[www.trains.com]

Yes, if you have batteries and a diesel aboard, you absolutely can and should have them set up to be used together as a hybrid. That's a no-duh. Add a pan for use where wire is installed and you have 3 modes + hybrid therefore "4-mode" according to the advertising types.

What's more interesting is that the proposed Amtrak replacement for dual-mode locomotives in the NY area sound a lot like electric-battery B units that take over when in the tunnels with the diesel shut down. Essentially, the diesel Chargers are unmodified, and all the gear needed to run the train in the tunnels or under NEC catenary is in a separate unit. While it's going to come from Siemens and be used for different reasons (mainly, for Amtrak, to get rid of the P32DMs), it's much like the Wabtec battery unit "hybrid consist" scheme that was tested, with significant fuel savings, on BNSF in California a few years ago.