Hello. How do you convert real train specs down to scale? Say for 1:32. For the length of a car you would divide by 32? For speed divide by 32. And weight divide by 32 to 3rd power, (for 3 dimensions)?
Big Boy loco weighs 1.2 million pounds, divide by (323232) = 36.6 pounds.
Thx.
Marty
Yes, that’s it
In principal, yes. But in practice, not so much. Consider the USA 1:32 Big Boy weighs in right at 100 pounds. And it needs all of it if you are gong to pull 400+ pounds of hopper cars.
http://www.youtube.com/watch?v=QhQMqKl38wU
Dimensions scale directly, mass however does not. Spend a couple of minutes and read the text accompanying the video.
Bob C.
The big boy is 1:29 … that scales to 49.2 pounds… except that the real loco weighs 762,000 pounds, scales to 31.2 pounds… how much does the model loco alone weigh?
If you look it up, the loco weighs 45 pounds… the tender 16 pounds…
Bob, where did you get 100 pounds?
Reference this site where the owner weighed each of his locos down to the ounces:
http://www.rayman4449.com/Locomotives.htm
Greg
p.s. dividing by the cube of the weight is accurate… try it on a box car and then look up the unloaded weight of the prototype
For what it’s worth, I remember seeing a USAT ad in which the BB was discussed. Ro said it weighed 65 pounds. When I weighed mine on our bathroom scale, the engine was 46 pounds and the tender 20. Considering that our scale isn’t designed for low weights, I think the engine is 45 pounds and the tender 20, which agrees with the 65 pounds Ro said.
The cast boiler, smoke box, and cab lift off easily as an assembly and are not very heavy, maybe 2 pounds. My belief is that the frame is very heavy for rigidity so that flexing forces on the cast parts are minimal.
As far as scaling the weight from prototypes, it seems to me that the weight of hopper loads should be scaled down and and be heavy, not just a few ounces. And when scaling down the weight of a box car, should the max weight be scaled (fully loaded car) or the empty weight? After all, no one can see whether it’s empty, partially loaded, or at max load. Same for tanker.
My belief is the ideal weight of cars is just enough for reliable operation. More than that puts more load on our engines. Engines should be heavy enough for good pulling power. So I don’t think weight should be scaled. Just my opinion.
The association that bears no name, that is to say, the NMRA, has a table of weights to be added to H0 and N scale cars to go some way to replicating a more realistic load behind locomotives in those scales.
I can’t recall the formula, but I’m sure that some of you clever folks can.
I agree with Mr Ness - we are not actually running revenue trains here, with locomotives straining to haul one last loaded car up Maria’s Pass.
There are genuine physical reasons why we don’t do that - I’ve rarely seen a large scale lash-up of five or six AC4400-series or Dash 9, eighty cars, another three/four big dismals, another thirty cars, and a couple of pushers. On both sides of the Columbia River, and the Fraser, that is not so exceptional.
I’ve only once seen a genuine 100-car train in Gauge 1, although Youtube has one in 1/29th, I recall. Marty Cozad runs HUGE trains, and so did another gentleman in GR with an even larger desert-localae track and many big locos.
Most of us, me included, settle for an affordable reality.
tac
PS - having said that, I recall that a pal of mine here in UK DOES haul hundred car trains, but in N scale. His fifty/sixty-foot long trains really do snake around his 250-foot layout in a custom extension to his garage, but he IS an exception.
Yes the NMRA has recommended car weights for HO an N scale. They do not have any that I could find for large scale. Just so long as my cars are all similar in weight, they run fine. 17 car trains are the longest my reverse loop can handle. I have a few scratch-built cars, and they are lighter then manufactured cars. I used to follow the rule that heavier cars are up front, and lighter cars in the rear. But I have found that it doesn’t matter with my short trains.
Scale weight is an interesting discussion, but so long as the trains track well and run properly, it isn’t really important. IMO. I have had discussions with folks who don’t understand that scale volume is the cube of the scale, and so is weight. those become interesting discussions.
Back to scale dimensions. I have purchased several scale rulers for kit-bashing and scratch-building, but I find that scratch-building in 1:24th scale is the easiest. 1 inch is 2 feet, half inch is one foot and so on. 1:24th scale requires simple math, that my simple mind can handle.
Another rough way to scratch build is to use the centimeter side of the ruler. You know, the side you don’t much understand
and pretend those are feet, not centimeters.
David Maynard said:
…
Back to scale dimensions. I have purchased several scale rulers for kit-bashing and scratch-building, but I find that scratch-building in 1:24th scale is the easiest. 1 inch is 2 feet, half inch is one foot and so on. 1:24th scale requires simple math, that my simple mind can handle.
I have a good stack of books with dimensioned drawings of the proto, along with a few original blue prints. The dimensions are, as is customary for engineering drawings, in millimeters. I just divide by 22.5 and … voilà. Accurate enough for my purposes.
Greg,
After checking, I apologize. That was the complete shipping weight, including the wooden cases, etc.
Bob C.