Author Archives: Jasper Calcara

Award Winning Shoring Key to Success

In recognition for the successful collaboration and the innovative shoring design, this project was awarded the 2020 Scaffolding & Access Industry Association (SAIA) Shoring Project of the Year.

Originally built in 1962, Climate Pledge Arena (originally known as Key Arena) is located in the heart of the historic Queen Anne district of Seattle. To take advantage of its prime but densely populated location, the arena was built down into the ground, with a pavilion-like sloping roof that has become a staple of the Seattle skyline. As part of a $700 million remodel, the Seattle Center Arena would get entirely new facilities, meaning the entire interior structure of the arena would be demolished and rebuilt from the ground up. With the majority of the arena built underground, this meant the existing concrete retaining walls would no longer have the concrete floors to support them and would require soil anchors be installed for support. In order to install those new soil anchors, an 18,000 lb micro pile drilling machine had to be driven on the existing slabs. However, the drill rig was a load the slab was never designed to support.

Due to the rapid pace of construction, it was immediately clear that coordination and clear communication would be required for the project to succeed. DHC was met on site by scaffolding contractor Performance Contracting, Inc.,  as well as representatives of both the general contractor and the structural engineer (SEOR) for the structure. The site to be shored was walked extensively, with each party noting critical locations that either needed to be shored, to be left open for access, or obstructions that needed to be worked around. The area of highest concern was over the Event Level ramp. The SEOR made it clear the Main Concourse slab above the ramp need to be shored to support the drill rig. At the same time, the general contractor was adamant that the ramp had to stay open and unimpeded in order for construction to stay on schedule. With demolition well underway, the ramp saw a constant stream of dump trucks as material was moved out of the stadium. The scope was to design a shoring system that fully supported the upper slab while taking up no space on the floor below.

After exploring some initial options, it was eventually determined that the most feasible way to adequately support the Main Concourse slab while simultaneously leaving the ramp open would be to essentially build a “tunnel” in the shoring; the slab itself would be shored up using modular cuplok scaffolding, which would then be set onto large steel beams spanning the width of the access ramp. After confirming the type of drill rig that would be used, DHC performed a detailed moving load analysis of the drill rig to model the loading that would be applied to the shoring. This drastically reduced the load on any one shoring beam, allowing for the use of lighter, more easily erectable beams.

Due to the slab above the ramp dropping as the ramp descended, as well as the presence of concrete beams at awkward angles, the modular, flexible nature of cuplock scaffold was used to its fullest as the main support of the Main Concourse slab. To support the steel beams on either side of the ramp, RMD Kwikform Super Slims were used as vertical post shores. While originally designed for use in falsework and concrete wall pouring applications, the Super Slims had high axial capacity and DHC had experience in using them in shoring applications. By bracing them to each other, as well as anchoring them to concrete wall and ramp for stability, a stabile base for the shoring tunnel was created that took up less than a foot of width. Once fully installed, the tunnel shoring allowed for the tie back installation to successfully move forward without any hinderance to the demolition work.

Mark Palmatier, PE – Branch Manager – (425) 559-9775

Jasper Calcara, PE – President – (760) 436-9756

Chicago Office Opening


D.H. Charles Engineering, Inc. has a long-standing tradition of servicing clients in the State of Illinois since obtaining our IL SE license, and has developed close relationships with contractors, IDOT and CDOT OUC over the past twenty years working in the area.  Even though we’ve felt confident we could continue to meet the needs of our customers, as had been proven with the hundreds of projects completed, we knew a local presence would provide the extra level of support we wished to offer.  Therefore, after many years of looking for the right opportunity we are thrilled to announce the opening of our newest office in Chicago.

Andrew Schwarz, PE, SE, was born and raised in the Chicagoland area and continues to call the area home. He has over twenty years of experience in the structural and geotechnical engineering discipline, including starting out in the bridge design industry while also working in the building design industry.  For the last 10+ years, he has been working in the underground shoring and temporary works industry expanding his close relationships with contractors in the area.   Andy is excited to be joining the DHC team and looks forward to growing the Chicago and Midwest operations for the company while assisting the company nationwide.


The success of the Seattle, Portland and New York offices has proven that although our resources are now spread throughout the Country, we can effectively work as a team and can be depended upon to share our wealth of design experience and knowledge regardless of location.  Our customers have come to expect collaboration and support from all our team members in developing state of the art and cost-effective solutions for their construction engineering needs.


Andy and the entire DHC team look forward to servicing an expanded customer base and providing more on-site support to projects in the area.  Please contact any of our team members to discuss how we can be of assistance on your jobs or bids.

Andrew Schwarz, SE, PE – Branch Manager/Sr. Engineer – (872) 240-8033

Jasper Calcara, PE – President – (760) 436-9756

Luke Griffis, SE, PE – Vice President – (707) 537-8282


East Coast Office Opening


After successfully servicing clients on the East Coast for over 20 years, D.H. Charles Engineering, Inc. is excited to announce the opening of its newest office in New York City.  Although originally founded and headquartered on the West Coast, DHC has worked tirelessly to prove to its customers that regardless of location or time-zone, excellent service can be counted on day after day.  A culture of immediate response to all calls, and expert support by experienced engineers, has resulted in long and valued relationships with our national accounts.


Branch Manager and Sr. Design Engineer Chong Kim, P.E., has developed personal relationships with contractors throughout the greater NY, NJ and New England areas for over a decade.  His experience in design of complex excavation shoring systems, along with many other temporary works designs, made him an excellent fit for heading DHC’s expansion East.  He’s passionate about what he does, and brings innovative design ideas to his projects, with a positive and creative attitude.


New NY Bridge – Photo By: New York State Thruway Authority

The success of the recently opened Seattle office has proven that although DHC resources are now spread throughout the Country, they can effectively work as a team and be depended upon to share their wealth of design experience and knowledge regardless of location. Their customers have come to expect collaboration and support from all team members in developing state of the art and cost-effective solutions.

DHC looks forward to servicing an expanded customer base and providing more on-site support to projects in the area.  Please contact any of our team members  to discuss how we can be of assistance on your jobs or bids.

Chong Kim, PE – Branch Manager/Sr. Engineer – (914) 292-4337

Jasper Calcara, PE – President – (760) 436-9756

Luke Griffis, SE, PE – General Manager – (707) 537-8282


(Another) Rewarding Day with Habitat for Humanity


On Tuesday, May 19, 2016, DH Charles Santa Rosa, returned to the Cotati Habitat for Humanity building site to work on the final house. This particular building site had its ground breaking on September 14, 2013 with plans for 5 single family homes and the final home is only weeks away from being completed. Volunteers complete 90% of the labor on these homes, which means the site foreman was happy to see us.


The sun came out early that day and the heat was strong, but we had motivation in view, right across the street was the house we had worked on last year, complete and being lived in. We were given only one major task, digging the driveway out. There was 14 inches of dirt and clay that needed to be dug up and hauled away. Everyone grabbed a shovel or a pick axe and got to work. Though the labor was hard, the team still had a good time taking turns digging with shovels, using the jack hammer to loosen the clay and dumping wheelbarrows full of dirt in the dump trailer.


While the driveway was being dug out another smaller group dug a 2 foot deep trench along where the porch will be. This trench is going to be used for the main water and sewer lines. Due to the placement of the trench the group had to continuously monitor and measure the depth and width of what they were digging, not deep enough and the pipes were at risk of exposure, too far out and they were digging into the front yard.


In 2015 Habitat for Humanity helped 1.8 million people worldwide, through home construction, rehabilitation, repairs or increased access to better shelters though products and services. Each year over 2 millions volunteers worldwide take time out of their days to make an impact, a bigger impact then they even realize.


Support Under Distress


The 6.0 magnitude Napa Earthquake struck on August 24, 2014,  and caused substantial damage to many structures in this popular tourist destination.  DHC received many calls during the aftermath of the earthquake, as the damage was widespread and structures were in need of temporary support.  Bracing and shoring was deemed necessary for many building simply to allow personnel to gain access, retrieve belongings, or survey the true extent of the destruction.

One building that was hit particularly hard was the Historic Napa Courthouse located downtown on Brown Street.  D.H. Charles Engineering, Inc. was contracted to develop a wall bracing system that could be installed without positive anchorage to the wall itself.  This was imperative, as the competence of the wall was unknown and workers could not be exposed to a potential collapse during bracing installation.  The resulting system consisted of vertical I-beams that were rotated upwards against the wall, and then diagonally braced with tilt-up braces anchored to the wood floor joists.  This scheme and installation process provided the necessary safe working environment, and ultimately allowed for temporary scaffold towers to be placed inside the room which provided temporary support to the roof.


DHC was also contacted by RMB Management Company to come up with a solution to recover personal items for customers of the heavily damaged two-story self-storage building at the Napa Self Storage facility.  The entire second story had  shifted out of alignment from its foundation such that the first story walls were heavily skewed and damaged.  The primary challenge was not being able to visibly see the full extent of the damage without first stabilizing the whole building and providing safe access to the structure.


Our first step was to design an exterior bracing system at the second floor, for global stabilization, and relieve load to the damaged interior walls.  We then designed an extensive plan to incrementally provide internal access to the lower floor units.  Modular scaffold shoring would be used throughout the building’s access points to simultaneously shore the lower level while providing safe entry for workers to evaluate the extent of the damage, recover personal belongings, and provide additional shoring within the storage units as necessary to stabilize the structure.

DHC enjoyed the opportunity to support their neighbors in a time of need, and help the residents and businesses of Napa return to normal life.

Steel Culvert Rehab

DHC has recently completed multiple designs of arch and elliptical shaped steel casings for culvert rehab projects for InfraSteel.   Structural load and stress calculations on the new casing sections were performed and submitted, to prove that the steel segments can safely support the full intended loading of the existing deteriorated culverts.  Once certified and approved by the governing agency, the casings are installed via the slip lining process as explained on the InfraSteel site:

The slip lining process rehabilitates a failing culvert without the need to remove the existing deteriorated pipe. During installation, bypass pumping helps to insure an environmental friendly worksite. The slip lining process is completed by installing INFRASTEEL® 242, smooth wall steel pipe, into the existing host pipe, and then grouting the annular space between the two pipes.

Watch installation in this YouTube clip: Install




By Cullom Walker III & Shanna St. Clair, July 22, 2015

The New York State Department of Transportation (NYSDOT) and St. Lawrence County Department of Highways worked together utilizing a shared service agreement to streamline the completion of two culvert preservation projects, ensuring motorist safety while saving taxpayers $816,800.

Ernest Olin, the resident engineer for NYSDOT Region 7, and Andrew Willard, the senior civil engineer for St. Lawrence County Department of Highways, worked in tandem to complete two large diameter culvert preservation projects. Both entities had large, failing arched culverts that needed repair. Willard had heard about InfraSteel from Precision Pipe and Products, and had mentioned InfraSteel to Olin. They knew thatInfraSteel could match the plate arch shape of the existing structures, providing a smooth wall ID that would not decrease the hydraulic capacity.

Also, because InfraSteel has added copper to the steel for corrosion resistance, and it has out-performed other products in abrasion resistance testing, Olin and Willard were assured a life expectancy of 50 to 100 years.
The state’s project was under Route 12 in the town of Hammond, N.Y. The existing structure was a corrugated plate arch that was installed in the 1960s; it had a 131-in. span and an 81-in. rise with a deteriorated invert that was completely rusted through.

The state’s failing culvert was under 2 ft of cover. NYSDOT structural engineers had ruled out the option of paving the invert because of concerns regarding the structural integrity of that type of repair. InfraSteel’s strength and thickness, coupled with the grouting of the annular space, offered improved structural integrity.

Basing their decision on existing round pipe options, NYSDOT hydraulic engineers deemed sliplining the structure not an option because round pipe would decrease the hydraulic capacity of the existing structure, which was not acceptable.

Since the Manning’s coefficient of InfraSteel’s smooth wall carbon steel is .012 in., which is better than corrugated metal, and because InfraSteel matches the exact shape of the host pipe, maximizing the area of flow, there was no loss of hydraulic capacity. Round liners do not typically provide enough hydraulic capacity to maintain existing capacity in large arched and elliptical structures.

The only other option that the state had for a solution was for the project to become a Job Order Contract Candidate. This would require cutting the road and replacing the existing structure. This method would have taken significantly longer to complete and had an estimated cost of $360,000.

Subsequently, Olin and Willard made a plan to create a shared service agreement that would preserve both of the existing structures and save taxpayers money. They agreed to share both manpower and equipment in order to get the job done. Also by working in tandem, the two failing structures were going to be repaired quickly and economically without the interruption of emergency vehicles and other traffic.

Detailed measurements of the host structures were taken in order to ensure that the shape of the InfraSteel liners matched the host structures. In order for the InfraSteel liner to be manufactured with matching radii of the host structure, the field measurements of the host pipe provided to the manufacturing plant are of critical importance. Precision Pipe has developed a detailed method of measuring and gathering information about the host pipe, which is provided to the manufacturing plant engineers so that they can convert that information into a matching liner. The liner is sized with exact rise and span measurements that allow it to be sliplined into place. Fish baffles and weirs are an option but were not required for these two sites. The plant engineers provided drawings back to the project engineers who signed off on them so that production could begin. The orders were placed with Precision Pipe and Products and the liner sections for the Hammond site were delivered within a few weeks.

InfraSteel is generally manufactured in 8- to 10-ft lengths to facilitate handling and shipping; however, longer lengths are available. Also, the standard .500-in. wall thickness was chosen for these sites, although InfraSteel can be manufactured various wall thicknesses up 1-in. thick.

The combined state and county crew began work preparing the host structure for slip-lining by laying down a simple rail system to facilitate the sliplining process. Two welders from the county worked with two NYSDOT bridge crew welders to weld the InfraSteel joints together. The liner is shipped with cross bracing, which is left in place until the installation and grouting are complete. The bottom section of the InfraSteel liner has an inverted bevel, allowing welding to be done from within the pipe so that welders do not have to get under the liner. The top and sides are welded on the outside. Ventilation was provided to the working space within the pipe. The welding time per joint was approximately two hours.

A 200 series track hoe excavator did the heavy lifting and pushed the liner inside of the host pipe. Even with short working hours during the construction period, the welding and sliplining were completed within a few days.

Grouting was done from within the structure through grout ports. The 2-in. grout ports were cut into the liner at top center, and wherever else deemed needed, which allowed grout to be pumped into the annular space from within the structure. It was also determined that the shoulder of the road could be extended by utilizing additional InfraSteel liner. When the dressing up of the site was complete, the entire installation took only two weeks. The total cost of the sliplining installation was $85,000, providing a savings of $275,000.

St. Lawrence County’s project was under CR 47 and was built similarly; however, there was 15 ft of cover. The existing CMP structure, which was installed in the 1960s, was skewed under the road. Also, there were utilities that would have to have been relocated if the road had been cut. Most importantly, open cutting the road would have required six weeks of road closure, detouring traffic 24 miles to Route 3, costing valuable time to emergency vehicles and the motoring public. An arched pipe liner totaling 104 ft of 97-in. x 61-in. was chosen by the Highway Department to be sliplined into the existing 103-in. x 71-in. culvert. The estimated cost to remove and replace the existing structure was $217,000.

Because St. Lawrence County’s welders had worked with the NYSDOT crew, a good working relationship had been established. Although it is generally recommend to stop the flow of water, by bypass pumping or other means, the St. Lawrence County crew operated with significant water flow, drying up the weld areas of the joints that were welded inside of the existing culvert. The crew welded the pipe together and sliplined it into place in 10 working days. The grouting and clean up took only two days. The actual material and construction cost using InfraSteel was $75,000. Subsequently, there was a direct savings of labor and material of $142,000 and there was the additional cost-savings of the detour to the traveling public of $399,800.

The construction methods used for these two projects saved the taxpayers of New York State and St. Lawrence County more than $816,800, demonstrating how to maximize maintenance dollars through teamwork and cooperation.



NCSEA – Award

DHC is proud to have been awarded the National Council of Structural Engineers Associations 2015 Excellence in Structural Engineering Award, for work on the Ballard Drive Bridge, in Seattle, WA.

Click here to read published article on the project.

The Ballard Drive Bridge is one of the many historic bascule bridges located in the Pacific Northwest.  The application of engineering design was necessary to overcome the challenges associated with providing access platforms and containment for blasting and repainting the structure, while allowing the bridge to perform its normal operations. These operations not only include supporting vehicular traffic, but raising 250 to 500 times a month to allow for vessels to pass under. The complex loading of this process presented extreme design challenges beyond that of a traditional horizontal platform. Such items included intense wind loading on the underside of the platform, stabilization during raising, analysis of all bridge framing from irregular loading, and counterweight restrictions.

Creativity of Structural Design/Complexity of Criteria or Unique Problems:

The structural design utilized a flexible Safespan platform to minimize the increased dead weight on the bridge as opposed to typical scaffold or other rigid suspended platforms. This was extremely important, as every pound of platform meant additional counterweight was necessary to balance the loading due to the limited capacity of the bridge’s original motors.  Precisely calculating the counterweight was extremely important for the analysis of all bridge members because the increased counterweight wanted to overload the bridge similar to having two sumo wrestlers on a child’s seesaw. However, although this light system meant less demand on the existing bridge, the flexibility allowed it to act as a sail in the wind during lifting events. To prevent the exposed face of the Safespan platform from slamming into the underside of the bridge under high winds as well as sliding under its own weight, a series of rigid anti-uplift and horizontal bracing members were installed to hold the deck firmly in place while strategically transferring the load into the stronger framing members. Horizontal and vertical suspension cables were also installed to allow the platform to shift orientation and eliminate any sag or sway of the deck toward the water. The creativity of this structural design was not only necessary to overcome the complex challenges of the dynamic system, but also allowed the general contractor to use existing/typical material and installation techniques, resulting in an efficient project execution.

Innovative Application of Existing Materials and Techniques:

Typical Safespan platforms consist of longitudinal wire rope cables supporting metal corrugated decking, intermediate wire rope tie up cables, and various attachment assemblies that are compatible with different bridge members.  All components in this design utilized existing Safespan assemblies with the exception of the rigid anti-uplift bracing. However, these members were devised out of scaffold tube and clamps, which are cheap and readily available.  This device was used to choke around existing bridge members and push tight against the decking to stop unwanted movement at the tie up cable locations. To further stabilize the platform, typical tie up cables were horizontally installed, giving resistance to sliding under gravity while the bridge was lifting.  The distinct quality of this design was its ability to take advantage of existing equipment without the use of specialty-prefabricated pieces, which can be both costly and time consuming to produce. D.H. Charles Engineering used all the parts and pieces available to construct multiple phasing models and employed a solution that was both technically sound and realistic for the contractor to install.

Ingenuity of Design for Efficient Use of Material and Labor:

Safespan provided the equipment for this platform; however, Purcell Paintings and Coatings performed the installation.  Although the design process was extremely extensive due to the complexity of the dynamic bridge structure, it was safely erected using typical installation procedures for horizontal Safespan platforms. The only caveat was that counterweight had to be added to the existing structure at each installation phase. However, this is a small price to pay when looking at the overall scope and ease of accessing such a complicated structure without impeding its functionality.

Exceeding Client/Owner’s Needs or Expectations:

Careful consideration and evaluation of all the potential risks, as well as close collaboration between the contractor, engineers and city representatives, were critical to the completion of this venture. The final product functioned perfectly throughout the duration of the project.  The entire system proved safe and stable, requiring very little modification or maintenance as the job proceeded. Even with rain on 70% of the workdays, there were no breeches of the containment system, and the job finished on schedule and within budget.  Given that some said a Safespan platform could not be successfully installed and function properly on this bridge under the dynamic conditions, the incredible success of the design proved to exceed the expectations of not only the client, but also the entire industry.

Suitability of the Structure for its Environment:

The nature of the project not only required complete containment of blasting operations for environmental purposes, but also demanded a fully functional bridge. Given both of these items were achieved, it is evident the design had an extremely low impact on the bridge and the surrounding environment. The structure came and went, leaving the bridge in better shape than before and with no signs of its existence.  This is the ideal result of a structure perfectly designed to fit its environment.








DHC Expands to Seattle Area

After much planning and the steady encouragement of many of our customers, DHC is proud to announce the opening of an office in the greater Seattle area.  With main branches in Santa Rosa & San Diego, and satellite offices in Oakland & Sacramento, the Seattle location becomes the 5th for DHC.

This new office is being managed by John Meissner, PE, who is a native of the Pacific Northwest and is excited about the opportunity to meet with many customers personally in coming months.

Even without local branches, DHC has maintained a tradition of effectively servicing contractors throughout the US and Canada, and has developed long-lasting relationships with many of them.  Nonetheless, we look forward to the opportunity to meet many new and existing customers in person, and plan to host various training programs and introductory meetings in the coming months and years.

If you would like to learn more about DHC, or to meet in person, please do not hesitate to contact John Meissner, President Jasper Calcara, or General Manager Luke Griffis.

Partial List of Engineering Services Provided:

  • Excavation Shoring/Safety
  • Tunneling and Boring
  • Scaffold Structures
  • Bridge Jacking and Support
  • Suspended Platforms
  • Crane and Rigging
  • False/Formwork
  • Structural Shoring
  • Re-shore
  • Fall Protection
  • Rebar Cage Stabilization
  • Containment Design





Industry Leader – Guest Lecturer – UCSD

D.H. Charles Engineering, Inc. (DHC) was invited to be a guest lecturer for roughly 120 graduating seniors of the University of California San Diego (UCSD) Structural Engineering department.  With an established passion for educating the construction industry in engineering challenges and safety, DHC was more than happy to accept the invitation, and had the perfect candidate to send to the classroom.


Chong Kim, P.E., a senior engineer and alumni of the same program at UCSD, has worked on thousands of construction engineering designs throughout the US and Canada in his career at DHC.  He took that experience on a wide variety of projects, and developed a presentation titled Temporary Structures and Construction Engineering Industry, to present to students taking the SE140 course.

2015-05-07 10.03.39

SE140: Structures and Materials Laboratory, introduces students to real world challenges and applications of structure design, including: Problem formulation, concept design, configuration design, project management, team working, ethics, and human factors.  –UCSD Course Curriculum

The variety of situations and challenges faced on a construction site can be overwhelming, with many codes and design approaches never discussed at the University.  Therefore, the presentation narrowed the field of construction engineering and focused in on the following key areas:

  • Excavation Shoring
  • Construction Slopes
  • and Slope Stability Analysis
  • Tunneling and Boring
  • Scaffold Structures
  • Bridge Jacking and Support
  • Suspended Platforms
  • Crane and Rigging
  • False/Formwork
  • Structural Shoring
  • Re-shore
  • Fall Protection
  • Rebar Cage Stabilization

Most students do not have the real-world experiences that come with time and that are hard to find in text books, so it was important to illustrate each subject area with as much photographs, colorful anecdotes, and challenges that were faced on particular projects.

excavation shorint

It was important to Chong that he connected with the students on a personal level, as he could clearly recall sitting in their position all those years ago.  He focused on the challenges and fears all young professional faces when starting their first jobs, as well as how to evolve as the their careers take them in different directions.  But most importantly, he wanted to exemplify how important it is to continue to take on challenges and overcome their professional and personal fears.  Presenting in front of peers was a first for Chong, and something he was very proud of accomplishing.

There were many insightful questions from students throughout the presentation, showing that they were truly interested in and engrossed with the subject matter.  The open discussions covered many aspects of construction engineering, codes, loads, workplace environment, as well as general challenges facing engineers in today’s world.


Evoking passion for what we do as engineers is the most important thing an educator can do, and based on the enthusiasm and response of the students, we are hopeful we were able to accomplish this.  We want to extend a special thank you to Professor Lelli Van Den Einde, Ph.D. for bringing us into her classroom and organizing the guest lecturer opportunity, and wish the best of luck to the class of 2016!


SSPC – George Campbell Award

DHC is proud to have been awarded the Society of Protective Coating’s (SSPC) George Campbell Award, for work on the Fremont Bridge, in Seattle, WA.  This honor is bestowed as recognition of outstanding achievement in the completion of a difficult or complex industrial or commercial coatings project.

In an attempt to paint a clear picture, imagine yourself working on the underside of a car in the median of a busy street.  In addition, assume you are constantly interrupted by someone jacking the back end ten feet off the ground.  To further complicate your task, suppose you are not resting comfortably on the ground, but suspended from the underside of the car itself.  Lastly, and most importantly, let’s envision that the car is not your own, but in fact is a historic 1965 Shelby GT350 in mint condition.  If you are able to put yourself in this scene, you may start to grasp the level of pressure put on the team approaching the Fremont Bridge project.

The respected and experienced firm of Purcell Painting & Coatings was awarded the contract to access, enclose and paint the bridge while protecting the local environment and ensuring roadway and boat traffic would not be impacted.  The Fremont Bridge is a double-leaf bascule bridge spanning the Fremont Cut and connecting the Seattle neighborhoods of Fremont and Queen Anne.  It was opened to the public in 1917, and added to the National Register of Historic Places in 1982.  According to WSDOT, due to low clearance, the bridge opens on average 35 times a day to allow for boat traffic.

After much planning and coordination, led by Sr. Engineer Josh Rubero, P.E. and President Jasper Calcara, P.E., D.H. Charles Engineering, Inc. developed and designed a lightweight Safespan suspended platform system which was capable of supporting workers and debris when the bridge was in use, while also remaining stable and secure when the bridge was raised throughout the day.  Raising the platform presented extreme challenges to the design team, as the suspended deck and bridge structure would be exposed to complex loading conditions not normally experienced by a traditional horizontal platform.  Intense wind loading on the underside of the platform, stabilization during raising, and very sensitive counterweight restrictions were only a few of the issues addressed throughout the design process.

With intimate involvement of WSDOT, the project was ultimately completed safely, on schedule, and to everyone’s extreme satisfaction.  Due to the historic significance of the Bridge, the vibrant, colorful and heavily populated neighborhoods it services (Fremont bills itself as the Center of the Known Universe), and the complex and unique challenges presented, DHC is proud to have been part of such a successful project.

-Josh Rubero, P.E.