G 12 conversion to 7.5" gauge?

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Glenn Brooks
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Location: Woodinville, Washington

G 12 conversion to 7.5" gauge?

Postby Glenn Brooks » Thu Apr 06, 2017 1:08 am

Hello all,

Has anyone converted an MTC G 12 train set to run on 7 1/2" track? It seems like this would be easy to do - make a set of 7.5" trucks to fit underneath a G12" loco and coaches.

I wonder if the existing body size would become unstable and liable to tip over or derail at 7.5" ga? How would one mitigate this, besides adding dead weight to the bottom of the coaches? Some sort of spring assembly or anti sway bar maybe??

Here is a photo of an original MTC G12 truck. Pretty basic. The loco is maybe around 2.5 to 3" scale- not quite 2x as large as most live steam club diesels.

IMG_1449.JPG
G 12 truck


IMG_1450.JPG


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....

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ccvstmr
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Re: G 12 conversion to 7.5" gauge?

Postby ccvstmr » Thu Apr 06, 2017 8:30 am

Hello Glenn, believe there are (2) MTC G-12's in my club converted to 7.5" gauge. Since the trains are articulated, you have the weight of two cars on each truck. Don't think sway or other provisions are necessary. Here's some photos of the equipment...

The 1st example is a 6 unit CB&Q train. Equipped with a Honda engine and a hydrostatic transmission.
xIMG_5180.JPG

Trucks were made from side frame castings from Dennis Goodman. Bolsters added along with the "tubes" for mating pins on the ends of the cars.
xIMG_5030.JPG

A side view of the truck frame. Frames are plain looking, but when tucked under the ends of the cars, you don't see much of the side frames.
xIMG_5031.JPG

The 2nd example is a 4 unit Santa Fe train. This is equipped with a water cooled, 4 cylinder fork truck engine. Don't recall the type of transmission. Very quiet on the rails when running. The trucks are equipped with what looks like Backyard Rails Blomberg truck side frames. Side frames are non-functional....bolt on decorations. Don't know if the original truck frames were used or not.
xIMG_4614.JPG

So to answer your question...yes, G-12's have been converted successfully to 7.5" gauge. Don't think either train has ever experienced any kind of tip-over incidents. Hope that helps. Carl B.
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Glenn Brooks
Posts: 794
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: G 12 conversion to 7.5" gauge?

Postby Glenn Brooks » Thu Apr 06, 2017 11:53 am

Thanks Carl. Very good to know. I appreciate the photos also!

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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BigDumbDinosaur
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Re: G 12 conversion to 7.5" gauge?

Postby BigDumbDinosaur » Fri Apr 07, 2017 11:31 pm

ccvstmr wrote:The 1st example is a 6 unit CB&Q train. Equipped with a Honda engine and a hydrostatic transmission.

Actually, powered by a 20 HP Briggs & Stratton industrial V-twin.

The 2nd example is a 4 unit Santa Fe train. This is equipped with a water cooled, 4 cylinder fork truck engine. Don't recall the type of transmission.

This one also has a hydrostatic transmission using a variable displacement, reversible pump.

I've both ridden in and operated both of these trains and can report that they are very stable.
Science makes it known. Engineering makes it work.

Glenn Brooks
Posts: 794
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: G 12 conversion to 7.5" gauge?

Postby Glenn Brooks » Mon Apr 17, 2017 1:40 am

Big dumb dinosaur,

Any idea who sells this style transmission these days, and what capacity it is that is installed in the 4 unit Santa Fe?

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....


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