Rock Products 120th Anniversary – Part 5

26 120YEARS 150


In This Issue, We Cover The Years 1940-1949.

26 120YEARS 400In 1939, German troops entered Poland to begin a string of seemingly unstoppable invasions that extended German Dictator Adolph Hitler’s control over much of eastern and western Europe. It was the start of World War II.

By the end of 1940, Denmark, Norway, Holland, Belgium and France were under Nazi control, and Italy and Japan had joined with Germany in the Axis alliance. Throughout 1941, German forces continued their march, invading Yugoslavia, Greece, the Soviet Union, and North Africa, and blitzed Britain with nighttime bombing of London.

34 120 400But mirroring the United States’ official neutrality, throughout 1939 and most of 1940, the European war was rarely mentioned in Rock Products. Residential construction was increasing in the U.S. and the Pennsylvania Turnpike, “America’s greatest single achievement in concrete highway construction,” neared completion after only 21 months. The turnpike required more than 2 million bbls of portland cement, 1.4 million tons of crushed stone and 844,000 tons of natural sand.

Following record aggregate production in 1939 – the highest level since 1929 – discussions at the 1940 National Sand and Gravel Association (NSGA) annual conventions focused on the need for a $50 billion project to build 25,000 miles of superhighways during the next 20 years. “We must put a stop to the present diversion of highway building funds,” said Paul Hoffman, president, Studebaker Corp., at the NSGA meeting. “If this were done, we could finance this huge project from present revenues derived directly and indirectly from motor-driven vehicles.”




Crushed Stone

Sand & Gravel














































Source: US Geological Survey   million short tons

Aggregate producers faced concerns about quality, particularly particle shape, chert content of gravels, and sand specifications. Impact crushers were gaining popularity as a method to obtain a more cubical particle shape and generally improve quality. Stockpile storage was mentioned as a way to eliminate undesirable material. Some hard cherts, it was noted, would soften and disintegrate when exposed to the weather for a considerable time.

Tighter sand specifications called for increased fines content, requiring more controlled classification and often blending fine sand from another source or manufacturing sand. Previously used only experimentally, the Pennsylvania Department of Highways reported use of 13,000 tons of manufactured limestone sand for concrete pavements. Some plants were built to split sand into three or four fractions that were then recombined. One producer “equipped his plant to produce as much as 7 percent, minus-100-mesh sand and 4 percent through the 200 mesh,” Rock Products reported. “He is probably being foresighted in anticipating a further trend in the direction of more fines by government engineers.”

Equipment Issues

35 120 300In quarries during this time, most loading at the face continued to be done with cable shovels, typically in the 1-to-3-cu.-yd. range. There was a pronounced trend toward use of larger hauling units such as trucks with rear- or side-dump trailers up to 12-cu.-yd. capacity. Rock Products reported that trucks used in a New York Trap Rock quarry in 1940 averaged 3.46 mpg. In some operations, barney cars, small push carts attached to cable systems, assisted trucks up grades as steep as 22 percent.

The Osgood Co. introduced a shovel with air-controlled hoist and crowd functions. One of the larger pieces of equipment reported in use was an 8-cu.-yd. walking dragline commissioned for stripping by Carbon Limestone Co., Hillsville, Pa. The unit weighed 910,000 lb. and had a 200-ft.-long boom and 125-hp swing motor.

Michigan Limestone & Chemical Co., a subsidiary of U.S. Steel, operated what was called the largest quarry in the world at Calcite, Mich. The world’s largest cement plant, Kaiser’s Permanente, Calif., facility, fired up and began grinding clinker in December 1939.

Cement producers faced several challenges during the early 1940s. New ASTM specifications defined five types of cement that producers needed to manufacture, store and ship. Although cement production increased 8 percent in 1940 to about 132 million bbls, this represented only about half the U.S. industry’s capacity. It was not unusual for a cement plant to temporarily suspend production in the middle of the year because of a lack of storage capacity for five types of cement.

New Cement Era

Rock Products called the period a “new cement era” in which “cement manufacture is becoming a more scientifically controlled industry – a unique scientific industry in that both users and manufacturers are still pretty much in the dark as to just what the product really is, or how it should be made.”

Cement producers paid greater attention to proportioning raw materials and controlling kilns through synchronizing raw material feed and firing. Progress was made in use of froth flotation to vary proportions of minerals in the limestone and clay, especially to concentrate silica to improve the silica-aluminum ratio in order to make high-silica cement. Other trends included greater use of dust collectors, air-quenching clinker coolers, and all-welded kilns. Pre-heaters were in development.

36 120 400By the fall of 1940, impending U.S. involvement in an escalating war was evident. Although the United States did not officially enter the war until Japan bombed Pearl Harbor in December 1941, the country began early to prepare its defense infrastructure. As a result, U.S. rock products operations set and broke production records in 1940 and 1941, reaching a peak of 497 million tons of aggregate in 1942. National Defense highway construction was expected to involve 3,112 miles of access roads at a cost of $212 million.

As a result of construction expenditures for national defense projects, which began increasing from late 1940 into 1941, Rock Products estimated the aggregates and cement industries would receive $300 million business. Defense construction accounted for 44 percent of all building in the United States in 1941 and was expected to increase to 75 percent in 1942. At the same time a government order barred all non-essential construction because of shortages of metals such as steel, lead and copper. Supplies of cement, aggregates, lime and gypsum, however, were adequate and available for building foundations and constructing roads, particularly around the nation’s busy industrial centers.

World War II: 1942-1945

Following Japan’s attack on Pearl Harbor and the United States’ entry into the war, U.S. forces geared up for initial action in the Pacific and North Africa. Defense infrastructure construction came to a standstill, lacking both materials and manpower.

As a result, aggregate production dropped more than 30 percent from a record 497 million tons in 1942 to 344 million tons in 1945. Cement production dropped 50 percent during the same period, from a record 34 million tons in 1942 to about 17 million tons in 1944, recovering to 19 million tons in 1945.

But demand for cement, aggregate and other rock products was spotty. More than 93 million sq. yd. of concrete airport pavement were built in 1942, according to the Portland Cement Association. That was more than twice as much as was used for all streets, roads and alleys combined. Producers fortunate to be close to defense projects or those quarrying limestone for steel production continued to be busy. Many others shut down.

Quarry in Missouri in 1949
Activity Cost per ton
Stripping, drilling, shooting and pumping $0.176
Pit loading and hauling $0.458
Processing and Stockpiling $0.224
Administration $0.252
Depreciation $0.252
Total $1.312
Source: USGS million short tons

“The president has the power to close any plant he deems not contributing to the war effort,” Rock Products reported, “and has the power to denude it of machinery and equipment over to an operator who is contributing to the war effort, provided fair compensation is given the owners of the closed plant.”

Operating plants faced a challenge maintaining equipment due to a lack of materials. Sand and gravel production in particular had a difficult time because unless they were located close to a defense project, they were not considered important enough to receive parts. Rock Products noted that, because of deferred maintenance and shut-down plants, substantial rehabilitation would be required after the war. “There is reason to believe there will be more new equipment purchased by this industry after the war because of obsolescence than because it is worn out.”
Besides equipment shortages, employee turnover as great as 300 percent, due to the selective service, hampered operations. A shortage of skilled shovel and crane operators was particularly acute in the rock products industry because contractors working on defense construction projects offered better wages.

After celebrating its 25th anniversary early in 1942, the NSGA cancelled its annual conventions during the war years in response to a call from the director of the Office of Defense Transportation to conserve transportation resources. The NSGA and National Ready Mixed Concrete Associations held their conventions in 1943 and 1944 but cancelled them in 1945. They defended the meetings as a “war industry conference to take stock of how our industry has performed in the war effort so far, what we can do further to assist in winning the war, and what our part shall be in the program of reconstruction that must follow.”

In 1945, the Office of Defense Transportation placed strict controls on trade, professional and industry conventions involving more than 50 people, requiring applications to hold meetings. Many applications were turned down.

Japanese and German defeats in the Pacific as well as in Europe began to mount in 1943. And, although the United States was still deeply entrenched in war, focus in the rock products industry turned to post-war markets. “Now is the time for stock-taking of rock products production and processing methods,” wrote a Rock Products editor, “and for intelligent, readable discussions of how they may be improved to meet the coming post-war period when producers and manufacturers will need all the technical assistance they can obtain to rehabilitate their plants for a period of fierce competition.”

At the 1944 NSGA convention, speakers urged producers to “keep their equipment in good repair and maintain a reasonable reserve of finished materials in stock in anticipation of a sudden construction revival.” Producers also were encouraged to take an active part in post-war planning for construction, working with local and state planning committees.

New Highway Bill

Late in 1945, as Allied forces pushed closer to a final assault on Germany, President Roosevelt signed a post-war highway bill, authorizing $1.6 billion in federal expenditures as part of a $3.2 billion, three-year program. States were required to fund 50 percent of projects in order to receive the money. In addition, pent-up demand for private construction awaited removal of government restrictions on use of labor and building materials.

38 120 400A New England producer predicted, “The crushed stone industry will have as a major problem the ability to meet demands which will probably exceed anything we have ever known. If the existing manufacturers of stone do not take care of their market, we may see an era of additional plants which will mean the ruination of the market after the federal spending boom is over.”

A Rock Products survey indicated the construction boom was not easy. The war affected equipment manufacturers as well as cement and aggregate producers. Few new mining and processing products were developed in 1942 and 1943 because many manufacturing plants were converted to production of war materials. Some manufacturers, however, had new designs on the drafting board waiting for the end of the war. Other manufacturers had supplied new aggregate-processing equipment for the war effort.

Cedarapids, for example, developed its Commander Series portable crushing and screening plants and supplied 852 of the plants to the U.S. military, particularly for Corp. of Engineers operations throughout the Pacific. The single-chassis plants combined a 30-in. reciprocating feeder, 4- x 10-ft. horizontal vibrating screen, 10- x 36-in. jaw crusher, and 30- x 22-in. roll crusher. An elevating wheel returned crushed stone to the screen to close the circuit.

Unavailability of new equipment and parts for civilian operations during the war years provided one benefit, the industry developed a greater awareness of maintenance problems and machinery life. Many plants underwent a life-expectancy test that highlighted design weaknesses.

Nevertheless, rising fuel costs and shortages forced cement producers to focus on advancements in firing controls. Cement plants began using more automatic controls and recording devices, such as optical pyrometers; automatic temperature-recording devices; and automatic air-damper, kiln-speed and coal-feed regulators. Large government defense projects increased the use of bulk rather than bagged cement to meet concrete production requirements. This drove development of bulk-handling methods, including pneumatic conveying.

Adapting to Peace: 1946-1949

In May 1945, Germany officially surrendered, ending the war in Europe. Less than four months later, following the dropping of atomic bombs on Hiroshima and Nagasaki, Japan surrendered.

By December 1945, the U.S. government lifted many wartime restrictions and gave the go-ahead for post-war highway construction. Quarry, sand and gravel pit, and cement plant restarts, acquisitions and expansion plans filled Rock Products’ new pages. A story on beautifying an abandoned quarry aptly reflected the nation’s changing focus from war to peace.

Return to a peacetime economy offered significant growth opportunities for the rock products industry; but not without problems. In 1946, aggregate and cement production increased pre-war levels, up 24 percent and 60 percent, respectively, over 1945’s production. Double-digit annual growth rates continued through 1948 before a slight fallback in 1949.

Residential construction, driven by housing shortages, and a rapid industrial expansion created most of the demand for non-metallic minerals immediately after the war. To supply steel mills operating at record levels, 40 self-unloading vessels operated on the Great Lakes, shipping limestone from northern lake ports. Furthermore, as residential and industrial construction peaked, highway construction began increasing.

As a result, demand for aggregates, cement and lime during the first two or three years following the war out-paced production capacity in many areas of the country, often leading to shortages. Efforts to update plants that suffered neglect during the war and to expand capacity were hampered initially by machinery shortages and then later by labor strikes that affected part availability and quality. Many producers put surplus used military equipment to work in their operations.

In addition, rail transport of products, the primary method of shipping aggregate, cement, and other non-metallic minerals, suffered from a shortage of freight cars. This forced some lime plants to suspend production for days at a time even though they had large back orders. One cement company in the eastern United States requested 20 railcars per day but received only two.

40 120 400The cement industry also was adversely affected by a Supreme Court ruling in 1948 that declared that the industry’s basing point system of pricing cement was illegal. Under the basing point system, cement companies often paid a part of the product’s transportation cost in order to be more competitive with cement producers closer to the customer. The court ruling required cement companies to adopt new pricing methods based on prices at the plant, charging the full cost of shipping.

Shipping and Labor

Although the industry’s shipping problems eased slightly as more railcars were built, it was too little, too late. By 1949, railcar shortages and high freight rates had spurred new competition for hauling bulk materials in many areas: trucks. This marked the beginning of the decline in rail shipment of aggregates and cement.

Following the war, producers anxiously welcomed back veterans to re-staff operations. But as in many industries at this time, labor union influence grew, sparking strikes with demands for higher wages and extensive benefits. A strike by 6,000 cement mill workers in the Northeast affected 33 mills and brought construction work in New York City to a halt.

A Rock Products survey indicated that labor costs increased 40 percent from 1940 to 1946. Plant modernization was the industry’s response to keep the wage contribution to total costs in line. “With cost reduction as an attainable goal,” wrote an editor, “there is little wonder that all the shortages, delays in securing equipment, and high prices have not discouraged the progressive operator’s plans to carry through plant rehabilitation programs.”
Greater production requirements, upward spiraling labor costs, and stricter adherence to construction material specifications, which had grown lax during the war, contributed significantly to the rapid development and application of new mining and processing technology in the products industry in the late 1940s. There was an increase in the use of primary surge piles and feeders to smooth out plant flow as well as use of conveyors to transport material between successive crushers and screens.

Many new portable plant configurations for gravel and crushed stone were developed by Pioneer Engineering Works, Universal Engineering, Lippman Engineering, Diamond Iron Works, Iowa Manufacturing and New Holland Manufacturing as highway work in remote areas increased. In fact, the 600,000 tons of asphalt and concrete aggregates required for the largest highway job in 1947, the Maine Turnpike, were produced entirely by four portable plants.

41 120 400Jaw crushers gained popularity over gyratory crushers as use of rolled steel plate and welded construction lowered their weight. Incorporating ball and roller bearings into jaw crushers sped up operation by 50 percent. Curved jaw plates also helped decrease choking. Lippman Engineering Works completed what was claimed to be the largest overhead eccentric jaw crusher: a 36- x 48-in. unit with a hard rock capacity of 210 tph at a 3-in. discharge opening. The crusher was about 11-ft. high and weighed 84,000 lb.; the movable jaw was 10-ft, 10-in. high and weighed 35,000 lb.

Allis-Chalmers introduced an automatic reset on its Type R crushers to move the crushing head back into position after passing tramp iron or other unbreakable material. Nordberg introduced a 22-in. Symons cone crusher mounted with electric motor or diesel or gas engine on a skid, which was transportable by truck. Crushing capacity was 20 tph at a ½-in. closed-side setting (css) to 60 tph at a 1 ½ -in. css.

Larger-capacity loading and hauling units were needed to keep pace with new crushing installations. In the early to mid-1940s, Koehring Dumpsters were popular. Looking somewhat like overgrown wheel barrows with four wheels, these 6-cu.-yd. units allowed the operator to five backwards looking over the dump bed, thus eliminating turnaround time. Larger-capacity haul trucks, about 20 tons, usually comprised a tractor pulling a bottom-end-, or side-dump wagon that often used an overhead hook and cable at the crusher to tip the bed up.

Manufacturers met the industry’s need by building larger, more powerful rigid-frame trucks. In 1947, Euclid advertised its Model T 22-ton-capacity haul truck with a 225-to-275-hp Cummins diesel engine.

Most quarry and sand and gravel pit operations used cable shovels, dragline and clamshell cranes as primary loading tools. But Frank G. Hough, who had developed a ½-cu.-yd., 35-hp wheel loader in 1939, introduced larger machines in the mid-1940s. After that, many lines of “tractor shovels” manufactured by almost a dozen companies hit the market, revolutionizing loading methods in the industry.

42 120 400Larger-capacity trucks in quarries created a need for more efficient drilling, blasting and secondary breaking techniques. Many operations used churn drills or wagon drills – a pneumatic drill mounted on a single-axle frame that had to be towed to where it was needed. The units required separate air compressors.

In 1948, Ingersoll-Rand introduced its Quarrymaster self-propelled drill. The single-chassis unit combined a compressor; an air-powered, piston-type drill with automatic bit rotation; and tracks powered by air motors. It was capable of drilling large diameter holes quickly.

Kingston Trap Rock Co. in New Jersey experimented with a jet-piercing drill that had been developed for mining taconite in Minnesota. The drill used a high-velocity, oxygen-hydrocarbon fuel flame that caused the rock to spall. Water used for cooling turned to steam and carried cutting out of the hole. While a conventional churn drill could penetrate the rock at 1 to 2 ft. per hour, the jet-piercing drill managed 15 to 20 ft. per hour, using 2,200 to 3,000 cu. ft. of oxygen and 12 gal. of kerosene per hour and 420 gpm water.

Superior Stone reportedly used the first rotary drill in the rock products industry in 1947 at its Kings Mountain, N.C., limestone quarry. Using a tri-cone bit, the Joy Manufacturing rig penetrated 12 ft. per hour; churn drills penetrated the limestone about 4 ft. per hour.

To improve detonation of larger blasts, DuPont advertised in 1947 an electric blasting timer for short-period delay blasting with intervals of 0.01 to 0.04 sec. Atlas Powder also developed a “delayed action electrical blasting machine” the same year.
But not all changes in quarry operations were due to new technology. A hot topic of discussion at a NCSA meeting in 1946 was the use of drop balls for secondary breaking. The drop ball, used in the early 1900s, was abandoned with the development of pneumatic drilling tools, which permitted secondary blasting of large boulders. But besides being dangerous, secondary blasting was manpower intensive. One producer replaced a nine-man secondary blasting crew – six jackhammer operators, a blaster, a handler and a blacksmith – with one man with a crane and drop ball.

A New Chapter

Rock Products described the era as “the start of a new chapter in the scientific development of cement manufacture.” High fuel costs encouraged the use of long (greater than 300 ft.) rotary kilns. Raw materials were being ground to 90 percent to 95 percent, passing the 200 mesh and faster kiln rotation speeds were applied: 75 to as great as 100 rotations per hour.

In early 1947, Lawrence Portland Cement fired up two 9- x 14-ft., dry-process kilns claimed to be the longest kilns in use in the United States “and probably anywhere.” Each kiln produced 1,500 to 1,600 bbls per day, consuming 65 lb. of 13,500-Btu coal per barrel. But by mid-1948, Riverside Cement broke the record with three, 350-ft.-long dry-process kilns. Each kiln produced 2,200 bbls per day consuming 1 million Btu per barrel.

42 120.2 400As the 1940s came to a close in the United States, manufacturers had recovered from the disruption of World War II; workers were enjoying a higher standard of living; the first digital computer and the transistor had been invented, although not practically applied; and attention was starting to focus on the need for improved transportation systems, particularly highways. But inflation and increasing unemployment threatened to slow continued progress.
Although spending for public construction saw double-digit increases each year and highway spending reached record amounts, the actual volume of work in 1948 was only 55 percent of that accomplished during the pre-war, peak road-construction period of 1930 and 1931. The Public Roads Administration reported, “60 percent” of the improved mileage now on the federal aid primary system will wear out within the next 10 years. The entire field of highway transportation needs to be re-analyzed in view of the present inability to keep pace with new demands for service.”

Rep. Staggers (W.Va.) introduced a bill to start federal construction of a $12 million superhighway network comprising a two-lane highway network comprising a two-lane highway on a 450-ft. right-of-way from San Francisco to Boston; New York to Florida; the Great Lakes to Florida; and Laredo, Texas, to Canada. But the country – and the rock products to industry – would have to wait almost another decade before such a project, on a much grander scale, would begin to solve transportation problems. 

Next Month: Rapid Growth in the 1950s. 

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