THE IMPACT OF DISRUPTIVE HYDRAULICS TECHNOLOGY
The next major technological change precipitated widespread failure in the industry. Beginning shortly
after World War II and continuing through the late 1960s, while the dominant source of power
remained the diesel engine, a new mechanism emerged for extending and lifting the bucket:
hydraulically actuated systems replaced the cable-actuated systems. Only four of the thirty or so
established manufacturers of cable-actuated equipment in business in the 1950s (Insley, Koehring,
Little Giant, and Link Belt) had successfully transformed themselves into sustainable hydraulic
excavator manufacturers by the 1970s. A few others survived by withdrawing into making such
equipment as huge, cable-actuated draglines for strip mining and dredging.
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Most of the others failed.
The firms that overran the excavation equipment industry at this point were all entrants into the
hydraulics generation: J. I. Case, John Deere, Drott, Ford, J. C. Bamford, Poclain, International
Harvester, Caterpillar, O & K, Demag, Leibherr, Komatsu, and Hitachi.
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Why did this happen?
Performance Demanded in the Mechanical Excavator Market
Excavators are one of many types of earthmoving equipment. Some equipment, such as bulldozers,
loaders, graders, and scrapers, essentially push, smooth, and lift earth. Excavators
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have been used to
dig holes and trenches, primarily in three markets: first and largest, the general excavation market,
composed of contractors who dig holes for basements or civil engineering projects such as canal
construction; second, sewer and piping contractors, who generally dig long trenches; and third, open pit
or strip mining. In each of these markets, contractors have tended to measure the functionality of
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mechanical excavators by their reach or extension distance and by the cubic yards of earth lifted in a
single scoop.
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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.
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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,
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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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Because their capacity was so small and their reach so short, hydraulic excavators were of no use to
mining, general excavation, or sewer contractors, who were demanding machines with buckets that
held 1 to 4 cubic yards. As a result, the entrant firms had to develop a new application for their
products. They began to sell their excavators as attachments for the back of small industrial and farm
tractors made by Ford, J. I. Case, John Deere, International Harvester, and Massey Ferguson. Small
residential contractors purchased these units to dig narrow ditches from water and sewer lines in the
street to the foundations of houses under construction. These very small jobs had never warranted the
expense or time required to bring in a big, imprecise, cable-actuated, track-driven shovel, so the
trenches had always been dug by hand. Hydraulic backhoes attached to highly mobile tractors could do
these jobs in less than an hour per house, and they became extremely popular with contractors building
large tract subdivisions during the housing booms that followed World War II and the Korean War.
These early backhoes were sold through tractor and implement dealerships accustomed to dealing with
small customers.
The early users of hydraulic excavators were, in a word, very different from the mainstream customers
of the cable shovel manufacturers—in size, in needs, and in the distribution channels through which
they bought. They constituted a new value network for mechanical excavation. Interestingly, just as the
performance of smaller-architecture disk drives was measured in different metrics than the performance
of large drives (weight, ruggedness, and power consumption versus capacity and speed), the
performance of the first backhoes was measured differently from the performance of cable-actuated
equipment. The metrics featured most prominently in early product literature of hydraulic backhoes
were shovel width (contractors wanted to dig narrow, shallow trenches) and the speed and
maneuverability of the tractor. Figure 3.4, excerpted from an early product brochure from Sherman
Products for its “Bobcat” hydraulic backhoe, illustrates this. Sherman called its Bobcat a “digger,”
showed it operating in tight quarters, and claimed it could travel over sod with minimum damage. The
Bobcat was mounted on a Ford tractor. (Ford subsequently acquired the Sherman Bobcat line.) The
featured attributes, of course, were simply irrelevant to contractors whose bread was buttered by big
earthmoving projects. These differences in the rank-ordering of performance attributes defined the
boundaries of the industry’s value networks.
Figure 3.4 Hydraulic Backhoe Manufactured by Sherman Products
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Source: Brochure from Sherman Products, Inc., Royal Oak, Michigan, early 1950s.
The solid line in Figure 3.3 charts the rate of improvement in bucket size that hydraulics engineers
were able to provide in the new excavator architecture. The maximum available bucket size had
reached 3/8 cubic yard by 1955, 1/2 cubic yard by 1960, and 2 cubic yards by 1965. By 1974, the
largest hydraulic excavators had the muscle to lift 10 cubic yards. This trajectory of improvement,
which was far more rapid than the rate of improvement demanded in any of the excavator markets,
carried this disruptive hydraulics technology upward from its original market through the large,
mainstream excavation markets. The use of hydraulic excavators in general contracting markets was
given a boost in 1954 when another entrant firm in Germany, Demag, introduced a track-mounted
model that could rotate on its base a full 360 degrees.
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