Mechanical Engineer, Thermal and Fluid Systems

Lemonergy; Torrance (CA); On-site; USD 125,000 - 150,000; Full time

Benefits offered by this job

Healthcare benefits

Parental leave

Generous PTO

401(k)

Relocation assistance

Job summary

Arc is hiring in Los Angeles for a mechanical/thermal engineer focused on electric marine propulsion. You will own thermal and fluid systems, perform structural/thermal analyses, and work with naval architects to integrate hull-to-machinery components. You will release drawings and BOMs while driving DFx with manufacturing and supply chain.

Role involves testing on bench, at the dock, and on the water, plus collaboration with electrical/controls teams. Occasional travel may be required.

Qualifications

• Bachelor’s degree in Mechanical, Marine, Ocean, or Aerospace Eng, Naval Architecture, or related field.

Responsibilities

• Own thermal and fluid systems across the vessel, including cooling loops and propulsion interfaces.
• Conduct structural and thermal analysis to size and validate components.
• Collaborate on hull-to-machinery integration with naval architects.
• Release drawings, GD&T, BOMs, and drive DFx with manufacturing and supply chain.
• Build and execute test plans on bench, dock, and water; iterate design based on data.
• Partner with electrical & controls teams to integrate powertrain.
• Support propulsion and drivetrain system design including shafting and bearings.
• Assist with USCG/ABS compliance and supplier evaluation.
• Travel up to 15%.

Skills

FEA

3D CAD

GD&T

PDM/PLM

Shop & water work

Education

Bachelor’s degree in Mechanical/Marine/Ocean/Aerospace Eng or Naval Architecture

Tools

SolidWorks

NX

CATIA

Job description

What we’re building

The marine industry supports recreation, global commerce, and national defense. And yet it runs on technology that hasn't meaningfully changed in fifty years. Until now.

Arc is on a mission to electrify the marine industry. We're rethinking powertrains, software, and vessel designs from first principles. And we're already executing. We started with consumers to develop and harden our core technology. We’re now scaling production of our flagship model with new models and sectors on the horizon. Now we’re extending our platform to commercial applications, starting with tugs, ferries, and defense, with years worth of signed contracts and a pipeline that spans every vessel type on the water.

The technology is proven, the momentum is building, and the opportunity is enormous. The marine industry is going electric and Arc is building the platform that powers it

Who we’re looking for

We're looking for someone fired up by the mission and ready to build. You'll thrive here if you move fast, take ownership, and care about the details.

This is a full-time, on-site role at our Los Angeles headquarters.

What You'll Do

• Owning thermal and fluid systems across the vessel, including cooling loops, pumps, plumbing, bilge, and ventilation


• Running structural and thermal analysis to size and validate components before they get built


• Collaborating with naval architects on hull-to-machinery integration, including packaging, weight and LCG, foundation loads, and appendage interfaces


• Releasing drawings, GD&T, BOMs, and specifications, and driving DFM/DFA with manufacturing and supply chain


• Building and executing test plans on the bench, at the dock, and on the water, then turning that data back into design changes


• Partnering with electrical and controls engineers to integrate Arc's powertrain into the vessel


• Supporting the design of marine propulsion and drivetrain systems, including shafting, couplings, mounts, seals, bearings, and steering hardware


• Supporting USCG and ABS compliance and evaluating suppliers for critical marine hardware


• Up to 15% travel

Minimum Qualifications

• Bachelor's degree in Mechanical, Marine, Ocean, or Aerospace Engineering, Naval Architecture, or a related engineering discipline


• 3+ years designing and releasing mechanical systems for production, ideally thermal, fluid, or structural systems on vessels or vehicles


• Experience owning a design through build, test, and iteration rather than handing it off at release


• Hands-on experience with structural and thermal analysis, including FEA and hand calculations


• Proficiency with 3D CAD (SolidWorks, NX, or CATIA), GD&T, and PDM/PLM workflows


• Ability to work hands-on in the shop and on the water, including occasional sea trials


• Ability to lift, push, and pull 50 lbs


• This position may require access to information controlled under U.S. export control laws and regulations, including the International Traffic in Arms Regulations (ITAR). Applicants must be a \"U.S. person\" as defined by ITAR (22 CFR120.62), i.e., a U.S. citizen, U.S. national, lawful permanent resident, or protected individual (asylee or refugee).

Bonus Qualifications

• Experience designing marine cooling, bilge, ventilation, or other commercial vessel systems


• Familiarity with USCG and ABS rules


• Experience with electric or hybrid marine propulsion


• Professional Engineer (PE) license in Mechanical (Thermal and Fluid Systems) or Naval Architecture and Marine Engineering


• Passion for taking a vessel from a blank sheet to on-water validation


• Comfortable working at a fast but sustainable pace


• Enthusiasm for boating and the water

At Arc, we encourage diversity and consider all qualified applicants equally for employment, regardless of background, identity, or status. You’re always welcome to reach out even if you don’t meet many of these qualifications. Passion and aptitude make up for a lot.

What we offer

The base salary for this role is P2: $125,000 P3: $150,000 annually,

Highly competitive equity grants are included with full time offers. As well as semi-annual bonuses tied to your impact, not just your tenure.

Additionally, Arc Offers Top-tier Benefits For Full-time Employees, Including

• Healthcare benefits — 99% employer-paid medical, dental, and vision


• Parental leave — 14 weeks fully paid for birthing and non-birthing parents


• Generous time off — Highly competitive PTO with an opportunity to earn more time with tenure


• Income protection — Life and disability insurance for all employees


• Retirement savings — Traditional and Roth 401(k) access


• Water fund — $500 for you to spend each year to get out on the water, however you choose


• Professional development — $500 annual reimbursement for professional development and a monthly AI stipend


• Safety Support- Annual reimbursement for PPE, ergonomic equipment and anything that ensures we keep our crew safe


• Captain training — Training and access to take Arc boats out with friends and family


• Office perks — Daily lunches, snacks, and good coffee while onsite


• Relocation assistance — Available depending on role eligibility.

Our values

We move with urgency and build with care. We value these five things above all else:

• Ownership over both your work and the company’s success


• Empathy for colleagues and for customers


• Humility in problem solving and collaboration


• Pragmatism for navigating ambiguity quickly and sensibly


• Inclusion of different backgrounds, opinions, cultures, and perspectives.

We want people who share and embody these values. It is vital that our values align - we’d be happy to elaborate on any or all of these during the interview process.