Appears to be dual-tabled. The smaller table would run higher RPM, to reach proper surface speeds.

A comparably large vertical lathe at Long Beach Shipyard, a Betts of 19'. 50hp, .32-12.8 RPM @ feed rates .004-1.5 inch per minute. Maximum table load was 165 tons at 0.75 RPM. Most VBL's of this size are D.C. generator drives to regulate 'infinitely variable' speeds. Most frequent use, boring of propeller hub tapers, max swing was 20'.