History

1900s

1900 - 1909

The company gets its start based on a simple idea: offer efficiency and consulting reports to manufacturers, the result of which would be comprehensive betterment reports that reveal how companies can increase productivity through the application of advanced technology.

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1901

The company is founded in Philadelphia when Charles Day, a young engineer, joins in a consulting partnership with Kern Dodge.  The firm is called Dodge & Day.

The company is founded in Philadelphia when Charles Day, a young engineer, joins in a consulting partnership with Kern Dodge.

1905

Dodge & Day add an architectural department and enlarge the company's construction workforce.  Moving beyond pur consultation work, Dodge & Day assume more direct responsibility for construction and moderniation projects.

Dodge & Day add an architectural department and enlarge the company's construction workforce

1907

John Zimmermann, a former classmate of Charles Day joins the company, bringing with him significant financial capabilities and business relationships.

1908

During the building of the Gatun Lock system in the Panama Canal, Dodge & Day attract considerable attention in the construction industry when they break the world record for hauling concrete. 

During the building of the Gatun Lock system in the Panama Canal, Dodge & Day attract considerable attention in the construction industry when they break the world record for hauling concrete

1909

John Zimmermann becomes an important behind-the-scenes influence, creating and maintaining relationships with large banking institutions, and leveraging extensive contacts with public utilities.  As a reflection of Zimmermann's growing importance, the company name is changed to Dodge, Day & Zimmermann.

1910s

1910 - 1919

By this time, Dodge, Day & Zimmermann would boast a client list of fifty, including influential and large companies, and a variety of work that spanned the industrial spectrum.  The company performed feasibility studies for banks, writing bettermant reports for industry, planning and overseeing plant construction for manufacturing companies, and managing power plants for public utilities.

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1911

Kern Dodge withdraws from the partnership and the company is renamed Day & Zimmermann.

Kern Dodge withdraws from the partnership and the company is renamed Day & Zimmermann

1914

Hershey Chocolate calls on Day & Zimmermann to design the foil wrapping machines for the company's famous Kisses.

Hershey Chocolate calls on Day & Zimmermann to design the foil wrapping machines for the company's famous Kisses.

1916

Day & Zimmermann begins construction on the Bensalem Bridge (Philadelphia) just before the U.S. entered World War I.  Though work was interrupted by the war, Day & Zimmermann completes the project in 1922.

Day & Zimmermann begins construction on the Bensalem Bridge (Philadelphia) just before the U.S. entered World War I.

1918

The war effort spurs a huge increase in business, including a contract to design and manage construction of a mammoth Quartermaster Terminal in Philadelphia. Built in six months, it was the largest project underaken up to that point.

The war effort spurs a huge increase in business, including a contract to design and manage construction of a mammoth Quartermaster Terminal in Philadelphia.

1920s

1920 - 1929

At twenty years old, Day & Zimmermann continued to be run by one of its founders and its chief visionary, and was still staffed by many of its earliest employees.  The company had evolved a culture that was close-knit, innovative, and based on Charles Day's standard of "99.9 percent effort" on every job.

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1921

TIn the company's 20th anniversary year it published an impressive financial record of its first two decades in business.  In the public utilities field it noted more than $75 million in managed properties, while the engineering reports division had produced industrial reports in 22 states and appraisals in 15 states.  Also in the first 20 years, the construction division had designed and managed construction for 40 plants with a total value of $40 million.

1926

One of Day & Zimmermann's largest revenue sources becomes the management of public utilities.  In 1926, the company takes over Penn Central Light & Power and the Municipal Services Company — umbrella organizations that link Day & Zimmermann's far-flung energy and rail interests.

In 1926 Day & Zimmermann takes over Penn Central Light & Power and the Municipal Services Company

1927

John Zimmermann negotiates to ally the company with the giant of Pennsylvania utilities, UGI, the United Gas Improvement Company of Philadelphia.  The public service and construction divisions of Day & Zimmermann would become outright divisions of UGI, while the industrial, engineering, investigations and reports divisions retained the Day & Zimmermann name.  The move marks the end of John Zimmermann's career at Day & Zimmermann, as he becomes president of UGI and would later be elected its chairman.

1928

Persistent health problems would prompt Charles Day to step down as president of Day & Zimmermann.  He is succeeded by W. Findlay Downs, one of the pioneers at Day & Zimmermann, who would retain his position as president until 1955.  One of his first moves is to join with Nicholas Roosevelt to buy back Day & Zimmermann — minues the utility businesses  from UGI.  Together they work to return to the company's roots of industrial engineering, analytical reports, and construction. 

Day & Zimmermann works to return to the company's roots of industrial engineering, analytical reports, and construction

1930s

1930 - 1939

Like most companies, Day & Zimmermann felt the effects of the Depression as engineering and construction work dropped off. The company relied on its consulting expertise, performing evaluations for banks and a variety of industrial clients.

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1936

Day & Zimmermann is hired, as part of sweeping public works programs, to build electric transmission lines for a massive project to bring electricity to the United States' rural areas.

Day & Zimmermann is hired, as part of sweeping public works programs, to build electric transmission lines for a massive project to bring electricity to the United States' rural areas.

1937

Day & Zimmermann is contracted to design a new kind of grocery store.  The resulting design for SafeWay is the first completely modern "supermarket" design, one that remained basically unchanged in the decades since.

1938

The company, which had been so involved with the military thorugh World War I, was an early and important contributor to the new war effort, facilitating industry's rapid shift toward defense production.

The company helped facilitate the industry's rapid shift towards defense production.

1940s

1940 - 1949

When war loomed once again, defense contracts began to pour through the economy. Throughout World War II, Day & Zimmermann played an important and direct role, building and managing ammunition plants thorughout the U.S.

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1940

What would become the Yoh Company was founded as Duncan Tool Design by a group of partners including Harold Yoh.

1941

Day & Zimmermann helps design and engineer the U.S. Marine Corp Depot of Supplies in Philadelphia.

Day & Zimmermann helps design and engineer the U.S. Marine Corp Depot of Supplies in Philadelphia.

1943

Day & Zimmermann engineers help design a steel plant in MonClova, Mexico.  The project relies exclusively on reclaimed and reconditioned parts from other plants, which were shipped to Mexico and reassembled.  The plant later launches the Altos Hornios Steel Corporation.

Day & Zimmermann engineers help design a steel plant in MonClova, Mexico.

1945

The Cressona Ordnance Plant in Cressona, Pennsylvania was originally built by Day & Zimmermann as an aluminum reclamation facility.

The Cressona Ordnance Plant in Cressona, Pennsylvania was originally built by Day & Zimmermann as an aluminum reclamation facility.

1946

Harold Yoh buys his partners out and changes Duncan Tool Design's name to the H.L. Yoh Company and begins to build a leading technical staffing company.

Harold Yoh buys his partners out and changes Duncan Tool Design's name to the H.L. Yoh Company and begins to build a leading technical staffing company

1949

Day & Zimmermann begins to see the effects of globalization as it takes on engineering and consulting projects in India, South Korea and other locations around the globe.

1950s

1950 - 1959

By the 1950's, Day & Zimmermann was operating throughout the United States, Canada, Europe, Asia, and Central and South America, and has grown steadily in reputation and expertise.  Day & Zimmermann's wide range of projects included work in engineering, construction, utilities consulting, valuations and appraisals, plant management and military work — an incredibly diverse blend.

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1951

Day & Zimmermann is awarded a contract with the army to manage Lone Star Army Ammunition Plant in Texarkana, Texas, a vast complex that sprawls over 16,000 acres with an impressive infrastructure of more than 900 separate buildings, 160 miles of roads and 40 miles of railroad track.

Day & Zimmermann is awarded a contract with the army to manage Lone Star Army Ammunition Plant in Texarkana, Texas.

1955

W. Findlay Downs announces his retirement.  Downs had run the company for more than twenty years, guiding Day & Zimmermann through the Depression, when the company scaled back drastically, then through the massive World War II buildup.  He remains chairman after his retirement.

1956

Day & Zimmermann's expertise is called upon for a comprehensive survey of energy requirements for the Republic of South Vietnam.  Following the survey, which took four years to complete, the company submitted recommendations for power generation, regulation and distribution and later provided managerial, financial and technical advisory services to help build the projects.

1957

Corning Glass becomes an important client and relies on Day & Zimmermann to help design Pyrex glass plants.

Corning Glass becomes an important client and relies on Day & Zimmermann to help design Pyrex glass plants.

1957

Day & Zimmermann's president Theodore Seelye, is succeeded by Thomas Hopper, head of the company's engineering department.

Day & Zimmermann's president Theodore Seelye, is succeeded by Thomas Hopper.

1960s

1960 - 1969

The true seeds of the modern Day & Zimmermann were sewn in the 1960's, when it was bought by the H.L. Yo Company.  Day & Zimmermann continued to grow as a broad-based engineering, consulting, and defense company, working on a variety of projects at home and pushing for continued international expansion.

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1961

Day & Zimmermann is purchased by the H.L. Yoh Company, a Philadelphia-based technical staffing firm.  Like Day & Zimmermann, it relied on the excellence of its engineering services.

Day & Zimmermann is purchased by the H.L. Yoh Company

1962

Major engineering projects included a joint venture to build what was at the time the largest electrical substation in the world —  the Niagra River Power Project.

1963

During the 1960's, when the U.S. was rapidly developing space exploration, the Yoh Company helped with the crucial program, including design of the Mercury and Gemini capsules.

During the 1960's, when the U.S. was rapidly developing space exploration, the Yoh Company helped with the crucial program.

1964

American Machine and Foundry (AMF) Company selects the Yoh Company, in conjunction with the St. Louis Car Company, to design and build the monorail for te 1964 New York World's Fair.

American Machine and Foundry (AMF) Company selects the Yoh Company, in conjunction with the St. Louis Car Company, to design and build the monorail for te 1964 New York World's Fair

1965

Hershey dedicates a plant in Oakdale, California.  The 400,000 square foot plant embodied the most advanced choclate-marking techniques and was built with the engineering, design and construction management help of Day & Zimmermann.

Hershey dedicates a plant in Oakdale, California

1965

President Lyndon Johnson issues a Presidential Citation to the Lone Star Army Ammunition Plant, where Day & Zimmermann is the operating contractor, for its cost- reduction program that saved millions of dollars in its first year of operation.

President Lyndon Johnson issues a Presidential Citation to the Lone Star Army Ammunition Plant

1967

To build the massive new Korat Air Base in Thailand, Day & Zimmermann enlists thousands of local workers, training them to build a spectrum of facilities, including hospitals, quarters, hangars, and landing strips.

To build the massive new Korat Air Base in Thailand, Day & Zimmermann enlists thousands of local workers

1968

With the escalation of hostilities in Vietnam, the Lone Star plant grew steadily through the mid-1960s.  To help the war effort, the Day & Zimmermann-operated plant produced and packed many kinds of ordnance, including bombs, large-caliber ammunition, rocket launchers, and grenades.

With the escalation of hostilities in Vietnam, the Lone Star plant grew steadily through the mid-1960s.

1970s

1970 - 1979

Though the Vietnam War was ending and munitions production operations were curtailed, Day & Zimmermann developed some of the United States' best munitions technology at the time, establishing the first improved Convention Munitions (ICM) load, assemble, and pack process for the U.S. Army.  Other growth and acquisition activity had Day & Zimmermann managing federal and commercial facilities, restoring historic buildings, and designing breweries.

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1970

Because of its long and successful association with the Lone Star plant, Day & Zimmermann is awarded a contract to manage the Kansas Army Ammunition Plant, which produced 155mm and eight-inch rounds, plus a variety of other ordnance.

Day & Zimmermann is awarded a contract to manage the Kansas Army Ammunition Plant

1971

When the Penn Central Transportation Company declares bankruptcy in 1971, Day & Zimmermann is called in to perform a system-wide asset appraisal, which takes several years.

Day & Zimmermann is called in to perform a system-wide asset appraisal of Penn Central Transportation Company

1971

Day & Zimmermann is chosen as the construction manager for Veterans Stadium in Philadelphia, with responsibility for construction coordination and inspection, change order approval, payment certification, and progress reporting.

Day & Zimmermann is chosen as the construction manager for Veterans Stadium in Philadelphia.

1975

Day & Zimmermann and Yoh Company personnel help with a massive three year modernization program for the U.S. Postal Service.  The huge program includes 645 separate modernization projects.

Day & Zimmermann and Yoh Company personnel help with a massive three year modernization program for the U.S. Postal Service.

1975

Significant acquisitions during this time included the purchase of Cole-Layer-Trumble Company, taking Day & Zimmermann into the property appraisal business.

1976

Spike Yoh takes over the helm of Day & Zimmermann, focusing on growth through acquisition and diversification.

Spike Yoh takes over the helm of Day & Zimmermann

1977

Day & Zimmermann acquires MDC Systems Corporation, a management services company with high-profile projects that addressed health care delivery, construction cost escalation, waste disposal and energy shortages.

1980s

1980 - 1989

As it entered the 1980's Day & Zimmermann was one of the nations twenty-five largest engineering firms, one hundred largest defense contractors, one of the five largest technical service firms, among the foremost sercurity firms in the power industry, one of the largest mass appraisal firms in the world, and one of the largest technical consulting firms in the Philadelphia region.

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1980

Day & Zimmermann engineers work on a huge expansion project at San Antonio International Airport that was delivered in 1984 on-time and under budget.

Day & Zimmermann engineers work on a huge expansion project at San Antonio International Airport

1981

Day & Zimmermann secures a major contract to operate and manage what is at the time the largest ammunition storage depot in the world — Hawthorne Army Depot in Nevada.

Day & Zimmermann secures a major contract to operate and manage what is at the time the largest ammunition storage depot in the world — Hawthorne Army Depot in Nevada.

1982

SEACOR, purchased by Day & Zimmermann in 1982, was one of the country's premier maritime engineering companies.  It worked with the U.S. Navy on engineering programs for a wide range of ships, including aircraft carriers.  In 1984, the company wins a contract for loading and off-loading ships around the world.

SEACOR, purchased by Day & Zimmermann in 1982, was one of the country's premier maritime engineering companies.

1987

Protection Technology Inc. evolves out of commercial security contracts being serviced by the Yoh Company and beomces a major security service provider with significant contracts with the Department of Energy.

1987

Life Sciences International is formed to provide engineering, design and validation services for the biotech and pharmaceutical industries.

1989

The acquisition of NPS Energy Services moves Day & Zimmermann into nuclear and fossil power plant maintenance.

The acquisition of NPS Energy Services moves Day & Zimmermann into nuclear and fossil power plant maintenance

1990s

1990 - 1999

Diversification becomes a hallmark of Day & Zimmermann as the business continues to extend beyond engeineering and munitions work with the power plant maintenance, security and Yoh staffing units growing quickly, partly through acquisition.

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1992

The Yoh Company acquires Salem Technical Services almost doubling its number of branch offices and greatly expanding its geographical footprint.

1993

Protection Technology Inc., Day & Zimmerman's security division, wins contracts to provide security at the Los Alamos nuclear laboratory in New Mexico and to provide nationwide security for DuPont.

Day & Zimmerman's security division, wins contracts to provide security at the Los Alamos nuclear laboratory

1995

NPS broadens its reach with the acquisition of Pullman Power Products Division of Rust International and in 1995 wins a major maintenance and modification services contract with the Tennessee Valley Authority.

1996

Yoh Company acquires United Technical Associates, a Pennsylvania-area temporary services firm.

1998

Day & Zimmermann receives the prestigious national "Family Business of the Year" honor.

Day & Zimmermann receives the prestigious national "Family Business of the Year" honor

1999

Harold Yoh, III succeeds Spike Yoh as Chairmain and CEO.

Harold Yoh, III succeeds Spike Yoh as Chairmain and CEO.

1999

Day & Zimmermann acquires The Mason Company of Lexington, Kentucky — also known as Mason & Hangar - a unique fit given munitions and base operations businesses, as well as engineering and security divisions.

2000s

2000 - 2009

Diversification becomes a hallmark of Day & Zimmermann as the buiness continues to extend beyond engineering and munitions work with the power plant maintenance, security and Yoh staffing units growing quickl, partly through acquisition.  Day & Zimmermann focuses on strategic growth by providing dynamic industrial, defense and workforce solutions, while maintaining the company's unique culture and focus on values.

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2001

Day & Zimmermann celebrates its one hundred year anniversary.

Day & Zimmermann celebrates its one hundred year anniversary.

2002

Yoh is awarded a contract to support temporary staffing requirements at NBC.

Yoh is awarded a contract to support temporary staffing requirements at NBC.

2004

Day & Zimmermann forms a joint venture with Lockheed Martin called DS2 to support the Department of Defense with equipment and facility maintenance services around the globe.

Day & Zimmermann forms a joint venture with Lockheed Martin called DS2

2006

Day & Zimmermann acquires The Atlantic Group, forming one of the largest maintenance and modification firms serving the power industry. The operations are renamed DZ Atlantic.

Day & Zimmermann acquires The Atlantic Group

2006

Day & Zimmermann acquires Reliable Security to broaden the geographic reach of its Security Services unit in the New England region.

2007

Day & Zimmermann acquires 100% of American Ordnance, previously a joint venture with General Dynamics.  American Ordnance operates both Iowa Army Ammunition Plant and Milan Army Ammunition Plant.

Day & Zimmermann acquires 100% of American Ordnance

2007

Mason & Hangar celebrates its 180 year anniversary.

Mason & Hangar celebrates its 180 year anniversary.

2008

Day & Zimmermann's Power Services unit purchases a fabrication and machining facility in Mississippi to complement existing maintenance and construction operations.

2009

Day & Zimmermann's Power Services unit forms a joint venture with AREVA called AREVA DZ, to provide integrated engineering, construction and maintenance services to the U.S. nuclear power plant fleet.

Day & Zimmermann's Power Services unit forms a joint venture with AREVA called AREVA DZ