Railroad and models without tables

I'd like to use railroad on my Rails model. Unfortunately, as I have to make some connections to a second database I've got some models like this:

class LegacyDb < ActiveRecord::Base         establish_connection "legacy_db" end

class LegacyDbData < LegacyDb        set_table_name "data" end

This is fine for the occasional call to the "data" table but railroad is not at all happy:

/usr/lib64/ruby/gems/1.8/gems/activerecord-2.2.2/lib/active_record/connection_adapters/abstract_adapter.rb:188:in `log': Mysql::Error: Table 'legacy_db.legacy_db_data' doesn't exist: SHOW FIELDS FROM `legacy_db_data` (ActiveRecord::StatementInvalid)

There are a few of these models and they're used in various places so removing them for running railroad is not really possible. Is there a means of either preventing railroad from trying to connect to the main application database for these models? Thanks for any suggestions.