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Thirty-three years ago Doug Hoyle,  John Tanner and Bill Thomas were working in the Manchester office of one of Boston's most prestigious civil engineering firms, Alonzo B. Reed.

In October of 1973 when they struck out on their own, Hoyle and Tanner had only a few employees including Jim Boothroyd, the company's current President and CEO. Today, Hoyle, Tanner & Associates, Inc. (HTA) has grown to become the largest locally based engineering firm in New Hampshire, with over 100 employees. Along the way, the firm established a reputation for quality and excellence based on its groundbreaking work in transportation and environmental planning and engineering. 

It was aviation engineering that provided the firm with its first major success, in projects that took the company far beyond the borders of Manchester. In the 1980s, when HTA became part of a team that designed major airside improvements to McCarran International Airport in Las Vegas, they had already completed airport design and planning projects throughout New England as well as in places like Hawaii, California, Minneapolis-St. Paul and Florida. In 1996 the Manchester-Boston Regional Airport Terminal Project, for which HTA provided site design services, was voted the New Hampshire Civil Engineering project of 1996 by the Consulting Engineers of New Hampshire.

One of the results of the firm's success was branch-office expansion. In 1980, Hoyle, Tanner purchased the Florida firm Hart Associates based in Miami, and eventually moved the office to Orlando where the focus would primarily be on aviation projects. Since then the Orlando office has continued to grow, and HTA has added offices in Hernando and Mount Dora, Florida.

On the environmental side, HTA soon reached recognition by designing the first fully integrated wastewater sludge processing and composting facility in the nation. The facility received worldwide recognition and won the 1982 NH Civil Engineering Project of the Year Award. HTA also designed an award-winning wastewater treatment facility atop Mt. Washington's summit, New England's highest mountain peak.


To further their environmental success, the firm also designed the largest spray irrigation treatment facility in New England, as well as the first major European-style vortex solids separator in the United States. HTA has also completed numerous water supply, storage, and transmission projects around New England and in Florida, as well as landfill closures and solid waste transfer facilities.

In Manchester the most visible evidence of HTA's design presence remains at the airport and the firm's efforts in designing and upgrading the city's numerous bridges. In 1987, HTA acquired Structural Design Services, which specialized in bridge design. It was through that acquisition that HTA entered into a five-year contract to upgrade, rebuild and maintain the City of Manchester's bridges including the rehabilitation of the Queen City, Kelly Street, and Amoskeag Bridges, as well as a half-dozen other Manchester bridges. That five-year contract has been extended twice. To date, the firm has worked on over 30 bridges in the city. 


Doug Hoyle



John Tanner



Jim Boothroyd



Bill Thomas


The successful growth in the highway/bridge group has enabled HTA to earn a national reputation for its niche market in the design, restoration and maintenance of covered bridges. HTA has designed the rehabilitation and/or inspection of over a dozen covered bridges in New Hampshire, Vermont and Massachusetts.

To further its' expansion, in 1996 HTA acquired certain assets of Kimball Chase Company, a civil engineering firm with offices in Portsmouth, NH and St. Thomas in the US Virgin Islands. HTA has gone on to do engineering work for several agencies on that island, and was instrumental in repairing much of the damage caused by several hurricanes in past years. In Portsmouth, a majority of their project log is in civil and site engineering projects, as well as a considerable amount of building projects. 


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