Seeing the Warner & Swasey name on the forklift reminds me of Warner & Swasey's developing and builing the "Gradall" excavator. I believe the first generation Gradalls were wholly a product of Warner & Swasey (or some division thereof). W & S had to have had a division setup to build construction or heavy equipment using welded construction and industrial hydraulics. This was quite a stretch from building turret lathes, and would require an entirely different type of physical plant. Just as W & S was diversifying by getting into the building of the Gradall, it would stand to reason they diversified the products in the division building the Gradall to include forklifts. As a very simplistic viewpoint: a division building forklifts as well as Gradalls would likely sell a lot more heavy-duty all terrain forklifts than Gradalls, and forklift sales might have been planned to keep the division afloat.
I think the Gradall was one of the first hydraulic excavators. For its time, it was quite a step up from cable operated excavators. Gradalls are still manufactured today, though the connection to Warner & Swasey was severed a long time ago. The design of the Gradall makes it an ideal machine for excavating trenching, as well as grading shoulders of roads and similar work. On my first job out of engineering school, in 1972, we had a W & S Gradall on the job. We were using it to dig a few miles of trenching for underground fuel oil and fire protection piping. As I recall, the Gradall had a large V-8 gasoline engine on the carrier, and a Detroit Diesel on the actual excavator. I remember marvelling at the fact the Gradall operator could move the carrier along from the "upstairs" cab while working. Years later, on our local tourist railroad, we got hold of a later Gradall with 'high rail' gear for running on railroad tracks. This Gradall was setup with a shorter boom and intended for trackwork such as maintaining embankments, ballasting, and ditching. Same setup: gasoline engine 'downstairs', Detroit diesel "upstairs".
As a kid, I remember seeing an advertisement for Warner & Swasey's turret lathes in some everyday magazine (maybe 'Time' or "Newsweek") in which they described how a W & S turret lathe took something like 90 lbs of metal off a casting to machine it in some very short time. I also recall seeing ads from after WWII in which the machine tool manufacturers were trying to diversify since the demand for large numbers of machine tools had dried up. I know Lodge & Shipley tried building a small one-wheel lawn tractor, and some of the other machine tool builders dabbled in other product lines. W & S was likely in this same boat with the building of Gradalls and forklifts. I suspect that W &S sold a lot more Gradalls than forklifts, or at least the Gradalls are a lot more visible.