Michigan Elevating Scraper

Sept. 28, 2010
Michigan scrapers were initially sold in three basic sizes: models 110, 210 and 310 with 10-, 18- and 27-cubic-yard heaped capacities.

In the mid-1950s, before the advent of articulated dump trucks and before hydraulic excavators reached maturity, scrapers were one of the most popular ways to move earth over mid-range distances. Clark Equipment Co., with its famous Michigan-brand wheel loaders established since 1954, launched its first motor scrapers in 1957.

The Michigan scrapers competed for a share of the rapidly expanding scraper market dominated by the likes of Caterpillar, Euclid and Wabco, who themselves had only seriously been in the motor-scraper market for less than a decade. Designed in-house, the scrapers were initially sold in three basic sizes: models 110, 210 and 310 with 10-, 18- and 27-cubic-yard heaped capacities. Except for an unsuccessful larger 410 model (heaped capacity of 44 cubic yards) sold between 1964 and 1970, Clark-Michigan's subsequent upgraded models and new introductions through the 1960s and 1970s were derivatives or variations from these three basic models.

In the 1960s, elevating scrapers became popular, although they had been around since the mid-1950s. Clark-Michigan introduced its first elevating scraper in 1965 by attaching one of its prime movers to a scraper designed and built by Hancock Manufacturing, a pioneer of this type of machine. The following year, Clark purchased Hancock and subsequently developed elevating versions for its entire Michigan scraper line.

The Michigan 110-15 was a 15-yard-capacity elevating scraper based on the 110 tractor furnished with a 225-flywheel-horsepower GM 6V-71T engine. The Michigan drive train included a single-stage torque converter with lockup and power-shift transmission giving nine forward and two reverse speeds. A top speed of 32 mph was quoted. The tractor unit featured the Michigan "Hydra-ride" suspension system installed between the drive axle and the tractor frame to isolate the driver from rough ground conditions. It consisted of a hydraulic cylinder mounted above each front wheel assembly with controlled pressure to absorb shocks. With a full rated load of 36,000 pounds, the tractor-scraper unit tipped the scales at 82,360 pounds.

The 110-15 elevator was driven by a hydrostatic motor positioned at the lower end of the elevator just above the cutting edge. It drove both sides of the elevator chains through a planetary axle, and allowed the operator to select the most appropriate speed to suit the material being excavated. Positioning the elevator drive closest to the ground where digging resistance is greatest helped to prolong the life of the drive chains and sprockets.

In 1981, Clark-Michigan discontinued its scraper production because of dwindling sales and concentrated on its line of wheel loaders. Then in 1985, Clark-Michigan became part of the Swedish-led VME (Volvo Michigan Euclid) Group N.V. Gradually, the Michigan loader models were phased out or merged into Volvo's Swedish-designed L-series loader line. Finally the Michigan name disappeared after a reign of more than three decades.

Bureau of Public Roads Manuscript Collection, Idaho State Archives
Knox Yellow road scraper.
Caterpillar image, Maier-Dailey Papers, HCEA Archives
On a road job near Galva, Illinois, in September, 1938, a Cat D4 with a High Loader is spreading fill, plus towing a disc and a pneumatic roller. It also ditched, placed pipe, and cleared brush. The machine handled excavation as well, including overburden, gravel, and earth and rock cuts.