Matt, The breakers on the old transformers are much to slow for the modern electronic trains we now have available to us. Hopefully some one here may be able to help you out with this. Maybe Gunrunnerjohn may have some ideas of what you may try. In the meantime I would recommend the purchase of at least the Lionel Lockon for the protection of the new generation of trains. I have gone to the use of the Legacy system, with Powerhouses and Powermasters, and am amazed at how quickly these things react to a short circuit.
Ray