Overview About M.C. Dean M.C. Dean is Building Intelligence. We design, build, operate, and maintain cyber-physical solutions for the nation's most mission-critical facilities, secure environments, complex infrastructure, and global enterprises. With over 9,000 employees, our capabilities span electrical, electronic security, telecommunications, life safety, automation and controls, audiovisual, and IT systems. Headquartered in Tysons, Virginia, M.C. Dean delivers resilient, secure, and innovative power and technology solutions through engineering expertise and smart systems integration. Why Join Us? Our people are passionate about innovative engineering that improves lives and drives impactful change. Guided by our core values—agility, expertise, and trust—we foster a collaborative, forward-thinking work environment. At M.C. Dean, we are committed to developing the next generation of technical leaders across our electrical, mechanical, engineering, and technology disciplines. Responsibilities Role Overview The Mechanical Systems Safety Engineer is the mechanical counterpart to M.C. Dean's electrical Energy Marshal role, focused on overseeing and managing the safe isolation of mechanical systems during construction, commissioning, maintenance, and operations at mission-critical data centers. This is not a design role, and you will not personally place locks or perform isolations — but you must be capable and knowledgeable enough to do so yourself. You will draw on prior experience with mechanical design documents, piping systems, and commissioning to read and interpret P&IDs, specifications, and sequence-of-operations, and translate them into safe, real-world isolation practices in the field. You will support the site's Mechanical Energy Marshal in administering the day-to-day mechanical LOTO and hazardous energy control program, with a growth path toward owning that program yourself. Our standard for success is simple to state and hard to achieve: zero uncontrolled releases of energy. That means overseeing and verifying that every isolation is executed correctly by the person doing the work, not just documented on a permit. Job Responsibilities Serve as an on-site resource for mechanical energy isolation — chilled water, condenser water, industrial/domestic water, compressed air, pneumatic, hydraulic, steam/hot water, and stored mechanical (spring, gravity, pressure) energy — supporting 24x7x365 mission-critical data center operations. Ensure safe working conditions have been established by reviewing documentation (procedures, job hazard analyses, and permits) and auditing the mechanical isolation program for construction, commissioning, maintenance, and operations activities. Work with construction and commissioning teams to ensure safe working conditions to properly test and validate the installation, operation, and performance of mechanical systems. Coordinate mechanical isolations/de-isolations with electrical Energy Marshals and other stakeholders where systems are interdependent (e.g., pump and fan motor LOTO, controls interlocks). Oversee and verify that absence-of-energy checks and two-person (pilot-and-copilot) verification are properly executed by field personnel before and during mechanical isolation activities. Reinforce execution-level ownership in the field — the person physically performing an isolation owns getting it right, and your role is to ensure that accountability isn't diluted by relying on a policy document or permit alone. Lead pre-isolation and startup kickoff meetings prior to first-of-kind (FoK) startup of mechanical equipment or systems. Understand the Commissioning Plan of Record and Commissioning specifications as they relate to the energization of mechanical equipment for the jobsite. Advance mechanical safety improvements on the job and for future designs. Support implementation of the site-specific Mechanical Hazardous Energy Control Plan. Review Near-Isolated Work scenarios and develop risk assessments that determine safe work practices for activities taking place within a partially isolated or energized environment. Maintain field presence during major commissioning or mechanical isolation activities (FoK startups, hydrostatic/pneumatic pressure testing, and turned-over spaces) for operational oversight. Coordinate with the Commissioning Lead on daily Commissioning Team activities related to mechanical systems. Participate in mechanical LOTO inspections and audits. Coordinate all LOTO and outage requests with M.C. Dean Safety, the General Contractor, the Client, and affected vendor/subcontractor parties. Coordinate mechanical isolation requirements and potential impacts to the Commissioning schedule for the jobsite. Train new and existing employees in mechanical energy isolation processes and procedures. Train and verify the competency of individuals performing LOTO by mechanical equipment type, contributing to a continuously growing pool of qualified and authorized personnel — not a one-time certification. Attend and participate in daily Commissioning meetings and weekly all-hands meetings for the jobsite. Develop, review, and approve mechanical LOTO permits. Have the ability to lead and attend M.C. Dean ORMs (safety briefs) with the Commissioning team/vendors. Assure PPE and necessary tools and equipment are suitable for mechanical isolation work. Program Support Support the site's Mechanical Energy Marshal in administering the mechanical hazardous energy control program: Assist in maintaining hazardous energy control documentation, isolation procedures, and LOTO permit records for mechanical equipment. Help administer the mechanical LOTO permitting process — issuing, tracking, and filing permits — and provide field feedback to support ongoing program improvement.

Qualifications Required Qualifications:

Bachelor's degree in Mechanical Engineering or a related engineering discipline required; with 2+ years of applicable industry experience in mechanical field engineering, maintenance, or commissioning, ideally in mission-critical facilities. Exposure to or direct support of mechanical system design activities — P&IDs, engineering calculations, specifications — sufficient to read, interpret, and apply these documents in the field. Hands-on experience with the startup and commissioning of mechanical equipment or systems, including resolving field issues. Demonstrated experience identifying isolation-related system vulnerabilities — single points of failure, improper isolation capability, control logic gaps — through P&ID review, sequence-of-operations validation, and field walkdowns. Understanding of mechanical system sequence of operations and the ability to isolate potential sources of mechanical energy with potential back-feeds (e.g., shared headers, standby pumps) and perform absence-of-energy verification. Working knowledge of data center or industrial mechanical systems: chilled water plants, cooling towers, CRAH/CRAC units, industrial/domestic water, compressed air, and fire protection. Understanding of hazardous mechanical energy sources — pressure, hydraulic, pneumatic, thermal, gravity, and stored mechanical energy — and the ability to help isolate them and verify a zero-energy state. Familiarity with

OSHA 1910.147

(Control of Hazardous Energy / Lockout-Tagout). Ability to read and interpret P&IDs, mechanical one-lines/schematics, and construction drawings. Working knowledge of absence-of-energy verification and two-person (pilot-and-copilot) verification practices, sufficient to oversee, audit, and enforce them in the field — this role manages and verifies the isolation process rather than personally performing lockout/tagout.

Preferred Qualifications:

Experience with piping and fluid system analysis tools (e.g., AFT or equivalent). Exposure to mechanical infrastructure audits or resiliency/availability assessments.

OSHA 10/30

certification. Prior experience operating under two-person or independent-verification protocols for energy isolation. Experience coordinating with electrical Energy Marshals or electrical safety programs.

Abilities:

Exposure to computer screens for an extended period of time. Sitting for extended periods of time. Reach by extending hands or arms in any direction. Have finger dexterity in order to manipulate objects with fingers rather than whole hands or arms, for example, using a keyboard. Listen to and understand information and ideas presented through spoken words and sentences. Communicate information and ideas in speaking so others will understand. Read and understand information and ideas presented in writing. Apply general rules to specific problems to produce answers that make sense. Identify and understand the speech of another person.

Qualifications:

Required Qualifications:

Bachelor's degree in Mechanical Engineering or a related engineering discipline required; with 2+ years of applicable industry experience in mechanical field engineering, maintenance, or commissioning, ideally in mission-critical facilities. Exposure to or direct support of mechanical system design activities - P&IDs, engineering calculations, specifications - sufficient to read, interpret, and apply these documents in the field. Hands-on experience with the startup and commissioning of mechanical equipment or systems, including resolving field issues. Demonstrated experience identifying isolation-related system vulnerabilities - single points of failure, improper isolation capability, control logic gaps - through P&ID review, sequence-of-operations validation, and field walkdowns. Understanding of mechanical system sequence of operations and the ability to isolate potential sources of mechanical energy with potential back-feeds (e.g., shared headers, standby pumps) and perform absence-of-energy verification. Working knowledge of data center or industrial mechanical systems: chilled water plants, cooling towers, CRAH/CRAC units, industrial/domestic water, compressed air, and fire protection. Understanding of hazardous mechanical energy sources - pressure, hydraulic, pneumatic, thermal, gravity, and stored mechanical energy - and the ability to help isolate them and verify a zero-energy state. Familiarity with

OSHA 1910.147

(Control of Hazardous Energy / Lockout-Tagout). Ability to read and interpret P&IDs, mechanical one-lines/schematics, and construction drawings. Working knowledge of absence-of-energy verification and two-person (pilot-and-copilot) verification practices, sufficient to oversee, audit, and enforce them in the field - this role manages and verifies the isolation process rather than personally performing lockout/tagout.

Preferred Qualifications:

Experience with piping and fluid system analysis tools (e.g., AFT or equivalent). Exposure to mechanical infrastructure audits or resiliency/availability assessments.

OSHA 10/30

certification. Prior experience operating under two-person or independent-verification protocols for energy isolation. Experience coordinating with electrical Energy Marshals or electrical safety programs.

Abilities:

Exposure to computer screens for an extended period of time. Sitting for extended periods of time. Reach by extending hands or arms in any direction. Have finger dexterity in order to manipulate objects with fingers rather than whole hands or arms, for example, using a keyboard. Listen to and understand information and ideas presented through spoken words and sentences. Communicate information and ideas in speaking so others will understand. Read and understand information and ideas presented in writing. Apply general rules to specific problems to produce answers that make sense. Identify and understand the speech of another person.