McKenna Process Company
Plant formerly located in Joliet, Illinois - ca. 1920.
Image 13 - Hot sawing
Hot saw - Overall
Image 13. Hot Sawing.  After leaving the Finishing 
Rolls, the rerolled rail is sawed at both ends to remove
bolt-holes and make the finished rail of standard
(33 feet) length. A device, shown to the right of the
saw, re-cuts short rails (under 33 feet) and thereby
avoids the necessity for cold-sawing.

Details scanned from the original print:

a. Hot Saw Trimming Rail Ends-Overall
b. Mechanism Details
c. Hand Forged Guard

Note: The hot saw works by heating the metal at the
edge of the saw so hot that it melts and is oxidized by
the oxygen in the air swept through the cut by the
rapidly rotating blade, much like an oxy-fuel cutting
Mechanism Details
Hot saw - Mechanism Details
Hand Forged Guard

Hot  saw - Hand Forged guard