Friday, August 24, 2012

FIRST TOWN SITE SUBROADBED PANELS


Upon completion of the first phase of benchwork structure, ¾” plywood panels have been added for subroadbed.  The primary, mostly full sheet, panels for Oakridge and Springfield have been placed, joined and attached to the stringers. 


Oakridge subroadbed with wye in foreground.


Springfield benchwork and primary plywood subroadbed panels.

Gaps have been left that will be filled by roadbed width strips of plywood and bridges.  Three streams must be crossed: 1) Salmon Creek on the RR-west end of Oakridge (crossed by both the mainline and the Pope and Talbot mill lead), 2) the North Fork of the Willamette River at Westfir, and 3) the full Willamette River between Springfield and Eugene. 


Westfir subroadbed panel.  Curve templates are placed where the mainline and one of the Western Lumber spurs will be located.

A design choice has been to keep all of the “valley core” from Eugene to Oakridge on one base level.  The actual railroad climbs almost 1000 feet from Eugene to Oakridge.  The plan for the stream crossings has been to place a plywood panel well below the main subroadbed level to serve as the streambed. 

As I begin implementing this design and construction, I am wrestling with how to scenic the stream areas.  The larger stream areas at Salmon Creek and the full Willamette crossing should have sufficient space to create a believable slope to the stream banks.  The Westfir gap appears too short.  Further, the backdrop treatment in this area needs to be considered.  One idea to help the scenery in this area is to slightly raise the mainline through Westfir.  Introducing a modest track profile hump, centered on the Westfir mainline switch might help the overall scene, but might not have much effect at the stream crossing. The actual bridge is fairly deep, as truss bridges usually are, and still has good clearance above the river.  An option under consideration is to replace the deck truss bridge with a simple girder, perhaps even a through plate girder.  This may become “a bridge too far” so the stream crossing might be eliminated.

As the space for the railroad becomes occupied by benchwork and subroadbed, it is becoming obvious that I will need to add lighting.  This can be seen in the Oakridge and Westfir photos.  Much of this was expected and planned for.  There are light fixture junction boxes intended for connecting track lighting strategically located in the ceiling.  Future construction, notably the backdrop spine weaving through the middle of the valley core, will further impact lighting.  Lighting additions will be considered as the railroad gets built.


Saturday, August 11, 2012

BENCHWORK CONSTRUCTION BEGINS


Considerable progress has been made in the past two weeks with the benchwork base for the “valley core” of the HO scale SP Cascade Line.  The table saw help by Dennis R., previously reported, netted a stack of plywood “dimensional lumber” that now has found its way into benchwork.  Legs were attached to the first L-girder which was attached to the central post and a wall in the basement on July 31.


First L-girder mounted to basement wall and post.

A couple of great ideas were gleaned from a visit with Jerry B. and the Corvallis Society of Model Railroaders.  The CSMR currently is in the midst of benchwork construction for their new, second layout in their Adair Village facility.  Jerry suggested rounding over the sharp bottom edges of the L-girders.  My back already appreciates this idea.  It is well worth the modest effort with a router.  Jerry also suggested ripping 2x6 into 2x3 for legs.  Good idea, but my execution with poor lumber choice was reported previously.  Jerry’s good idea for legs that has worked out is the use of lag screws for leg height adjustment.  No matter how “perfect” one’s carpentry, adjustments still are necessary.  Thanks Jerry!


 Inverted L-girder section on left shows bottom edges rounded with a 1/8” round-over router bit.  2x3 leg on right has 3/8 inch lag screw in bottom for height adjustment.

With the first L-girder mounted, it was relatively easier to erect additional L-girders alongside the first the flesh out the base structure for the Eugene Depot and Oakridge yard areas, which are back to back, surrounding the central post in the basement.


Cross bracing has been applied to leg pairs using 1x2 furring strips.  The 1x2 furring is cheap and easily managed by me.  It also comes with rounded edges so I did not have to spend time with the router on it.  With stringers attached on top of the L-girders and cross bracing on the legs below, the benchwork is VERY solid!


Cross bracing.

With the first major spine built for Eugene and Oakridge, base benchwork construction proceeded around to the Springfield lobe.  Stringers are now being attached to this new section. 


Springfield lobe benchwork.


Base benchwork as seen from Westfir corner.

Stringer placement is assisted by the track plan on the floor.  A couple of stringers have been moved a bit to avoid switch machine locations.  This is the beauty of L-girder construction, as it is easy to move a stringer and reattach with a few screws.  The principal alternative of open grid benchwork has its place, but is not so easily modified.

Note that all of the benchwork assembly of the past two weeks has been done by me alone.  Clamps, work jigs and a bit of thought has found solutions where a second set of hands ordinarily would have been used.   The positive aspect of this singular construction is that I have the time to think through construction issues and develop solutions without impacting others.

The next steps are completion of stringer mounting, adding base plates and other structure for the river areas (three are within the general area of this construction), and mounting the ¾” plywood subroadbed.