Changes in the Offing

Work on the Allegheny Eastern has been at a total standstill. Life keeps getting in the way. This hasn't been a total loss, however, because sometimes these long pauses allow time for better ideas. Two major design elements have been modified.

THE HELIX

Helix

The minimum radius has been changed from 18 inches to 30. There are two reasons for this. The primary purpose is to allow enough trackage to provide a gentler grade between Gallitzin and East Altoona. Grades are measured in percentage. a 1% grade rises 1 inch vertically for every 100 horizontal inches. A 2% grade is pretty steep in railroad terms and the design engineers goal is to stay below that. This is also true for model railroads. I want the grade of the helix to be less than 2%.

The problem with a helix is not just the total climb between end points. Since the loops of the helix are directly above each other there needs to be space between each level to allow the for the height of the sub-roadbed, the roadbed, the track and any trains that use the helix. In N scale you could figure 2 inches or less for this clearance. I prefer to add some additional room for easier access to the track and trains. So on this helix I set the vertical clearance to 3". By using a 30" radius I am able to reduce the required grade to about 1.6%. The helix will climb a total of 6 inches using two loops 188 inches in length. This is a total of 356 inches or about 31 feet (almost a mile in N scale at 1:160 to 1). Not only do I get a gentle grade, I get an extra scale mile of main line run. The wide curves also make for better performance for my passenger trains and long freights.

The second reason for the wide curves is purely esthetic. An 80 foot passenger car looks a lot better rounding a 30 inch curve. If I had the space I would set all the mainline curves to a 30" minimum radius.

ALTOONA

Altoona

I wasn't satisfied with the overall design for Altoona until I discovered David Smith's plan for Ridgely Yard. His idea looked more like what I had envisioned for the yard area. I like the fact that the separate freight yards give me the general "feel" of the Altoona freight yards. I modified Dave's plan with additional tracks for the passenger mains.  By flipping the plan around I was able to keep the engine terminal between the passenger and freight mains in East Altoona. The result will be a fair sized roundhouse and facilities. I'm hoping to create an overall impression of a large Pennsy installation.

This redesign requires the Altoona side of the layout be extended 12". I had originally thought I would just extend the benchwork another foot on cantilever supports. Having had some time away from the project it occurred to me that this wasn't the best idea. One of the things I wanted to do with the layout was create a place for a rather extensive collection of railroad related books and magazines. I was going to create shelves or something below the Altoona area for this purpose, but never really decided on a solution. Now the plan is to create three 60 inch long bookcases about 48 inches high that will support the Altoona extension. This will look much better than just 2"x4" legs with some shelves. It will also provide a space to display my railroad memorabilia and other knick-knacks. The main control panel for the layout will also be located in this area.

All in all the lack of progress allowed me to work out a few details and come up with improvements. Maybe it's a good idea to walk away from the hobby every now and then. Maybe you get too close to a thing. Whoever said "you can't see the forest for the trees" might have been a model railroader.