Re Gauging to 4 3/4" from 5" gauge.

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FRED DADDI
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Re Gauging to 4 3/4" from 5" gauge.

Post by FRED DADDI »

Thinking of buying a 5" gauge 0 4 0 Sweet Pea any thoughts?


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Glenn Brooks
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Re: Re Gauging to 4 3/4

Post by Glenn Brooks »

It’s always about whether the firebox is to wide for the intended smaller inside measurements of the wheels and frame.

Glenn
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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....
Pontiacguy1
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Re: Re Gauging to 4 3/4

Post by Pontiacguy1 »

IF you have enough space, you could always add some wider (to the inside) tires which would change the gage inward. That's how the manufacturers changed the gage on all those 'Russian Decapods' back in 1918. The bolshevic revolution caught several hundred 2-10-0s during their construction before delivery, and all of them were built to 5 foot gauge. They were re-gauged down to 4' 8 1/2" and distributed to power-needy lines all over the country. If you look at any of the remaining Russian decapods, they had a really wide tire applied to the drivers that hung over the back-side of the wheel a couple of inches, and which moved the flange back by the correct amount. The lead trucks were just re-gauged the conventional way. Tender trucks were changed out to 4' 8 1/2" gauge ones, and the locomotives were ready to go.
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Builder01
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Re: Re Gauging to 4 3/4

Post by Builder01 »

Wider tires could be made, but, there is usually not enough room to do this as each flange would have to have to come inward, toward the frame, by 1/8". This could be determined if you have the drawings or good photos of the loco in question.

If you are building from scratch, it is pretty easy if the locomotive has outside cylinders. I have built a Super Simplex and re-gauged it from 5" to 4-3/4". If you are going to modify an existing locomotive, that could be very problematic. Here are the things I had to change from the drawings to re-gauge a 5" loco, to 4-3/4".

-Frames were moved in 1/8" per side (1/4" total")
-Frame stretchers narrowed by 1/4"
-All axles shortened by 1/8" on each end
-Smoke box saddle casting modified to fit to the new dimension of the frames.
-The boiler (in my case) is a keyhole type and fits between the frames. The barrel diameter was not changed, but, the fire box legs needed to be moved in 1/8" on each side. Both the inner and outer wrapper of the firebox had to be moved 1/8" to maintain the water space inside the legs. Back head and throat plate were also changed to fit. This also causes the grate to be 1/4" narrower. Other types of boilers may not need to be modified.

I left everything above the running boards exactly as drawn.

David
FRED DADDI
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Re: Re Gauging to 4 3/4" from 5" gauge.

Post by FRED DADDI »

Builder01 wrote:Wider tires could be made, but, there is usually not enough room to do this as each flange would have to have to come inward, toward the frame, by 1/8". This could be determined if you have the drawings or good photos of the loco in question.

If you are building from scratch, it is pretty easy if the locomotive has outside cylinders. I have built a Super Simplex and re-gauged it from 5" to 4-3/4". If you are going to modify an existing locomotive, that could be very problematic. Here are the things I had to change from the drawings to re-gauge a 5" loco, to 4-3/4".

-Frames were moved in 1/8" per side (1/4" total")
-Frame stretchers narrowed by 1/4"
-All axles shortened by 1/8" on each end
-Smoke box saddle casting modified to fit to the new dimension of the frames.
-The boiler (in my case) is a keyhole type and fits between the frames. The barrel diameter was not changed, but, the fire box legs needed to be moved in 1/8" on each side. Both the inner and outer wrapper of the firebox had to be moved 1/8" to maintain the water space inside the legs. Back head and throat plate were also changed to fit. This also causes the grate to be 1/4" narrower. Other types of boilers may not need to be modified.

I left everything above the running boards exactly as drawn.

David
Thanks David. Just checked the Sweet Pea book quick calc shows 3/16 per side if tires were to be made. Not some I want to chance. I have a cousin who built a Simplex and basically did what you did to get it to 4 3/4. No small task for the engine I looked at...its on ebay..


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Builder01
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Re: Re Gauging to 4 3/4

Post by Builder01 »

Yes, if the boiler is already built, as on the Ebay Simplex, it will not ever fit between the frames if they are brought together by 1/4". I think this is exactly what Glenn mentioned above.

David
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Fred_V
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Re: Re Gauging to 4 3/4

Post by Fred_V »

I regauged a Sweet William to 7 1/4". there was room so just had to take 1/16" off the axle shoulder and end. Then makd new longer crankpins.
Fred V
Pensacola, Fl.
FRED DADDI
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Re: Re Gauging to 4 3/4" from 5" gauge.

Post by FRED DADDI »

Fred_V wrote:I regauged a Sweet William to 7 1/4". there was room so just had to take 1/16" off the axle shoulder and end. Then makd new longer crankpins.
I have sweet william drawings ill check. Any way to contact the designer?


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jcbrock
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Re: Re Gauging to 4 3/4

Post by jcbrock »

I don't know where you are located Fred, but the St Croix RR in Hudson, WI does have a 5" gauge rail on their elevated, fwiw.
John Brock
FRED DADDI
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Re: Re Gauging to 4 3/4" from 5" gauge.

Post by FRED DADDI »

Pa live steamer 4 3/4


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Fred_V
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Re: Re Gauging to 4 3/4

Post by Fred_V »

FRED DADDI wrote: Wed Jan 31, 2018 10:20 am
Fred_V wrote:I regauged a Sweet William to 7 1/4". there was room so just had to take 1/16" off the axle shoulder and end. Then makd new longer crankpins.
I have sweet william drawings ill check. Any way to contact the designer?


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Your drawings should show dimensions for both gauges; the Sweet Wm. drawings had both. you shouldn't need to contact the designer if you have drawings.
Fred V
Fred V
Pensacola, Fl.
FRED DADDI
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Re: Re Gauging to 4 3/4" from 5" gauge.

Post by FRED DADDI »

I have an ancient setbof sweet pea drawings ill have to find them.....


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