No. 30: Marion RPM, Part 1

One of the great things about having a blog is you can recognize people for their good work.

I was fortunate to attend the 2011 and 2013 Central Ohio Railroad Prototype Modeler’s (CORPM) Meet at Marion Union Station, Marion, Ohio.  I wrote about it in the SCL Modeler online magazine in 2013.  What follows is an excerpt of that article, plus a lot more photos and info.

Known by the modeling community as “Marion RPM”, this event followed the successful RPM format, with clinicians, model displays, layout tours, no contests, door prizes, and plenty of time for fellowship. About 75 modelers attended the 2011 and 2013 events–many from as far away as Georgia and Pennsylvania and Canada.   Also in attendance were many family members and railfans that flock to Marion every weekend.  I counted 700 models on display in 2013.

The meet is hosted by Denis Blake, a Norfolk Southern engineer and a longtime Seaboard Air Line RR modeler.  Denis is an interesting guy and a lot of fun to be around.  Denis is actively involved with numerous historical societies, hobby manufacturers, authors, and provides the Marion RPM as a non-profit service to the hobby community. Under Denis’s direction, proceeds from the meet go directly to the Marion Union Station Association, which maintains the facility and the historical artifacts on the site. Denis has hosted the meet since 2010 and is assisted by Kevin Tweed, his wife Robin and his daughter Jeannine Blake.  The late John Peters also helped Denis host several of the early events.


The view above greets you at Marion RPM.  This is one of the entrances at the Marion Union Station museum.

Unlike most RPM meets, which are hosted in a hotel or convention center, Marion RPM is held in the restored Marion Union Station, which is located in the middle of three busy double-track main lines—two CSX and one Norfolk Southern—about 45 miles north of Columbus, Ohio. In the glory days these lines were the very busy Pennsylvania Railroad Columbus to Sandusky main line, the New York Central St. Louis line, the Erie Railroad New York to Chicago mainline, and the Chesapeake and Ohio main line north of Columbus.  Marion was also the home of the world-famous Marion Power Shovel Co. which was an industrial giant and major employer in the city.

Today, the depot is a museum and the three big main lines still host 60-75 trains a day from NS and CSX.  The RPM event is confined by space and is a little smaller than most, but the clinics are always good and the railfan action can’t be beat.  There is also a large room with an old-school layout built by  model railroading icon Joe Slanser.  You may remember Joe from a late-1970s article in MR featuring his large basement Erie RR layout.  As a young teenager I thought that layout article was fantastic.  30 years later it was a real thrill to meet Joe and see his other large layout in the depot-museum’s baggage room.  More on that later.


Above, an eastbound CSX auto train is seen from the restored Erie AC Tower window at Marion. The train is on the former Erie-NYC shared right-of-way route through the interlocking.


Above. Marion is full of surprises.  Here an eastbound CSX local scoots through the interlocking with a former NYC caboose in tow.


Above. RPMers and railfans mix it up at Marion during CORPM 2011.  On the right is the great Warren Calloway.  He is not be found in front of the camera often.  Below.  Just on the other side of the depot, an NS engine pushes a northbound coal train through the junction towards the Lake Erie docks.  It is not uncommon for trains to be moving on both sides of the depot simultaneously.


The restored Marion Union Station is a destination in itself.  The depot museum includes CTC and tower panels from area sites, train control equipment, signal equipment of all types, books, photos, and historical documents on the station and area railroading.  A view of some of the equipment can be seen below.  In my humble opinion CORPM has hands-down the best location of all the RPM meets in the US.



Above.  A few miles north of the depot, this PRR coal dock still stands across the now NS main tracks.  Below is a photo from the Marion Station collection, showing the coal dock in action.  The J-1 is heading north.


The heart of the museum is the former Erie Railroad AC tower (seen below).  The tower was built in 1902 and includes one of only two fully-restored, vintage interlocking machines in the nation. The tower still has the original model board and interlocking machine and still operates thanks to dedicated volunteers who have fully restored the machines mechanically and electrically.

The passage of real trains is detected and displayed on the model board, and visitors can work the signals and switches to clear trains through the interlocking using all of the original equipment. Volunteers even use the original oils to lubricate the interlocking devices so the machine smells like it did when in operation.  I spent 90 minutes working trains through the interlocking during my visit and it was an unforgettable experience.  AC Tower is literally a hands-on time machine and is worth the trip by itself.



Above. The interlocking machine in AC Tower.  The “model board” showing the junction diagram mounted on the ceiling above.  Below the front face of the machine, below the red knobs, are the “locking dogs” (seen below) which are the heart of the mechanical interlocking machine.   The dogs are small, flat steel panels which move up and down and interlock to clear routes and provide safety in the event a leverman attempts to clear conflicting route. The dogs are built specifically for each interlocking machine and serve as a mechanical computer.  As it was explained to me, the dogs are the actual interlocking machine–not the levers or rods or anything else you see outside the tower.


A few more photos of the equipment are included below.  It smells wonderful–not quite like gun oil, but close.






Above is a view of the restored model board. The tower was donated to the Marion Union Station Association in 1995 by Conrail. The restored model board shows the pre-Conrail track alignment, with the Erie and New York Central lines going from left to right, and the Pennsylvania and Chesapeake and Ohio main lines going top to bottom (right and left, respectively). The round glass devices are mechanical timers which are part of the intricate system used to protect trains moving through the interlocking plant.

The lights on the model board actually light up when a CSX or NS train enters the interlocking limits.  To “play”, you must line up the route using the pistol-grips below when a train enters the limits of the plant.  You’ve gotta be quick, and smart–and it helps if there is an experienced guy there to help you.  The interlocker will let you know right away if you make a mistake.  Moments later the real train will rumble by and you can watch from the window.  Forget model trains, Brother–this is the coolest thing you will ever do.



When I was there in 2011, George Detwiler (at right), one of the principal men responsible for moving the tower to its present site and restoring the interlocking machine, assists a railfan in setting a timer to clear the interlocking during a simulation. George is a former railroad employee and understands the interlocking logic well, and is a very patient instructor.

You can read more about Marion Union Station at

I’ll cover the RPM aspect of the meet in my next post.  – John









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