The Hall's Creek Bridge 3 - Still a work in progress

My last two posts have focused on the construction of a simple bridge based on the Hall’s Creek bridge on the abandoned section of the Merriwa Branch line. I am now at a point where the bridge structure must be ‘planted’ on the layout so the final landscaping can be integrated with the overall landscaping of the module.

I fashioned the bridge abutments from  stripwood and the other retaining walls from Wills timber planking. The check rails were fabricated from a length of Code 75 track, glued to the sleepers, and then painted with Rail Brown (part of my dwindling stock Floquil paints).

My activities are now concentrating on the construction of the surrounding landscape and laying the track leading to the bridge. Once the adjoining track height has been established, the position and height of the bridge will be adjusted to ensure the correct alignment. With the bridge finally located, the surrounding terrain including the actual water course can be shaped and sceniced. 

I am reasonably happy with the outcome, but as always, there is room for improvement. As a whole, the bridge looks OK, although some individual components are below par if subjected to close scrutiny. Perhaps the most disappointing elements are the concrete columns. After several attempts, I couldn't replicate the impression of the timber formwork planking that can be seen on the prototype. I probably should have cast something in plaster, but if it bugs me too much, I can install these retrospectively.

Photo from "NSW Steam Train Ride To Merriwa - John Gaydon  (http://steamtrainstories.com/category/australia/nsw/)

I could spend more time tweaking the detail but I need to keep moving towards the helix and upper deck construction, otherwise the bridge will become a "bridge to nowhere" and end up like its prototype.

The Halls Creek Bridge

Photo from Merriwa Rail Society website - Photographer Unknown

After removing the non-prototypical and very distinctive brick viaduct, I still would like to have at least one reasonably sized bridge on the layout. Over the last few months, I have been searching the internet for possible prototypes and came across the bridge over Halls Creek at Sandy Hollow on the now disused Merriwa branch line. Interestingly, Google Maps (a very definitive source??) names the watercourse at the crossing point as Giants Creek but all of the literature that I have found refer to it as Halls Creek.

Photo from Merriwa Rail Society website - Photographer Brian Leedham

According to the Byways of Steam article on the Merriwa line (Byways of Steam 10 p62), this bridge was one of three on the branch line and the only one no longer in service. It is also the most basic but perhaps, the most interesting of the three with a combination of steel and timber superstructure and a mixed arrangement of piers. The other great attraction for this bridge is that a gentleman by the name of Brian Leedham took some photos of the main span which was still in place in 2009 and these have also been published in the Merriwa Railway Society's website (http://www.merriwarailwaysocietyinc.org/alongtheline.htm). The photos have been a great help in determining the arrangement of the main beams and the internal bracing for these. They also give an idea of the arrangement of the timber bearers on the shorter spans.

My intent is not to create an exact copy but use the bridge as a guide. Unfortunately I have not been able to locate any drawings for the bridge, and therefore, the dimensions that I am using to create the model are approximate based on comparisons with locomotives and rolling stock shown in several older photos of the bridge.

To date, I have fabricated the major span steel bream arrangement from styrene and the timber piles from bamboo satay sticks and stripwood from Northeastern Lumber. I have also added bolt heads from Tichy Train Products on the timber pier sets but drew the line at adding rivet heads to plate web girders. I have also cheated a little by not including all of the internal vertical cross bracing and the horizontal cross bracing attached to the bottom flange.

Once the individual components bridge are painted, I'll probably finish the bridge upside down, fixing everything to a length of track before placing it in position. 

The bridge when completed will not form part of the main layout but will be shown as a cameo scene on the branch line before it enters a helix that will provide access to the upper level.

More to follow as the project develops.