Hi all
I found this shot on the Web , I was wondering if anyone has any idea what this box is under the cab of DT&I Locomotive , Thanks Pat

my best guess is there isnt much room on the tender for extra storage so they made a compartment there. Otherwise it may be the location for a stoker engine.

DT&I was owned by Ford, right? It's the toolbox to carry the screw jack, monkey wrench, and combination slip-joint pliers / screwdriver that came with every Ford vehicle.

Sorry, I couldn't resist.

Actually Dennis, you aren't that far off with that guess! DT&I locomotives during the Ford era were equipped with a comprehensive tool box that even included a drop light to inspect the running gear.

Tool storage or a box containing a signal system for the locomotive....? Seems a bit odd of a place for a tool box, as it blocks the injector and makes maintenance more difficult...

It's not blocking anything - engine has a lifting injector, located in the cab. What you see underneath is just the water hose connection to the tender. It's most likely a tool box that's much roomier than a seatbox. Would be easier to tell if the pic wasn't so small.

There are plenty of pictures of locomotives equipped with tool boxes on this website:

DT&I Steam Locomotive pictures

For some reason, the DT&I cab seats during that era were just seats with sturdy legs- no seatbox.