The articulation (ability to turn tight radius) of locomotives such as Penn Centrals , Class P1-A or Illinois Terminals , Class C/D is amazing. The Illinois Terminal Class C was designed to turn corners on city streets on intersections. Are there other locomotives that were designed for tight radius?
Personally, I’m not sure but I know that there’s a few maybe more people who know about that
Gabe
There’s always the BB1 pairs…
Pennsylvania Railroad class B1
The Uintah articulated steam locomotives could handle some very sharp curves, though not quite as sharp as the IT’s Class C’s could.
Wasn’t that the purpose of all steam locomotives?
Articulation was pretty useful in mountainous areas.
Rich
I’d imagine the 2-6-6-2Ts that the Black Hills Central Railroad have can take some pretty tight curves
OK, a few thoughts. Articulated electric locomotives like the PRR GG1, P1-A and similar locos on other lines were not really articulated for sharper curves.
They were are articulated for better performance and higher speeds on the standard curves on those lines.
Locomotives with longer rigid wheel bases, like some big steam, not only require larger curves but must slow down for the sharpest curves they can handle and they lose some tractive effort on sharper curves.
One of the things that made first generation diesels successful was their typically short length and the common B-B truck arrangement, which provided virtually no loss of power in any curve it could handle.
Another example, this time steam. If you compare big “rockies” steam (Big Boy) to big Appalachia steam, you will notice the N&W Class A and the C&O Allegheny are 2-6-6-4 and 2-6-6-6 wheel arrangements compared to the Big Boy’s 4-8-8-4 arrangement. Yet both of these east coast locos are similar in power to the Big Boy.
Big Boy’s worked in open country, they needed speed and power, if they had to slow down for a few curves no big deal.
But in Appalachia there is no open country, from the piedmont plateau to the Ohio Valley rail lines are an endless series of snake like curves - mostly fairly broad curves, mostly all curves.
So east coast articulated steam was designed with smaller drivers, like the N&W Y6b, OR, fewer drivers like the Class A or the Allegheny. Both of which were fast, nimble and powerful and could maintain moderate speeds thru winding trackage.
So it is not so much about how sharp the curves are, but how many curves there are, one after the other, and not losing speed or power on those curves.
Same rules apply to those electric locos the OP mentioned.
Locomotives designed strictly for industrial trackage are a completely different story.
Like these on the B&O: https://images.app.goo.gl/PnkwrbKwiyGQixEQ9
Sheldon
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Point well taken. Interesting.
Rich
Sheldon,
Very informative post and I love the pictures of the B&O 0-4-0s!
OK, now an example of balancing the need to navigate sharper curves but have bigger power.
The C&O had a fairly large roster of 2-6-6-2 locomotives (about 300 locomotives) that were largely used to pull long coal drags out of the the Appalachian mining branch lines.
These locomotives were about similar in power to a heavy 4-8-2, 2-8-2 or 2-8-4, but they were much more nimble (and a bit slower).
Some were used in mainline service as well, moving coal drags to larger yards and distribution points.
These locos first appeared in 1912. They were the basis for the USRA 2-6-6-2 in 1918, and the C&O like them so much they bought the last 10 in 1949 - one of those survives and runs today. #1309.
Here is my ATLANTIC CENTRAL version.
Sheldon
They really are great, I have three for the ATLANTIC CENTRAL and two in C&O.
Sheldon
I digress. The turn radius of the Illinois Terminal Class C locomotive, which has a turn radius of 35 feet, is not comparable to the turn radius of a big boy. What we are looking for here is “highly articulated” as opposed to “simple articulation” .
But that locomotive had a highly specialized purpose, as did a number of other industrial switching locomotives. I acknowledged that specialization in my reply, you did not really address that in your original post.
But articulation was not the common answer to that issue except with steam in mining and logging operations.
The Uintah Railroad had a 66 degree curve that may have been eased for the articulateds showed up. The ultimate in articulated steam locomotives were the Shays, Climaxes and Heislers.
Well, I did not directly answer your final question, “are there other locomotives that were designed for tight radius”.
But you did not sat other “articulated” locomotives. I did give the ultimate tight radius locomotive example, the B&O C-16.
The Illinois Terminal Railroad was a heavy class interurban and as such had operating conditions fairly unique to that type of railroad. Other interurbans had various box cab and center cab locos, generally of the B-B configuration, that could handle very sharp curves like you describe.
Few of these railroads had power requirements that would require more axles on the rial and require the B+B-B+B configuration of the ITR class C. The ITR had several light duty bridges that required them to keep axle loads low - a problem not every interurban had to that degree.
My reply focused on the issue of articulation, which was done for a number of reasons, on a number of different types of railroads, not exclusively to negotiate extremely tight curves.
Sheldon
Yeah, that was the case with the Illinois Terminal Railroad. It operated almost solely in downstate (southern) Illinois at grade level.
Rich
Partly before my time, a short line interurban ran in the part of Maryland where I grew up. Interestingly it was electrified, but most freight movements were handled by a few small steam locos, then later a GE 70 tonner.
Originally it linked Baltimore, Washington DC, and Annapolis in a kind of triangle. But after WWII all that remained was the line from Baltimore to Annapolis.
It ran right past the first apartment my parents lived in when I was a baby. In that same building was a barber where I got my hair cut for most of my childhood.
And across the tracks from that building was the train station, that starting in 1966 has been the home of the Severna Park Model Railroad Club which I was a member of from age 15 to about 27.
In those years, passenger service was long gone, but the GE 70 tonner would waddle its way back and forth to and from Annapolis with 6-10 freight cars a few times a week.
Today part of the right of way is used for the Baltimore Light Rail system, the rest is walking trail.
https://www.facebook.com/spmrc/
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I didn’t grow up in Severna Park but i did grow up in Maryland. I love learning about those little bits of local history. I grew up near Ellicott City, not even realizing that the B&O station there is the oldest surviving passenger station in the United States.