Senior Mechanical Engineer

Amentum is a global leader in advanced engineering and innovative solutions, supporting critical missions across defense, intelligence, energy, and civilian sectors. Our people are our competitive advantage, driven by purpose, collaboration, and a commitment to delivering excellence for our customers and communities. We are currently seeking a Senior Mechanical Engineer to support our Projects
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As a senior-level mechanical engineer, you will serve as a technical leader responsible for the design, coordination, and delivery of building mechanical systems for industrial and government facilities. This role includes oversight of HVAC, plumbing, and piping system designs; leadership of mechanical engineering teams; and accountability for technical quality and compliance throughout the project lifecycle.

The successful candidate will work closely with project management, discipline leads, and clients to deliver fully coordinated, code-compliant, and high-quality engineering solutions in accordance with Amentum’s established quality procedures.

• Lead and oversee the design of HVAC, plumbing, and piping systems, including B31.3 process piping
• Serve as technical authority for mechanical system design within assigned project scope
• Review, approve, and check engineering calculations, layouts, specifications, and drawings
• Apply advanced engineering judgment to resolve complex design issues
• Support project planning by assisting with:
• Scope definition
• Equipment sizing
• Schedule development
• Budget control for mechanical design activities
• Coordinate mechanical designs with structural, electrical, architectural, and process disciplines
• Apply applicable codes, standards, and procedures (e.g., IMC, ASHRAE, NFPA, ASME)
• Interface with clients and other stakeholders as a senior technical contributor
• Provide senior‑level support during procurement and construction phases, including review and resolve RFIs, submittals, and field issues
• Mentor and guide engineers and designers on applicable codes, standards, and best practices
• Ensure all work under your technical responsibility complies with Amentum’s engineering and quality procedures

• B.S. Mechanical Engineering from an ABET accredited engineering program
• 15+ years in industrial/government design of Mechanical, HVAC, Plumbing Systems, and related mechanical building systems
• Demonstrated experience delivering projects from concept through detailed design completion
• Proven ability to lead teams of engineers and designers within budget and schedule constraints
• Proficiency with discipline-specific tools such as:
  Carrier HAP, Trane TRACE, Pipe Flo, AutoCAD, Micro Station, etc.
• Thorough knowledge of applicable codes & standards (International Mechanical Code, NFPA, ASHRAE, etc.)
• Professional Engineer (PE) license required

• Prior nuclear, DOE, or high‑hazard facility design experience
• Experience working under a formal quality program (ISO 9001, NQA
  1)
• Strong leadership, communication, and technical mentoring skills
• Demonstrated attention to detail and commitment to technical excellence
• Proficiency with Microsoft Office (Excel, Word, Outlook)

• Primarily office-based work in a secure engineering environment
• Amentum office location is preferred; hybrid or remote work may be available by prior agreement based on role and project requirements
• Occasional exposure to industrial facilities, which may include elevated noise levels, hazardous materials, or controlled areas
• Site visits may be required

• Ability to sit or stand for extended periods
• Ability to lift up to 35 lbs occasionally
• Vision correctable to 20/20
• Ability to read and use computer-aided design software effectively
• Appropriate PPE and training will be provided as required

• U.S. Citizenship required (no dual citizenship)
• Valid driver's license is required
• Ability to obtain and maintain a security clearance
• Ability to passpre-employment background investigation and drug screening
• Willingness to work overtime or outside normal hours as needed
• Professional appearance appropriate for a customer‑facing engineering…