In U.S. 3ft gauge practice, outside frame locomotives came into being about 1900 (a very few in the 1890s). By then, the narrow gauge boom was pretty much over, as were the reasons for using narrow gauge. U.S. 3ft gauge was used where and when:
- significant savings could be obtained by using a roadbed about 2/3 as wide (think mountain and canyon sides)
- interchange was not an issue either due to location (no other railroads near) or era when started. Universal interchange in standard gauge didn't really get started until the 1880s and really took off in the 1890s to 1900 as things like couplers and brakes were standardized. Also, labor to unload/load cars became more of a factor, and shipments were going much further (outside the local region) as the rail system expanded. Interchange costs probably did more to kill narrow gauge than anything else.
- the size of narrow gauge rolling stock was greater then 75% of the equivalent standard gauge cars. This was the other economic downfall of narrow gauge. One of the assumptions was that you could get 80-90% of the capacity of standard gauge for 75% of the cost. In the 1870s, there was some truth to that premise. But by 1900, the growth in capacity of standard gauge rolling stock and train length had turned the economics on its head.
In an attempt to grow train length and capacity to something approaching standard gauge again, some of the narrow gauge railways tried using steel underframes for their cars, and buying larger engines. The path provided by Baldwin and others to larger engines was outside frames (and trailing trucks) which enabled larger fire boxes and steaming capacity. The fireboxes on older inside frame locos were limited in size by the space between the rails. Almost all of the U.S. 3ft gauge outside frame locomotives were purchased between 1900 and 1925.
my thoughts
- significant savings could be obtained by using a roadbed about 2/3 as wide (think mountain and canyon sides)
- interchange was not an issue either due to location (no other railroads near) or era when started. Universal interchange in standard gauge didn't really get started until the 1880s and really took off in the 1890s to 1900 as things like couplers and brakes were standardized. Also, labor to unload/load cars became more of a factor, and shipments were going much further (outside the local region) as the rail system expanded. Interchange costs probably did more to kill narrow gauge than anything else.
- the size of narrow gauge rolling stock was greater then 75% of the equivalent standard gauge cars. This was the other economic downfall of narrow gauge. One of the assumptions was that you could get 80-90% of the capacity of standard gauge for 75% of the cost. In the 1870s, there was some truth to that premise. But by 1900, the growth in capacity of standard gauge rolling stock and train length had turned the economics on its head.
In an attempt to grow train length and capacity to something approaching standard gauge again, some of the narrow gauge railways tried using steel underframes for their cars, and buying larger engines. The path provided by Baldwin and others to larger engines was outside frames (and trailing trucks) which enabled larger fire boxes and steaming capacity. The fireboxes on older inside frame locos were limited in size by the space between the rails. Almost all of the U.S. 3ft gauge outside frame locomotives were purchased between 1900 and 1925.
my thoughts
That's
:thumb: :thumb: Moderating here keeps me busy so I don't have much time to keep up on forums like this one. I'll take the opportunity while I may, to say I like the projects you are working on, and appreciate the level of craftsmanship displayed. Nice work!!:thumb:
Pete
sumpter250 said:That's
Moderating here keeps me busy so I don't have much time to keep up on forums like this one. I'll take the opportunity while I may, to say I like the projects you are working on, and appreciate the level of craftsmanship displayed. Nice work!!:thumb:
Pete
Not sure what the praise is directed at, but since you quoted me... thanks!
The praise is directed at "here" in your signature Every pic you've posted shows exactly what I am praising. I'll continue to follow your progress as time allows.Pete
Oh right I see!
I really do need to get on with that... actually there are some unposted photographs and drawings that I could post in the mean time...
I really do need to get on with that... actually there are some unposted photographs and drawings that I could post in the mean time...
Canopus is right on about outside frame being an early idea. Outside frame has clearly been popular right from the start...
Here's 1835...http://www.steamlocomotive.info/vlocomotive.cfm?Display=1781
Or this famous American/British hybrid with inside cylinders http://www.steamlocomotive.info/vlocomotive.cfm?Display=309
Here's 1835...http://www.steamlocomotive.info/vlocomotive.cfm?Display=1781
Or this famous American/British hybrid with inside cylinders http://www.steamlocomotive.info/vlocomotive.cfm?Display=309
When you go back that far you see more parallels between American and British locomotive design. That vertical boiler locomotive for instance is clearly based on the Welsh DeWinton design.
I realize that this is an old post, but I thought I would throw out the main reason that the D&RG began using outside frame engines on it's narrow gauge lines. A lot of what has been mentioned in this thread is very accurate. However I did not see one of the largest contributing factors of outside frame VS inside frame locomatives mentioned. The NG engines operating on Colorado railroads were becomming worn out and needed to be replaced. Most of the Consolidations and Moguls could not haul the necessary pay loads
to justify spending money for new engines.
Someone in the shops recognized that by simply moving the drive wheels to the inside of the frame of a standard gauge engine it would allow them to run on 36 inch gauge rather than 4 Ft 8 1/2 inches. It would give them greater pulling power, and could still negociate 3 to 4 percent grades and the tight curves of mountain railroading.
All South Park and C&S locomotives as far as I know were "outside frame"
C Webb............................
to justify spending money for new engines.
Someone in the shops recognized that by simply moving the drive wheels to the inside of the frame of a standard gauge engine it would allow them to run on 36 inch gauge rather than 4 Ft 8 1/2 inches. It would give them greater pulling power, and could still negociate 3 to 4 percent grades and the tight curves of mountain railroading.
All South Park and C&S locomotives as far as I know were "outside frame"
C Webb............................
It's only in the past couple years that I've learned to like steam in general (and I certainly don't include all steam) and dieselized narrow gauge, and it's only in the past month or so that I've realized I like outside frame engines. Now I like the bulky look of narrow gauge steam, and outside frame seems to be the way they should look.
Hi, being one of the principal "instigators" in getting this outside-frame debate going, and somehow having lost the thread to this thread, let me say that all the info has been very enlightening. Fortunately, I came across a photo (I think somewhere here on this forum), which was clear enough to depict the innards of an outside frame loco, and I finally understood what that was all about. In any event, thanks to all for their input..!!
Canopus...I though your name came from a passion for astronomy....
Canopus...I though your name came from a passion for astronomy....