locomotive question

[denveroutlaws06]

Whats the oldest locomotive that is still active?

[owlsroost]

According to the current Trains 'Locomotive 2016' magazine, Metra has a 1939 vintage EMD SW1 switcher in active use at one of their Chicago area maintenance facilities.

[RME]

denveroutlaws06

Whats the oldest locomotive that is still active?

Euclid has one earlier than 1939.  I suspect there are other 'critter' size diesel-mechanicals like the one Central Colorado Railcar had (1930) that are still running.  If those don't count, look for things like HH600s at ag facilities (does Gopher Scrap still run theirs?).  And then there is this, I think:

[Firelock76]

To my knowledge the oldest locomotive currantly active is a 4-4-0 at the Henry Ford Museum in Greenfield Village, Michigan.  It was built in the 1870's, and there's YouTube videos to been seen of it in operation.

There's the "William Mason" at the Baltimore and Ohio Museum, a 4-4-0 built in the 1850's, but it's not in regular service, they only trot that one out on special occasions.

Hey man, you didn't specify diesels!

[CSSHEGEWISCH]

The OP may not have been specifying diesels, but it is safe to assume that the implication was for locomotives in common carrier or industrial service, not tourist or park operations.

[Big Bill]

I don't know why that would be safe to assume. I am active, but retired.