As the Korean War was winding down the Air Force tried some new technology in its battle with the trains.

Bell Telephone Labs of New Jersey handled the project to use new Infrared technology to find trains on the blackest of night using a one of a kind piece of equipment. The on-the-scene project officer, whose name is lost to history, gave his name to the only aircraft to have a two letter tail identifier, "Mc".
When the moon was full the B-26s could get down low and find trains in the moonlight. When the moon was down the trains could run at night with impunity.

"Mc" was equipped with an infrared detection device in the nose that could find the train in the dark from its engines heat emission. Packing the sensor with frozen CO-2 -- dry ice -- cooled down the infrared equipment immediately before each mission. The equipment operator in the nose observed a 3-inch scope to indicate the presence of a high heat source.

The tactics were to fly a two-ship mission; with airplane "Mc" flying low along the railroad and the other plane armed and prepared to attack the train when located. As "Mc" passed over a locomotive the equipment operator would see his scope become "spindly", i.e., the scope would flash like the spokes on a wheel. Immediately upon recognizing the high heat source "Mc" would toggle off a firebomb to mark the spot. The train, having been marked by "Mc", would then be attacked by the accompanying killer B-26
The project appears to have not been well managed. Mac, the project officer, completed his missions and rotated in the midst of the project, leaving no paperwork in regard to the success of the tests except a two-page checklist. There were no tech reps from the manufacturer on the scene and apparently no debriefings in regard to determining the success of the mission or tactics.

It is appropriate to remember that this device was new technology. Finding a train was only the first step in the mission. Although the device could find the train, it couldn't determine in which direction the train was moving. The firebomb would mark the spot where the train was when located but in a matter of minutes the train would be someplace else. It would then require re-locating, and the killer plane must still contend with his inability to see and attack the train while avoiding the surrounding hills and obstacles.
"Mc" was highly secret and photos were prohibited. That restriction was sure to guarantee that someone would photograph it. Sigmund Alexander was a navigator that flew many of the plane's test missions and the photos on this page are from "Alex".

 

See the 13th bomb Squadron web site for original article

 

The a/c in the photo below was equipped with an experimental infrared detector for night attack, AN/AAS-1, 'Project Redbird', photo taken March 1953 in Korea. It belonged to 13th BS/3rd BW. 41-39401 was among those a/c contracted as A-26B but delivered as A-26C. By the time of the photo, it was referred to as B-26C.