Fitchburg Northern--Part II
Building the Locomotive
by Harry Hungate
Example locomotive above built by Russ Steeves. My loco will be nearly identical.
Updated: July 18, 2020
NOTE: THIS IS A WORK-IN-PROGRESS (THERE MAY BE PHOTOS MISSING, TEXT OVERLAPPING PHOTOS, ETC.) I ADD TO IT AS I HAVE TIME.
This is the build blog for the locomotive itself: a 2-6-0 narrow gauge live steam locomotive in 1/5 (2.5 inches per foot) scale in 7.5 inch gauge. It was designed by Tom Rhodes in the 1980's. Many examples have been constructed. The locomotive is a bit over three feet long and will weigh around 250 pounds when complete. The empty boiler alone weighs over100 pounds. The locomotive will burn propane to produce saturated steam at 120 pounds per square inch. Water for the boiler is carried in the tender (See Fitchburg Northern Part I) which also provides a seat for the engineer, and a propane fuel tank will be hidden under a dummy cargo on the D&RGW 6000 Series flat car behind the tender. It will be a real workhorse and will easily pull upwards of ten or more passengers.
Part I covered the building of the tender (coal car). Acting on good advice I built the tender before starting the locomotive, as the tender is much less complex than the locomotive. While requiring attention to detail, the tender provided a very good training platform on which I could develop my machining skills in preparation for the locomotive build.
A note about the contents of this builder’s blog: I am writing this not to provide instructions on how to build a live steam locomotive, as relatively few people would be interested in undertaking a project of this magnitude, but to share with the interested reader some of the challenges and frustrations and indeed joys of bringing a mass of various metals together into a live, fully operational steam locomotive. It is now nearing completion and I hope to raise steam by June 2020. (I did, but just barely!)
This locomotive is referred to as a free-lance design in that it is not an exact replica of any particular steam locomotive, although it resembles Baldwin locomotives. It is typical of narrow gauge industrial locomotives built in the late 1800’s and early 1900’s. These were used in mills, quarries, logging operations and plantations. The locomotive at the Jacksonville Beach Museum is a good example. Have a look at www.allenmodels.com for more details on this locomotive, of which there are many!
Several months before I completed the tender in October 2016, I ordered several feet of ½ inch square C-1018 cold rolled steel bar stock for the locomotive frames. I also ordered the rough castings for the six driver wheels and two pilot truck wheels from Allen Models. I had already started reading up on the intricacies of building the actual locomotive. My machining skills were very much improved to the point that I felt sufficiently confident to begin the locomotive.
I purchased a large spiral bound notebook in which I pasted copies of the prints of the various parts to be machined and also typed up a series of instructions to guide my progress. I usually went back and revised these instructions while they were fresh in my memory. As time went on these notes were very valuable especially when something did not turn out exactly right, and I could go back and usually determine how to correct the problem.
Note book on left. Inside are copies of sections of the thirty-two large "blue prints" and my typed instructions complete with dimensions, drill and thread sizes, with hand-written notes.
A few words are in order about the machine tools that I own or have access to:
I purchased a used Chinese 9x20 inch lathe and spent a few weeks derusting it, repairing it and upgrading it with a four bolt tool post mount, variable speed drive and electronic tachometer. I added a larger four independent four jaw chuck, live center, cut-off tool and several high speed steel cutting bits which I later ground to suit my needs. I already had a drill press and rotary/X-Y table, hand drill, drill bits, files. Precision measuring tools were acquired as time went on: vernier micrometers from one inch up to six inches, vernier calipers from four inches up to twenty-four inches, and six inch capacity digital calipers. I purchased two of these from Harbor Freight because they were cheap and I conveniently overlooked the old lesson: "You get what you pay for". These proved quite expensive all to soon as I ruined several castings due to erratic readings. I then purchased a new Mitutoyo six inch digital caliper. It was ten times the price of one Harbor Freight caliper, but it has never let me down in almost six years of heavy use. Lesson learned: DO NOT GO CHEAP on precision measuring equipment. Very good deals on name brand vernier micrometers and calipers (Starrett, Brown and Sharp, TUMICO, etc) are available on e-bay. It seems that industry is moving to digital equipment, so the old but still accurate vernier equipment is no longer in demand.
I added a rotary table with indexing plates and four jaw scroll chuck to my inventory.
The retirement community that we now call home has a wonderfully equipped community workshop. We have a fully equipped wood-working shop and a Maximat 7 lathe/vertical mill with many accessories, a Myford ML-7 lathe with milling attachment, four jaw independent and scroll chucks, three jaw scroll chucks, collets, boring head with carbide tools, end mills of 1/16" up to 5/8", fractional and numbered drill bits, Silver and Deming drill bits up to 1 1/2", a power hacksaw and two drill presses with X-Y tables.
I purchased a box of firebricks from Ace Hardware to provide a hearth for silver-soldering. (I am careful to do all silver-soldering outside--this photo on the left was staged when I first started.) A roll of 56% silver solder, white and black fluxes, propane torches, igniter and a Pyrex bowl of old battery acid for pickling the freshly soldered items rounded out my silver-soldering inventory.
New fire bricks for the silver-soldering hearth. I made the brass parts to repair my lathe.
Turning one of the six driver wheels in the 9 x 20 inch lathe. The wheel casting is held on an arbor machined in the chuck to obtain extreme concentricity.
I managed to ruin a couple of the wheel castings in the process. Lesson learned: stop work after two hours maximum. Take a break and do something mindless, such as clean up the shop. I also remembered to use the shop vac to contain as much of the carbon and castiron swarf as possible. The finished diameter of the driver is 5.000 inch and the tolerance between all wheels is 0.010 inches. I actually got it down to 0.004”.
The axles were turned from one inch diameter 12L14 cold rolled steel round stock, as was done for the four axles on the tender. This alloy is relatively easy to machine and a very smooth surface finish is achievable. Oil passages were drilled in each end of the axles to provide oil lubrication to the bronze bearings.
I ruined a few axles due to mismeasurement (cheap digital calipers), but also due to inattention while using the automatic feed on the lathe (which produces a better surface finish) and by not allowing the axle to cool to room temperature before taking a measurement. Lesson learned: keep your eyes and mind on the job and do not allow visitors to distract you. In fact, simply turn off your machine when a visitor arrives. If they are workshop sensitive they would not disturb you in the first place, and if they are not workshop sensitive you had best escort them out as soon as good manners will permit.
Turning one of the four axles between centers on the Myford ML-7 lathe.
Completed wheels and axles temporarily assembled.
Frames, pedestals and journal boxes under construction.
Locomotive frame being assembled: frames, pedestals and journal boxes.
The pedestals are simply short pieces of the same ½ inch square stock as the frames, and easily machined to very accurate length in the metal lathe using the four jaw chuck. The pedestals were center-drilled and tapped in the lathe for accuracy. The frames and pedestals were bolted together after drilling the many holes in the frame bars. No Loctite this time, as the frames were to be disassembled a few times over the next couple of years as the build progressed.
Laying out the journal boxes with height gauge and surface plate.
The locomotive frame is built up of ½ inch square C-1018 cold-rolled steel bar stock. I laid out the positions for the pedestals on the frames as accurately as I my skills allowed. Milling the slots in the frames for the pedestals requires extreme accuracy in order to insure a straight (and square) frame. To accomplish this, I turned to Eric Veale, a professional machinist. (www.tavtekmachine.com). I cut the four frame bars a couple of inches over finished length so I could drill holes in the extreme ends of the bars and bolt them together securely. Eric has a Wells Index Standard vertical milling machine with a DRO and he milled the 0.250 inch deep slots across all four frame bars in a single pass. This job began a warm friendship, one for which I am forever grateful for his extreme accuracy, sound advice, good humor and extremely fair prices. He just added an impressive CNC machining center to his equipment list. The capability and accuracy are phenominal.
This is an optical center punch--a must for precision work.
Boring the journal boxes on the Myford ML-7 lathe.
A note about precision measuring equipment: As I began this project I owned a one inch Vernier micrometer and a good quality digital caliper, precision six inch and twelve inch rules, inside and outside calipers, scriber, and many hand tools. One mistake that I made was wasting money on Harbor Freight digital calipers, simply because I wanted to have a digital caliper at our community workshop in addition to my home workshop. They soon proved unreliable, but not before causing me to ruin several items with their erratic measurements. Lesson learned: always buy the best precision measurement instruments. Stick with brand names and do not under any circumstances go cheap. Used name-brand vernier micrometers and calipers and height gauges are available on e-bay at surprisingly low prices, apparently because today’s machinists want digital instruments as they are easier and faster to read and less prone to reading errors. Carefully store your instruments and periodically check them with the standards provided.
Left: Mitutoyo digital caliper, engineers precision square, engineers clamp, hammer and file, Starrett vernier micrometers with standards and Tumico 12" vernier caliper. Right: Various chemical products.
I also purchased a new set of fractional twist drills 1/16 inch up to ½ inch and a set of numbered twist drills 1 through 64. Lettered twist drills are only rarely needed for this project, but I have a few.
Later I acquired taper and bottoming taps and dies from 2-56 up to ½”-20. I also made a die holder for use on my lathe from a piece of round stock and a purchased Morse #2 taper chuck adapter. Many of the bolts and nuts are custom made from brass or steel, and some must be case-hardened—yet another skill to be mastered. Chucking reamers were acquired as needed.
Twist drills, taps, dies and holder, Criterion boring head and reamers on left. Dial test indicator and Noga holder, telescoping bore gauges and combination square with center finder on right.
Drilling and boring the holes in the journal boxes was done on the Myford ML-7 lathe. First mark the center of the hole with the optical center punch, then use a center drill and gradually enlarge the hole until a boring bar can be inserted.
To obtain the most accurate measurements use a telescoping bore gauge and micrometer rather than inserting a caliper into the bore, and remember to let the work cool to room temperature as you approach final dimensions. Do not rely on a caliper for accurately measuring bores. A set of telescoping bore gauges is quite inexpensive and the technique is very simple to learn.
The axles were a trial. I originally used C-1018 cold rolled steel for the tender axles, but could not obtain a decent surface finish. I switched to 12L14 steel which contains a small amount of lead to improve machinabilty. It is certainly strong enough for the axles and the surface finish resembled sterling silver! The axles must fit the drivers with no slop, but with a couple of thousanths of an inch clearance to provide space for the Loctite 620 adhesive which I decided to use instead of cutting keyways in the driver and axles. This is incredibly strong stuff when cured and it requires the metal to be heated up to 450 degrees F to release. I know this for absolute certainty, but more on that later!
After obtaining the 12L14 round bar for the axles I managed to ruin a couple of them by using my cheap Harbor Freight digital calipers (erratic reading) and not waiting for the freshly machined axle to cool to room temperature before measuring with a micrometer. In hindsight it would have been better to turn the axles to the specified diameter and then use an adjustable reamer to fit the drivers to the axles. (Isn't it amazing how wonderful hindsight can be?)
Building a locomotive is a huge collection of smaller tasks, and a good thing, too, as there were many opportunities to take a break from some tedious and frustrating task such as the axles. Brake shoes, turnbuckles, clevises and clevis pins, brake arms and hangers, etc., etc., absorbed many enjoyable hours on the lathe and milling machine.
When the six journal boxes were completed I machined phosphor bronze bushings and press-fit them into the journal boxes. The bushings will be reamed to provide a smooth fit on the driver axles.
Bronze bushings turned to fit the journal boxes, then press fit into the journal boxes. Then bored to fit the axles. Cylinder bars secured with keys being trial-fitted. Bolt holes to be drilled later.
One of eight leaf springs. The brass "ears" are silver-soldered to the top leaf in this jig.
I purchased the eight spring steel leaf spring assemblies from Allen Models. They were already cut to length, curved to form and the center bolt holes were already punched. The decision was based on economics: I could have done the work, but the expense of many small end mills that I would have destroyed or worn out would have easily exceeded the cost of the ready-to-use springs. I made the jig in the photo above to hold the uppermost spring leaf while the end supports or "ears" were being silver-soldered to the leaf. I milled the "ears" from brass bar stock. I have used 56% silver solder throughout my project. It has the lowest melting point of any of the silver solder alloys and is certainly sufficiently strong. The largest hardware store propane torch that I could find soon became my first choice for silver soldering anything except very small items. The key to successful silver soldering is to clean the joining surfaces to bright metal, prick punch the flat surfaces so that two or three thousandths of an inch clearance between the surfaces to be soldered will permit the molten solder to be drawn in by capillary action, and to use white flux for small items that can be quickly brought up to solder melting temperature and black flux for everything else. The technique is to bring the largest of the two items to be joined up to melting temperature of the solder as quickly as possible. This means quantity of heat delivered to the metal and not excessively high temperature such as that provided by an oxy-acetylene torch. Go sparingly on the silver solder. A little bit goes a long way and it is not inexpensive! A Pyrex bowl containing old battery acid is my pickling system to remove flux and oxides after soldering. A good stainless steel wire brush will scrub the metal back to a bright finish.
The many pieces of the suspension system consumed many enjoyable hours on the milling machine, lathe and drill press. As these pieces were fairly low-precision the work was fairly relaxing. Assembling the suspension system and adjusting it with the journal boxes and axles in place made the mound of parts actually begin to resemble a locomotive.
Suspension and journal boxes installed. The oil passages are visible in the axle.
Main rod beginning to take shape, on left and side rods soon to follow.
This photo of the completed main rod and both side rods shows the knuckle joint between the front and rear side rods. The main rod has two "keys" and lock bolts (on either side of the lubricator). These are non-functional, but represent the prototype faithfully.
Fabricating the connecting rods and main rods required a lot of hack sawing, filing, milling and drilling. For absolute accuracy and repeatability I farmed out the drillng and reaming to Eric Veal (). His huge Wells Index vertical milling machine with super accurate DRO insured the required accuracy. I followed the designer's prints for the main rods, which included dummy bearing adjusting keys, and I also added a couple of 2-56 key locking bolts for added realism. Oilite bushings were cut to length, oil holes drilled and then pressed into the holes in the rods. The lubricators keep the bushings from rotating in the holes.
I followed the Tom Rhodes' design for the equalized locomotive brakes as it is indeed prototypical, down to the twin steam operated brake cylinders. The brake linkages required many threaded rods for which my home-made die holder yielded excellent service. The rod ends and clevises and clevis pins required milling and drilling, but were soon completed. For Christmas of 2016 I received a rotary table and four jaw scroll chuck which I used to locate, drill and tap the brake cylinder head bolts. Accuracy was such that I can mount the heads in any position. The brass cylinder and head castings from Allen Models were a joy to machine.
The brake pistons are silver-soldered to the piston rods and then held in a collet to be turned to exact concentricity and diameter. Turning the ring grooves required many trial fittings as the rings are actually Viton O-rings, and a lot of experience is required to obtain the proper fit.
I also made the retract springs from spring steel stock provided by my train club buddy and builder of a three truck Shay live steam locomotive, Scott Thompson.
The brake shoes were machined from Allen Models castings. The cast iron brake shoes were machined on my 9x20 lathe fastened to a face plate so that the 2.5 degree taper of the driving wheels could be matched.
My machist friend, Eric Veale, machined the rear frame extensions as they were too large for my Maximat 7 milling machine. With the frame extensions installed I could mount the brake arm bearings and cylinders. (MORE ON THIS LATER!) Adjusting the brakes would have to wait until the driving wheels were installed.
I had already turned the six crank pins for the drivers from O-1 oil hardened steel alloy. My fellow train club loco builder, Scott Thompson, hardened and tempered the crank pins for me in his industrial forge at work. Eric Veale located and drilled the crankpin holes in the drivers for me, to insure repeatability, accuracy and coplanarity with the axles on the six drivers. The crank pins would be Loctited in place during the driver quartering process.
The highest degree of precision on the entire locomotive is the valve gear. This locomotive has Stephenson's valve gear as was typical of the period. Castings for the four eccentrics, eccentric straps, rocking arms, lifting arm and lifting links were obtained from Allen Models. I purchased the expansion links and die blocks from John Pilling as they were way beyond my ability to produce accurately. Riveting the saddles to the expansion links was accomplished with annealed 1/16 inch diameter drill bits as I could not find commercially available rivets. I turned to Eric Veale again to drill the rocking arms as they must be perfectly coplanar to prevent binding. (The large box provided refuge for the earlier set of rocking arms that I drilled.)
Machining the cast iron eccentrics was accomplished in the four independent jaw chuck on my 9x20 lathe. Again, a few scrap pieces gained entry into the large box before four good eccentrics made their way into the small box. Both boxes were well populated by now.
The locomotive has eighteen lubricators (oil cups) which I turned from 1/4 inch brass hex stock and threaded 6-32. After a little practice I could turn out a lubricator in less than twenty minutes on my 9x20 lathe.
Steam brake cylinders: one assembled and one in pieces: cylinder, piston, spring and heads
One of the four valve gear eccentrics complete with two set screws to lock to axle.
Bronze eccentric straps and rods.
The driver wheels must be locked to the axles exactly 90 degrees apart so that the locomotive will always be self-starting, that is, not ever stopped on dead-centers. To accomplish this exacting task, various methods can be used. I built a quartering jig shown on the left (below). It was close, but not close enough, however. Later on, I set up our Myford ML-7 lathe which has a flat bed, and with a combination of spacers and combination square, I was able to set the drivers accurately while maintaining the correct gauge (distance between the wheels).
The rest of the story is that once assembled, the running gear had binding problems which I traced to small errors in the quartering, and also errors in the location of the knuckle joint bolts in the side rods. The locomotive was disassembled, and a propane torch was used to heat one driver on each axle to 450 degrees Fahrenheit to break the bond of the Loctite locking compound. This required stripping and repainting the driver wheels.
Quartering the drivers using a jig. Quartering the drivers on the Myford ML-7 lathe.
A jig was made to hold the side rods at the exact dimensions, allowing me to locate the knuckle bolt hole in a new bushing. This method proved highly accurate and successful. The running gear now revolves without the slightest hint of binding, and in fact, may prove to be too tight for smooth running.
Side rods on spacing jig allowing extremely accurate layout.
Completed parts for pilot truck and upper and lower radius bars.
I had never paid the slightest attention to the pilot (the smaller front wheels) on a locomotive. After all, what is the big deal about two wheels or four wheels? Well, surprise, surprise, the pilot truck assembly is a quite complicated affair. Machining the two wheels and one axle were by far the easiest parts of the pilot truck.
The pilot truck supports the front end of the locomotive and guides it around curves. It has to swing from side to side to follow the curved track and hence lead the fixed drivers around the curve. It has to support enough of the weight of the locomotive to maintain firm contact with the track, but not so much weight that it harms the tractive effort of the locomotive by causing the drivers to slip. Most parts were machined properly on the first attempt, but a few did make their way into the large box.
Steam cylinders and smoke box saddle. This is the "engine" on the locomotive.
The above photograph consists of seven castings and two cylinder lubrication check valves. Not yet added are the two snifter valves, front and rear cylinder heads and smokebox saddle bottom plate, both pistons and rings and the cylinder drain cocks and piping. These castings exceeded both my skill level and the capacity of my lathe and milling machine. I attribute the excellent machining to Eric Veale of Tavtecmachine. The cylinders are bored to 1.375 inches and my train club buddy and fellow steam locomotive builder, Scott Thompson, generously honed the cylinders to a mirror-like finish.
I drilled and tapped the many holes. The material is cast iron, easy to work, but creates a truly horrible mess to clean up afterwards.
Next up was the cylinder heads which I was able to machine on my equipment. The slide valves, well, remember the large and small boxes? It took me a couple of tries to get an acceptable pair. The slide valves are bronze castings and once milled to dimension must be "spotted" on the mating surfaces on the cylinders. This means taking a few hours to patiently rub the slide valves against the mating surfaces until a minimum of 70% of the slide valve surface is perfectly matched to the cylinder surface. There is an old saying amongst the steam railroaders that "piston valves wear out, but slide valves wear in....." I have a much better understanding now.
The cylinder heads are sealed to the cylinders with Permatex high temperature flange sealant, rather than with the traditional gaskets. I have opted to utilize modern materials where there are decided advantages to do so.
Also, I have tried to use fasteners that more closely resemble the prototype, such as hex head cap screws rather than use socket head bolts as some builders have done.
Steam chests, covers and slide valves.
Machining the left front steam cylinder head. Completed Front and rear steam cylinder heads.
Overhead crane with trolley and come-along lifting the boiler on to my workbench.
The boiler for the locomotive was ordered from Ridge Locomotive Works in Michigan in late 2017. Marty Knox is the premier builder of live steam locomotives in the United States, in my opinion. Lead time was over one year and Marty periodically emailed photos of the progress. When the boiler was completed and hydrostatically pressure tested to 300 psig, Marty transported the boiler up to his good friend, Tom Bee for delivery to me at Ridge Live Steamers' Winter Meet in Dundee, Florida in February 2019. This is as good as it gets, as I was able to avoid the risk of shipping damage had the boiler been trusted to the gentle care of the typical shipping company. Tom Bee also brought two pairs of his Bettendorf Freight Car Trucks for me along with the boiler. I used one pair of trucks on my D&RGW 6000 Series flat car. The other pair will eventually find their place under a caboose.
The empty boiler alone weighs over a hundred pounds. I can still lift it, but just barely. I built the overhead crane in the above photo to provide a handy and safe method of getting the boiler off of my workbench and on to the locomotive. Scott Thompson provided the TEE angle iron and welded the trolley for me. The trolley rides on ball bearings. Two by sixes laid over the ceiling joists spread the load safely. I calculate that the crane can safely handle 800 or 900 pounds--quite a safety margin considering the maximum weight of the completed locomotive is 350 pounds.
It was the better part of a year before I was ready to work on the boiler, however.
Steam operated cylinder drain cocks and piping.
The steam piping in the above photo is 3/16" diameter. Some of the pipe fittings were purchased as rough castings (TEE's, ELL's and couplings) and drilled and tapped by me. The unions were purchased ready to use. The joints are either silver-soldered or assembled with high temperature sealant. The union collars are coated with high temperature thread lubricant so that they will be removable at some future date.
Valve gear eccentrics and straps on mid axle and all parts installed.
Side rods installed--things are getting quite cramped for space.
Main rod connected to crosshead.
While all of this was going on I forgot to mention the axle pump. It feeds water into the boiler while the locomotive is in motion. I originally planned to fit the drive eccentric on the middle axle along with the valve gear eccentrics, but discovered late in the game that there was insufficient room on the axle for the fifth eccentric.
I puzzled over how to remove the eccentric from the already assembled axle assembly for quite a while. The solution came in an unexpected form when I discovered that due to binding of the side rods I had to disassemble the locomotive to requarter the driving wheels on their axles. The axle pump eccentric was moved from the mid-axle to the front axle upon reassembly, but only after I assured myself that this was indeed the correct place for it. (I don't ever want to disassemble this locomotive again!)
There is a Fitchburg Northern Builders Group to turn to for advice and guidance which I learned about somewhat late in this saga. A request for guidance on axle pumps resulted in several phone calls with a builder of one of the very first Fitchburg Northern locomotives. He lives in a retirement home in California and is in his early 90's. Still sharp as a tack, he gave me sound advice and assurances that I was on the right track. This is a wonderful hobby.
He recommended that I mount the axle pump to the bottom of the smokebox saddle, with the valve block forward of the saddle to avoid the high temperatures. Easier said than done, but it worked out just fine (eventually!) It's now July 1, 2020 and I am still waiting on the Viton O-rings to arrive so I can finish the piston and assemble the pump. This must be done prior to lifting the boiler into place as it will be very difficult with the boiler in place.
L-R: Pump cylinder being bored. Completed cylinder, piston and rod, valve body and smokebox saddle bottom plate and mounting arms. Assembled pump and lubricating piping. Supply and discharge piping are 1/4"-40 MTP.
Slippers and bolts in crosshead.
One of the practices that I have developed is to work on several pieces at a time. It provides a break from routine, and also provides much-needed thinking time when I run into problems. I mix simple tasks with more complex tasks. For example, while working on the crossheads and guide, I started work on the reversing lever. This is simply a length of 3/8 inch square cold-rolled steel bar stock with a fancy "finial" or handle silver-soldered on to the top end and several holes carefully drilled and either reamed or tapped for the pivot pin and latch mechanism.
Reversing lever and reversing quadrant.
The notches in the reversing quadrant were marked and formed after the valves were timed and adjusted.
A major milestone in the construction of a live steam locomotive is the timing and adjustment of the valves. This seemed to be an absolutely daunting task. (And, it was!) I spent hours reading and re-reading the assembly procedure and the many steps in timing or adjusting the valve gear to operate properly. Some parts had to be remade or adjusted (some needlessly as I condemned some in error!), but finally the big day came shortly after New Year's day 2020 when I had the locomotive running on air.
To accomplish that feat I had to construct a "rolling road" out of steel angles and ball bearings to support the six driver wheels. The rolling road allows the locomotive wheels to turn without the locomotive moving.
Enjoy this short video clip! Too bad that you cannot hear me shouting for joy in the background.
Smoke box door under construction (left) and completed and painted (right).
With the locomotive finally running successfully on compressed air, I could now turn my attention to the boiler. I ordered the burner assembly, propane regulator and hose and water gauge glass assembly from Jeff Dute at Locoparts.biz. He is a great guy and is a good solid provider of advice. In fact, every supplier to this hobby that I have dealt with so far I am proud to call them friends.
Drilling holes into the very expensive boiler made me extremely uneasy and I checked with the builder, Marty Knox before I drilled each hole. He has a fantastic supply of patience and a calming manner. Needless to say, the holes got drilled where they were supposed to be drilled, but the boiler is too big to fit into the small box.
Milling and drilling the firebox door frame and door also required holes in the boiler as did the mounting bolt holes for the propane burner. All were done successfully and I moved on to the smokebox throttle valve and associated piping.
Even though the boiler arrived pressure-tight, there were several tasks that needed completion before use. Top left: firebox door frame machined and bolted into position. Note the hole under the left lower corner: this hole was drilled and tapped for the lower connection of the water gauge glass.
Lower left: stainless steel disc machined to prevent water carry-over in the steam dome. Top right: steam dome interior with brass top cap. Bottom right: both baffles and spacer completed. Note the print shows the dry pipe offset for a steam dome throttle valve. My loco has a dry pipe centered in the steam dome and a smokebox throttle valve--builders' choice.
Steam dome and steam dome cover in position. Steam dome drilled and tapped for whistle and two safety relief valves. The two brass plugs are temporarily installed for hydrostatic pressure testing. More on the whistle later......
Boiler being fitted for hydrostatic pressure testing (left). Underside of boiler firebox showing stainless steel burner array--the brass hex plugs are temporary spacers.
It is mid-May 2020 and the boiler is ready for hydrostatic pressure testing of the throttle valve and piping. The tender feed water pump will be used to fill the boiler and raise the pressure to 180 psig. I will then inspect for leaks and repair them if any are found. This step is necessary prior to installing the boiler on the locomotive frame as the smoke box will limit access to the throttle valve and piping once it is installed.
Smoke box mounted throttle valve, steam drier coil and steam distribution manifold.
The pressure test of the throttle valve and piping was successful. The boiler was then scrubbed, sanded and spray painted with Rustoleum rattle can 2000 degree Fahrenheit primer and black paint. It is now ready for hot washing to remove rust, mill scale and swarf. The thirty pound horizontal propane tank is due to arrive this week (June 2020) after which the fire can be lit for the first time! Three or more wash cycles clean the boiler satisfactorily. The next day steam was raised to slightly above atmospheric pressure to flush out the steam dome piping all the way through the throttle valve and steam supply piping. Then the boiler is now proven and ready for the insulating blanket and stainless steel jacket. Then it can be installed and finally, the piping can begin.
Boiler jacket pattern on left and ceramic fiber insulation blanket on right.
Steam admission lines from throttle manifold to steam chests are trimmed to length, ready to be flared.
When I trial-fitted the smokebox I discovered that the pilot guide pin (brass acorn nut on right) interfered with the smoke box. Nothing for it but to cut off 3/8" from the guide pin, taking care not to destroy the threads.
With the successful pressure testing and hot washes of the boiler completed, the next step was to fabricate the jacket for the boiler. Schultz Roofing and Sheet Metal owner, Mike Schultz, is greatly interested in my project (he cut the aluminum sheet for the tender five years ago), so I took the poster board pattern to him to have him cut the jacket from 24 gauge stainless steel sheet, and roll it to seven inches diameter. I cut the four inch diameter hole for the steam dome with aviation snips and the eight one inch diameter holes for the feed water inlets and steam outlets with a Greenlee conduit punch. Two sets of clamps were silver-soldered from brass 1/8" x 3/8" stock and drilled and tapped 8-32 for the clamp bolts. The jacket was then hand-sanded thoroughly to provide a suitable surface for the paint to latch on securely.
I turned six hand rail stanchions from 3/8" diameter brass rod and drilled the ends for 3/16" diameter brass rod for the hand rails along the top of the boiler. These were bolted to the boiler jacket from the underside and Loctited in place as they will be impossible to tighten when the jacket is installed. Drilling the two mounting holes for the stanchions on the smokebox required some careful measuring, but it turned out just right.
I primed and painted the jacket with Rustoleum rattle can primer and paint, choosing Hunt Club Green Satin for the color coat to match the tender.
I mounted the insulation and jacket on the boiler the next day before the paint had fully cured to prevent cracking. It seems to be holding up very well.
Greenlee conduit punch used to cut one inch diameter holes in the boiler jacket.
Freshly painted boiler jacket complete with hand rails
Jacket, sand and steam domes, smoke stack and valves installed. The copper device is the smoke stack petticoat to funnel the hot exhaust gases into the bottom of the smoke stack.
The paint cured without cracking to my immense satisfaction, but the next day I noticed that the center of the jacket was bowed out at the seam. Nothing for it, but to remove the jacket and add a third set of brackets. In the process of removing the jacket (remember that it is 24 gauge stainless steel and very springy?) the jacket slipped from my grasp and shot across the workbench, wrecking the paint job in an instant. I've just returned from the paint shop and will try again tomorrow. I repainted the sand and steam dome bases gloss black to match the tops. I keep telling myself that this is no museum piece and locomotives were brush painted with whatever passed for a brush. (But it still hurts.)
Some time ago I mentioned that there were many side projects involved in building a live steam locomotive, and here is a beautiful example: the mechanical lubricator which pumps lubricating oil into the cylinders. My train club buddy, Scott Thompson built the case for me from two inch square brass. He also drilled and tapped the twelve 2-56 holes for the top. I milled and tapped the frame for the level gauge and Jane's brother-in-law (finely talented glass artist) cut the glass "window" for me. The filler pipe will extend through the left running board. When complete the lubricator will have two pumps and a ratchet gear drive operated from the valve stem.
The last few days were spent fabricating and silver-soldering the sway bars that run from the smoke box down to the pilot deck. The sway bars are 1/4" diameter brass rod with ends silver-soldered to the rods. The ends are bolted into tapped holes in the smoke box and the pilot deck. With the sway bars completed it was time to bolt the smoke box on to the smoke box saddle. But a few details needed attention: wrap the steam supply lines with ceramic fabric insulation and fabricate and install the brass trim on the sides of the pilot deck. And, oh yes, prime and paint the pilot deck after drilling the holes for the sway bars.
The smoke box saddle was given a thin coat of non-hardening Permatex and then bolted on to the saddle with ten 8-32 x 3/4" hex head stainless steel cap screws and nuts. I installed the smoke stack temporarily for the photo.
Painted pilot deck on left and smokebox and sway bars on right. The pilot beam and coupler pocket will be added at the very last. The cab is a masonite mockup to confirm the dimensions for the real thing.
July 17, 2020--Major milestone event: Boiler lifted into position! Now comes the piping.
The exhaust blower piping required some extensive modifications before installation plus several custom made 3/16" tubing to 1/4"-40 MTP adapters.
From this to this required the better part of three day's work.