Modern And Old Freight Car Compatibility

Coupler height has been standardized for a LONG time, and has nothing whatsoever to do with the size of the car wheels.  Mismatches of an inch or so in vertical height are more likely caused by spring compression of a heavily-laden car coupled to an empty (or a boxcar loaded with ping-pong balls.)

The biggest reason that you won't see modern cars coupled to 50s-era cars is that the 50s-era cars timed out at forty years and went to scrap before 2000.  It has nothing to do with coupler compatibility.

Chuck

Differences in wheel size are accomodated by differences in the shapes of the transverse truck bolster, the mating car bolster, and the overall design of the car frame.

beaulieu

Coupler height is indeed standardized, but wheel size is not. Car wheels vary from 28" to 38", with Tri-level Autoracks using the small ones, and 286k freight cars the big ones. Not only the wheels vary but so do the truck side frames.

beaulieu

Coupler height is indeed standardized, but wheel size is not. Car wheels vary from 28" to 38", with Tri-level Autoracks using the small ones, and 286k freight cars the big ones. Not only the wheels vary but so do the truck side frames. Autoracks are fairly light and the small wheels helps to lower the top of the car.

   You might find this link of some interest:  http://findarticles.com/p/articles/mi_m1215/is_8_201/ai_64752052/

FTA:  "...One of the few things a supplier can do is improve coupler metallurgy, says McConway & Torley Director-Foundry Sales Scott Mautino, but there are limits. "We can improve the appearance of our castings, because better-looking, smoother castings have a longer life under load conditions. But the railroads are reluctant to pay for any of these improvements." One of McConway & Torley's newest products is its CX coupler pin, a more flexible C-10 pin that allows coupler parts to move without fatiguing the pin, one of the weakest point in the link..."

FTA: "...The biggest problem with couplers is "slop," or excessive slack action. MCSCM members standardized on a reduced-slack design just under two years ago that is starting to gain acceptance..."

And Lastly, I thought this was kind of an interesting point; FTA: "...Improving coupler knuckle service life is the next issue the MCSCM will tackle, says AEC-NACO's Becker. "If a coupler is going to fail, the knuckle is the part you want to have break first because it's the easiest to replace," he says. "But our customers don't want them breaking as frequently as they do now..."

(EDIT)And the referenced 40 year car rule is a reality:

Link to UP RR's policiy on this:  http://www.uprr.com/customers/equip-resources/overage.shtml

FTL:  Association of American Railroads Over Age Car Guidelines:

According to the Association of American Railroads (AAR), when cars are 40 years old, built prior to 1974, they are no longer allowed for "Free Interchange" service.  They may be handled between participating railroads on an exception basis or must go through a recertification program per AAR Rule 88 Rebuild or AAR Rule 88 Extended Service Status (reference the AAR Office Manual Rule 88 for the explanation of the requirements for the recertification programs).  The recertification must be approved by the AAR Equipment Engineering Committee.

Cars built from July 1974 to present or cars which have received an AAR Rule 88 Rebuild or AAR Rule 88 Extended Service Status may continue in interchange service to 50 years of age.  After these cars reach the 50 years of age they may be handled between participating railroads by agreement of all railroads concerned. 

The fourty-year-old freight car rule is only for cars that have not been upgraded with parts like  break appliances.

ACF, now ARI, officials have stated in TRAINS that a properly Maintained ACF Center Flow Covered Hopper should last 100 years if properly maintained. It did not come across as a joke in the article.

Andrew

Andrew Falconer

The fourty-year-old freight car rule is only for cars that have not been upgraded with parts like  break appliances.

ACF, now ARI, officials have stated in TRAINS that a properly Maintained ACF Center Flow Covered Hopper should last 100 years if properly maintained. It did not come across as a joke in the article.

Andrew

The AAR Rule 88 requires that cars built before July 1, 1974 be barred from interchange service the month it will become 40 year old unless they are rebuilt according to AAR Rule 88.C.1.c, are accepted as Extended Service Status Units (88.C.1.f), or Increased Life Status Units (88.C.1.g), All of these require approval by the AAR Equipment Engineering Committee, inspections, etc. It is not a manner or just replacing a standard list of parts.

Andrew Falconer

The fourty-year-old freight car rule is only for cars that have not been upgraded with parts like  break appliances.

ACF, now ARI, officials have stated in TRAINS that a properly Maintained ACF Center Flow Covered Hopper should last 100 years if properly maintained. It did not come across as a joke in the article.

Andrew

(emphasis mine - zug)

Unfortunately, such a beast has never been seen,...

Andrew Falconer

ACF, now ARI, officials have stated in TRAINS that a properly Maintained ACF Center Flow Covered Hopper should last 100 years if properly maintained. It did not come across as a joke in the article.

The 40 year old rule is more about trying to keep the car fleet commercially viable and allowing upgrades to eventually take hold in the car fleet. It is generally not about safety.

Let's say the industry wanted to move to an improved freight car truck design someday to allow higher operating speeds. They'd do this thru the AAR and, after 40 years at the max., the whole fleet would be equipped.

ACF is still around. They just do not make cars anymore. They sold that business to ARI.

ACF's address is 101 Clark Street, St. Charles. MO. ARI's address is 100 Clark Street, St. Charles, MO. If the address system is the same there as it is here, they are across the street from each other. However, I cannot find anything about any current affiliations between the two on their websites.