Category: History

A History-Mystery: Determining the shoreline of a lake before it was dammed

Hoyle Tanner is working to repair the causeway and replace the Crystal Lake Road bridge over the northwest section of Crystal Lake where Nelson Brook enters in the Town of Gilmanton, New Hampshire

It is unknown when the bridge was first installed, however, we know that it consisted of a timber superstructure* supported on dry-stacked stone masonry abutments constructed along a manmade causeway. The bridge was rehabilitated in 1929 when the superstructure was replaced by a reinforced concrete rigid frame. The replacement bridge will be a precast-prestressed concrete deck beam superstructure founded on a precast concrete cap with deep foundations.

Where Does a Lake Begin?

Since replacing the bridge is going to result in some disturbance, or impact, to the lake on the downstream side of the bridge, a Wetland Permit was required to be issued by the New Hampshire Department of Environmental Services (NHDES). However, as our environmental coordination staff began to complete the permit application, it became evident that one important piece of information was lacking: Where does the shore end and the lake begin?

This may seem to be a pretty simple question to answer – the lake begins at the edge of the water! However, the State of New Hampshire, which has legal authority to regulate and permit work done in lakes, has a set definition of a lake that comes from both New Hampshire RSA 485-A:2 and Chapters 100 and 400 of the NHDES Wetland Rules. Those define a lake as a surface water with the normal high water line as the elevation of the boundary between a lake and upland or shore. For most naturally-occurring lakes or ponds (that have not been created by a dam), a licensed surveyor can visit the site of the proposed work area and use visual evidence to determine the water elevation where under normal or typical conditions the waters of the lake are at their highest on the adjacent bank or shore.

But for Crystal Lake, there are factors to consider that made this a bit more challenging. Crystal Lake is approximately 450 acres in size, making it large enough to be considered a public water per New Hampshire RSA 271:20 II: Public waters in New Hampshire include natural or artificially impounded (dammed) surface water bodies that are over 10 acres in size. NHDES issues an Official List of Public Waters (OLPW) that includes data for each water body such as location, dammed status (dammed or not?), the Dam Bureau number if it is dammed, and for some water bodies, the normal high water line/elevation. Crystal Lake in Gilmanton is listed as RD or raised by damming, Dam # 91.11, without providing a normal high water elevation. Why not?   

A lake that is noted as RD is a water body that was a natural lake that was more than 10 acres in size originally, but at one point the water level has been elevated by construction of a dam at the outlet, or “raised by damming.” Per the RSA and NHDES rules, only the areas of land underwater that are below the original normal high water elevation before the lake was dammed are Public Waters. Because there is not elevation provided on the OLPW, that elevation has not been officially determined by NHDES. How do you determine that elevation? By doing quite a bit of sleuthing!

Establishing a Timeline

For Crystal Lake, we enlisted the assistance of both the local surveying team, Sandford Surveying and Engineering, Inc., and our in-house super-sleuth and Right-of-Way acquisition specialist, Betsy Bosiak. Together, they reviewed current and historic mapping such as tax maps, USGS maps and survey plans for lots around the lake as they were recorded as sold or subdivided. In addition, deed records were reviewed for when the land near the dam and bridge changed ownership; other local Town records were reviewed and local authorities were interviewed. Historic books and internet sites were also scoured for any available historical information. From this collective information, our team was able to determine that the dam has been in place for at least 100 years and a timeline of ownership for the property along the lake was established.

Data from the time of the dam’s installation was gathered and reviewed in detail to glean any water elevation data that could provide the water elevations in the lake before the dam was installed.

The first available plans for the dam come from references to notes that were unable to be found, however the first photo of the dam was found dated July 1934, so we believe that the dam was installed around that time.

Careful review of plans from 1957 for a dam reconstruction project provided enough information to determine the natural mean high water elevation before damming was  617.2 feet – this was based on plan figures showing the bottom elevation of the dam to be set at 616.7 feet, with an assumed normal flow depth of 6 inches. To compare that to current conditions, the water elevations for the full lake conditions (that is, when the lake is reached its maximum volume as regulated by the dam) is 624.25 feet, or more than 7 feet deeper than the historic water levels! 

The History Mystery Took…A While

Identifying this elevation took over six months! Ultimately, all of the supporting data that was used to “tell the story” was provided to NHDES in order for the Dam Bureau and the Wetlands Bureau to determine if the proposed elevation could be used for identifying impacts to the lake and Public Waters of the State of New Hampshire. NHDES ultimately concluded and agreed with the water elevation that we presented based on the depth of supporting evidence that was uncovered.

Identifying such an important piece of information was quite a challenge for our team; however, we were able to meet this challenge while keeping the project on schedule and within the Town’s expectations of cost. Additionally, Hoyle Tanner’s bridge design team worked hand-in-hand with the environmental coordination team to successfully design a bridge replacement project that resulted in no impacts to Public Waters of the State.

7 Things to Consider When Preserving Historic Bridges

Engineering students receive extensive training in math, science and engineering topics related to their specific field of study. For Structural Engineers, this includes courses on analyzing structures constructed from the most common building materials – steel, concrete, prestressed concrete, and in some cases, timber and masonry. These courses generally focus on modern design codes, material properties and construction techniques. While these courses do provide a good technical background, they do not typically include much instruction related to historic bridges. When we are entrusted to work on these special structures, engineers should keep the following in mind:

  1. History of the Bridge. The year the bridge was built is an important piece of information as it can provide an understanding of the design codes, standard vehicle loads (if any), material properties, and construction techniques of the time. The history of maintenance, repairs and rehabilitation of the bridge is also good information to review to have a complete picture of the bridge before beginning any structural analysis.
  • Plan Availability. Locate the original design drawings of the bridge, if possible. These drawings are not generally available for most structures built before the 1920s; however, some of these bridges may be covered by patented designs which can provide valuable information on design procedures and assumptions. It is important to note that even if plans are available, they are not typically ‘as-built’ plans and the field conditions may vary from what is shown on the plans. If design drawings are not available, the Historic American Engineering Record has prepared detailed drawings of select historic bridges that can supplement field measurements.
  • Material Properties. The materials used in historic bridges (steel or concrete) have different properties compared to modern materials which effect their strength, durability and weldability (for steel structures). There are number of excellent references that provide appropriate design values for these materials which can also be supplemented by testing. For less common materials such as cast iron, timber and stone, conservative values are typically used as these materials are typically less uniform and more variable in their physical properties.
  • Inspection Access. A thorough assessment of all bridge elements is needed during the evaluation phase of the project. Many historic bridges, however, are posted for reduced live load capacity which does not allow for the use of traditional bridge inspection equipment. In these situations, access can be gained through rope-access inspection techniques or remotely through Small Unmanned Aerial Systems (drones). We utilized the rope-access for the inspection of the Coos Bridge in Byron, Maine which was posted for 5-tons but where a hands-on inspection was required for fracture critical members. A drone was used for the inspection of the Kingsley Covered Bridge in Clarendon, Vermont.
  • Community Needs. While preservation of historic bridges is the primary goal of many project stakeholders, it is important to consider the needs of the community. A bridge with weight or height restrictions can have significant impacts on first responder response time and use by school buses or fuel delivery vehicles which have a negative impact on residents’ quality of life. In these situations, engineers need to be creative in their approach to meeting the communities’ needs while maintaining the historic integrity of the bridge. Our team rose to this challenge for the rehabilitation of the Union Village Covered Bridge in Thetford, Vermont: The bridge had an 8-ton live load capacity which was not sufficient for fire trucks used in the area and required them to take a long detour which increased response time. Our rehabilitation design included the installation of timber glulam stringers beneath the bridge to share load with the trusses and increase the live load capacity to 20-tons. This treatment is reversible (i.e. the beams could be removed at a later date) and the use of wood for the support members improved the aesthetic of the bridge as opposed to steel beams.
  • Coordination with Resource Agency Partners. The majority of historic bridge projects must be reviewed under Section 106 of the National Historic Preservation Act of 1966. This act requires that the effect of any proposed work to historic structures be reviewed and evaluated. While engineers are typically most concerned with the structural concerns of the project, resource agency professionals are charged with preservation and appropriate treatment of historic structures. Therefore, a strong knowledge of the Section 106 process and roles of each party is important to project success.
  • Aesthetics. All work completed must keep with the strong aesthetics that these historic bridges possess. This can be accomplished by using appropriate repair materials, matching the finish of replacement members to existing members (rough sawn timber, for example), and using period-appropriate hardware such as ogee washers. One simple but effective example of an aesthetic treatment was the application of a protective coating over the concrete railing of String Bridge in Exeter, New Hampshire. This two-span concrete rigid frame was built in 1935 and had undergone numerous repairs to the railings which resulted in a “patchwork quilt” appearance of the rail. We recommended a light-colored protective coating which served a dual purpose of protecting the concrete while also improving aesthetics with a more uniform appearance that matched the existing concrete. Just like I mentioned in item 6 of this list, we coordinated with the Historic District Commission before installation for approval.

Preserving historic structures is one of the many bridge services that Hoyle, Tanner provides our communities. For more information contact me, Sean James, PE, Senior Vice President and Structural Engineer for our Bridges & Structural group.

A Tribute to Our Roots

Hoyle, Tanner founders gathering around a document signing

As we begin our 47th year in business, we pay tribute to our founders who exemplified courage, resilience, commitment and innovation while building the solid foundation from which the company operates today.

Doug Hoyle was a lot of different things — a graduate of Brown University, a Korean War veteran, a licensed pilot, an avid skier, motor sport enthusiast and co-founder of a company that still bears his name. Although his list of personal accomplishments is long, throughout his career, his key interest remained the same: to be recognized as Chief Engineer. In 1973, Doug Hoyle along with John Tanner and Bill Thomas founded the engineering firm Hoyle, Tanner & Associates, Inc. and opened an office in the Ammon Terminal building at Manchester Airport. This marked the beginning of what now has become a very successful 46-year history in the civil engineering business.

Together, the original team of three built Hoyle, Tanner from the ground up; their individual beliefs, experiences, talents and business strategies complemented each other nicely.

Doug would take the lead for the company in the field of environmental engineering. Doug understood that by utilizing the availability of funding from the federally-sponsored Clean Water Act of the1960s, water quality could be significantly improved, and this was to be especially relevant to the many municipalities in New Hampshire’s Lakes Region. This work would become an important source of repeat business for the company, as well as establishing a reputation for high quality engineering in environmental services.

John Tanner also recognized the importance of a reliable source of funding for projects. His interest was in public transportation; he utilized the federally-funded Airport Development Aid Program which assisted airports by providing funds to finance capital improvements and maintenance projects. John led the way in this effort and was instrumental in building a national reputation for Hoyle, Tanner within the aviation industry. Unlike the other two founders, Bill Thomas was not an engineer but an experienced and insightful businessman who played a crucial role in business development, serving as the face of the company, and playing an instrumental role in important business decisions that affected Hoyle, Tanner’s future. Their personalities interwove together perfectly.

Doug Hoyle, a man of unwavering honesty and integrity, was a competent and traditional professional who made rational and calculated decisions. His pride was not in the name on the door but instead in his duty as Chief Engineer.

John Tanner was a gifted manager and a natural leader. John was always forward-thinking with big ideas and an ability to listen to a room full of people and distill a complex discussion to its core elements.

Bill Thomas was very personable; a natural conversationalist at ease in any social or business situation. Bill possessed the sound judgement and insights that would help to establish the firm’s culture and guide the company through future technological changes.

Together, the founders created a company culture of customer-driven quality and professionalism that is still very much in evidence at Hoyle, Tanner today. For 46 years, the company has been resilient and adaptive, embracing challenges and taking measured risks that are in the best interest of both our clients and our employees. Engineering is a continuously evolving industry. Hoyle, Tanner’s ability to adapt, anticipate these changes and persevere is something that has been with us since we first started in 1973 and that will continue to see us through our 100th year in business.

Founders black and white photo with names

This piece was written by Grace Mulleavey and Frank Wells.

5 Extraordinary Women in Engineering

March 8th International Womens Day

On International Women’s Day, we celebrate social, economic, cultural and political achievements of women today and throughout our history.

As engineers, we understand the need to increase the involvement and participation of women within our industry, as well as the other STEM fields. Today at Hoyle, Tanner we are celebrating a few extraordinary women throughout engineering history who have made a tremendous impact in our field and shown tremendous strength in times of opposition.

Martha J. Coston (1826-1904)
At the age of 21, Martha Coston was already a widowed mother of four children struggling to make ends meet. So when she happened upon a design for night flares that her late husband left behind in a notebook, she took advantage of the opportunity and went to work. For 10 years she revised his original design and even added pyrotechnic components in order to achieve a multicolored system that could be used for coded messaging. It was a long road, and along the way, Martha was forced to overcome unimaginable challenges, including the death of one of her children. However, all of her hard work eventually paid off when she succeeded in creating a bright, durable and long lasting tool that could be used for ship-to-ship or ship-to-land communication. When she patented the invention in 1859, the Navy purchased it from her for $20,000. (the equivalent of half of a million dollars for the time period). In addition, she won the rights to manufacture the devices for the United States Navy. Historians argue that the “Coston Flares” were a major contributing factor to the North’s victory during the Civil War. To this day, pyrotechnic devices are still used as a means of communication by the U.S. Navy. Throughout her lifetime, Coston demonstrated a profound ability to overcome failure and persist through hardship, and for that reason she is an inspiration to not only all women, but all engineers.

Helena Augusta Blanchard (1840-1922)
Helena Augusta Blanchard was born into a wealthy family from Portland, Maine. When her family lost everything in a financial crisis, Blanchard went to work using her talents to single-handedly restore their fortune. At the age of 30, she patented the zigzag sewing machine, her first and most famous invention. From there she went on to hold 28 patents, most of which were related to sewing machines. However, notable inventions by Blanchard also include the surgical needle and the hand crank pencil sharpener. She went on to open the Blanchard Overseam Machine Company in 1881 with the help of her sister. Helena Augusta Blanchard is the most prolific and successful female inventor of the 19th century. She loved what she did and continued to improve upon her designs and create new ones up until having a stroke in 1916.

Emily Warren Roebling (1843 – 1903)
Unlike others on our list, Emily Roebling never intended to become an engineer. However, when her husband became ill in 1872, she assumed the role of “first woman field engineer,” overseeing the construction of the Brooklyn Bridge — one of the biggest engineering projects of that time period. For 14 years, Emily executed many of the chief engineer’s duties, which included day-to-day supervision, project management, and even acting as a liaison with the bridges board of trustees. Although throughout the construction processes, Emily’s contributions were largely hidden due to the circumstances of the time period, today you will find a plaque on the bridge honoring both her and her husband.

Edith Clarke (1883-1959)
Edith Clarke was born in a small Maryland town and found herself an orphan by age 12. When she was 18, she made the courageous decision to spend all of her inheritance money on an education in mathematics at Vassar College. After graduating in 1908, Clarke worked as both a teacher and a computing assistant for AT&T before deciding to study at the Massachusetts Institute of Technology, where she became the first female to graduate from their electrical engineering program. In 1922, Edith accepted a salaried engineering position at General Electric, making her the first professionally employed female electrical engineer in the United States. Edith Clarke was a loyal employee and stayed with GE for 26 years. During that time, she invented and patented her most famous contribution to the field, the graphical calculator “that simplified the equations electrical engineers used to understand power lines.” Edith Clarke was a pioneer for women in the engineering fields. Other firsts for her include being the first woman to present a paper before the American Institute of Electrical Engineers (AIEE), the first woman to become an accepted voting member of the AIEE, and the first woman to be elected a fellow of the AIEE. Edith Clarke is honored in the National Inventors Hall of Fame for her extraordinary career.

Hedy Lamarr (1913-2000)
Hedy Lamarr is most commonly remembered as a beautiful movie star from the late 1930s to the 1950s. However, many are not aware of her talents off screen as an inventor. When Lamarr found herself bored with her daily duties as an actress, she started to spend all of her spare time on various inventions, despite a lack of formal training in the field. Her commitment to her hobby paid off when Lamarr patented a remote-controlled communications system that would be used by the U.S. Navy to jam enemy systems that interfered with torpedoes during World War II. The frequency hopping theory behind the design is the foundation for our communication technologies today, such as Bluetooth and Wi-Fi network systems. It was not until 2014 that Lamarr was inducted into the National Inventors Hall of Fame. There is no doubt that Hedy Lamarr was an incredibly talented woman who did what she loved despite the limitations of the time in which she lived. Next time you go to log onto your email or connect to Wi-Fi, take a moment to remember the woman who made it possible for you do so.

Written by Grace Mulleavey

Act Like a President, Think Like an Engineer

Presidents Graphic

The majority of our nation’s past presidents came from an academic or professional background — such as law, writing or education — rather than a technical or scientific one. In honor of President’s Day and as the kick-off to this year’s annual Engineers Week, we are celebrating five unique presidents who proved to have minds for engineering.

George Washington – (Presidency: April 30, 1789 – March 4, 1797)
Most famous for being the first President of the United States and cutting down cherry trees, many people are not aware that amongst George Washington’s many talents was a knack for both geography and cartography. In fact, Washington spent his early professional career as a surveyor before some of his more distinguished endeavors as a business man, war hero and president. History shows that when serving as a military officer during the revolutionary war, Washington preferred to create his own field sketches as opposed to having them drawn up for him.

Thomas Jefferson – (Presidency: March 4, 1801 – March 4, 1809)
Perhaps one of the most famous and influential figures in United States history, our third president, Thomas Jefferson, certainly thought like an engineer. Although classicism was his official expertise, Jefferson is often celebrated as America’s first great native-born architect. Even more impressively, Jefferson was self-made, gaining all of his architectural knowledge from books because of the lack of schools in colonial Virginia. Evidence of our founding father’s talent can be seen at the University of Virginia, or the state capitol building in Richmond, Virginia (both of which he designed). Jefferson’s work is uniquely American and still influences modern day architecture.

Abraham Lincoln – (Presidency: March 4, 1861 – April 15, 1865)
Most famous for abolishing slavery, our 16th president of the United States, Abraham Lincoln is known as both a successful lawyer and politician. However, most people are not aware that Lincoln spent a great deal of time studying mathematics, which qualified him for his early career as a land surveyor. In fact, in fall 1833 Lincoln spent countless days and nights pouring over texts such as Gibson’s Theory and Practice of Surveying and Flint’s Treatise on Geometry, Trigonometry, and Rectangular Surveying, both of which prepared him for making measurements in the field.

Herbert Hoover – (Presidency: March 4, 1929 – March 4, 1933)
President Hoover is the only president who had an official background in engineering. In 1985, he graduated from Stanford University with a Bachelor degree in mining engineering. Before winning the presidential election by a landslide in 1928, Herbert Hoover had a colorful career. The 31st president of the United States built his foundation working around the world on mining and railway projects, participating as a member of several war boards and councils and also serving as the Chairman of the American relief administration engaged in children’s relief in Europe. President Hoover greatly enjoyed his work as an engineer and spoke of the profession in high regard.

“It is a great profession. There is the fascination of watching a figment of the imagination emerge through the aid of science to a plan on paper. Then it moves to realization in stone or metal or energy. Then it brings jobs and homes to men. Then it elevates the standards of living and adds to the comforts of life. That is the engineer’s high privilege.”

Jimmy Carter – (Presidency: January 20, 1977 – January 20, 1981)
Next to President Hoover, Jimmy Carter is the second closest of all 45 presidents to have an official background in engineering. He attended the Georgia Institute of Technology for one year before enrolling in the United States Naval Academy at Annapolis where he received a Bachelor of Science degree and became a submariner. While serving as a submariner in Schenectady, New York, he took graduate classes at Union College in reactor technology and nuclear physics. Carter served in the United States Navy for seven years on nuclear submarines. In fact, Carter was preparing to become the engineering officer in 1953 for the Seawolf before he abruptly resigned in the event of his father’s passing. Carter’s love for engineering is evident in the years following his presidency through his extensive work for Habitat for Humanity.

Written by Grace Mulleavey

45th Anniversary Announcement – A message from our President

Original Office in Terminal Building

Forty five years ago, Doug Hoyle and John Tanner opened the doors to Hoyle, Tanner & Associates, Inc. — an engineering firm, which at that time, specialized in aviation and wastewater services. Since then, we’ve experienced tremendous growth as a company, expanding our services across multiple engineering sectors, and opening branch offices throughout New England and Florida. Our success is attributed to our resilience in the face of challenges, our willingness to adapt in times of change, and our ability to be insightful in our decisions overtime.

Over the years, we have established a strong reputation as a firm that continuously provides innovative, high-quality and sustainable solutions to our clients. As president, it is a great honor to serve in a role that helps this company and the communities we serve to accomplish everything we have set out to achieve. Our employees are not just a means to production, but part of a unique family, united under a culture of respect, social responsibility and collaboration. It is truly a joy to come to work every day and both mentor and learn from some of the best professionals in the industry.

Looking ahead, our future as a company is promising. We have been and will continue to be a small firm with large firm capabilities. We will grow not for the sake of growing, but to provide extended opportunities to both our clients and our employees. We will do so organically by promoting from within and forming strategic mergers and acquisitions. I am confident in the capabilities of our team and am enthusiastic about our future, which shines bright with the promise of continued innovation, creativity and insight. This year, on our anniversary, Hoyle, Tanner proudly acknowledges the past 45 years, but more importantly celebrates the outstanding, innovative and quality engineering that will see our company through the next 45 years and beyond.