Who says 18" curves are unrealistic?

Model Railroader General Discussion (Model Railroader)
1

http://railpictures.net/viewphoto.php?id=339228&nseq=0

The caption makes a comparison to HO scale curves. Just goes to show, if it’s done on the model, it’s probably been done in real life [:D]

2

Can real locomotives take that curve? Or just Trackmobiles?

3

Nobody says they are unrealistic, they just don’t work that well for longer locos or cars on the models.[*-)]

There really is a 'prototype for everything" just the models may not work as well as the real life situations. [:#]

I’ve seen some pretty tight curves that real railroads navigate s l o w l y but on a model it may not work.[#oops]

4

Thanks for sharing.

I wonder if the railroad did anything special for that curve like widening the gauge or modifying the couplers. I also wonder what speed they’re moving. I know it’s real slow but how slow.

Enjoy

Paul

5

Try that with 85 foot cars, or maybe a SD 70, Big Boy, etc.

Rich

6

Trolley cars and small switchers navigate even steeper curves. That is a good find though.

7

Hamltnblue,

I must admit that the link to that photo was sent to me by a friend and fellow model railroader - I just thought you guys would like to see it.

Cheers,

tbdanny

8

I do! It looks interesting but still silly even in the prototype. In fact, it highlights how small 18" radius curves would be in real life. And we still have people who get angry when their big boys don’t go around them smoothly. go figure…

The tightest curves I’ve seen in non-industrial tracks were the 24 degree curves on the Monarch Branch of the D&RGW. An SD9 could not navigate them and they had to run 4 axle locomotives on that branch.

9

I love the bridge on the left side of the photo. I wonder if this complex was built when 40’ boxcars were the norm.

10

There used to be a curved track back in my home town that was so tight that Pullman used it to test the now common 89’ flats on when they were still under R&D. They easily derailed on it for a long time before they figured out something about how the cars twisted under force. It probably wasn’t much broader than the curve in the foreground of that picture above. They didn’t run anything much bigger than second generation Geeps and ore jennies on it either.

11

Just for the heck of it, I went to Bingmaps. The whole area looks like an old school, bowl of spaghetti track plan. That’s not the only loop there. There were other loops within loops, you name it. Yep, whoever designed that track plan sure didn’t use a linear shelf layout. [:D]

12

Is that a 4-8-8-4 Trackmobile or a 4-6-6-4 Trackmobile?

13

The ‘bridge’ noted by the poster above is actually the ship-loading conveyor, which enables loading of the commodity along the entire length of a bulk carrier.

It is definitely possible to justify tying your trackwork in knots if you pick your prototype with care. The Uintah (original home of the Mantua 2-6-6-2T) had curves that scale down to 12 inch radius in HO. Way back when, street railroads would fit coupler extenders on the then-standard forty footers and use their radial-coupler-equipped box motors to snake them around street corners. My pet prototype ran 4-wheel hoppers behind 4-wheel steeple cabs on dual-gauged streetcar tracks to reach the wharf in Hakata port where coasters loaded the output of the local collieries. (The steetcars were standard gauge.)

BUT!!! Note that none of these were operated at track speed by stiff, long-wheelbase locomotives. About the only part of a Big Boy that can round curves of this nature is the pilot truck - detached from the rest of the locomotive. As for Pullmans and humonguboxes, fugghediboudit.

Chuck (Modeling Central Japan in September, 1964 - with some very tight curves)

14

You mean street running, like this?

Wolfgang

15

It’s interesting to contrast the trackage in that photo with Norfolk Southern’s current industry track minimum radius requirement, 462 feet. What a difference. Not that NS serves Portland, OR, but I happened to have recently looked at their customer owned trackage requirements.

16

Just shows that there’s a prototype for everything. There’s a sharp curve near here that goes around the lumber mill that works out to about 22" radius. The big locos (AC44’s, SD70’s) can take it OK but no faster than 40 mph. This is on the mainline, not a spur or siding. The KCS has the grease the inside edges of the rail heads twice a day to keep the traffic from tearing the rails to pieces. Even so the cars set up a horrific shriek when going around the curve.

17

It’s worth remembering that in some really tight situations, cars would be uncoupled and pulled with chains. I imagine poling might have been helpful in some tight curve situations. I wonder of in some places very short idler cars were assigned to certain tasks.

18

How slow? Probably not much more than walking speed, as they are not likely to be moving the cars very far anyway. Industrial settings are purpose built with no points awarded for appearance.

19

Any chance of the link please?

[8-|]

20

I live in Portland and looking at the googl maps it is a great place to model. if you follow the tracks from the UP yard you can see all kinds of sidings that would make a great model layout. There is even a nice long tunnel from the UP yard that runs under the North Portland neighborhood. I bet most folks done even know they have a train running under their house.