Wednesday, September 10, 2008
Namoi Bridge, Part II
The 4914, once more, with a train of RU wheat wagons on a very spindly bridge over the Namoi River. . .a mock-up of the 240-some-odd foot crossing between Narrabri and Narrabri West on the North-West NSW layout. . .
I've been putting off working on the west bank of the Namoi River bridge area for a bit now. The first go-round on the east bank (up side) went well, but the ceiling tiles left a God-awful mess sur-forming them to shape. But, apparently I've got that figured out--liberally spray the tiles with soapy water as you carve along, and most of the dust is eliminated.
The other reason for pushing it lower to the list is because I've never built such a bridge before. One of my Aussie Angles came to my rescue with a great set of plans for standard NSWGR pile trestles with 24' pier spacings, so I really no longer have an excuse anymore!
Ceiling tiles stacked up on the west bank of the Namoi River. These have been roughly cut and cemented in place; when the glue is dry, they'll be contoured into riverbanks and the bridge approach.
So I spent a little time this afternoon cutting and gluing stacks of ceiling tiles on the west bank, roughly cutting them to contour. After several hours of letting the glue set up, I got out the rasp and did a little preliminary contour work. I'll hold off the rest until the glue fully cures.
I did start thinking of how I'd build the bridge. I came up with around 226' in length from abutment to abutment, and with 24' pier spacing, that came up to 9 piers. Since the height of the bridge would be below 18', I cna get away with the 3-post piers, seen in this view of a bridge near Wee Waa (if I could recall where I got this photograph, I'd either credit the photographer or thank him personally):
A pair of "candy" 48 Class Alcos on a passenger special in 1991 approaching Wee Waa, atop a three-post pile trestle. These appear to be much closer together than the 24' NSWGR plans I have. . .
There is some question when the actual bridges (there are two--one for the river itself, one for a flood plain) between Narrabri Jct. and Narrabri were rebuilt to the current concrete-and-steel-girder construction. Could it be before 1978? In this case, I'm going for the downtrodden-and-rustic look regardless of what the prototype used at the time. I like wooden pile trestles, and this is my layout's one big bridge. . .
I'd measured out the location of the piers and set some long drywall screws into the scenery, placing my section of Micro-Engineering Code 70 bridge track atop it. And. . .i couldn't resist. . .I once more mocked up a scene. I think this will be a fine looking scene: image it with a real trestle, static-grasses and other weeds, a small but muddy river, and a smattering of tall trees in the back of the scene.