped on the crankshaft, and threw the timing out.  Not the easily accessible low or high pressure valve, but the intermediate one, which needs another teardown to get to it.

But Hey!  It will work.  I can see the light at the end of the tunnel.

One of my readers has requested a description of the triple engine timing procedure, so that will appear on this blog soon.  Unless you have a particular need for the timing info I suggest that you give that post a miss.

Triple Expansion Steam Engine Cylinder Cocks

Some further progress on the triple.

I bought cylinder cocks from Reeves UK, and the picture shows them fitted.  In case I eventually install a mechanism to open all of the cocks simultaneously, they are in straight line, which necessitated making extension peices for the high pressure cylinder cocks.

The handles required bending to clear the pipework.

The cocks look a bit strange to me.  Too big, and the handles are wrong.   I am thinking about making a set from scratch.  But that can wait.

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Drain pipes from the cocks will be installed at some stage.  Still deciding where to run them. And whether to join them into a common trunk.

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The engine turns over by hand, but it is still a bit stiff.  There was a tight spot which took many hours to locate.  It turned out to be a valve rod thread which was about 0.5mm too long, touching the inside of the high pressure valve chest.   Fixed in a jiffy.

I hooked up the engine to a small compressor at 30psi, but general stiffness prevented the engine from rotating.  So I gave it an hour being rotated in the lathe at 200 rpm.  It is noticeably more free, and getting very close to working.  The valve timing is approximately correct (checked by my expert friends Thomas L, and Rudi V), but will need fine tuning at some stage.

Traction Engine Oiler

The oiler which had been made for the 3″ Fowler compound steam engine looked OK, with a nice rounded brass cap, but despite various adjustments I could not induce it to work reliably.  The pawls were very thin brass, not hardened steel, and the supporting bracket was very thin sheet steel which had little resistance to flexing.

I decided to replace the oiler.   I could have made one from the engine plans, but when I saw some photos of these Foster Lincoln oilers on scale model traction engines, I decided to purchase.

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The one which I purchased was designed for a 4″ scale traction engine, bigger than my 3″ Fowler, but the external dimensions were similar to those specified on the Fowler plans, and the Fowler is a 2 cylinder engine.  So I decided to go “too big” than risk “too small”.

It arrived by mail today, from the U.K.   Cost £116 + £10 p&p from “Live Steam Models”.  Not cheap, but the quality appears to be excellent.   Heavy brass body, hardened steel pawls and ratchet wheel, stainless steel water drain, and a powerful spring operated pump.  The lid closes with good tight fit.  Some filing will be required on a cut edge of the lid, but no big deal.

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The pump in the oil cavity.

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TRACTION ENGINE STUFF

My brother and I visited a well known local machinery enthusiast.  Some of my readers might be interested in the photos.

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An excavator from the 1940’s, due for restoration.

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Said to be incredibly noisy and heavy for the operator.

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Excavator diesel engine works.

 

My miniature Fowler traction engine does not have a steam injector and I am considering installing one.  So here are photos from a full size Fowler, and another from a  Ransomes traction engine.

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Fowler R3 steam injector, located near the bottom of the rear water tank.

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Ransomes injector located similarly.

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A pin, for a pin, for a pin, for a winch. (Fowler traction engine)

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Why do the boiler stays have holes bored into them?  When a stay breaks it usually occurs on the inside of the boiler.  The break can be undetected.  If there are blind holes bored like this, steam will escape through the hole if there is a fracture, revealing the problem.

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The countersink on the stay holes here is decorative only, serves no useful purpose, and probably weakens the stay.   The differential gear on the left is very worn, but still useable.

 

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Ransomes traction engine on the left, and Fowler R3 heavy haulage engine on the right.  2 tonne rear wheel removed and chained to the post, while transmission gears are being remachined.

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The ash pan from the Fowler R3, after 4 days of continuous steaming at the Geelong Show.  Of interest to me, because on my 3″ scale (1:4) Fowler the ash pan has been almost exactly scaled and I suspect that it would benefit from a redesign.

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Kelly single cylinder traction engine.  Working condition.

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Kelly engine.  Everything visible.  Note the very useful steam dome.

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Fowler R3 nameplate.  I can see something similar appearing on my 3″ Fowler.

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Front wheel on the Ransomes traction engine.  Both front wheels were torn off in an accident in 1920.  Going down a long steep grade at Shelford, Victoria, there was insufficient steam pressure to brake the traction engine towing a heavy load, so the driver deliverately crashed the engine into the road cutting, at considerable speed.  It was succesfully repaired by a blacksmith.  The driver survived.

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The Ransomes engine.  The “Rolls Royce” of traction engines, according to the owner. (But I suspect that he prefers his Fowler).

So, I hope that you found these pics interesting.  John.

MODEL ENGINES in the cage at the GEELONG SHOW

The following short videos show some of the engines on display by GSMEE in the Vintage Machinery Shed at the recent Geelong Show.  GSMEE is Geelong Society of Model and Experimental Engineers.  All engines are running on steam, except of course the Stirling engine,  the Farmboy, and the Atkinson engine.

These engines will be running again at the GSMEE exhibition 25-26 Nov 2017, at The Lifestyle Pavillion, The Geelong Showgrounds.  Several scale model traction engines, trade exhibits, outside entries, and the engines in the Vintage Machinery Shed will also be on show.  The Hatherly Challenge competition will be judged.  This year the challenge is to make a reversing horizontal mill engine.  Entry is free (gold coin donation accepted with gratitude).

Stirling Engine, running on heat from exhausted steam,  spinning a CD with spiral image, made by John V.

 

 

Stuart Victoria Twin, made by Malcom W

 

 

Bolton12 Beam Engine made by John V

 

 

Farmboy internal combustion engine, running on propane, made by Stuart T

 

 

Horizontal Mill Engine running on steam, reconditioned by John V,  (GSMEE exhibit)

 

 

Atkinson Engine, running on petrol, made by Rudi V.  FIRST PRIZE.

 

 

Stuart 5, running on steam.  Reconditioned by Rudi V.  GSMEE exhibit.

 

 

Beam Engine “Mary”, completed by Stuart T.  THIRD PRIZE.

 

 

Mill Engine, running on steam GSMEE exhibit.

 

 

Mill Engine running on steam.  GSMEE exhibit.

 

 

Mill Engine, running on steam, made by Malcolm W.

 

 

Triple expansion marine steam engine by John V.  Almost completed.  SECOND PRIZE.

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Triple Expansion Engine Update

Well, almost another whole year has elapsed, and still the triple is not finished.  Come December, and that will be 3 years that this project has occupied my thoughts and workbench.  With a few other projects in between.

Last week I assembled the components, in preparation for the Geelong Show.  GSMEE is a bit light on for new models, and it was suggested that the triple might fill some shelf space, despite being unfinished.

So I bolted it together.  All 429 fasteners!  And stood back and admired it.  It really is quite impressive, complex, and interesting.  So I took some pics.

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This is the condenser side, and the Edwards pump

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The other side is a bit lessy fussy, showing the steam inlet valve, the Stephenson’s links, weigh shaft  and controls.

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And the top, showing some of those 429 fasteners,

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The high pressure valve chest cover.  I will fill those holes where bolts cannot go.

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And the low pressure end, and links for the pump.

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And a close up of the steam valve and weigh shaft.

Not quite ready to run it yet.

It needs side covers for the cylinder block, drain cocks for the cylinders, and general freeing up.  It is still very tight.

Not to mention painting.  I expect that I will paint this one.   No idea of colours yet.

Compound Traction Engine

A few of my readers will have no idea what a “traction engine” is, much less a “compound traction engine”.

I have recently bought one of these machines, so here it is….

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To be accurate, it is a miniature traction engine.  1/4 size.  A full size one would weigh between 14-18 tons, and a bit beyond what SWMBO would have agreed to me spending.  I see ads in the English sites offering them for between 250 and 400 thousand pounds.

This one weighs about 250kg, and it cost me a bit less than a full size one.

It is powered by lighting a coal fire in its belly, and producing steam.  The engine sits on top of the boiler.  You can see the cylinders, connecting rods, crankshaft and gears in plain view.   The steam is under a pressure of 100lbs per square inch.   It passes through the high presssure cylinder (the small one) then through the low pressure cylinder to convert the heat energy of the coal into kinetic energy of motion.   The fact that the two cylinders are powered by the same bit of steam is the reason it is called a “compound” steam engine.

Steam traction engines were the predecessors of modern diesel tractors.

As road locomotives, they pulled loads of many tons, at low speeds, from 1869 to the end of WW2.  This one was a scale model of a road loco of circa 1918.  Other types were used on farms as tractors (not terribly effectively, because of their weight), in saw mills to power the saws, and as stationary engines to power some factories.

Rather surpisingly, they are a quiet machine in comparison to more modern diesel and petrol powered ones.  They sound a bit like a steam train, puffing and chuffing along.  I fine the sound is very appealing.  I also like the exposed mechanicals.

The coal smoke is not quite so pleasant, but the Welsh steaming coal which I am using, produces very little visible smoke.   Most of the white stuff which is seen is esacaping or exhausted steam which has been cooled to become water vapour.   Steam, as I have discovered, is invisible.

So back to my traction engine….    It was made by a gentleman in Adelaide, commencing in 1984, and completed in 2016.   He also made quite a few steam train engines and traction engines over the same years.  He told me that the compound engine was difficult to make due to its complexity, and the tight squeeze of all of the components.

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The square box with the brass lid is the mechanical lubricator,

The boiler is constructed from copper sheet, 4mm thick, riveted and silver soldered.    It has been tested, and certified to 100psi.  Re-certification is due, and is planned to be tested again in a couple of weeks.

I have found a few issues with the engine, and am gradually attending to those issues.   The piston rod glands, valve chest, main throttle, and starting valve were leaking steam.  Those leaks have been reduced to a level that is acceptable.

One of the big ends is noisy.  I noticed that the plans called for adjustable wedges, and they have not been used.  So at some stage I plan to make them and install them.  That should tighten up the noisy bearing.  The valve eccentric straps are a bit loose, with noticeable movement, but they should be fairly simple to tighten.

The mechanical lubricator is not working.  I have cleaned and adjusted it, but to no avail.  There does not seem to be enough movement in the driving arm to click the gear over.  Might need a re-design or a new lubricator altogether.

Some of the water supply pipes are modern flexible types and look totally wrong, so they will be replaced with rigid copper pipes.

The painted colours are appropriate for a working road machine, but I am planning a more fancy appearance with brass belly strips, polished steel cylinder covers, some pin striping, and a name plate.   Also a Fowler coat of arms.  (It is a Fowler Class R3).

Still contemplating the name.  Traction engines seem to be named after girlfriends wives or mistresses, famous people, Lords and Earls.   There is a nice movie from the 1960’s about a traction engine named “The Iron Maiden”.  Its rival was named “England Expects”, a name which resonates.   I have long been an admirer of Sir John Monash, so that is quite a possibility.  Monash was the leader of the Australian Army 1916-18, and he was so effective that the British Prime Minister of the day said that WW1 would have been a year shorter if Monash had led the allied forces.  Monash was also my university.  And we share first names.  But still considering.

So you can see that I intend to place my own stamp on this machine, and have lots of interest and fun doing it.

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Boiler fire started, extractor fan on the funnel to increase the draft through the firebox, Ange, Tom and Stuart waiting for steam pressure to rise.

I attempted to upload a 2 minute video, but just too slow.  Might try later.

 

A Base for the triple, and some oil holes…

Thinking about the options for a base for the triple expansion marine steam engine..

I looked at every photo I could find on the net, and thinking about whether I want to be historically accurate, or just really solid, or a bit interesting with an historical flavour.

At this stage, the decision is not set in concrete, but I am going with the last option.  Photos later in this post.

But first, I have pulled all of the major components apart, and I am spending time doing a few of those jobs which I had been avoiding because they are difficult and imprecise, and if they go badly it will be a major disaster at this stage.  Like drilling the oil holes and wells for the big ends.

Nothing precise about this.  The con rods and big end shells and bearings have been painstakingly machined, and I do not want to think about remaking them if I stuff up.  And drilling into curved surfaces, with a 1.5mm drill bit…

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That thread is 3mm dia.  The hole above the nut is the oil way, 1.5mm dia.  Very tricky and too anxiety provoking to be thinking about a video.   Amazingly, it all went well!   I now have 2 oil holes for each of the 3 big ends.  I will need to fill the well with oil with a medical syringe and fine needle, but.

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The crankshaft, turned from stainless steel a year or two ago, and the conrods.  The big ends now with lubrication points.

And here are the major engine components, after partial disassembly.

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At top left is the condensor, then the cylinder block in 2 parts, then the steam supply valve.  The square section tube is going to become the base.  And so on.  You get the picture.  I will count the bits at some stage.

Then I cut and drilled the square section aluminium tube for the base.

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The cast base of the triple, with main bearing studs and column studs in place.  All sitting on the square section alu.  Have not decided whether to bolt it together, or just Loctite it. 

Those holes in the square section were drilled and chamfered on the CNC mill.

 

Assembling the Triple

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I got this far in assembling the model triple expansion steam engine, then lost courage and put it aside (again).  You can see the high pressure steam chest labelled “top”, the steam valve and handle, the drag links and levers for the reversing mechanism for the high pressure cylinder, and the worm and gear and control wheel for the reversing mechanism.   The reversing levers will need pinning with taper pins when the correct positions are finalised.  The short rod in the middle of the pic is temporary.  I need to make those properly.  The drag links clash with the condenser cover.  That was predicted in Bertinat’s notes.  The cover will need some material removed.  Slowly progressing, but taking frequent breathers.

The high pressure mechanisms are the most exposed, and easiest to access, and they were very tricky, and not yet compeletely installed.  I dread to consider what the intermediate pressure ones will be like, buried in the middle of the engine.   Then there is the valve timing.  Help!

SS Valve Rods

Making the new valve rods, as predicted, took me an entire day.  They required a high degree of precision, and being in stainless steel, not an easy material to machine, and quite thin and delicate, multiple stages in the machining.

But before I started on the valve rods I made myself a new spanner for the collet chuck on the CNC lathe.  I had been using an adjusting spanner, which was continually  going out of adjustment and causing angst.  The tool merchants did not have anything suitable (46mm opening, and thin profile), so I made my own.

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The 46mm spanner being cut from 6mm steel plate.

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It is a bit prettier after this photo and being painted.  The rounded jaws facilitate easy application to the collet chuck.

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Tightening the ER40 collet chuck with the new spanner.  It works very well.

So then I got on with the new valve rods.  Some end of day photos follow.

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The valve rod is the silver coloured rod.  Actually stainless steel.  This photo shows the high pressure cylinder valve and valve chest.  There are 2 other valves, one for each cylinder.  All different sizes.

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The high pressure valve chest and valve, the valve rod and guide.  On the right is the Stevenson’s link, yokes and eccentrics which control forward and reverse.  This setup is repeated for each of the 3 cylinders.  This is hooked upto the worm and gear which was shown a blog or two ago.  There are 22 components for each, not counting fasteners.

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The low pressure setup.

And thank you to those readers who responded to my whinge about likes and comments.  I will continue this blog until the triple expansion steam engine is finished, and hopefully running.  Not sure after that.

Triple Underbelly

“Underbelly” has a particular resonance for readers who know what the Yarra is and that Collingwood is a place and not a British admiral.

In the instance of my triple expansion steam engine, it refers to the bits and pieces underneath the cylinder block.  The glands which prevent steam leaks from the con rods and steam valve rods, the and valve rod guides.  These unsung heroes of the steam engine have taken 2 entire days to make.   And here they are….

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This is the cylinder block, upside down.   You can see the valve rods. the valve rod guides, the valve rod glands, the piston rods, the cross heads (unfinished), the piston rod glands,  and the cylinder bases.   Give yourself 2 marks for each correctly identified item.  The 6 hex plugs on the side are temporary, until I get around to making some cylinder drain valves.

I started to count the number of holes drilled and tapped in this view, but gave up at 100 and still not half way.  This engine better bloody work!

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Note the letter stamped into the cylinder base.  Many parts are similarly stamped.   The studs in the intermediate piston gland are temporary.

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Just a different view.

I have decided to replace the valve rods which are made of brass, with stainless steel ones. That will take an extra day, which might exceed my second, self imposed, deadline.  But if it does, well too bad.

By the way….   I am considering whether or not to continue this blog.   It does take time, and is not free.  If you read this and are not totally bored, the odd “like” would not go un-noticed.  A comment would be even better.

Reversing Gears and Handwheel

Another 2 days in the workshop.  Heaven.

I had made a worm drive and gear using an M14 x 2 tap, but it did not look the part, despite being functional.   The problem was that the threads were sharp triangular and they did not look correct.

So I made a worm drive and gear using Acme specifications.  The teeth have a chunkier squarish look.  More authentic.

I ground a lathe cutter and used it to make the worm drive in gunmetal, and another identical thread in 14mm silver steel (drill rod).   The steel thread had cutting edges formed, and when finished it was hardened by heating red hot and quenching.  After hardening, a file would not mark it.  I did not bother to anneal it, since it would be used only to cut cut brass or gunmetal.  The hardened tool was used to make a gear in gunmetal.  Unfortunately I did not take pictures of those steps.

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Showing the handwheel, worm drive and gear.  the shaft is mounted in gunmetal bearings which are bolted to the columns with BA8 bolts.    The thread is Acme. 2mm pitch.  The handwheel will control forward-reverse of the triple expansion steam engine.

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In order to determine the position of the bearing bolt holes for the worm drive, I used SuperGlue to tempararily join the worm and gear.  

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When the position of the bearings was determined, the holes were drilled 1.8mm and tapped.  the taps were BA8, about 2mm diameter.  The engine is held vertically on the milling table, being cramped to a large angle plate.  The holes were drilled accurately on the mill.  The threads were made using a tapping head made by me from plans published in “Model Engineer” by Mogens Kilde.   The double parallelogram of the tapping tool keeps the tap vertical.  The tap did not break.

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Close up photo of tapping the BA8 threads.  Showing the bearing, shaft, worm drive and gear.  Note the Acme thread.  The bearing is Super Glued into position to facilitate the drilling and tapping procedure.  The Super Glue will be removed later.

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The final step for today was to make the handwheel.  It is 1.5″ diameter.  The rim is 1/8″ brass and the spokes are 1/16″ brass.  I made 4 of these, with each being better than the last.  I softened the 1/8th brass before winding it around a 32mm pipe to form the rim.  The join in the rim was silver soldered.  Then the rim and the hub were drilled using a tilting indexing head on the mill.  I soft soldered the spokes on intital handwheels, but the final (and best) examples were glued with Loctite.  Loctite allows a few minutes for adjustment of the spoke lengths, whereas there is only one go with the soldering.

It is looking interesting, Yes?  And there are 3 spare handwheels.  The rest of the reversing mechanism components were made several months ago.  Almost ready to install them.

Broken Tap Removal

In a previous post I admitted to breaking a BA7 tap in the Edwards air pump of the Triple Expansion Engine, and being unable to remove it.

The hole being threaded was one of 4 to be used to hold a water pump to the air pump. It was 2.5mm diameter (i.e. pretty tiny)

I tried to grasp with pliers the fragment still protruding but it then broke below the surface.

I tried to break up the embedded tap, using a HSS punch, with partial but inadequate success.

I briefly considered drilling a hole from the other end, and punching in the reverse direction, but that would really have compromised the pump.

So I decided that the three remaining bolts would have to be enough.

A night sleeping on the problem.

Next day, with a fresh determination, I decided to attack the problem again.

I had some used carbide milling cutters 2mm diameter, and I was prepared to sacrifice one or two of them.   So I carefully set up the Edwards pump in the milling machine.

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You can see the three good tapped holes.  The carbide milling cutter chomped away at the broken tap, and using gentle pressure, and ignoring the metallic screeches, the tap was broken up and most of the fragments came out.  I was prepared to sacrifice the milling bit, but it seems to have survived this insult.  The harder metal always wins.   It was probably fortunate that the tap was carbon steel and not HSS.

Somewhat surprisingly, the tapped hole was in reasonable condition, and it accepted a BA7 bolt, although I will not be aggressively tightening this one.

MAKING SMALL SPLIT BEARINGS FOR THE TRIPLE EXPANSION STEAM ENGINE

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The bearings in the drag link are not split, because they can be slid onto the shaft.  But if there are obstructions to sliding, (such as big ends on a crankshaft), the bearings must be split, and assembled when in position on the shaft.  The bore in the intact bearings in the photo is 4mm.  The split bearings have a 5mm bore.  They are all bronze, but the split bearings have been heated then dipped in sulphuric acid so the colour has changed.

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The first step in making split bearings is to machine 2 strips of metal, of identical dimensions.

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Next the strips are soldered together.

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The bearing holes are drilled and reamed exactly to finished size.

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The strip of soldered metals is attached to a sacrificial base plate and the outside of the bearings are machined to final size and shape.

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Holes are drilled to take the bolts which will eventually hold the halves of the bearings together.  (1.6mm holes in this case).  The bearings are then heated to melt the solder and separate the halves of the bearings.  Sulphuric acid was used to remove the carbonised crap left on the surface of the bronze by the heating torch.

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The bosses around the holes was an extra machining step.

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