Reply to yieldmap:
That's OK. Glad to know I'm following in the footsteps of Oz. Great minds think alike!!!
The guy with the T-7 should be selling used cars with bananas in the rear axle and sawdust in the transmission, he's so full of it.
The Trackson Co built their first cable Trackson loader on a Cat in late 1937 .. fitted to a model Thirty (6G) crawler .. and it was sold as the "Trackson Shovel option".
Soon after, Trackson produced the T4, fitted to the D4 .. then followed with models for every other Cat, up to D7 size. By 1946, the model range was T2 (D2), T4 (D4), T6 (D6) and the T7 (D7).
The cable Trackson loaders on Cat crawlers were built by the Trackson Co, from early 1938 to December 1951, when Cat bought the Trackson Co., lock, stock and barrel. By the mid 1940's, Trackson merely called all their loader range, just Traxcavators (from "tractor excavator").
Upon purchase, the Trackson loaders were gradually renamed Caterpillars (although the Traxcavator nameplates remained for a year or two) .. and the cable Tracksons were rapidly phased out, in favour of the hydraulic Traxcavators (Trackson had produced the all-hydraulic HT4 in 1950 - and it sold alongside the cable Tracksons loaders, for over 2 years, before the cable Trackson production ceased). The hydraulic HT4 Traxcavator was designed by both Trackson and Caterpillar engineers, in a co-operative effort, that commenced in 1948.
The No.6 Shovel, released in early 1953, was Cat's first all-new, totally-Caterpillar-designed, hydraulic traxcavator .. and the No.6 sold along with the HT4 up to early 1955, when the 933, the 955 and the 977 appeared on the scene. The release of the No.6 Shovel saw the end of production of cable Traxcavators.
I have a 1951 Trackson Co, 12-page brochure, which displays ALL the Traxcavator models at work. In this brochure, there are shown, no less than SEVEN, T7's .. at various worksites .. in states ranging from CA, KS, CO, IL .. to even Venezuela!
Once Caterpillar purchased Trackson, the T7 was given a Caterpillar S/N prefix of 34C .. and was built for almost another 2 years. I would not be in the least surprised to find that many hundreds of T7's were built .. but unfortunately, nowhere can I find production records of any of the Trackson cable loaders.