Here are some pics from my paper mill, long since sold to a guy in Florida.
The text for the first draft of the article is below.
Danica Forest Products: An N Scale Paper Mill
By Bernard Kempinski
A modern paper mill assaults the senses. The strong sulfurous odor makes an indelible first impression, but the mill’s sprawl of pipes, tanks, conveyors and steam belching stacks also leaves their mark. More than just visually interesting, they are beehives of railroad activity. Like their precursors, modern paper mills still rely on railroads to deliver raw materials and ship finished products. Paper is a heavy and bulky product, thus ideally suited for rail transport. For every ton of paper produced, two tons of pulpwood, plus considerable quantities of other chemicals, bleaching agents, additives and coatings are required. Distilling these elements into a model railroad industry can be a fun and rewarding challenge.
In November 1998 issue of Model Railroader Jim Hediger described the basic operation and functions of a modern paper mill and gave some model design tips. In this article I will describe how I used the two Walthers Paper Mill kits to simulate a typical southern paper mill in N Scale. However, many of the design and modeling ideas can be applied to the larger HO Scale.
Selecting a Prototype
Situated on a narrow peninsula between the Pamunkey and Mattaponi rivers, the mill at West Point, Virginia is a typical southern paper mill. While it has changed owners over the years, the basic mission has remained the same, convert logs from the nearby and abundant pine forests into paper products.
The riverside location and its linear arrangement make this paper mill an ideal prototype to visit and model. I made both land and aerial trips while researching the project. During my visits I was able to observe a wide variety of transport operations. Pulpwood arrived in the form of whole trees stripped of their branches on trucks, and cut logs by bulkhead flat rail cars. Large capacity gondolas, tractors hauling semi-trailers and barges brought in wood chips. Finally, there was an area of the mill devoted to processing recycled paper.
Each delivery mode had a specialized machine for unloading. The pulp log flume had a custom excavator that resembled a backhoe mounted on a rail based gantry. It unloaded the bulkhead flats in quick time. A large jib crane handled the whole trees like stacks of toothpicks. A bewildering array of conveyors and pipes shuttled logs, chips and chemicals to their next step in the process.
The aerial photos were invaluable in providing an overview of the facility. Using them I was able to study details of the mill not accessible from public property. Matt Coleman of The Association of Pulp and Paper Institute was very helpful in identifying the various components of the mill. Immediately apparent from the photos was that the tanks and pipes associated with the chemical recycling and by-products recovery were as important, at least visually, as the wood and paper handling aspects of the operation.
This mill uses a thermo-chemical process to manufacture the wood pulp. In the Kraft house the wood chips cook with chemical liquor in a reactor to make pulp slurry. The mill recycles the liquor through the recovery boiler, refining columns and rotary kilns. In this process turpentine and other chemicals are generated as by-products. Tucked away in the center of the mill is an area where the mill personnel load tanks cars with commercially useful by-products. Like most modern mills this facility has several prominent water treatment facilities.
The raw pulp combined with recycled pulp, that arrived from a different part of the mill, moves to the paper machine building. There it flows through a fourdrinier machine to make the paper products. The finished rolls go to a warehouse where trucks and rail cars ship them out. With a wide variety of type and modes of incoming raw materials and products to ship out, the paper mill makes an ideal industry for a model railroad.
Track Plan
Given that the prototype mill is over a kilometer long and a half-kilometer wide, I needed compromises in developing the design for the model track plan. I identified key features, focusing on the rail transport for inclusion on the mill. Thus, while the jib crane was highly visible in the photos, only trucks served it, so I omitted it from the plan. On the other hand the log flume, wood chip unloading, pulp building, recovery boiler and paper machine building I considered "must have" features. To add operational variety I wanted to include a representation of the chemical by-products loading and coal unloading spur for the steam plant.
I decided to use a 2x7 ft oNeTRAK module for the main mill area. Seven feet is a good upper limit for module length since it makes maneuvering rooms with 8-foot ceilings easy. To provide additional room for a storage track, I extended the main and siding onto the next module.
The model track plan does not follow the prototype plan exactly since I had insufficient room. However, the model plan does draw several design cues from the prototype. For example, the main track extends down the middle of a “canyon” of mill structures and the general layout of the structures is similar.
The key sidings include two pulp wood tracks serving the log flume, a coal track for the steam plant, an additive track, a chemical by-products track, a wood chip unloader and two warehouse tracks. These sidings respectively provide spots for bulkhead flats with pulp logs coal hoppers, tank cars and covered hoppers with kaolin, high capacity gondolas and boxcars.
Storage tracks are a key feature if you plan to operate the model. The prototype mill had a large yard to store cars. Norfolk Southern maintains an engine there to switch the cars. As mentioned above, my storage track extends onto the next module. I probably could have used a couple more and would have included them if space permitted. To compensate, I can use the warehouse track to temporarily store cars during operations.
I used Micro Engineering code 55 track and turnouts. I had to hand lay the curved crossing since no commercial one was available. I used Tortoise switch machines to actuate the turnouts from a central control panel.
Structures
To capture the sprawl and looming mass of the prototype, I used two Walthers Paper Mill kits. This kit comes with two primary structures, a metal siding pulp building and a brick sided paper machine building with built-in warehouse. The kit also comes with a nice variety of tanks, pipe bridges and details.
I used the metal siding buildings to represent both the pulp and the recovery boiler buildings. I scratch built an addition to the top of the pulp building to house exhaust stacks and pollution control equipment. Because of the stretched angular placement of the pulp building, I needed to make an additional wall using a sheet of Evergreen corrugated siding. This made the kit look even bigger.
I built the recovery boiler building essentially stock, except that I trimmed off one corner and the back wall to fit the angled location. I filled the open back with a plain sheet of styrene. Using the left over pieces, I fabricated another small structure that simulated a building with just a small corner showing. Placing a smokestack in front of this corner helps disguise the small size. This building housed one end of the scratch built rotary kiln.
I followed the prototype paint scheme including the neat gray, green and white scheme on the recovery boiler.
While the metal building in the kit is close to scale size, the paper machine building kit is not long enough to convey the true size of the prototype. Using two kits, splitting them in half, flipping the back pieces to the front and arranging them in a long row makes them appear four times the size of the original kit. Used in this manner the mill really looks like a facility with enough capacity to need rail service. I had to use a sheet of 0.060-inch styrene to make the roof, as the new roof has more surface area than can be obtained from patching the stock kit pieces together.
The aerial photos showed that the portion of the mill devoted to chemical processing resembled a refinery connected by an amazing array of pipes, tanks and wood chip conveyors. The Walthers Oil Refinery kit provided basis for my model by-products facility. To this I added an assortment of tanks, pipes ladders and Alkem Scale Model catwalks. I used several different materials to make the tanks including sections of PVC pipe, caps from hair spray cans, parts from my scrap box and several Tomix industrial detail kits.
Another interesting machine was the rotary kiln. I scratch built one using a section of PVC pipe. I cut the rotating bands from the next larger size of pipe using my chop saw. Styrene shapes completed the details.
I used a Walthers Power house for the steam plant. A pipe bridge connects this older building to the Kraft house. I added a shed to the front side to make a spot for unloading coal hoppers. Since the steam plant generates much waste heat in the form of hot water I added two Alkem Scale Models cooling towers and scratch built settling ponds. Pollution control systems for both air and water are vital components of any modern paper mill.
As in the prototype, wood chips can arrive by barge, rail car, however, I omitted the truck unloader. A modified GHQ excavator formed the top while I scratch built the base for the log unloader. The cut logs travel via the log flume to a scratch built drum debarker and chipper. Alkem Scale Models conveyors link these structures in a manner similar to the prototype.
I used lots of cast and etched details to complete the module. Notable are the electrical transmission tower and construction trailer by Into Details. While complex, modern mills are very neat and well maintained. For example, I observed a worker using a hand broom to sweep chips from an access road under the conveyors during my visit. So I went easy on the junk and clutter in detailing the model.
