Modeling B&O- Chessie Bob K. www.ssmrc.org
Thanks for your reply..now I'm on the same page.
There were two traction pinion to axle gear ratios. Freight of course was lower due to pulling more tonnage ar lower speeds and passenger had a taller ratio due to lighter tonnage and faster speeds. The axle gear was not much larger in over all dia and my memory fails to recolect the tooth count, but I do remember one had to mark a gear tooth with chalk, then count teeth not to make a mistake in grabbing the wrong axle to mount in the traction motor. The gear when pressed on were done in the same axle press. There was no difference in the actual axle between frt and passenger, the gear was the only difference.
About the B & O F3s, Different roads had different master mechanics. However our F3s were upgraded over time to use the same parts as the 7s.
So now if ya want to bet those guys a cup of coffee on the gear size NOT being so small, bet two cups, Ill take mine with cream LOL
Frt and passenger units were not mixed of account of wheel slippage and heat buildup from mixing the ratios. however I due recall a time or two passenger unit pressed into freight, only because the road was short on power and a valley haul, during the Viet War. When a passenger was returned to freight duty, (the day after the California Zepher died ) We removed the traction motor on the drop pit, removed the passenger axle, exchanged the traction motor pinon to freight ratio, installed the frt axle in the same traction motor and re-installed in the truck.
I was an machinist apprintice (locomotive mechanic) and worked the CZ passenger units on the outbound lead on its last run, was a downer day as everone took a lot of pride in WPs passenger units. The WP museum in Portola Ca. has a passenger unit and it looks as proud as ever.
The only other change we made from passenger to freight service, was to reverse the air from indirect to direct. This was a simple reversal of a two bolt cover (about three inches long, bolted on the side of a brake valve down in the nose, held with two 3/8 capscrews). On account in passenger service the air brakes are set up from the back on the train to the front so that the engeneer can strech the trains couplers out without jarring his passengers, as he brings it in to the station, and later in smoothly pulling away getting quickly up to speed. While freight on the oter hand would set up from the engine back the crummy, front to back.
eh gads there I go degressing again, I try to keep this to a minimum LOL Take care...John
jwar wrote: bogp40 wrote:Are these to be detail displays for the machine shop? Some of the higher geared trucks actually had to have the gear machined into the axle itself (too small a gear for a axle/gear press. Are these the gears you are looking to model for the machine shop?I have no idea of what your referring to. Other then a slight difference in the outer diameter, due to gear tooth count, the iner size (the bore) is aproximatly the same on low or hi geared axles, and are mounted in the same wheel press. Or at least that was the way we did it when I was a wheel shop forman, but then that was a few decades ago LOL.Yes I will be modeling a machine shop, tread lathe, traction motors and such, this is why I want to find or make the gear so that I can have a few wheel sets in front of the lathe.If this comes out half as good as I think it will, I will be pleased with it. Should be somewhat done with it in a month or so....John
bogp40 wrote:Are these to be detail displays for the machine shop? Some of the higher geared trucks actually had to have the gear machined into the axle itself (too small a gear for a axle/gear press. Are these the gears you are looking to model for the machine shop?
I have no idea of what your referring to. Other then a slight difference in the outer diameter, due to gear tooth count, the iner size (the bore) is aproximatly the same on low or hi geared axles, and are mounted in the same wheel press. Or at least that was the way we did it when I was a wheel shop forman, but then that was a few decades ago LOL.
Yes I will be modeling a machine shop, tread lathe, traction motors and such, this is why I want to find or make the gear so that I can have a few wheel sets in front of the lathe.
If this comes out half as good as I think it will, I will be pleased with it. Should be somewhat done with it in a month or so....John
John,
Have I been misled by disscussions on the B&O group about the passenger gearing? Since you where refering to the gear/ axle machining, I believed you to be using these. The passenger F3s couldn't be regeared w/o changing out the axle assy. Are these older units machined this way, or does the group misunderstand this particular gear ratio? I'm led to believe that this high ratio on the F3s had a gear small enough that fitting to the axle wasn't possible and needed to be machined as an assy.
Do you think that those brass offerings from NWSL will represent the prototypical gears themselves? You, better than any others here really should know. Would be a nice touch for the machine shop.
Northwest Short Line sells gears.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com