Largest of the early 1950s machines made by the Logan Company the 145/8" x 40"" employed a much more massive, ground-finish bed than the smaller models, a full 10" wide across the ways (as a comparison, the rugged 12" Colchester Student has a bed 83/8" wide). Although a large, heavy, machine no separate powershaft was fitted for sliding and surfacing speeds, the same simple, slotted leadscrew arrangement as used on the lighter lathes being employed instead - however, the apron was oil filled, a screwcutting gearbox and power feeds were supplied as standard and the tailstock was fitted with a No. 3 Morse taper socket.
Spindle speeds, running from 38 to 186 rpm in backgear and 240 to 1200 rpm in direct drive, were controlled by a continuously-variable transmission, exactly as used on the other lathes, with the power supplied by a 1750 rpm, 2 H.P. 3-phase motor controlled by a factory-fitted drum-type reversing switch. The drive system was dynamically balanced, to ensure the smoothest possible running and minimise the transmission of vibration marks to the workpiece.
Like that of all Logans of the period the 13/8" bore spindle, ran on pre-loaded, grease-sealed precision ball bearings - a pair of double-row bearing at the front and a single row bearing at the rear - and carried a 2.25" diameter 8 t.p.i thread. Fortunately a L-00 taper was available as an optional extra and, all things being equal, a used lathe with this fitting would be much preferable to one with a screwed nose.
Supplied with each lathe was a driver plate, two No. 3 Morse taper centres, a dial thread indicator, a spindle sleeve adaptor to No. 2 Morse taper - and a tailstock wrench.
The machine had an overall length of  83", a width of 27" and was 51" high. With a motor installed it weighed approximately 1850 lbs.
A developed version of the machine - the Model 6565 - featured a top speed of 2500 rpm, a hardened bed, and possibly other improvements.