Big drivers (steamer wheels) vs. Small drivers...

[spankybird]

JImBo - see why I love siderods and cow catchers.

[Jim Duda]

Whew! After that one of the two babes on your crane kit, I was afraid you might show them kissing it...! I always love your pics, Jon!

[highrailjon]

Nothing like the touch of a woman polishing that siderod or big driver[:D]
(click to enlarge)

[lionelsoni]

Ottergoose, the wheels on cars are usually 33 inches. However, cars with heavy axle loadings have 36-inch wheels; and cars that need to be closer to the ground have 28-inch wheels. Diesel-electric locomotive wheels vary a few inches, but are in the 40-inch ballpark.

Of course, the wheel diameter varies with wear; and the wheels start out conical (but not as much as "fast angle" wheels) and wear to approximately cylindrical. Furthermore, many of them are designed for more than one "wear". That is, they can be turned down and used again at a slightly smaller diameter. You can often see the wheel data painted on the ends of the car--nominal diameter and how many wears are allowed.

[Anonymous]

QUOTE: Originally posted by philo426

In O scale terms,my Lionel 4-4-2 Atlantic is very quick and at low voltagestoo,probably because the wheels are so large.In contrast,my MTH Turbine with its smaller wheels delivers more low-end torque than blinding speed.I'm glad to see that there is an actual mathematical formula to back up all the antecdoal evidence!

When you're talking about the differences in pulling power & speed between two locomotives, the difference in the wheel diameter is only one factor that explains the difference. In addition to the wheel diameter, you have to look at the gear ratios in the drive train & how fast the motors themselves turn.

You can always make a weak motor deliver more torque ("pulling power") by increasing the gear ratio. This allows the motor to spin faster, which the gears convert into more torque at the output end. Conversely, to go faster, you want to decrease the gear ratio. This sacrifices torque, but gets the output end of the gear train turning faster.

So, strictly speaking, until you determine what effect the gear trains in each engine have, you don't know how much of the performance difference is because of the gears & how much is because of the wheels.

But, in general, taller wheels gives you a faster high end.

Tony

[3railguy]

Jim, your B6 has incredible magnetraction.

[philo426]

In O scale terms,my Lionel 4-4-2 Atlantic is very quick and at low voltagestoo,probably because the wheels are so large.In contrast,my MTH Turbine with its smaller wheels delivers more low-end torque than blinding speed.I'm glad to see that there is an actual mathematical formula to back up all the antecdoal evidence!

[ottergoose]

QUOTE: Originally posted by Lehigh Valley Railroad

The standard wheel on diesel is 44"

Is that the same size as the wheels on other pieces of rolling stock?

[webenda]

palallin said,

QUOTE: The railroads long fought the problems which were created by the uneven motion (see the other thread on the subject). They used the counterweights visible on the drivers, bobs welded to axles, light-weight alloy rods, and the various disc driver centers as weapons in the war. The victims of the the war included not only the engines but the track.

Interesting specification (5.21) for balancing locomotive wheels at <http://www.5at.co.uk/5ATspecifications.shtml>

It specifies that the imbalance shall be not greater than those allowed by the 1928 Bridge Stress Committee at 5 Hz.

[Anonymous]

The SP gs4 which many of us saw as the freedom train loco has 80" drivers and man does it a 6 foot person like myself look small on the photo my wife took standing next to them.
I have a cassette tape conversation of a retired engineer for the northwestern who started out as a fireman in 1913 and he tells of a time,(before speed rules) were used, about 1919 when he was late on a passenger and had a 4-4-2 with 84 inch drivers up to 102 mph and the conductor pulled the air on the train as he got scared.
The engineer said it was just starting to run good at that speed.
Dave

[palallin]

QUOTE: Originally posted by trainut1950

I've ridden that Ft Leonard Wood spur a couple times now on my speeder. That is a fun trestle to go over. I thought it looked like there used to be a different one there since there is what appears to be an old roadbed at one end, maybe that's when a new trestle was built. That spur is very well maintained by yours and my tax dollars. John[8D][:o)]

Are you local, John?

[ben10ben]

Bob,
Once again, you are correct. After multiplying my calculated distances by 60, I divided by 5280 without dividing by 12 first.

[ben10ben]

Bob,
Thanks for pointing out my error. I have no idea where the heck I got the numbers that I got. Anyway, I recalculated converting first to feet, then to miles, and got the same thing that Wayne got.

I stand corrected!

[Anonymous]

I've ridden that Ft Leonard Wood spur a couple times now on my speeder. That is a fun trestle to go over. I thought it looked like there used to be a different one there since there is what appears to be an old roadbed at one end, maybe that's when a new trestle was built. That spur is very well maintained by yours and my tax dollars. John[8D][:o)]

[palallin]

The railroads long fought the problems which were created by the uneven motion (see the other thread on the subject). They used the counterweights visible on the drivers, bobs welded to axles, light-weight alloy rods, and the various disc driver centers as weapons in the war. The victims of the the war included not only the engines but the track.

One example of a skirmish in the war on dynamic augment:
The Frisco was cursed with a large class of drag-freight-era 2-10-2s built with lots of tractive effort, small drivers, and heavy rods. Thye had a reputation for being able to pull everything out of the yards, including the yard itself, but they were limited to 35 mph because, beyond that limit, they literally tore the rails out from under themselves.
By 1940, all but two had been cut up or converted into high-horsepower 4-8-2s. The pair of survivors--numbers 19 and 40--were rebuilt to work the then-new Fort Leonard Wood spur, a branch that ran from Bundy Junction (near the division point at Newberg, MO) to the base it was named after. Built to mailine standards, the branch saw very heavy use during WWII (and, incidentally, continues to see heavy use), and it included a fairly tall, splindly, and curved trestle over the Big Piney River.
Now, wartime traffic was both heavy and fast, and the operating department tended to look the other way when engineers would beat the stacks to move tonnage over their single-tracked line--it was not uncommon for 60 trains a day to run between St. Louis and Monett. In their haste, they forgot about how large a mess those 2-10-2s could make of the roadbed. One day in '41, a hogger got just a little bit too frisky with #40, and it kicked the rails out from underneath itself on the curve of the trestle and all 569,600 lbs. of engine and tender sat down on the bridge deck high above the river below. Just imagine the fun the wrecking crews had dealing with that little fiasco! (As a footnote, numbers 19 and 40 were rewarded with an early date with the scrappers).

[underworld]

mersenne6 I remember reading about that in high school. Must have been quite a rush back then. now I think they just draft behind race cars
(boring[:p])

underworld

[:D][:D][:D][:D][:D]

[highrailjon]

"From the beginning, the B&M had problems with their Lima built Berkshires. The problem was with the trailing four wheel truck. Because of the large firebox and large ashpan the locomotive had to have an articulated frame. The back end of the firebox had to rest on a moving base and it was subject to buffeting and twisting, resulting in chronic leakage at the mudring, side sheet staybolts and the throat sheet, as it tried to wiggle from side to side to follow the motion of the trucks. Also, this arrangement would sometimes cause the rear wheels to derail while backing up. "

Not the dreaded chronic leakage at the mudring!!!![:0][:0][:D]

[lionelsoni]

Wayne, Ben just forgot to convert inches to feet.

[laz 57]

Miss Train Manners,
CHUGA CHUGA CHOO CHOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
laz57

[Jim Duda]

QUOTE: Hey Jon, I do like your town......seems to be a very high ratio of babes! - underworld

...that's why Vergun spends so much time cruisin' up and down the streets over there...! He and Missy need to hook up - assuming their couplers are compatible...

[mersenne6]

Underworld, I don't know about a steam powered racing bike but there were a number of high speed bicycling records set around the turn of the 20th century where bicycles were drafted behind high speed steam locomotives. If memory serves me right I believe they reached speeds in the 100 mile an hour range.

[highrailjon]

"When I click on the babes, they get bigger, but when I click on Miss Train Manners, nothing happens"

Wayne, LMAO!!![:D]

[webenda]

MATH! Oh boy!

C = PI x D (INCHES)
V1 = C INCHES x REVOLUTIONS/MINUTE (INCHES/MINUTE)
V2 = V1 INCHES/MINUTE x 1/12 FEET/INCH (FEET/MINUTE)
V3 = V2 FEET/MINUTE x 1/60 MINUTE/SECOND (FEET/SECOND = FPS)
V4 = V3 FPS X 60/88 MPH/FPS (MPH)
CONSTANT = PI x (1/12) X (1/60) X (60/88) = PI/1056

ben10ben's problem:
VELOCITY = PI x D x RPM / 1056
VELOCITY = PI x 44 x 1 / 1056 = 0.13 MPH
VELOCITY = PI x 79 x 1 / 1056 = 0.24 MPH
Why are those values different from ben10ben's?

Diesel RPM = 90
VELOCITY = PI x 44 x 90 / 1056 = 12 MPH
VELOCITY = PI x 79 x 90 / 1056 = 21 MPH
Speed if steam wheels turned same RPM as diesel engine.

How many RPM (79 inch wheel) for 100 MPH?

RPM = (1056 x VELOCITY)/(PI X D)
RPM = (1056 x 100 MPH)/(3.141 X 79) = 425 RPM

[underworld]

Hey Jon, I do like your town......seems to be a very high ratio of babes!
Steamers are kinda like racing bikes....the real fast ones have really big wheels. ***wondering about a steam powered racing bike***

underworld

[:D][:D][:D][:D][:D]

[webenda]

Jon,

When I click on the babes, they get bigger, but when I click on Miss Train Manners, nothing happens. [%-)]

[Anonymous]

Hello All: With all the talk about Hump yards & smoking up the basement, small drivers & big drivers in the last few weeks it reminded me of a short story. The bigboy steamer pulls into the roundhouse & asks the biglady steamer "Do you smoke after X" she replied " I don't know I have never checked " That one is for Jim. Have a good night all. Kind regards Steve

[highrailjon]

You're a slick man, Jim!! But I know as well as you do,that pound for pound, diesels have more tractive effort!!![:D][8D]
Miss Train Manners is winking at that, also!!

[Jim Duda]

Gasp! Jon - Please don't tell me that Missy prefers double heading to pull the train...! Big drivers...small drivers...I'm switchin' back to diesels - they're much safer!

[Anonymous]

Ooh baby, where did you get her highrailjon? I gotta have her twin for my layout. John[8D][:o)]