1.5" SP A6 Atlantic

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Glenn Brooks
Posts: 2930
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: 1.5" SP A6 Atlantic

Post by Glenn Brooks »

Great find! Atlantic’s are my favorite engine. This one looks like a museum piece! Very interested in the diameter of your boiler and how the original builder configured your front end. Any photos of the blast pipe?

If you have a traditional single pipe blast nozzle, a worthwhile upgrade might be to consider installing a multi port blast nozzle, aka Lempor design or similar. These significantly improve steaming capability and will increase liveliness and your Hp rating at the drawbar...

Either way, a look at the smoke box design would be very interesting.

Thanks,
Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Rwilliams
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Joined: Thu Dec 22, 2005 2:45 pm
Location: Central California

Re: 1.5" SP A6 Atlantic

Post by Rwilliams »

Nice to see the rare detail of the house valves so seldom modeled in such detail. Nice little elbow on the top will finish up the appearance when that time arrives. The SP seemed to apply the house valves in many different methods and this design was one of the more elegant.

Here is a rare close view of the SP 2419 showing the house valve in detail. Look just below the running board.
Attachments
SP 2419 with steam chest relief vavle details.jpg
Berkman
Posts: 679
Joined: Wed Aug 16, 2017 7:55 pm

Re: 1.5" SP A6 Atlantic

Post by Berkman »

Appears to be a "poor mans" drifting valve.

Did they have a separate drifting valve in addition to the globe valve?

I've seen photos of some smaller/ NG locomotive that just had a globe valve like that which would be cracked when the locomotive was sitting idle.
tyleire
Posts: 95
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: 1.5" SP A6 Atlantic

Post by tyleire »

Glenn Brooks wrote: Sat Jul 17, 2021 12:56 pm Great find! Atlantic’s are my favorite engine. This one looks like a museum piece! Very interested in the diameter of your boiler and how the original builder configured your front end. Any photos of the blast pipe?

If you have a traditional single pipe blast nozzle, a worthwhile upgrade might be to consider installing a multi port blast nozzle, aka Lempor design or similar. These significantly improve steaming capability and will increase liveliness and your Hp rating at the drawbar...

Either way, a look at the smoke box design would be very interesting.

Thanks,
Glenn
I keep forgetting to measure the boiler diameter but here's a photo of the single port blast nozzle. Multi port nozzle sounds interesting, I'll look into it.
PICT0082.JPG
Rwilliams wrote: Sun Jul 18, 2021 10:39 am Nice to see the rare detail of the house valves so seldom modeled in such detail. Nice little elbow on the top will finish up the appearance when that time arrives. The SP seemed to apply the house valves in many different methods and this design was one of the more elegant.

Here is a rare close view of the SP 2419 showing the house valve in detail. Look just below the running board.
Here's my inspiration for the house valve from sister engine #3002. The engineer side plumbing is much simpler than the fireman's side with the booster piping.
IMG_7696.PNG
tyleire
Posts: 95
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: 1.5" SP A6 Atlantic

Post by tyleire »

214392214_10225861044451385_2155809647557171896_n.jpg
Smokebox plumbing is coming along nicely with larger 1/2" ID fittings and the 850 degree high temp valve from Swagelok mounted at a 45 degree angle to prevent lockups. I plan to attach lubricator lines before and after the valve.

Also fabbed up a simple ash pan for the wok-style impingement burner left over from a friend's project that SHOULD be completely removable without pulling the boiler.
IMG_1822.jpg
Glenn Brooks
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Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: 1.5" SP A6 Atlantic

Post by Glenn Brooks »

Front end work coming along nicely. Your soldering is superb.

One thing l forgot to mention. Single nozzle blast pipes are just fine with propane. Makes life much easier. The multi port designs are most useful with coal, as they increase air flow through the fire box with better vacuum in the front end... but you control the propane fire by regulating gas pressure- so no need for the multiport design...

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
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kcameron
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Joined: Wed Aug 17, 2011 4:23 pm
Location: Syracuse New York

Re: 1.5" SP A6 Atlantic

Post by kcameron »

Exactly how were the house valves used on the prototype? I know they existed but curious of the how. Yes, they used local steam in the engine preparation but no details like when connected, disconnected, objectives.
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Mike Walsh
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Joined: Sun May 06, 2007 10:14 pm
Location: St. Louis, MO

Re: 1.5" SP A6 Atlantic

Post by Mike Walsh »

I believe they were opened up when the engine was parked overnight so that steam could not build up in the cylinder due to a leaky throttle and set the engine in motion (i.e. runaway into the turntable pit, etc).
tyleire
Posts: 95
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: 1.5" SP A6 Atlantic

Post by tyleire »

Glenn Brooks wrote: Wed Jan 05, 2022 10:13 am Front end work coming along nicely. Your soldering is superb.
Thanks but that photo was taken before silver soldering! I marked and laid out the fittings how I wanted then let my friend David Lazarus take over the silver soldering as his background in HVAC made quick work of the job.

Lots of odds and ends to check off my list before I can bolt down the boiler.
IMG_6867.jpg
Picked up some nice Berkshire smokebox hinges to replace the ugly originals.
IMG_7532.jpg
Relocated the air compressor to the engineer's side. The former mounting pads on the fireman's side will work perfectly for the planned Worthington Feedwater Heater.
IMG_0763.jpg
Mounts for air tanks.
IMG_7606.jpg
IMG_7694.jpg
Oh and a temporary reverser quadrant while RLS member Jerry Blake finishes up my Dave Moore Power Reverse. (Ignore the rust, Southern CA has been a little soggy lately)
Rwilliams
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Joined: Thu Dec 22, 2005 2:45 pm
Location: Central California

Re: 1.5" SP A6 Atlantic

Post by Rwilliams »

The house valves were used to vent any steam leaked to the valve chambers by a less than perfect throttle valve seat. Most double seated dome throttle valves were notorious for leaking as to lap them into a perfect sealing condition was an art form and very time consuming. Most shops did not have the time or the talented patient help to achieve steam tight seats.

Another way steam could reach the valves was through the hydrostatic lubricator. What few know about is the small vent port or vent hole drilled in the steam supply valve disk at the top of the lubricator condenser chamber. Even when the steam supply valve is full closed, this 1/16 diameter hole insures a small bit of steam to the lubricator at all times to avoid build up on condensation. If the main turret stop valve leaks, the lubricator will still supply steam in small amounts to the cylinders causing leakage as the cylinder cocks and a wisp of steam at the drifting valves even if the throttle is correctly seated.

Therefore, the house valves or cocks as they were often called, were an important safety device simple in function. Easy to open them once the locomotive was spotted in the shop area and left open until the locomotive was ready to be moved at any time.
Mike Walsh
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Joined: Sun May 06, 2007 10:14 pm
Location: St. Louis, MO

Re: 1.5" SP A6 Atlantic

Post by Mike Walsh »

Rwilliams wrote: Wed Jan 05, 2022 10:27 pm Therefore, the house valves or cocks as they were often called, were an important safety device simple in function. Easy to open them once the locomotive was spotted in the shop area and left open until the locomotive was ready to be moved at any time.
And easy to figure out if you've forgotten to close them when moving out of the shop.... And easy to close :)
tyleire
Posts: 95
Joined: Thu Sep 24, 2015 3:18 pm
Location: North Hollywood, CA

Re: 1.5" SP A6 Atlantic

Post by tyleire »

Busier than ever with work this summer but still trying to make progress when I can.

IMG_1140.jpg
First up was the booster exhaust pipe. Laying out the smokebox details was essential to figuring out placement as the prototype's exhaust appears to be recessed into the side of the smokebox, I'm assuming for forward visibility. I repeatedly annealed and slowly bent a longer piece of tubing, taking care to avoid dents, then trimmed it down to size.


IMG_1179.jpg
Once happy with the details placement on the smokebox, I painted with rattle can Stovebrite charcoal hi temp paint. Details will be painted black with the exception of the smokebox front painted in Stovebrite silver.
IMG_1248.jpg
Liquid gasket sealed and bolted down the smokebox for (hopefully) the last time.
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