Madison or Irvington?

You've basically said it all, Dominic. Just a short-hand way of referring to heavyweights, that changed based on what Lionel was currently producing - Irvingtons in prewar days, and Madisons in the postwar era (even though both Madison and Irvington cars, as well as Manhattan, appeared in postwar years).

Of course, those terms were only used in reference to toy train models. They are still just called "heavyweights" to scale modelers and to the rest of the world.

Jim

Lionel didn't give that series a name of its own. Production ceased after 1950 (Lionel's 50th anniversary). Collectors started calling them "Irvington cars" or "Madison cars." The latter became more popular.

"Baby Madisons" are different cars. They are smaller. They were made in the MPC era, when Lionel trains were manufactured by Model Products Corporation of General Mills. In LIONEL: A COLLECTOR'S GUIDE AND HISTORY (Vol. 4: 1970-1980), authors Tom McComas and James Tuohy quote former engineering director Dick Branstner, who explains, "We just weren't prepared to do a car like the Irvington from scratch. I decided to do a compromise car. Come out with a nice-looking car based on the same kind of prototype the Irvington car was based on."

He sent a Canadian designer, Gordon Hathaway, to Toronto to take pictures of old passenger cars sitting around the Toronto yards. Hathaway took the dimensions of all the cars he photographed. He returned to Windsor and made wood mock-ups.

"We made a bunch of wood models of various lengths and widths and ran them with standard trucks to find out if they would clear all the accessories," says Branstner. "We did that a lot with any new item. If they didn't clear we would shape and narrow them until they did. The extremities of the wooden block were the same as the model we wuld eventually make. Sometimes we even took pictures of the wooden mock-up for the catalog. You can see the passenger car mock-ups in the advance catalog that came out in the spiring of 1973."

The first three sets were the Milwaukee Special (1973), the Broadway Limited (1974), and the Capitol Limited (1975). Southern Railway President Graham Claytor helped to make the Southern Crescent (1977) a truly beautiful set. The Blue Comet (1978) featured new metal 6-wheel trucks. These "Baby Madisons" have been in production ever since.