Applied Knowledge

Infrastructure Vulnerabilities to Explosions and Natural Disasters

On Saturday October 8, 2022, news broke of an explosion on the Kerch Bridge in Crimea that caused severe damage to one of the structural bays of the bridge, and ignited a severe fire on an adjacent rail bridge that had a train transporting fuel. This devastating attack showed key vulnerabilities for critical infrastructure that could have been mitigated during the design phase with a detailed threat and vulnerability assessment taking into account potential threats and adjacencies

Bridges are generally very robust structures designed for heavy gravity loads caused by moving vehicular traffic and are optimized for the travel direction of the heavy loads. These design requirements result with the bridge deck generally being supported on the large vertical piers, relying on the heavy self-weight of the bridge to provide stability. In these situations, uplift is not the governing load direction, and the connection design therefore focuses much more on the gravity loads. However, in seismic areas, these connections may be upgraded to support severe lateral and uplift load. This creates a potential vulnerability such that, under severe load condition such as explosions, the bride deck could fail under load reversal caused by direct uplift loads or rebound caused by the dynamic vibration of the bridge.

Another vulnerability that could have been prevented during the assessment and design phase is associated with adjacencies of critical systems. It is very common to utilize bridges and other infrastructure to transport critical utilities (gas pipes, electrical/communication systems, etc.) without paying attention to the effects that the failure of the bridge can cause on these systems and the areas affected. Also, the adjacency between the vehicle bridge and the railroad bridge, which was likely considered to optimize cost, can result in propagation of damage with a secondary fire in the rail bridge.

This example, and other examples like the collapse two bridges within a matter of weeks in the amazon that caused the isolated of a large community, show that infrastructure planning is missing key design studies like threat and vulnerability assessment before and after construction as well as disaster recovery plans that can help mitigate the disruption effects.

New Job! Structural/Blast Design and Testing Engineer

Stone Security Engineering is an internationally recognized consulting firm specializing in the protection of people, buildings, and structures from accidental and manmade hazards. We focus on Extreme Loading (including blast, ballistics, vehicle ramming, and forced entry resistance) and safety, engineering and design. Stone has offices in New York and the Washington DC Metro area and supports testing at the Stone-OBL Large-Scale Blast Test Facility in Bend Oregon.

This position is based in Salem Oregon and will support Stone’s operations related to:

  • Research, product development and testing for extreme loads (blast, ballistics, and forced entry), and
  • Protective design consulting work for our east coast offices.

Research, Product Development and Testing 

The position will provide support for product development, test planning, test setup design, and test execution support for extreme loading test efforts for a variety of Protective Design Products and/or techniques applicable to the Protective Design Industry. Roles include the following:

  • Provide structural engineering analysis and detailing support for development of Protective Design Products for customers. This will be accomplished under the guidance of, and collaboration with, the overall Stone technical team.
  • Regular interaction with Stone’s in-house testing technical team and the customer program team to define test objectives and execution requirements to support program implementation.
  • Coordinate with the test team, customer test lead, and test site manager on execution processes, procedures, quality control and documentation requirements.
  • Attend meetings and provide guidance on test objectives and requirements during the test planning process.
  • Develop and document test plans and/or test plan inputs required by the customer to execute program testing.
  • Structural design of test-setup configuration, develop and/or review and approve shop drawings, and inspect and/or supervise construction related activities at the test site.
  • Work with materials sub-contractors to ensure test apparatus structural elements are properly constructed, on-time, and well-coordinated with the test site team.
  • Post-process test data and coordinate with the instrumentation engineer to finalize data capture, photo, and video formatting, and the required customer deliverables.
  • Documentation of pre- and post-testing conditions and develop test reports.

Protective Design Consulting Work

Because our testing programs have seasonal highs and lows, the position will also support Stone’s overall protective design consulting work. This may include blast vulnerability assessments, blast resistant building design and detailing, building assessment site visits, etc. This will be accomplished under the guidance of, and collaboration with, the overall Stone technical team.

Required Qualifications:

  • Bachelor of Science, or higher degree, in civil, structural or mechanical engineering and 5+ years’ experience.
  • Practical experience and knowledge of structural design and construction, including concrete, steel, wood, glazing and other building materials.
  • Works well within a team but does not require constant supervision.
  • Able to communicate easily and efficiently with both technical and non-technical staff, clients and contractors.
  • Experienced user of MS Office products, AutoCAD and Sketchup.
  • Ability to travel to Bend Oregon on a regular basis.
  • Ability to obtain and maintain a Department of Defense Secret clearance as needed, which includes U.S. citizenship.

Desired Qualifications:

  • Experience with test procedure development and test execution.
  • Experience with on-site building construction.
  • Experience with dynamic and/or blast resistant analysis and design.
  • Licensed Engineer in the State of Oregon or able to obtain licensure.
  • Knowledge in test methodology, project management, and requirements verification/validation.
  • Experience in documenting test performances, failures and corrective actions.
  • Experience in and supporting test program for design reviews, schedule meeting, liaison with test ranges. Etc.

If you are interested, please send your resume and cover letter to or see our LinkedIn or ZipRecruiter posts.

What Perimeter Barriers are Right For You: First Questions To Ask

Perimeter barriers – whether they be crash rated or not – are an important part of many of the projects we all work with on a day-to-day basis.

The following is a quick exercise that you can use to start your mind, and the project team, working in the proper direction.

Imagine that you have not yet put pencil to paper and you are just starting to think about what types of perimeter protection your site might need. Click here for some (but not all) questions you should ask yourselves. Many of the answers to the questions below will be provided by the project brief, but you must still know the answer to start the perimeter design.