Page 426 - Peterson 85 Years and Going Strong

The PK-MK Siamese Twin for Garrison Dam contract circa 1951
collaborated on it together. The October 1952 is- sue of the eM-Kayan discussed the experimental HD38 at Garrison Dam in North Dakota. “For- ty-seven Allis-Chalmers tractors, including three ‘Siamese’ (two HD-19s joined side-by-side), are on the job. With this mighty fleet, PK-MK [Peter Kiewit and Morrison-Knudsen] last month was placing an average of 80,000 yards of earth daily on the fourth-stage section of the embankment. Nearly a third of the 18-million cubic yards of fill had been placed.”9
A single set of controls operates both machines. Peter Kiewit and Morrison-Knudsen—contrac- tors at Garrison Dam—are using the experimental model, one of the first of its kind. The twin HD-19 is appropriately called the HD-38.”10
A 1950s Allis-Chalmers film called The Big Job claims that PK-MK mechanics built the HD-38 Siamese Twins in their own on-site shop. “This Si- amese dozer is another world’s largest—built right on the job by Peter Kiewit and Morrison-Knudsen maintenance personnel. The blade on this giant is 20-feet wide and nearly 4-feet high and is pushed by two 20-ton tractors connected into one mighty power unit operated by one man. It levels off the fill in one pass.”11
As a pilot, Buster Peterson often flew to remote construction sites to confer with contractors. His son, Don Peterson, remembers such trips back to the Midwest as a youngster, but just faintly. It is believed that Buster conferred with MK-PK over their Twin up at the Garrison Dam site in North Dakota. However, the only documentation is a photograph of their Siamese Twin on-site, imprinted with a “Peterson Tractor & Equipment Co.” stamp on the front, found in Peterson’s ar- chives.
COAL TWIN–PART ONE (1950)
For years, the Coal Twin was believed to be Bust- er’s second build. And while it left many memories in its wake, it is not recorded in Peterson’s SEQ logbook. Like the Hungry Horse Twin, it too was assembled by another Cat dealer closer to its final destination, using conversion parts and blueprints supplied by Peterson. An article in Construction Equipment explains (see top of next page).12
The Coal Twin at Tanners Creek Power Plant circa 1952
A Bismarck, North Dakota, newspaper also cited the experimental use of the Siamese tractor, which “consists of two Allis-Chalmers HD-19 trac- tors fastened together and running on two tracks.
9 “Garrison Dam Booms Under Fourth Stage Construction”, The eM-Kayan, October 1952, p12-14.
10 “Siamese Twin Experimentally in Use at Garrison Dam”, The Bismarck Tribune, May 26, 1951, p8.
11 “The Big Job–An Allis Chalmers Job”, Allis-Chalmers film, 1950s, published on YouTube, 04:57–05:22 minute mark. 12 “Heavy Work Unit Combines Record-Size Bulldozer and Twin D8”, Construction Equipment, February 1951, p11.
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