Testing transformers at full current

I start with a REALLY LARGE 18 ohm resistor, then I use heavy-duty clip-leads to parallel sections until I measure the proper load.  I use a Sperry clamp-on meter to measure the current.

I use to build load banks with light bulbs. They were cheap and available.  Surface mount sockets were also cheap. Series/parallel banks were easy to build and if jumpering  out lamps, or putting in plug fuses did not work, just change to a different wattage lamp. The most available lamps are 120 volt, but 12 volt Edison screw base lamps are also available from the boat and camper people.  I also has several variacs that could be used to adjust the load. Drawings in the Electric Railway Journal show this method of building load banks goes back over 100 years. There are also some very nice commercial load banks, one I used at Westinghouse was built on slate panels. But power resistors are expensive these days.  I use to get 100 and 200 watt custom wound resistors from Milwaukee Resistor and they could run $20 each depending on the type of terminal. 

Dale has the deluxe edition, no doubt about it.  I think if I were going to build a load like that, I'd probably add a volt and ammeter to it for an all-in-one test box.

I'm not very familiar with Lionel's modern transformers. Is the 180W brick just a transformer inside?

Yep, it's a transformer with a fancy electronic circuit breaker.  The "heft" is all plain old transformer, the breaker is a small circuit board inside with a relay to kill the power.