Yes, this is apparently a HMRT train and it appears to belong to Houston Fire HMRT. How do I know this? Well, if you have good eyes and are attentive to detail, you will notice a very small emblem under the front window on the cab of this diesel engine. Though the emblem itself cannot be read, it does bear the shape and colors of the Houston Fire Dept. official logo.

I'm not sure what the exact story is behind them aquiring the training (a diesel engine, a few box cars and a tank car) but most likely it was donated to them by a railroad corporation (CSX, Union Pacific, etc). On the day this photo was taken the train was being used to training Houston HMRT members in derailment response.

Nonetheless, it's a very unique HAZMAT resource. Hopefully Houston HMRT are nice enough to let other area HAZMAT teams play, eh, conduct training exercises with it every now and then.