Modeling Standards

As mentioned in earlier posts, I desire to model the Brooke Avenue Yard as accurately as possible in N scale (1:160); within the limits of reliable operation. With an operating model, it is impractical to model it to exactly 1:160 proportions. At that scale the 5 1/2” wide wheel of the prototype becomes 0.0344”, which is a bit larger than 1/32” including the flange! That is much too narrow for reliable operations and would be very difficult to construct and even more difficult to maintain on a model that is subject to movement (although there are a few brave souls who are attempting it).

Fortunately, there has been a lot of thought placed into just how much fidelity can be achieved without sacrificing reliable operations; provided careful attention to details and standards is adhered to during construction. These “fine scale” standards have been developed for American prototypes and are published by the National Model Railroad Association (NMRA) as S3.1 and S4.1. For all intents and purposes the “fine scale” standards give the impression of being true to scale and highly detailed and realistically weathered models using these standards are often difficult to identify as N scale and can look very prototypical in photographs.

It has been my experience that there are only a few “dead give aways” that a photo is of N scale equipment:

1. Track rails that are too tall: Realistic rail size in N scale is around code 40. Although code 55 rail is considered acceptable, anything larger looks disproportionate and ruins the illusion of realism. Code 40 rail scales to about 6 ½” tall which equates to something around 123# rail, which would have been typical for this yard.
2. Track flange ways that are too wide: Track designed for the normal standard N scale (oversized) wheels must include extra space between the rails and guard rails and switch points to allow the much too fat flanges to pass. One glance at this track work dispels any illusion of realism. Using the closer spacing of fine scale (due to the narrower flanges), the track work can look very prototypical.
3. Wheels that are too fat and flanges that are too big: Another obvious indicator of N scale equipment is the extremely wide wheels and oversized flanges, especially of the older equipment. To solve this problem and the two track-related problems above, special wheel sets must be used with specially constructed track. Note that this will eliminate any possibility of normal equipment running on your track and may prevent your equipment from running on normally constructed track.
4. Couplers: if the track and wheels look proportional, the next clue is the oversized couplers. Here a compromise must be accepted if one desires “operating” couplers (as I do). The best option currently available is to use Z scale body mounted couplers made by Micro Trains. These actually scale out quite close to 1:160, however, the smaller coupling faces require very smooth track to prevent inadvertent separation (usually due to vertical misalignment).
5. Missing details on track work. As a minimum I intend to model the joiner bars (metal plates used to join the 39’ rail sections together; spikes (used to hold the rails to the ties) and tie plates (metal plates between the rail and the tie used to protect the tie). All one really needs to do is look carefully at photos to see all the little details that go into constructing railroad tracks. Turnouts and crossings are another area where emphasis to details can result in very prototypical looking track.

With the decision to model using fine scale standards, I had to determine the best method for modeling these details. There are several companies that provide highly detailed parts such as spikes, joiner bars and tie plates and although not excessively pricey, the large number required even for a small yard does add up. This coupled with the overseas shipping to Sri Lanka (which can quickly double the cost of lower cost items), has made me consider “home grown” options. In fact, I’ve determined that I want to model using materials that are available in Sri Lanka to the greatest extent possible (as part of the modeling challenge). Thus my overseas purchases will be largely limited to:
1. Rail (Micro Engineering c 40);
2. Spikes (P87 Stores “scale spikes”);
3. Ties (wooden and PCB) as I do not have the equipment to produce these myself;
4. Wheel sets (North West Short Lines c50);
5. Rolling Stock (locomotives and freight); and
6. Special detail parts such as automobiles and figures.

I intend to model the majority of the structures using heavy card stock and plaster (styrene and strip wood is not available here). All ground cover will be locally produced.

All for now,
Dave O.