The_Innovators_Dilemma__Clayton

mechanical excavators by their reach or extension distance and by the cubic yards of earth lifted in a
single scoop. 8
In 1945, sewer and piping contractors used machines whose bucket capacity averaged about 1 cubic
yard (best for digging relatively narrow trenches), while the average general excavation contractor used
excavators that hefted 2 1/2 cubic yards per scoop and mining contractors used shovels holding about 5
cubic yards. The average bucket capacity used in each of these markets increased at about 4 percent per
year, a rate of increase constrained by other factors in the broader system-of-use. The logistical
problems of transporting large machines into and out of typical construction sites, for example, helped
limit the rate of increase demanded by contractors.
The Emergence and Trajectory of Improvement of Hydraulic Excavation
The first hydraulic excavator was developed by a British company, J. C. Bamford, in 1947. Similar
products then emerged simultaneously in several American companies in the late 1940s, among them,
the Henry Company, of Topeka, Kansas, and Sherman Products, Inc., of Royal Oak, Michigan. The
approach was labeled “Hydraulically Operated Power Take-Off,” yielding an acronym that became the
name of the third entrant to hydraulic excavating in the late 1940s, HOPTO. 9
Their machines were called backhoes because they were mounted on the back of industrial or farm
tractors. Backhoes excavated by extending the shovel out, pushing it down into the earth, 10 curling or
articulating the shovel under the slice of earth, and lifting it up out of the hole. Limited by the power
and strength of available hydraulic pumps’ seals, the capacity of these early machines was a mere 1/4
cubic yard, as graphed in Figure 3.3. Their reach was also limited to about six feet. Whereas the best
cable excavators could rotate a full 360 degrees on their track base, the most flexible backhoes could
rotate only 180 degrees.
Figure 3.3 Disruptive Impact of Hydraulics Technology in the Mechanical Excavator Market
Source: Data are from the Historical Construction Equipment Association.
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