Chartered mechanical engineering consultancy delivering mechanical analysis and design for New Zealand's defence, heavy industry, and infrastructure sectors. Independent. Rigorous. Wellington-based. Available to work throughout New Zealand and Australia.
Procurement is demanding. Equipment must perform under extreme load conditions, comply with rigorous standards, and be independently verified before they are fielded. The cost of a structural failure in a military context — to personnel, equipment, and mission — is unacceptable.
Crutchworks provides the independent mechanical engineering rigour that defence contractors, prime suppliers, and government procurement teams require. As a chartered engineer with deep FEA and mechanical design experience, Andrew Crutchley brings the technical depth of a consultancy with the accountability and responsiveness of a specialist practitioner.
Using ANSYS Mechanical, we perform detailed stress, strain, fatigue and deformation analysis on military and heavy-industry components. FEA allows the analysis of complex geometry and loading scenarios that are not possible with manual calculations — including dynamic shock, impact, and vibration — to be assessed without costly physical prototyping. Reports are produced to support regulatory sign-off and procurement requirements.
We design and certify Operator Protective Structures for military and heavy vehicles, including Rollover Protective Structures (ROPS), Falling Object Protective Structures (FOPS), and Operator Protective Structures (OPS). Designs are validated against ISO 3471, ISO 8082, AS/NZS standards and WorkSafe NZ requirements — critical for any NZDF vehicle or plant procurement.
From concept through to detailed design, we produce 3D models and engineering drawings using Autodesk Inventor. Clients receive design packages suitable for manufacture, procurement documentation, and long-term asset management. We work alongside your existing design teams or independently as lead designer.
Structural designs are assessed against applicable New Zealand and Australian standards including AS3990, AS4100 and AS1418. For defence work equipment can be assessed against standards such as STANAG 4569 and can produce verification documentation to support formal procurement processes.
Providing an independent engineering review of designs submitted by prime contractors or OEM suppliers. We assess structural adequacy, identify design risk, and produce written reports that procurement teams can rely on. Independent verification is increasingly required under NZ Government procurement rules for defence-related acquisitions.
For projects requiring mechanical engineering oversight from concept to field deployment, we provide project management support — managing scope, schedule, technical risk, and stakeholder communication. Our experience spans mining, heavy industry, and defence environments where programme discipline and technical rigour must coexist.
FEA is the backbone of modern mechanical engineering for defence applications. Where physical testing is cost-prohibitive or operationally impossible, FEA delivers verified performance data. We use ANSYS Mechanical and LS Dyna — the industry standard for high-consequence structural and mechanical analysis — to evaluate components and systems across a wide range of scenarios.
Capabilities include static structural analysis, fatigue and lifecycle assessment, ballistic and blast simulation, dynamic loading and shock analysis. Our FEA outputs are documented to a standard suitable for regulatory submission, procurement assurance, and design authority approval.
For specialist requirements, access to LS-DYNA (for crash and impact simulation) and nCode (for durability and fatigue) is available, enabling full lifecycle and survivability assessment.
The design and certification of ROPS, FOPS, and OPS for military vehicles and plant equipment is a specialist discipline. Structures must not only pass physical or analytical test criteria — they must be certified by a suitably qualified engineer and documented to a standard that satisfies regulatory and procurement requirements.
We design protective structures for light and heavy vehicles, conduct FEA-based Grade 2 certification analysis, and produce full certification packages. Whether you are procuring new vehicles for the NZDF, modifying existing plant, or need a review of a contractor-supplied design, Crutchworks can provide the independent engineering sign-off your project requires.
Andrew Crutchley is a Chartered Professional Engineer — the formal benchmark of engineering competence in New Zealand. Our verification and certification outputs carry the weight of professional accountability that procurement processes and regulatory bodies require.
Over 15 years of applied Finite Element Analysis using ANSYS Mechanical. We don't just run the software — we understand the physics, the failure modes, and the limitations of the analysis, and we communicate findings clearly to both technical and non-technical stakeholders.
As a specialist practitioner rather than a large firm, you work directly with the engineer doing the analysis. No layers of project management between you and the technical work. Faster turnaround, clearer communication, and direct accountability throughout your project.
Mining, heavy industry, and defence share demanding structural environments and zero tolerance for failure. Our experience across these sectors means we bring hard-won practical understanding — not just theoretical analysis — to every engagement.
Situated in New Zealand's capital, we are geographically close to the NZDF, the Ministry of Defence, and the network of defence industry partners operating in Wellington. Local presence matters for engagements that require in-person attendance at design reviews or procurement briefings.
Our analysis reports, certification packages, and design documentation are produced to a standard suitable for formal submission. We understand that in defence procurement, the quality of engineering evidence is as important as the engineering itself.
Selected defence and heavy-industry projects from our portfolio — each anonymised but technically accurate. Click any project to read the full engineering approach and outcomes.
Full design and FEA-based Grade 2 certification of a ROPS for a military light utility vehicle, packaged for NZDF procurement submission.
Static and dynamic FEA of a weapon system mounting bracket including muzzle impulse loading, supporting formal design authority review.
Seven case studies across mining, infrastructure, defence, and heavy industry — filterable by discipline.
Whether you are a prime contractor seeking local sub-contract engineering capability, a procurement team requiring independent design verification, or a defence supplier needing structural analysis and certification — we would like to hear from you.