Digging Up the Past

Peterson's Offset D8 Pipelayer

In the early 40’s, Peterson’s Special Services Shop (SEQ – Today’s Fab Shop), began designing customized equipment for its customers. Several of those designs put Peterson “on the map” in the heavy equipment industry and helped carve a reputation that still stands today. One of the early design successes was the Offset D8 Pipelayer designed for Bechtel’s Super Inch Pipeline project in 1949.

The $150 million, 1,600-mile project stretched from Texas to San Francisco with the largest gauge pipeline used to that point – 34” diameter. The California portion of the giant pipeline posed a serious tippage problem for the contractor’s fleet of D8 pipelayers. Peterson’s SEQ shop stepped in with a solution. The design entailed offsetting the left-hand track 53 inches from the centerline, a 20-foot boom and 10,000 lbs. of hydraulically adjustable opposable counterweight.

A special Cat report called “Performance Data” - dated March 20, 1950 - described the machine onsite: “The world’s largest natural gas pipeline (34” dia.) required more lifting capacity from Cat tractors, equipped with Trackson Pipe Layers, than the standard D8 was capable of lifting. As a result, the “Caterpillar” Offset D9 Tractor was designed and placed on the job. Although it was designed and produced in less than 30 days, it has had no downtime in over 400 hours of rugged work.”

According to the November 1950 issue of Western Construction Magazine, “... Peterson Tractor & Equipment Co, designed, prepared drawings and submitted an estimated cost for offsetting a single track to raise the tipping, or maximum working capacity to 82,000 lb. Upon authorization from the contractor, one such machine was built and placed in operation two weeks later. After the first tests, the contract authorized the Peterson firm to widen seven more of the contractor’s own D8 tractors, and finally three more for a total of eleven.” Patent rights were filed in November 1949, granted in July 1955, and subsequently purchased by Caterpillar and added to Cat’s product line.

The Super Inch Pipeline was built between
California & Texas using offset D8 Pipelayers
Peterson designed specifically for
Bechtel 's $150 million contract

The D9 version of Peterson's Offset D8 Pipelayer,
which was patented in July 1955, subsequently
bought by Caterpillar and added to their product line