Sr. Mechanical Engineer - Site Development

Job Description

Date Posted:

2026-07-22\n

Country:

United States of America \n

Location:

US-MA-MARLBOROUGH-MA1 ~ 1001 Boston Post Rd ~ BLDG 1 \n

Position Role Type:

Onsite \n

U.S. Citizen, U.S. Person, or Immigration Status Requirements:

The ability to obtain and maintain a U.S. government issued security clearance is required.​ U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance \n

Security Clearance Type:

DoD Clearance: Secret \n

Security Clearance Status:

Active and existing security clearance required after day 1\n

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At RTX, the world's largest aerospace and defense company, 185,000 great minds are united by purpose and inspired to make a difference solving the world’s most complex problems. With our three market leading businesses, world-class operations and investments in research and development, we offer capabilities and opportunity no one else can. Together, we push the boundaries of known science and find new ways to connect and protect our world. 

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Raytheon brings the strength of more than 100 years of experience and renowned engineering expertise to meet the needs of today’s mission and stay ahead of tomorrow’s threat. We deliver solutions that help our nation and allies defend freedoms and deter aggression, creating a safer, more secure world. Join us and help shape the future of aerospace and defense.

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At Raytheon, the foundation of everything we do is rooted in our values and a higher calling – to help our nation and allies defend freedoms and deter aggression. We bring the strength of more than 100 years of experience and renowned engineering expertise to meet the needs of today’s mission and stay ahead of tomorrow’s threat. Our team solves tough, meaningful problems that create a safer, more secure world. 

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Raytheon Mechanical Engineering (ME) is the premier organization for mechanical hardware design, development, production, and research. ME strives to minimize total systems cost, while maximizing production. This is achieved through commitment, training and continuous improvement using common tools and processes. The capabilities encompass a broad range of technical disciplines which include engineering, operations, technical services, materials and processes, analysis and test and documentation.

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The Tactical Radars and Effectors department within Raytheon Hardware Engineering supports the development, production, and deployment of multiple defense products including radars, missiles, command and control systems, and naval electronics. The products support US Government and international customers.

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The Mechanical Engineering Department is seeking an Sr. Mechanical Engineer to provide Site Development and Integration expertise. The Site Development & Integration section performs large scale, complex site development and onsite support. Engineers will perform research, design, support construction and development of military and commercial facilities.

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The position is for the Marlborough, Massachusetts location. This position is an onsite role.

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What You Will Do

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• Provide assistance with collecting, compiling, and analyzing data from the physical work site, surveys, blueprints, schematics, technical drawings, HVAC load calculations, system performance reports, and other engineering inputs used for HVAC system design and construction.
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• Apply mechanical engineering techniques and HVAC design principles in working with senior engineering staff to identify improvements across project phases including concept development, preliminary design, final design, and construction administration.
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• Perform HVAC engineering design work in a professional manner, and conduct field assessments of proposed and existing site conditions, mechanical rooms, HVAC equipment, and system distribution to determine conformance with applicable codes, industry standards, for team review against project performance goals.
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• Aid in preparing overall mechanical plans and updates to infrastructure layouts requiring coordination with owners, architects, electrical engineers, sub‑consultants, clients and other in-house senior staff.
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• Develop and incorporate standard HVAC design technologies, digital controls, and building systems strategies to aid senior staff in developing future‑ready design solutions.
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• Verify site characteristics and provide mechanical/HVAC technical assistance related to documenting existing building conditions – including automatic temperature control systems, air distribution systems (supply, return, exhaust), hydronic systems (chilled water, heating water), and general building mechanical equipment.
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• Work with cross‑functional teams of engineers, designers, and technical professionals to execute HVAC‑focused project work, including system calculations, equipment selections, permit documentation, must be proficient with Revit/AutoCAD deliverables, and compliance analyses.
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• Prepare HVAC‑related data and visualizations such as load calculation tables, equipment schedules, airflow diagrams, heat transfer calculations, and mechanical drawings in AutoCad/Revit design software.
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• Interact with subcontractors, and clients in a confident and professional manner regarding HVAC system compliance and design intent.
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• Collaborate with architects, structural engineers, electrical engineers, and project managers on multiple office design.
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• Remain current in the latest HVAC engineering design strategies, innovations, energy‑efficient system designs, and industry expected sustainability practices.
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• Use preliminary sketches, diagrams, and other engineering information to generate conceptual layouts for notional facility systems using CAD tools such as Autocad, and Revit.
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• Develop facility requirements and design development documents for defense system equipment in accordance with system requirements.
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• Work with Architect/Engineering (A/E) contractors facility design effort.
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• Document and manage action items, field issues, and change requests including coordination with home office engineering, equipment suppliers, and onsite teams.
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• Collaborate and coordinate work activities with Raytheon, Government, and subcontractors.
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Qualifications You Must Have

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• 5 to 7 years of relevant post‑education experience with direct HVAC and mechanical system design.
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• Proficient with HVAC engineering principles, basic/standard system design processes, and their application to overall building projects.
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• General/Developing knowledge of HVAC system design for buildings and infrastructure, including airside and waterside systems.
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• Experience with HVAC load calculations, mechanical system efficiencies, energy code compliance, and general consultant construction administration of HVAC systems.
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• General/developing working knowledge of mechanical and HVAC codes, standards, and regulations including ASHRAE, IMC, IECC, and related compliance requirements.
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• Well‑developed ability to perform HVAC calculations including heat gain/loss, duct and pipe sizing, system pressure calculations, and equipment selection.
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• Ability to assist in planning and conducting visual observations of HVAC equipment installations, mechanical rooms, ductwork, hydronic piping, and control systems.
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• Effective communication skills – both verbal and written.
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• Demonstrated attention to detail, self‑leadership, and ability to manage multiple HVAC design tasks simultaneously.
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• Proficient with AutoCAD, mechanical design software, load calculation tools, and spreadsheets used for HVAC system analysis.
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• Strong critical thinking and problem‑solving skills to assist in developing efficient, code‑compliant HVAC solutions.
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• Ability to work schedules that are conducive to project requirements may extend beyond the typical work week.
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• Bachelors degree from an ABET accredited University and has passed the fundamentals of Engineering Exam (EIT/FE) plus six (6) years of related experience or demonstrated equivalency of experience and/or education.
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• Familiarity with building codes for commercial, industrial and military/Department of Defense (DoD) facilities including United Facilities Criteria’s (UFC).
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• The ability to obtain and maintain a U.S. government issued security clearance is required.
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• U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.
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Qualifications We Prefer

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• Experience working with and developing Facility Requirement Documents.
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• Comfortable working in a high energy environment with multiple concurrent and quick-turn deadlines.
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• Willingness to learn and desire to overcome challenges to achieve individual and team success.
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• Strong written and oral communication.
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• Strong attention to detail and orientation to produce high quality work products.
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• Capable of using spreadsheet, word processing and standard Microsoft software.
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• Ability to work with and collaborate with a multi-disciplinary team.
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What We Offer

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Our values drive our actions, behaviors, and performance with a vision for a safer, more connected world. At RTX we value: Trust, Respect, Accountability, Collaboration, and Innovation.

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Learn More & Apply Now!

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  Employees who are working in Onsite roles will work primarily onsite. This includes all production and maintenance employees, as they are essential to the development of our products.

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• Please consider the following role type definition as you apply for this role.
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• Onsite: Employees who are working in Onsite roles will work primarily onsite. This includes all production and maintenance employees, as they are essential to the development of our products.
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• Relocation Offered Based On Eligibility.
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• Please consider the following role type definition as you apply for this role.
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• Onsite: Employees who are working in Onsite roles will work primarily onsite. This includes all production and maintenance employees, as they are essential to the development of our products.
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• Please ensure the role type defined below is appropriate for your needs before applying to this role. This position is classified as:
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• Onsite: Employees who are working in Onsite roles will work primarily onsite. This includes all production and maintenance employees, as they are essential to the development of our products.
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• Hybrid: Employees who are working in Hybrid roles will work regularly both onsite and offsite. Ratio of time working onsite will be determined in partnership with your leader.
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• Remote: Employees who are working in Remote roles will work primarily offsite (from home). If you live within a reasonable commute of an RTX site with other colleagues you interact with, your manager will discuss whether there is a degree of onsite presence associated with this role.
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• Candidates will learn more about role type and current site status throughout the recruiting process. For onsite and hybrid roles, commuting to and from the assigned site is the employee’s personal responsibility.
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• Requires advanced knowledge of work area typically obtained through advanced education combined with experience. May have practical knowledge of project
  \n management. Practical to substantial knowledge of RTX projects, programs or systems with the ability to make enhancements and leverage in daily work.
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• Typically requires: A University Degree or equivalent experience and minimum 5 years prior relevant experience, or An Advanced Degree in a related field and minimum 3 years experience
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• Engineering/Other Technical Positions: Typically requires a degree in Science,Technology, Engineering or Mathematics (STEM) and a minimum of 5 years of prior relevant experience unless prohibited by local laws/regulations.
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As part of our commitment to maintaining a secure hiring process, candidates may be asked to attend select steps of the interview process in-person at one of our office locations, regardless of whether the role is designated as on-site, hybrid or remote.

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The salary range for this role is 86,800 USD - 165,200 USD. The salary range provided is a good faith estimate representative of all experience levels. RTX considers several factors when extending an offer, including but not limited to, the role, function and associated responsibilities, a candidate’s work experience, location, education/training, and key skills.\n

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Hired applicants may be eligible for benefits, including but not limited to, medical, dental, vision, life insurance, short-term disability, long-term disability, 401(k) match, flexible spending accounts, flexible work schedules, employee assistance program, Employee Scholar Program, parental leave, paid time off, and holidays. Specific benefits are dependent upon the specific business unit as well as whether or not the position is covered by a collective-bargaining agreement.\n

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Hired applicants may be eligible for annual short-term and/or long-term incentive compensation programs depending on the level of the position and whether or not it is covered by a collective-bargaining agreement. Payments under these annual programs are not guaranteed and are dependent upon a variety of factors including, but not limited to, individual performance, business unit performance, and/or the company’s performance.\n

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This role is a U.S.-based role. If the successful candidate resides in a U.S. territory, the appropriate pay structure and benefits will apply.\n

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RTX anticipates the application window closing approximately 40 days from the date the notice was posted. However, factors such as candidate flow and business necessity may require RTX to shorten or extend the application window.\n

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RTX is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability or veteran status, or any other applicable state or federal protected class. RTX provides affirmative action in employment for qualified Individuals with a Disability and Protected Veterans in compliance with Section 503 of the Rehabilitation Act and the Vietnam Era Veterans’ Readjustment Assistance Act.

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