YMSPRR Jenny Railcar project planning maybe bulding soon.

[fresnojay]

So during an outing with the family about 2 weeks ago I chose to stop in at the Yosemite Mountain Sugar Pine Railroad. I was hoping to take the kids and wife for a ride on the Shay but instead stumbed on a little jem that I think would make an interesting and different 2 1/2" scale project. For those that don't know about the Jenny's they are a modified Model "A" that the logging RR's used to ferry crews and equipment around on thier runs. There are Geese running around all over but I have yet to see one of these. So as of now it is in the information gathering stage. Any information anyone has or input they would like to share please feel free to help out. I am planning on stopping in at YMSPRR in the next few weeks when the family and I head up to Mariposa to visit some friends.

Jason

[fresnojay]

Here are the pics I couldn't find yesterday when I started the topic. Also have a few of the Engine house that they let me wander through. But alas they are not great quality as they are from my phone. Didn't have my cam with me on the trip. I do also have video of the ride we took on the Jenny on this trip on my youtube. But again taken with my phone.

Jason

[Harlock]

Would you adjust the dimensions so you can sit inside of it like Steve Easlon's yellow critter? Or forgoe the roof.

[fresnojay]

Mike,
I have been tossing up how I would go about riding it or if I would just make a wagon in tow the riding car. Since these did pull MOW carts behind them its wouldn't be a stretch to see one pulling one. As you can see in the pics there are draw bars for that reason. Plus during my online searching I did see pictures of them pulling a simple little 2 axle wagon.

I have thought about since I was looking at going 2 1/2" scale just beefing up the roof supports and roof with hidden bits of metal maybe in a sandwich type fashion. Also beefing up the foot boards so they could be usable for the rider. The foot boards wouldn't be an issue really as it would just mean thicker guage steel for the brackets and bracing. The roof however in order to keep the wood and prototypical look may by a different story. Another option that just crossed my mind is to have the roof removable so it can be put on while static and taken off during operation. But even then at 2 1/2" scale only the little ones would fit. But if nothing else give them a cool spot for a ride . Its size would be compairable to that of your Chloe height wise and about 2/3 as wide. Scaling it up to something like the size of Steve's critter would be an interesting thought though.

Time will tell once I can get some quality crawl on and over time on my next trip up there. The staff when I told them about being in the hobby were all to happy to let me wander around and check stuff out. They even offered to let me spend some time in the engine shed but since I had my daughter with me opted not to. We did peek in the doors though . After the next trip I will have some workable numbers to crunch and play with so I can look at all options.

Jason

[fresnojay]

A little update.

Going to be heading up the our friends place in Mariposa again this coming week. Will be giving the folks as YMSPRR a call to see if I can stop by to get the needed info for the project.

Have been poking around and looking at various pieces that can be picked up from vendors. From what I have guess-tamated the wheels will probably be in the 26"-28" diameter range. Also by guessing my hieght vs the hieght of the railcar and compairing other pictures that I had took on that outting. I am guessing the railcar will probably be around 30" tall at 2.5" scale. But should have good numbers this next week. Already have a good sketch up ready for dimensions and measuring tapes ready.

Jason

[Greg_Lewis]

They even offered to let me spend some time in the engine shed but since I had my daughter with me opted not to.

Jason, you gotta indoctrinate them when they're young!

[fresnojay]

Hi Greg,
She has been introduced already but still has bunches to learn yet. She loves going to any of the meets. She does well but not ready to move on to the big boys just yet. But she is well on her way .

Jason

[fresnojay]

Well was finally able to make it back up to Sugar Pine today. The engineer's of the Shay's were totally awesome considering the RR was closed they allowed me to have my way with one of the railcars. They just happened to be on property servicing #15 for a private party run tomorrow. When I told them about my plans they were all to happy to let me get what I needed. The Jenny's had been buttoned up for the season but they engineer's said I could roll up the sides to get at whatever I needed to. Long story short I have most of what I think I need to get this project going if not done entirely.

On a side note after arriving home from the visit with friends in Mariposa this trip to Sugar Pine which I was gone for 2 days. Found my home's yards thuroughly trashed thanks to the insane winds yesterday and today. So I now have some scrap metal from my now destroyed patio cover that might lend itself to building the frame of this project .

Jason

[Harlock]

Boy those are funky wheel spokes.

[fresnojay]

I agree but if you look as some of the first pics I posted in my first post. You can see another type with what looks like lightening holes milled into them. My best guess is that the Model "A" drive train may have had issues with the weight of the un-modified wheel sets. So the funky spoke arrangement of the wheel I posted a pic of may be to prolong or ease of wear on the A's drive train. The holey wheel type is actually on the drive wheels of the railcar I measured and posted pics of.

Now I have a question. I am ready to start the coversion of the measurements to 2.5" scale. But here is the thing I am having some issues and have tried a couple different formula's but not sure which one if any are right. I have also looked online with no joy. Example: Railcar Length is 14' 4" front of bumper to front of bumper. So using one method I got 5.73' or 68.8" long. The other I got 35.83" long. Any help on actual formula's or if I am even close?

Jason

[Harlock]

I agree but if you look as some of the first pics I posted in my first post. You can see another type with what looks like lightening holes milled into them. My best guess is that the Model "A" drive train may have had issues with the weight of the un-modified wheel sets. So the funky spoke arrangement of the wheel I posted a pic of may be to prolong or ease of wear on the A's drive train. The holey wheel type is actually on the drive wheels of the railcar I measured and posted pics of.

Now I have a question. I am ready to start the coversion of the measurements to 2.5" scale. But here is the thing I am having some issues and have tried a couple different formula's but not sure which one if any are right. I have also looked online with no joy. Example: Railcar Length is 14' 4" front of bumper to front of bumper. So using one method I got 5.73' or 68.8" long. The other I got 35.83" long. Any help on actual formula's or if I am even close?

Jason

7.5" gauge divides pretty evenly into 2.5" scale, so that can be used evenly with only tiny tweaks on the back-to-back dimension of the wheels.

Couple of ways to calculate. First the division method.

36 / 7.5 = 4.8.

So take your full size measurements and divide them all by 4.8.
Nice even divisor.

Second way is the multiplication method.

2.5 / 12 = .20833.
or 7.5 / 36 = .20833.

Lets try that out.

36" gauge X .20833 = 7.499... 7.5" gauge for all intents and purposes.

One happy accident that has come about from most of the US adopting 7.5" gauge instead of 7.25" gauge is that it multiplies evenly for 2.5" scale @ 7.5" gauge. For 1.5" scale, 7.25" gauge is correct for that, which is why some people out here do 1.6" scale. Since the western and mid-western united states has the greatest concentration of narrow gauge modelers, this is dandy.

[Fender]

The reason for the two different wheel styles, is that the one with the curved spokes is cast iron, and the other is pressed steel. The pressed steel is a more modern design. The spokes are curved to reduce the likelihood of cracking when the wheel casting is made.