Here is a great collection of photos showing early freight cars built at Harrisburg, PA.

http://www.library.upenn.edu/collection ... isburgcar/

Lovely collection of photos! Two in particular aroused my curiosity. Item 20 is a NYC&HR box car lettered "Compromise." Item 31 is a small industrial hopper which is lettered "Broad Tread."

Do both of these perhaps relate to cars that could operate on both 4'8.5" and 5'0" gauge track? Or something similar?

I think this might be the company that built a former Bridgton & Saco River RR 2ft. tank car, the tank of which still exists at the WW&F Ry. Museum in Maine.

Wow, what a collection. I'm not sure I've ever seen a set of car builders photos from that era like that.

But here's one for the assembled multitude: If you look at those shots, there's not much on a lot of the cars for dimensional data or information. But many of the cars have a very conspicuous "B T" painted on one corner. Not all cars, and not always on the RH side. What in the world did that mean?

And on this one:
http://www.library.upenn.edu/collection ... ar-26.html

Look at the placard under the sill: I think I can read it. "This car must not be diverted between the line between New York and Cleveland". Can you imagine routing instructions like that painted on cars? Forerunner of "when empty return to...". And the big 'ol "B T" is rather evident.

I bet you already have the answer. "B T" must stand for Broad Tread. That was obviously important before everybody agreed on an actual standard gauge, which nowadays we take for granted.

I recall that I read someplace that Original sections of the Pennsylvania were laid to 4'9".

There was a wide variety of gauges and it took the industry a while to convert to 4'-8.5".

There is an interesting discussion about the gauge problem and the conversion in this book: The American Railroad Network, 1861-1890 from the University of Illinois Press.

I think the Pennsylvania was always 4'-8.5". But other roads were built to 4'-9", 5'-0" and many other gauges. Some railroads tried to interchange between standard gauge and 4'9" and maybe other gauges by having wide treads with the flanges set for standard gauge. This caused problems tracking though switches and other special work on both broad and standard gauge roads and such wheels were often alleged to be the cause of derailments.

One interesting thing with this collection of photos is that it shows cars lettered "White Line", "Blue Line" and "Red Line." The were early interchange associations allowing for through cars from the east coast to inland points (like Chicago). Before the creation of these associations railroads generally did not interchange cars and the freight had to transloaded where one railroad stopped and another stopped.

Generally the cars were painted in the color of the "Line."

A compromise car could probably run on both Standard Gauge 4 feet, 8-1/2 inches lines, and 4 feet, 10 inches lines like the Lake Shore & Michigan Southern. On a trip between Cleveland and New York City, the gauge change point was probably Buffalo, N.Y. The Angola, N.Y. wreck of Dec. 19, 1867 on the LS&MS involved a compromise car.

It would be interesting if there was a list of surviving rolling stock made by this company. Since its a early manufacturer I doubt much has survived.

Here is a link to an earlier discussion of the Harrisburg freight cars. It also includes some photos, and begins with finding a Harrisburg tank car. Looking at all the photos, I find the design and style of these early freight cars to be very appealing. Today they are historical antiquity, but in their time, they convey a modern, even futuristic attitude. How common is scale modeling of this genre of equipment?

viewtopic.php?f=1&t=34090&hilit=harrisburg+cars

Two previous Harrisburg Car threads that might be helpful:

http://www.rypn.org/forums/viewtopic.php?f=1&t=34090&hilit=Harrisburg+Car+tank

http://www.rypn.org/forums/viewtopic.php?f=2&t=35173&p=197737&hilit=Harrisburg+Car+tank#p197737

Steve Hunter

The Pittsburgh Fort Wayne & Chicago, controlled by the Pennsylvania by this time, was also 4' 10 gauge, making use of compromise or broad tread cars a necessity for through traffic with the PRR proper to Philadelphia.

I also suspect there was a distinction between "broad tread" and "compromise" wheels. It seems to me broad tread is just that; an extra inch or so added to the width of the wheel to prevent them from falling in the gauge on the wider track.

When Dr. Wesolowski was doing the research for his 1" scale model of "The Lincoln Car" which now resides in the Lincoln Museum in Springfield, IL. He came up with a wheel profile that had a step in the diameter of the tread. This appearantly worked as a false flange to keep the wheels centered on wider gauge track, and thus likely would have been suitable for running on five foot gauge lines. What happened when these wheels came to a switch frog I can only guess, likely the tapered ends of the wing rails gathered the flange to the proper alignment, leaving the wheels to wander around after leaving the switch until they fell back between these false flanges and centered themselves on the track. I suspect these were compromise wheels in the terminology of the day.

Wish I could find a close-up photo; I know Wayne put them on the model.

Here is some information on the Pennsylvania RR and compromise cars.

https://books.google.com/books?id=7T3qE ... ad&f=false

The Angola Horror put an end to compromise cars in 1867.

https://en.wikipedia.org/wiki/Angola_Horror