This page is a chronicle of the fabrication and assembly of my Allen Models 1/8" scale, 7 1/2" gauge live steam locomotive.
This locomotive was started in 1987 by my father before he passed away. My goal is to have it completed by the end of 2012.
(Note: If you're looking for my video game level design page, I've taken it down, sorry.)

Prototype Locomotive, CRIP #750

The plumbing begins... - December 2011
(click to enlarge)

  • Got the stainless steel supply pipes bent and installed in the front end, got most of the boiler fittings installed, and did a compressed air leak test.
  • Throttle finished up today and started fabricating the running boards.
  • Working on the turret and the quadrant. Got a few days off for the Christmas and New Year holidays, so I should be able to get a lot done.
  • More turret work and finished the quadrant.
  • Lubricator added and all hooked up, injector is all plumbed up, next up is to make the operating lever for the cylinder drain cocks.

  • Misc Pieces and Parts - November 2011
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  • Not much shop time lately -- finally back at it. Ashpan is done, now working on modifying pneumatic safety valves.
  • Saftey valves are done, front end is ready to have the steam supply pipes bent up and installed, and the boiler is back on for what I hope is the last time in a long, long time.

  • Boiler - September/October 2011
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  • Drilled the stay holes; still have to tap them all and then clean everything up really well. Then it's damn near time to weld it all up!
  • Stays welded in, backhead welded on, mudring welded up. Next up is the front tube sheet.
  • Almost done with boiler construction. Need to ream the tube sheets and roll the tubes in. Then it'll be ready for a hydro test. Then lots of cleanup work and priming.
  • The boiler is now, well, a boiler. Rolled the tubes in and hydro tested it today. A few leaky stays and bushings at first but they all got sealed up nicely.
  • For the first time, the boiler sits on the locomotive! This was an alignment fit so I could measure the spacing between the frame and the mudring, as well as align the brackets that attach the smokebox.
  • Took the mogul out to the RR and had one of the other guys push it around to check the elqualization and whatnot now that it has the boiler. A little too heavy on the lead truck -- split a switch and damaged the pilot!
  • Got the throttle installed. The bowtie-shaped piece of stainless is to keep the throttle centered (rigid) inside the dome.

  • Boiler - August 2011
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  • All the busings are welded into their appropriate holes in the boiler parts.
  • Firebox side sheets welded up today.
  • Final positioning and tweaking of firebox inside boiler shell, getting ready to tack weld in place to facilitate drilling and tapping the stay bolt holes.

  • Boiler & Smokebox - June & July 2011
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  • Got started on the boiler with help from my friend Don. Starting with a piece of seamless pipe.
  • More boiler work. A couple of nights working out the bends in the firebox. Was going to bend the whole thing as one piece, but that didn't work out, so split it in half to be welded together later. Ran out of press strength last night though putting the second bend in each piece!
  • Smokebox door done (sans marker lamps, which will come much later).
  • Firebox welded up. Taking a break from the sauna where the welder is and will be cutting the firebox end of the boiler pipe next.
  • The main boiler pipe is 99.9% ready to start welding on. One last hole to drill in it (bushing for the pressure gauge). The pipe was pretty rusty on the inside so I got some electrolysis going on it.

    Smokebox - May 2011
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  • Back to work on the smokebox and starting on the smokebox door. I'm fabricating my own rather than using the Allen aluminum casting.
  • Work continues on the smokebox.

  • Finishing Tender & Boiler Work - April 2011
    (click to enlarge)

  • Finished boring out the front tube sheet. All that's left to make for the boiler (in my shop anyway) are the two girder stays for atop the crown sheet.
  • Almost done with my laser-cut boiler parts. Just have to bore out the flues in the front flu sheet as well as drill the holes for the washout plugs.
  • Tender is sealed (I used Caswell two-part gastank epoxy) and painted. Plumbing is 99% complete. Assembling it for the final time -- I hope! In one of the photos above there's a tall brass rod; there's a coarse brass screen as a filter at the bottom. The rod is a handle so I can unscrew it through the fill hole when the top is bolted down on the tender.

  • More Tender Fabrication & Boiler Work - March 2011
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  • Work continues on the tender. Top is done; next up are the two water valves and then the rest of the detailing.
  • Started painting tender parts tonight. Getting ready to start drilling stay bolt, plumbing fitting, and flu holes in boiler material. I had the pieces laser cut at a local shop.

  • Tender Fabrication - February 2011
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  • Holes... so many holes... and I'm not even 1/4 of the way done!
  • About half way through drilling rivet holes. Starting to take shape now.
  • Tender is nearing 75% complete. Next up is the top and plumbing.

  • Tender Fabrication and Cylinder Plumbing - January 2011
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  • Removed cylinders and smoke box saddle so I can finish machining, clean and paint. Smokebox radius cut into the saddle.
  • Plumbing for steam supply and exhaust dry fit, waiting on paint to dry on the smokebox saddle.
  • Cylinders and saddle fully reassembled with new plumbing installed.
  • Tender sheet metal cut and rolled.
  • Getting ready to start drilling rivet holes in the tender sheet metal. All the internal supports (angle iron) are cut and drilled.

  • Pilot and Tender Frame Fabrication - November & December 2010
    (click to enlarge)

  • I've been doing a lot of shop clean-up and organization the past couple weeks. Getting started on the pilot.
  • Pilot is done and painted, being re-assembled. Taking a break from the loco to build the tender, the frame is shown in the photo above.
  • Pilot is complete.
  • White Christmas here this year! What better to do than work in the shop? Tender frame nearing completion.

  • Running on Air - October 2010
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  • On Halloween I got the mogul running on compressed air -- some 24 years after it was started.

  • Crossheads and Main Rods, Valve Timing - September & October 2010
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  • After a few months of inactivity (job, hot & humid, lazy), work begins again. One of two crossheads started and fitted. Main rod work.
  • Both crossheads and main rods complete, a few remade valve gear parts. Next step, set the timing on the valve gear and tighten everything up.

  • Valves - June 2010
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  • Both valves installed. Next up are the crossheads and main rods.

  • Valves and Cylinders - May 2010
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  • Getting the last bits and pieces for the valves and cylinders done. Snifter valves completed tonight.
  • Starting work on the valves, cylinder drain cocks done and installed. Left valve installed.

  • Cylinders - Early 2010
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  • Machining front and rear cylinder heads, test fitting the right-hand piston in the cylinder. Note my mistake in the background... broken ring. Oops.
  • Equalizer bar and radius bar done and in place.
  • Temporary plubming for steam supply in preparation for running on air.

  • Cylinders and Steam Chests - December 2009
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  • Starting work on steam chests and cylinders.

  • Valve Gear - October 2009
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  • Finishing valve gear and cab brace.

  • Brake Rigging and Valve Gear - 2007
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  • While living in Texas, late 2007, I resumed work (briefly), getting brakes and valve gear work done.

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