17 TIME OUT

Not much progress on the railroad during April and the first part of May. The president of the ATSG Railroad spend much of this time entertaining some cardiologists at Dixie Regional Medical Center. Unfortunately the procedures required some restrictions of activity and crawling around under a railroad was one of these restrictions. We are happy to report that the recovery is almost complete and the most recent visit to the physicians said no restrictions. However the chairman of the board still has a few restrictions being somewhat more conservative than the doctors.

So we are back and ready to move forward as seen in the next couple of posts.

16 STAGING

Before proceeding with the roadbed at Ascape, it was thought the better part of wisdom to complete the staging yard underneath. Once again previous experience and the many scars on top of my head from installing staging under a complete railroad suggested that it is easier to reach through the open benchwork than to reach into a 10 inch shelf to install roadbed and track. By the way my wife bought me a hard had for working under the railroad. When I remember to wear it I don't get so many scars form whacking my head.

Staging is an important concept in model railroading. The best thing to do is think of a Model Railroad as a stage where action takes place for the viewing public. On a stage there is a back stage area where actors prepare to enter the stage and perform their role. A model railroad is similar. There is a staging area where trains are prepared to enter the visible part of the railroad to perform their role, moving across the railroad while delivering rolling stock to various industries, picking up or delivering passengers, etc. For the AT&SG this staging area is under the town of Ascape on the left side of the railroad. The staging area is about 10 inches below the ruling grade of the railroad. Trains enter the railroad by entering a helix at the left side of the staging yard or the bottom of the diagram shown here. (See the post on the helix for more details).

On the ATSG Railroad the staging yard serves both ends of the railroad via the helix. The trains enter at one level of the helix, travel across the railroad and return at another level of the helix to return to the staging area.

The operation of staging is as follows: trains enter at the left (bottom of the diagram) and travel though the ladder track to the short track on the near side (right side of the diagram). They then proceed around the reverse loop and enter an assigned yard track via the ladder at the right side (top of the diagram) where they await their next assignment.

Staging also allows a staging operator to use the reverse loop as a yard lead to switch the staging yard to rearrange trains for their next assignment or trains can merely wait for their next turn configured as they were when they entered staging. Trains leaving the staging yard can travel either direction across the railroad depending at which level they leave the helix.

The staging yard is suspended from the benchwork above as shown in the photos. The base is 3/8 plywood covered with homasote as a base for the track. The homasote we used is in 3 inch strips so these strips are staggered to accommodate the ladder tracks rather than covering all of the staging area.

The reverse loop at the end of the yard is constructed via spline roadbed as previously described. The spline in this case is suspended by supports from the benchwork above. One could never construct a railroad of this size without the help of friends. Craig Harding and Doug Whetstone deserve an award for duty exceeding all expectations as they labored several hours before they successfully got the suspended spline roadbed installed under the benchwork.

The other engineering challenge was to match the height of the roadbed to the homasote. The homasote is 1/2 inch thick, the cork on top of the spline is 3/16 inch so the spline had to be adjusted to come just above the height of the plywood base of staging to match the homasote.

At this posting the staging area is complete, the homasote in place, the cork installed on the reverse loop and in most of the helix and we are ready to begin laying track.

15 SPLINE ROADBED

The Roadbed is the support under the track. The management chose to use spline for the roadbed for several reasons. First, it is much easier to bend the spine around curves than it is to cut plywood to the proper curvature. Second, spine tends to form a natural curve that provides natural transition curves.

A transition curve is one that gradually decreases the radius of the curve rather than a sudden change from straight to a curve of a given radius. This makes for much more pleasing curves that replicate curves on the prototype (real railroad) much more closely. However, the curves on a model railroad have a much smaller radius than the equivalent curve on the prototype because of the limited space.

So what is a spline? First we cut 1/4 inch Masonite into 1 inch strips. The first strip is placed on the joists or on risers to follow the plan for the track of the main line. This strip is held in place by screws placed temporarily on either side on each joist or riser.

After the first strip is in place the main line of the railroad is defined. The next step is to glue additional strips of Masonite to this guide strip. We mostly use hot glue to glue these splines together. The spline for this HO railroad required 8 splines to be glued together to form the roadbed that is 2 inches wide.

This process goes pretty fast but it does take a lot of strips and even more hot glue. If you have worked with hot glue you know that you have to work fast. We found that it is easier with a track crew (2 people), one to apply the glue and the other to immediately position and hold the spline in place. It is important to keep the top edges of the splines as level as possible during this gluing process.

The track crew found that when there is a turnout that the roadbed must accommodate this by allowing a spline to branch from the main spline. The crew found that gluing a small triangle to the first spline at the place of the turnout facilitated keeping the angle of the branching roadbed correct. The triangles were cut to accommodate the angle of the turnout. Most of the turnouts from the mainline on the Ascape Tennsion and Sulphur Gulch are #6 turnouts meaning that the branch line diverges 1 unit for every 6 unites of length. Again much more abrupt than the prototype but more practical for a model.

Where there are parallel tracks such as for a passing siding the crew found that it was more efficient to place a 1x2 between the splines as long as the parallel tracks were straight.

Once the splines have been glued it is critical that the top of the roadbed is level. We don't want the trains to lean from side to side as they proceed along the track. A very small difference in height on one side of the roadbed can made a noticeabledifference at the top of a railroad car as it moves over the track. It is inevitable that one or more splines slips up a fraction of an inch as it is glued in place. To level the roadbed the track crew found that a small belt sander was the tool of choice. The top of the roadbed is sanded until it is smooth and also to be sure that it is level.

With the spline roadbed in place it will be time to move to large flat areas where spline roadbed is not practical. This includes the staging area, the yard at Ascape, Park City, and Coalville. We are still working on the spline but come back soon for a description of the next phase.

14 THE TRESTLE AT SULPHUR GULCH

14 The Trestle at Sulphur Gulch

At last we get to see something that looks like a railroad rather than just lumber.

With the helix in place we needed to determine the location of the trestle at Sulphur Gulch. This trestle was constructed for the first version of the ATSG Railroad. It is based on a trestle that actually existed on the Southern Pacific Railroad many years ago. It is unique in that the trestle is on a grade (3%) and a curve. This was a challenge for the construction of the trestle. The trestle was constructed a number of years ago but perhaps a few details of its construction are of interest here.

The lumber was sawed from a single 1x4 piece of clear pine wood. Using a radial arm saw the 1x4 was first sliced into 1/4 inch strips. Using a miniture table saw these strips were then sawed into scale lumber of the various sizes needed for the trestle. Once the lumber was sawed the construction began.

The bents were constructed first by laying out the upright supports over the blueprint and held in place by double stick tape. The cross pieces were then glued in place for each bent. The glue was allowed to dry overnight and then the bent was turned over and the other side glued. This process was repeated for several weeks until all the bents had been constructed. A curve of plywood was then sawed to match the curve of the track where the trestle would be placed. This curve of plywood was then elevated to match the grade of the track. The track support on the top of the trestle were then placed on this curve under the location of the track and held in place with double stick tape. The bents were then glued to the track supports and held in a vertical position using a level. Then the cross pieces between the bents were glued in place. With the major construction completed the details were added such as ladders, a walkway, railings, etc.

This trestle has been stored for several years and has suffered some minor damage mostly to handrails and a few cross pieces but no structural damage.

Back to the present. It is necessary to have the trestle located before laying out the roadbed so that it is in the exact location necessary. The benchwork for the trestle is then build to accommodate its location. The operation has trains coming from staging into the helix and after a few turns exiting the helix onto the trestle. When the scenery is in place there will be a tunnel entrance just beyond the end of the trestle. The other end of the trestle leads to a track that has been blasted out of the side of a very steep cliff. This mountain and cliff will hide the helix when the scenery is in place.

So our challenge was to position the trestle to make sure it is lined up perfectly with the helix and then to build benchwork toaccommodate the roadbed leading to the other end of the trestle. Thisadditional benchwork was build around the benchwork that holds the helix as shown in the photos.

Once the benchwork was in place then the spline roadbed was lined up with the end of the trestle and supported on tall risers that will be hidden in the cliff that will go from above eye level (over 6 feet) to just above the floor. The track will then appear to have been blasted out of the cliff and then onto the trestle. You may not see this wonderful scenery in your mind's eye yet but check back in the near future and this scenery will appear.

If you have been following the progress on this reconstruction you may have noted that the location of Sulphur Gulch has moved from the peninsula in the middle of the room to in front of the helix. The chairperson of the board was very concerned that with narrow aisles for operators that a trestle on the back curve of the peninsula was sure to get damaged by giants in the land. Isn't it amazing that we can move a geological feature such as Sulphur Gulch to accommodate better viewing of this key feature of the AT&SG Railroad? Of course we will have to rewrite the history of the railroad to justify this move ... revisionsist history! The new location is much better, it provides a wonderful scene as visitors enter the railroad room and puts the key feature from which the railroad gets its name right up front. It is wise to listen to the chairperson of the board!

13 BENCHWORK

With the helix in place it was time to expand the benchwork. For those who may be new to model railroading the benchwork is the table that holds the model railroad. However in this case the management want flexibility for scenery. This means that we will use an open table consisting of support beams and open joists to which we will fasten the track and the scenery. With an open grid the scenery can extend below as well as above the top of the table. With a flat table top the scenery can only extend above the scenery.

The side of the benchwork against the wall is supported by TGI beams. These are beams that are usually used for floor joists. The advantage is that they are strong and can have a long span without supporting legs. We placed the TGI beams around the walls supported every 8 to 12 feet by a 2x4 leg that extends up past the TGI beam and thus supports the backdrop framework. (See post #7).

The front of our benchwork (table) is formed with an "L" beam. This is constructed of two 1x3s forming an L shape. The advantage is that the vertical board provides support and the horizontal board of the Lprovides a surface to which the joists can be screwed. The L beam is supported every 8 to 10 feet by a 2x2 leg. The L beam and legs were placed parallel to the TGI beams and vary in distance from the beams depending on the width of the railroad along the three walls.

Since the railroad room is a finished room with a hardwood floor which we covered with a non-glue vinyl floor covering (See post #4 ) it is very level, unlike some basement or garage floors. Therefore it was unnecessary to place levers on the bottom of the legs. To protect the floor there is a felt pad glued to the bottom of each leg.

The top of the benchwork consists of joists fastened to the TGI beam on one end and to the L beam. The joists overlap the L beam by several inches to enable the L beam and legs to be back from the edge of the layout. If the legs are at the edge of the layout there is a tendency to trip on the legs when running trains.

With the benchwork in place it is time to begin to lay the roadbed, the support for the railroad track.

12 THE HELIX

The first big (and we mean BIG) project was to construct a helix for the railroad.

If you are a model railroader you know what a helix is and its purpose. For the rest of you that may read this blog let's explain a bit.

The Ascape Tennsion & Sulphur Gulch Railroad is a bit like a stage play. There is the main stage where the action of the play takes place and then there are the wings or staging area where actors wait until it is their turn to appear on the scene and play their parts. Well a model railroad is similar. On the part of the railroad which the visitor sees, trains enter to deliver their freight cars to various industries and then leave the scene on their way to some distant unseen destination. A train enters at one location, travels across the visible part of the railroad, and then exits at the other end of the visible portion of the railroad.

Where do the trains come from and where do they go? Like a stage the model railroad has a staging area where the trains wait until it is their turn to enter the seen railroad and play their part, that is make their trip, deliver their goods or passengers, and then exit back to the staging area.

On the AT&SG the staging area is at a lower level under the town of Ascape. This staging area consists of a large rail yard where trains and rolling stock (freight cars and locomotives) can sit waiting for their turn to run on the railroad. On the far end of this staging area on the AT&SG there is a loop that can be used for turning trains. So when a train enters the staging area it goes around the loop and then into a siding in the yard ready for its next turn to enter the railroad.

On the other end of the staging yard is the helix. A helix is a spiral of track that allows trains to raise from the lower staging yard to the level of the main line of the railroad. The staging area of the AT&SG is about 10 inches below the main part of the railroad hidden under the scenery (or what will be scenery). When a train is ready to enter the railroad it enters the helix at one end of the yard travels around the spiral about 4 times until it is at a level where it can enter the main line of the railroad.

The journey across the AT&SG takes a train over the railroad on a lower level and then returns at a higher level back over the railroad. After completing its journey is enters the helix at a higher level and returns to the staging area having completed its work.

The remainder of this post is for those who are interested in how the helix was constructed. For the casual reader you may want to exit at this point.

Constructing the helix was an engineering challenge for the construction crew of the AT&SG. The challenge is a very smooth surface, a minimum grade sufficient to raise the trains to the appropriate level, and sufficient clearance between levels so that the trains have space to travel.

The construction crew decided to construct the helix from 3/8" plywood. Two complete circles of plywood 5 inches wide were cut from each of two 4x8 sheets of plywood. The outside diameter of each circle is 24 inches making the track radius 22 1/2 inches ( a rather tight radius, but since the AT&SG is circa 1937 most of the equipment is small with short 40 foot cars. There are a couple of 60 foot passenger cars but they can navigate these curves as well.) Using the remainder of the plywood 3 more circles were pieced together in sections.


The circles were then cut at one point to enable a spirial. The second section was attached to the first section using 1/4 in dowel pins with a piece of 1/8 Masonite glued to the underside to provide more stability at the joints. When all the joints were completed there was a spiral of 6 1/2 loops of continuous plywood ramp. This spiral of plywood loops was then secured to a framework base that raises the bottom of the helix to match the staging yard.

The next engineering challenge was how to support the spiral of plywood loops. The construction crew decided to use threaded rods and secure the loops with a nut and washer below and above each level. The original intent was to drill the holes in the plywood loops themselves but keeping the holes in line turned out to exceed the capabilities of the construction crew so an alternative method was devised. The posts were placed outside the plywood loops and a thin piece of fir (left over from ripping 2x4 studs for legs) were used under the plywood loops as shown in the illustration.

The tedious part was threading each of the 12 rods with 12 nuts and washers inserted between the supports. When the rods were all finally threaded with a nut and washer below and above each support the rods were secured into the platform framework to hold them securely in place.

The next step was to carefully raise each support to the correct level to promote a smooth upward spiral with a grade of 3% and a clearance between levels of 4 inches. When each support was at the correct level the nuts were secured both top and bottom of each support. When all was secured, the elevation checked, and the clearance checked then the plywood spirals were hot glued to the supports to provide stability.

When all was completed the helix was secure, stable, and ready for track and being connected to the track from staging and from the main line. It was critical to complete the helix before installing roadbed for either the staging yard of the main line. That is next. Check back for progress on this next phase of this project.

11 SKY

 With the muslin pasted and dry we were ready to create the sky. Oh! Oh! Oh!

Creating a sky that looks like a sky is really a challenge. The sky painter finally adopted the approach recommended by Dave Frary in his How to Build Realistic Model Railroad Scenery. A similar technique is described and illustrated by Darryl Huffman in his videoEasy Backdrop Painting for Model Railroaders. The trick is to get the sky dark at the top and faded to a very light color at the bottom.

Benjiman Moore Utah Sky looked like a good color in the Ace Hardware paint store. However in reality it is way, way too dark and too intense. Experience suggests that subtle is better. So the sky painter mixed his own paint. He created four intensities of blue. The first mixed the Utah Sky blue with white at a ratio of 6 parts white to 1 part blue. This gave a good dark blue for the top of the sky. The second mixed 12:1, the third 24:1 and the bottom 50:1. This seemed to provide a pretty good transition. Next time (is there going to be a next time?) the second would be a bit whiter. Wow! Does a little blue paint go a long way. The illustration shows the four cans of paint.

We started at the top with a narrow band of our 6:1 blue. Using Darryl's technique we painted until our brush was dry and then dry brushed down into the second level with what was left on the brush. We applied the next intensity 12:1 and dry brushed it into the dry brush of the darker color and dry brushed into down into the next layer. Where the two colors mixed we scrubbed and scrubbed with the brush until there seemed to be a nice blend of the two colors. (Use cheap brushes, this destroys brushes.

The next layer used the same technique blending the 12:1 color with the 24:1 color and so forth with the bottom layer blending the 50:1 color with the 24:1 color. In most places, where brushed really scrubbed the paint the blending looks pretty good. In a couple of places the chairman of the board commented, "the sky painter must have been getting tired when this corner was painted!" The painter protested, "those are clouds." The chair person did not seemed convinced. Perhaps there will be a bit of touch up and the "clouds" eliminated.

With no benchwork and no scenery in place this is a lot of sky. About the lower half of the sky will be covered with scenery once the benchwork, track and scenery is in place. By itself there is a lot of light sky at the bottom but most of this will be covered. It was much easier to paint the sky with no benchwork in the way. Later the backdrop will be expanded with some mountains but this will have to wait until some scenery is in place.