Post by triplex on Sept 27, 2011 19:17:29 GMT -5
www.steamlocomotive.com/northern/?page=sp
This lists all GS-series as having essentially the same evaporative heating surface. I would assume they had the same external boiler dimensions as well, but...
The 73.5"-drivered GS-1/2/6 have 20' rigid and 45'10" total wheelbase. The 80" GS-3/4/5 have 21'6" and 47'8".
The problem comes in trying to reconcile these with photographs. If the wheelbases are different but the boilers are the same, there should be an obvious difference in the position of the wheels relative to the boiler.
www.yesteryeardepot.com/SP4460.JPG GS-6.
www.yesteryeardepot.com/SP4420B.JPG GS-3, deskirted and out of service.
The higher drivers are evident by comparison to the air tank and pumps. However, I can't tell anywhere the length difference is made up. That is, the boiler looks the same length, and the drivers and overall wheelbase seem to span the same part of it.
I know it's not wise to judge dimensions from models. They're often inaccurate, particularly regarding driver size (due to deep flanges) and pilot truck wheelbase/position (to clear cylinders, due to sharp curves and those same deep flanges). Still...
shastasprings.com/brass/Bal_GS2.jpg
shastasprings.com/brass/WSM_GS-4_FP.jpg
I can see the difference in driver size. The boilers look the same - or do they? The section above the GS-4's last driver might be longer. Oddly, the overall wheelbase looks the same, as does the trailing truck's position relative to the firebox and cab.
I ask because the only diagram I've been able to find online is for a GS-4 (predictably).
This lists all GS-series as having essentially the same evaporative heating surface. I would assume they had the same external boiler dimensions as well, but...
The 73.5"-drivered GS-1/2/6 have 20' rigid and 45'10" total wheelbase. The 80" GS-3/4/5 have 21'6" and 47'8".
The problem comes in trying to reconcile these with photographs. If the wheelbases are different but the boilers are the same, there should be an obvious difference in the position of the wheels relative to the boiler.
www.yesteryeardepot.com/SP4460.JPG GS-6.
www.yesteryeardepot.com/SP4420B.JPG GS-3, deskirted and out of service.
The higher drivers are evident by comparison to the air tank and pumps. However, I can't tell anywhere the length difference is made up. That is, the boiler looks the same length, and the drivers and overall wheelbase seem to span the same part of it.
I know it's not wise to judge dimensions from models. They're often inaccurate, particularly regarding driver size (due to deep flanges) and pilot truck wheelbase/position (to clear cylinders, due to sharp curves and those same deep flanges). Still...
shastasprings.com/brass/Bal_GS2.jpg
shastasprings.com/brass/WSM_GS-4_FP.jpg
I can see the difference in driver size. The boilers look the same - or do they? The section above the GS-4's last driver might be longer. Oddly, the overall wheelbase looks the same, as does the trailing truck's position relative to the firebox and cab.
I ask because the only diagram I've been able to find online is for a GS-4 (predictably).