Senior-Level Mechanical Designer (Hybrid/Remote)

Amentum•Oak Ridge, TN

1d•Hybrid

About The Position

As a senior-level mechanical designer, you will provide support for the design and development of HVAC, piping, and plumbing systems for industrial and government (nuclear / DOE) facilities. This role is responsible for the creation, coordination, and checking of complex 3D models and drawing packages, while working closely with mechanical engineers and multidisciplinary teams to deliver high‑quality, fully coordinated design deliverables. The Senior Mechanical Designer serves as a technical leader within the design team, providing mentoring to junior designers and ensuring designs comply with project requirements, codes, and established quality procedures.

Requirements

High School Diploma or GED
15+ years of experience in mechanical design for industrial or government facilities
Strong experience with HVAC, piping, and plumbing layout design
Proficiency with 3D modeling tools such as: SmartPlant 3D / Plant 3D / Revit
Ability to read and interpret engineering calculations, P&IDs, and specifications
Experience producing fully coordinated drawing packages
U.S. Citizenship required (no dual citizenship)
Valid driver's license is required
Ability to obtain and maintain a security clearance
Ability to pass pre-employment background investigation and drug screening

Nice To Haves

Associate Degree in Drafting, Design, or Engineering Technology preferred
Prior industrial, nuclear, DOE, or high‑hazard facility design experience
Experience working under a formal quality program (ISO 9001, NQA 1)
Strong organizational and communication skills
Demonstrated attention to detail and commitment to technical excellence

Responsibilities

Develop and maintain 3D models for HVAC equipment, ductwork, piping, and plumbing systems using SmartPlant 3D, AutoCAD Plant 3D, Revit, or similar tools
Produce detailed design deliverables, including: Equipment layouts, Duct and piping plans, Isometric drawings, Sections, and details
Incorporate engineering design criteria, markups, and redlines into constructible models and drawings
Coordinate designs with mechanical engineers and other disciplines (architectural, structural, electrical, process, I&C, etc.)
Participate in interference detection and resolution (clash reviews)
Perform peer checking and quality reviews of drawings and models created by other designers
Ensure design outputs comply with applicable project standards, client requirements, and quality assurance procedures
Provide direction and mentorship to junior and mid‑level designers
Assist with task planning and workload coordination within the design team
Support training and standardization efforts for design tools and workflows