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.
National Inventors Hall of Fame
Nihf Bobcat

Open-Top Concrete Transporters

April 24, 2024
These ready-mix predecessors could carry 1 to 2 cubic yards of concrete.

Concrete has been carried from where it is mixed to where it is poured by many means and for millennia. Early forms of transport included hand-carried hods, wheelbarrows, horse- or mule-drawn carts and wagons, and narrow-gauge railroad cars. 

The development of the motor truck in the first part of the 20th century soon led to their use as concrete carriers. The earliest versions were buckets and small dump bodies mounted on trailers or on the truck’s chassis. Capacities were in the 1- to 2-yard range. T.L. Smith had entered the mixer business in 1900 and by 1930 had an extensive line of stationary models and wheeled and tracked portable mixers and dry-batch pavers. Blaw-Knox entered the market by acquiring A.W. French, with its large line of stationary and portable mixers, in 1929.

In the late 1920s and early ’30s, Blaw-Knox, T.L. Smith, and others offered truck-mounted, open-top mixers with fan-type agitators powered either from the truck’s engine or from a separate small engine. These were discharged by tilting like a dump box, and scissors-lift risers offered by Heil and Anthony could be added to elevate the discharge point. By the late 1930s, the open-top mixer was replaced by the more efficient closed-drum transit mixer that could mix a dry batch enroute. Moreover, dry-batch pavers, developed in 1919, streamlined concrete production at the paving site and rendered these transporters largely obsolete.  

About the HCEA

The Historical Construction Equipment Association (HCEA) is a 501(c )3 nonprofit organization dedicated to preserving the history of the construction, dredging and surface mining equipment industries. With over 3,500 members in a dozen countries, our activities include operation of National Construction Equipment Museum and archives in Bowling Green, Ohio; publication of a quarterly magazine, Equipment Echoes, from which this text is adapted, and hosting an annual working exhibition of restored construction equipment. Individual annual memberships are $45 within the U.S. and Canada, and $65 elsewhere. Our next International Convention and Old Equipment Exposition will be August 7-10, 2024, in Canandaigua, New York. We seek to develop relationships in the equipment manufacturing industry, and we offer a college scholarship for engineering students. Information is available at www.hcea.net, or by calling 419-352-5616 or e-mailing [email protected]