Senior Mechanical Design Engineer – Large Structures Permanent | Sheffield Flexible start and finish times | Hybrid working options Benefits: 25 days holiday bank holidays (rising with service) Holiday buy scheme Enhanced pension and life insurance A fast-growing, PE-backed engineering business is expanding its mechanical design team to deliver landmark projects across defence, nuclear, aerospace and high-integrity moving equipment. This is an excellent opportunity for a Senior Mechanical Engineer who enjoys solving complex design challenges within a collaborative, technically driven environment. You’ll take ownership of mechanical design for large fabricated and precision-engineered structures such as cranes, lifting systems and heavy mechanical handling equipment. Projects span the full lifecycle from concept and substantiation through to commissioning and client delivery. The Role * Lead mechanical design across complex, bespoke, large-scale moving structures * Produce and review detailed engineering calculations to verify and substantiate designs * Design and validate large fabricated components including box girders, linkages and assemblies * Approve 3D models, 2D drawings and documentation to ensure CE/UKCA compliance * Work closely with systems, controls and EC&I teams to deliver integrated solutions * Provide technical support through manufacture, installation and commissioning About You * Proven background in mechanical design of cranes, lifting systems or large machinery * High proficiency for stress and structural calculations * Skilled with CAD software such as SolidWorks or Inventor and familiar with drawing standards * Working knowledge of Eurocodes, CE/UKCA compliance and design risk assessment * Strong communicator who enjoys working collaboratively across disciplines and with clients * Degree-qualified in Mechanical Engineering (Chartered or working towards is ideal) This role is being managed by Connected Search, a specialist recruitment partner to engineering and advanced manufacturing businesses across the UK