I'll add a little to what has been written so far...
First off, disconnected trucks were common, but not universal. What kind of log car an operation used was largely a reflection of what the company's harvest practices were, and, to a large part, what was available. Skeleton log cars were perhaps the most commonly used, as they presented a number of advantages- no car deck for bark to accumulate on, the ability to have train brakes, and rugged construction. However, as noted, the use of flatcars and/or skeletons limited the length of logs that could be loaded. Where the companies chose to buck their logs- i.e., cut a downed tree into smaller, more manageable chunks- played a large roll in this. The most common approach was to buck the tree on the ground as soon as it fell, which made the job of skidding the log to the railroad landing that much easier. In such a case, flats or skeletons were far more practical than disconnects. An additional factor is if the logging railroad operated its trains over any common carrier trackage, as ICC and state rules generally prohibited the use of disconnects on common carrier lines, though exemptions could be obtained. However, if the company operating practices dictated delivery of longer logs to the mill, then disconnects would have been used. Era plays a part in it to- disconnects were more prevalent in the early years. Loggers seemed to transition later to flats or skeletons, especially if they had any sort of steep decending grades on the line, as with a train of disconnects you only had the engine brakes and manual application of hand brakes on each disconnect to fight gravity.
In addition to log cars, your typical logging railroad would also have a collection of service equipment. Nearly every operation had at least one or more steel flatcars with heavy frames, used to move logging equipment into and out of the woods. The logging railroad was often used to provide supplies to outlying logging camps, which would require at least a couple boxcars and maybe a refrigerator car or two. Logging equipment itself burned a lot of fuel, and the logging railroad would often have fuel cars- either wood flats equipped with wood racks for wood powered equipment, or steel tank cars for fuel oil. Gasoline cars became common in later years as internal combustion replaced steam powered logging equipment. Water was also a never-ending need in most operations- in the earlier years to keep men and animals hydrated, later to keep water in the boilers of steam powered logging equipment. Your typical logging railroad would likely have numerous water cars, ranging from wooden boxes on flatcars to steel tank cars, to meet this need. And then there would be a few pieces of more specialized equipment- a locomotive crane or two, a snowplow if you operated in snow country, ballast hoppers for ballasting track, your track gangs would likely have a small collection of work flats dedicated to the never-ending chore of building new log spurs and picking up the old ones, you would need a few fire cars to fight forest fires- mostly water cars equipped with pumps, hose, and firefighting tools, and then a lot of operations had outfit cars that housed track construction or logging crews out in the woods.
For a good overview, I'd recommend finding the January through April 1984 issues of Railroad Model Craftsman. RMC carried a four part series on pacific coast logging in those issues- January featured an overview of the logging industry, February covered the steam locomotives used in logging service, March covered steam era rolling stock and other equipment, and April covered the diesel era.
As for specific recommendations, I'd suggest finding Kadee or Rivarossi skeleton cars, or Bachmann log flats, or Tichy Train Group's 42-foot flatcars- a very close representation of flatcars built by Pacific Car & Foundry that were extensively used in the logging inudstry. Add a wood boxcar, a couple Life-Like 8,000 gallon tank cars, and a caboose- either one of Bachmann's 4-wheel models, or better yet one of MDC's old side door cabooses- and you'd have yourself a fairly accurate train to go with your Shay.
Jeff Moore
Elko, NV
First off, disconnected trucks were common, but not universal. What kind of log car an operation used was largely a reflection of what the company's harvest practices were, and, to a large part, what was available. Skeleton log cars were perhaps the most commonly used, as they presented a number of advantages- no car deck for bark to accumulate on, the ability to have train brakes, and rugged construction. However, as noted, the use of flatcars and/or skeletons limited the length of logs that could be loaded. Where the companies chose to buck their logs- i.e., cut a downed tree into smaller, more manageable chunks- played a large roll in this. The most common approach was to buck the tree on the ground as soon as it fell, which made the job of skidding the log to the railroad landing that much easier. In such a case, flats or skeletons were far more practical than disconnects. An additional factor is if the logging railroad operated its trains over any common carrier trackage, as ICC and state rules generally prohibited the use of disconnects on common carrier lines, though exemptions could be obtained. However, if the company operating practices dictated delivery of longer logs to the mill, then disconnects would have been used. Era plays a part in it to- disconnects were more prevalent in the early years. Loggers seemed to transition later to flats or skeletons, especially if they had any sort of steep decending grades on the line, as with a train of disconnects you only had the engine brakes and manual application of hand brakes on each disconnect to fight gravity.
In addition to log cars, your typical logging railroad would also have a collection of service equipment. Nearly every operation had at least one or more steel flatcars with heavy frames, used to move logging equipment into and out of the woods. The logging railroad was often used to provide supplies to outlying logging camps, which would require at least a couple boxcars and maybe a refrigerator car or two. Logging equipment itself burned a lot of fuel, and the logging railroad would often have fuel cars- either wood flats equipped with wood racks for wood powered equipment, or steel tank cars for fuel oil. Gasoline cars became common in later years as internal combustion replaced steam powered logging equipment. Water was also a never-ending need in most operations- in the earlier years to keep men and animals hydrated, later to keep water in the boilers of steam powered logging equipment. Your typical logging railroad would likely have numerous water cars, ranging from wooden boxes on flatcars to steel tank cars, to meet this need. And then there would be a few pieces of more specialized equipment- a locomotive crane or two, a snowplow if you operated in snow country, ballast hoppers for ballasting track, your track gangs would likely have a small collection of work flats dedicated to the never-ending chore of building new log spurs and picking up the old ones, you would need a few fire cars to fight forest fires- mostly water cars equipped with pumps, hose, and firefighting tools, and then a lot of operations had outfit cars that housed track construction or logging crews out in the woods.
For a good overview, I'd recommend finding the January through April 1984 issues of Railroad Model Craftsman. RMC carried a four part series on pacific coast logging in those issues- January featured an overview of the logging industry, February covered the steam locomotives used in logging service, March covered steam era rolling stock and other equipment, and April covered the diesel era.
As for specific recommendations, I'd suggest finding Kadee or Rivarossi skeleton cars, or Bachmann log flats, or Tichy Train Group's 42-foot flatcars- a very close representation of flatcars built by Pacific Car & Foundry that were extensively used in the logging inudstry. Add a wood boxcar, a couple Life-Like 8,000 gallon tank cars, and a caboose- either one of Bachmann's 4-wheel models, or better yet one of MDC's old side door cabooses- and you'd have yourself a fairly accurate train to go with your Shay.
Jeff Moore
Elko, NV