Friday, March 28, 2014

Abutments for the girder bridge

Over a year ago I had built a girder bridge to carry the AsiaNrail line over the 3 Ntrak lines.  The building of this bridge was presented in a couple of posts in November 2012.  The time is now getting close to actually installing this bridge on the module.

The wood structure that will support the code 55 AsiaNrail line and this bridge is already in place and the next step will be to finish off the abutments.

The sides of the abutments are covered with .020 plain polystyrene sheet.  I used Liquid Nails adhesive and clamp the sides as shown here until the adhesive had set.

The ends of the abutments are also covered with .020 polystyrene attached with Liquid Nails.

The method I use to secure it until it's set is shown here.  Handy things, coat hangers.

I find it really difficult to get a good corner where the polystyrene meets so I use angle strip material to cover the corner seams.

Also, I added a section of 1/4 inch gray plastic material with the bottom portion cut at a 45 degree angle to each abutment.  This is what the bridge will actually rest upon.

These are now ready for painting with Floquil concrete color paint.

Friday, March 21, 2014

Bridges for the Ntrak lines - Part 2

I was happy with this but still needed to come up with some sort of simple bridge abutments. What I did was to got back to the .250 x .125 styrene strip and cut off more pieces the same length as had been used for the horizontal beams on the bents.   These were glued in an upside down L shape as can be seen in the photo below.

To attach the abutments, I cut a small opening in the side of the hill and glue the abutment in with Liquid Nails adhesive.  The abutment is held to the bridge with alligator clips until the adhesive has set.

At this point all of the bridge parts were painted with Floquil concrete at the air brush with the abutments being painted on site.  As the module is on wheels I was able to roll it right over the the spray booth to do that.  This was the first time I got to use the air brush with the new compressor and spray booth so that itself is a big step and big improvement over the old setup.

After painting, I glued the the trestles in place using the Liquid Nails.  A number of methods shown in this photo are used to hold the bents in alignment with everything else while the adhesive sets.

The clamp is holding 2 bamboo skewers under the bridge which are also under the beams on the bents.  The V shaped clamps on either side of the bridge are made from coat hanger metal and are holding the bents against the ends of the horizontal beams in the center span of the bridge.   Bamboo skewers and coat hangers are always something handy to keep around.

Next I'll need to get the river bed scenery done under where the bridges will be before I can do the final installation of the bridges.

Wednesday, March 19, 2014

Bridges for the Ntrak lines - Part 1

On the Hot Springs Junction Ntrak module, the three main Ntrak lines known as Red, Yellow, and Blue have to cross a stream.  I wanted to keep the the riverbed scene as visible as possible so I needed to be careful what types of bridges to use.  I was also concerned that the track would be accessible for cleaning and as the tracks were only about 15 to 20 scale feet above the river there was not much clearance underneath.

What I decided on was to use three single track concrete trestles with a ballasted deck.  I got inspiration from some parts I found in Green Max kit # 47-5.  There was a set of trestle bents with 3 posts that were vertical.

Seeing this I knew I could make something similar but with the outer legs angled outward like they are in some of the prototype  photos I've seen.

In this photo notice I mention the use of 4 penny finishing nails.  Holes are drilled through horizontal beam and the nails provide additional strength to the posts and beam connection.

To have some additional variety, I made another similar set using the same styrene material for the horizontal beam on the top but then used .100 square tube.

Instead of using nails on this one I used brass rod to strengthen the connection between the posts and beam connection.

The bridges themselves are rather simple.  To give them extra strength I built them around a piece of .100 inch acrylic sheet.

The best way to explain the construction of these bridge structures is with a drawing of the end view.  All of the styrene pieces go the full length except for the quarter rounds which are only in the middle.

Each bridge is a slightly different length and were test fitted along with the bents before painting.  This photo shows all three along with their tracks at this stage.

Thursday, March 13, 2014

Interface between Ntrak and AsiaNrail

The most common way to connect sections of a modular layout is to use clamps of some sort from underneath.  Any small offset because of a difference in the height of the module frames can normally be compensated for by using a deep clamp.  Because of the extended profile board on the front of the Hot Springs Junction module there was going to be a big difference in the height of this module vs any AsiaNrail modules that would be connecting to it.

I made this small 8 x 7.5 inch module from some scraps of cabinet grade plywood that was what was left of one of the old heavyweight sky boards.

As seen in this photo, the side connecting to the Ntrak module has an extension that will allow it to be bolted to the Ntrak module below the main deck of the Ntrak module.

The other end will then present a 2-1/4 inch high clamping surface to the AsiaNrail layout.

Here's an overhead view showing both the Hot Springs Junction module and the adapter module. When the Hot Springs Junction module is used in an Ntrak layout without AsiaNrail, the adapter would be left off.

At this point, all of the cork road bed is in place and I'm almost ready to install the track.

Sunday, March 9, 2014

Japanese style retaining walls

During the times I have been in Japan I have noticed two common types of retaining walls along side the railroad tracks.  On the Hot Springs Junction Ntrak module, the Ntrak lines will be passing through the module through a cut in the hills and I wanted to model both types of retaining walls on this part of the module.

I have never gotten any good first hand photos of these walls but searching on the internet I did find a couple that illustrate both types.

On the right had side of this photo is an example of a retaining wall that appears to be made up of square tiles stacked in a diagonal orientation.  There is often vegetation growing between the tiles or over over the top partially covering the wall.

To make walls like this, I cut 1/8 inch square tile Evergreen polystyrene sheet material at a diagonal.  These sheets normally snap easily along the tile seams so after scribing with an X-acto blade, I snaps these along the scribe line while aligning the it on the edge of a block of wood.

Some of these walls can be quite high.  In this photo, I am making a wall 30 feet tall.  To get a good 45 degree angle I first use a sharp pencil to mark the path of the cut on the existing tile seams as shown in this photo.  For long sections, these cut tile sheets are spliced together by laminating them with plain .020 sheets.

This photo shows an example of the second type of retaining wall I have often seen in Japan.  This type appears to be square concrete columns arranged in a vertical / horizontal pattern.  There is normally bare earth or vegetation between the columns.  Sometimes these walls are really bent like the one in this photo and sometimes they are straight.

The method I came up with to model this type of wall was to use .020 polystyrene sheet as a base cut to the desired shape.  Then I use .080 square polystyrene rod to make the actual columns.  The horizontals are solid pieces and the verticals are cut into lengths 5 scale feet long.  They are placed every with 5 scale feet in between using a wood spacer as a guide.  This gives the square pattern.  As this type of wall is a bit tedious to make, most of my retaining walls with be the first type.

The plan is to build these in large sections that will fit into a particular spot on the module and then paint with with the airbrush before actually installing them.

Tuesday, March 4, 2014

Finishing the insulation board terrain

With renewed purpose I have started again on the Hot Springs Junction Ntrak module.  Where I had left off on this project was the insulation board terrain which I posted on in December of 2012 and that's where I'll pick it up again.

At one point I had considered using a tunnel on the AsiaNrail line to separate the scenes and had even picked up some tunnel portals on the last trip to Japan.  After testing things out with the tunnel portals, I thought it would seem unrealistic without a much more massive mountain which I did not want to build so both the AsiaNrail and Ntrak mountain division lines pass through cuts in the hill.

The major build up had been done with 1 inch thick pink insulation board.  That's all gone now so I'll be finishing up with some Styrofoam than came as packing in Ikea cabinets that I had put up in the new train room.  I normally don't like using Styrofoam because it's more messy and soft but this stuff was not bad and it's just a few small spots that needed to be finished up.

After the terrain is shaped the way I want it, I use drywall joint compound to seal it.  I start applying it with a 1 inch putty knife then smooth it out further with an old paint brush.  Joint compound will give an outer shell that is firm, but not has hard as plaster products and that's why I use it.