Who We Are
Promech is a mechanical engineering consultancy dedicated to technical excellence. Backed by a skilled team of Mechanical Engineers, Heavy Vehicle Certifiers and Chartered Professional Engineers (CPEng), we bring innovative, sustainable thinking to every design. We specialise in navigating complex requirements to deliver high-value results for our clients.
The Promech Advantage
A Collaborative Approach
We operate as an agile, user-friendly practice. We actively build a team environment with our clients, ensuring open communication, trust, and mutual success.Sustainable Innovation
Environmentally Sustainable Design (ESD) is at the core of our philosophy. We future-proof your assets while maximizing long-term commercial value.Enduring Relationships
We measure our success by the longevity of our partnerships. From local government bodies to private entities, we protect your investments through elite engineering.
Our Journey
1978: Babbage established an office in Tauranga to provide local engineering expertise.
1992: Transitioned ownership trading as Babbage Tauranga, continuing to expand regional services.
1997: Relocated to our current headquarters at 103 Wharf Street, Tauranga.
2002: Launched our Hamilton branch to support clients across the Waikato region.
2003: Formally rebranded the practice.
2014: Promech Consultants Ltd acquired the engineering division.
2026: Launched new website showcasing professional expertise & work history.
Our Mission Statement
To provide high quality personal service and practical solutions for projects that display design competence and exceed client expectations.
Why Clients Choose Us
Deep understanding of engineering regulations and certification processes
Practical, workshop-friendly engineering solutions
Fast turnaround to minimise downtime
Strong communication with certifying authorities
End-to-end support — from concept to compliance
We understand the realities of the engineering sector — tight schedules, operational pressures, and strict safety standards. Our role is to make the engineering and certification process straightforward, compliant, and efficient so you can focus on running your business.
Heavy Vehicle Transport Services
Heavy Vehicle Certification & Design
Promech specialize in LT400 certification, engineering design, and compliance assessments across a comprehensive range of heavy vehicle domains to NZ Rules:
Load Anchorage (HVEA): Design and certification for chain hooks, plates, rope rails, and twistlocks.
Chassis Modification (HVEC): Structural chassis repairs, customized modifications, and engineering design. Along with seatbelts and seatbelt anchorages.
Brake Systems (HVEK): Advanced brake system design, modifications, and certified testing.
Log Bolsters (HVEL): Specialized log bolster attachments, custom modifications, and structural repairs.
Towing & Couplings (HVET): Certification and design for towbars, drawbars (A Frame, pole, telescopic), drawbeams, 5th wheels, and kingpins.
HVS - Static Roll Thresholds (HVS1, HVS2): We provide regulatory stability assessments and advanced analysis for both standard and complex heavy vehicle setups to meet legal rollover limits. For definitive validation, we measure precise performance benchmarks using computer-simulated models.
Certified Transport Repairs
We inspect, engineer solutions for, and certify common heavy vehicle wear-and-tear issues, including:
Tie Rails & Hooks: Aligning, reinforcing, and replacing damaged tie-down points.
Structural Fatigue: Expert crack repairs, welding remediation, and structural reinforcement.
Corrosion & Wear: Rust heave remediation, plating, component wear analysis, and full-service replacements.
Bring your COF sheet with the defects & we can assist with repair certification. Jobs & billing are prioritised by the degree of urgency & expertise required.
Contact the office to book an inspection.
HPMV, 50MAX, Overweight and Overlength Vehicle Compliance
We have extensive knowledge of 50MAX, HPMV (High Productivity Motor Vehicles), overweight and overlength permit applications.
We will prepare all necessary layout drawings and documentation and submit the application on the client’s behalf, acting as their authorised agent throughout the approval process.
Contact us to discuss your requirements.
We Support:
Heavy vehicle operators and fleets
Owner-drivers
Vehicle and trailer manufacturers
Body builders and modification specialists
Transport and logistics companies
Workshops
In addition we are able to apply for Rule Exemptions where engineering conditions support deviations from prescriptive design to comply with performance based standards.
Heavy Vehicle Work Examples
We offer design, analysis, testing & certification, including but not limited to the following
Work Examples
A-trains, Agricultural tractors, Air suspension, Accident damage repair certification
Ball & socket couplings, Bolsters, B-trains, Bulk tippers, Bitumen sprayers, Bitumen tank wagons, Bailee bridge, Boat trailers
Central tire inflation (CTI), Cherry pickers, Container lifters, Curtainsiders, Campervans, Crane trucks, Caravans
Dangerous goods vehicles, Drill rigs, Drive trains, Drawbars
Ejectors, Engine repowers, Gradability, Startability
Ferry hooks, Forklift docks, Fuel tankers, Goods vehicles, GVM upgrades
Heavy haulage vehicles, Hook units, Horse floats, House transporter & IBC trailers
Lazy axles, Leaf suspension, Load anchorage, Load cells, Load security, Load sharing suspension, Loggers, log trucks, log trailers, LVG trailers, Low loaders
Mezzanine floors, Mobile drilling machines, Motorhomes, Mobile dental trailers
Passenger Service Vehicles (PSV), Physical testing, Pintle, pulp & platform trailers
Recertification (recert), Recovery vehicles, Rubbish compactors, Roll on roll off (Ro ro) ship lashings, Road sweepers
Steer axles, Stock crates, Super singles, Mega tires, Swap body, Swift lifts, Swinglift, side loaders, Seatbelt certification, Stressed seats, Slippery decks, Stinger trucks, Semi-trailers, Skeletal (skele) trailers, Steering & Stock trailers
Tankers, Through loading trailers, Tipper bins, Tipulators, Toolbox mounts, Tractor units, Tail lifts, Tow trucks, Twin steer conversions, Trombone & tube trailers
Underlifts, Underrun protection, Vacuum tankers (sucker truck)
Walking beam suspension, walking floors, wide wheels
Hydro Power Services
Mechanical Engineering
Stress Analysis & Design — Advanced wall-thickness calculations, and transient pressure (water hammer) analysis for high-head surface and shaft plant.
Seismic Engineering Assessments & Design — Comprehensive structural modeling of mechanical plant and retrofitting to ensure powerhouses, dams, and control infrastructure survive severe seismic events.
Weirs & Boils — Hydraulic engineering, structural design, and energy-dissipation calculations for upstream weirs, spillways, and tailrace boil zones
Work Examples
Bearing design
Cranes & Monorails
Dewatering shaft staircase design
Eel Bypass
Gate conditioning monitoring, Gates lifting systems & upgrades, Gates system stability
Lifting jigs
Penstock coatings & repaints
Pole turning jigs
Rotor bolts
Seals, Stoplogs, Switch yard phase cross-over beams
Transformer mountings & containment bunds
Ultrasonic flow detectors
Gates, Valves & Water Control Systems
Radial Spillway Gates — Robust structural and mechanical design of high-discharge radial gates, ensuring reliable flood control and optimised lifting.
Fixed Wheel Vertical Gates — Heavy-duty vertical lift gates engineered with custom roller wheels to handle high hydrostatic forces during emergency closure or maintenance.
Diversion, Intake, Low & High-Level Gates — Custom water-control gates engineered for all elevations, built to withstand immense pressure differentials and harsh environments.
Machine Inlet Valves (MIV) — Precision design and selection of main inlet valves (butterfly or spherical) for absolute isolation and safe turbine maintenance.
Gates Condition Monitoring: Intake, Spillway, Diversion, Low-Level and High-Level Gates.
Work Examples
Accumulator relief valves, Auxiliary machines
Dam bypass gates, Dewatering gates, Diesel hydraulic power packs
Dewatering tunnel gate refurbishment
Emergency gate lifting systems
Fall arrest anchors, Flow regulator systems
Gantry cranes, Generator slip rings, Gate actuation design
Hydraulic servo actuators & cylinders, Hydraulic motor drives
Intake screens, Intake structures, Isolation valves
Log cranes, Log dams, Load pins
Nets
Penstock platforms, Personnel davits
Rotor balancing, Rotor crack repairs
Spillway gate locks, Static lines, Station bypass line, Stator circularity and realignment, Seismic mounts
Intake Protection & Environmental Compliance
Intake Screen Design — Engineering high-strength trash racks and intake screens to optimize flow profiles while blocking debris and protecting downstream assets.
Eel & Fish Bypass System Design — Eco-compliant downstream and upstream bypass channels, downstream guidance screens, and fish-friendly passages to satisfy strict environmental regulations.
Work Examples
Eel bypass
Elver trap
Diversion gate & bifurcation
Attractant flow concept
Main & auxiliary intake screens
Hydro and Geothermal Services
Work Platforms & Access Systems
EWP Engineering — Design verification and compliance support for elevated work platforms.
Access Structures — Secure engineering layouts drawings for industrial gantries, walkways, and stairs.
Safety-Critical Systems — High-level validation of fall protection and structural safety anchors.
Work Examples
Draft tube platforms
Elevators
Mobile Access Platform Certification
Penstock platforms
Salt evaporator platforms
Gantry platforms
Access way & staircases
Geothermal Engineering
Turbine Stress Analysis — Predicting component life and preventing catastrophic fatigue failures under extreme thermal and centrifugal loads.
Rock Muffler Design & Acoustics — Engineered noise attenuation for high-pressure venting systems to guarantee environmental and regulatory compliance.
District Heating & Heat Exchangers — Optimising thermal efficiency and heat transfer loops for industrial processes and community energy networks.
Process & Pressure Piping — Full-lifecycle piping compliance, flexibility analysis, and wall-thickness certification to PE standards.
Advanced Heat Transfer Calculations — Precision thermodynamic modeling using conduction, convection, and radiation analysis to eliminate energy waste.
Work Examples
Acoustic design, Analysis of thermal crack strains
Confined spaces
Heat exchangers
Iso diagrams, Isolation valves
P&ID system design, Pipelines
Rotor balancing
Seismic design, Station bypass lines
Turbine running clearance analysis
Working at heights
Condition Monitoring & Digital Assets
Condition Monitoring Services — Real-time vibration, thermal, and acoustic tracking to catch mechanical faults early, preventing costly unscheduled outages.
2D Drawings, 3D Models & Drawings — Delivering precise, constructible multi-discipline engineering drafting, 3D CAD modeling, and legacy drawing digitisation.
Work Examples
Intake, Spillway, Diversion gates
Water treatment plants
Forestry & Construction
Forestry Equipment Engineering & Safety Certification
Promech provide comprehensive engineering services for heavy machinery operating in demanding New Zealand logging environments. All safety-critical assessments are signed off by a Chartered Professional Engineer (CPEng):
Operator Protection Certification: Full engineering compliance and validation for ROPS (Roll-Over), FOPS (Falling Object), and COPS (Cabin Operator) protective structures.
Design Verification: Rigorous mechanical evaluation and sign-off for custom forestry attachments and machinery builds.
Structural Assessments: Advanced stress analysis and fatigue inspections to ensure structural integrity under extreme working loads.
Equipment Modifications: Certified engineering design for heavy machinery modifications, performance upgrades, and chassis alterations.
Work Examples
Bolsters
Expert witness
Failure analysis
Grapple design
Harvest line
Log Haulers
Shackles, Shovel logging, Slack pulling carriage, Steep slope harvesting engineering design
Tow lug hitches, Traction line
Winch assist, Winch attachments
Forestry & Construction Protective Structures
We design review and certify heavy-duty ROPS, FOPS, and OPS structures tailored to your machinery.
Maximum Visibility: Bullet-proof glass or polycarbonate to optimise the operator’s direct line of sight.
Factory-Fit Appearance: Profiles mirror original factory cabs, featuring standard or custom raised risers.
Built-In Protection: Internal roof-mounted hydraulic door rams and recessed lights prevent hazard damage.
NZ Certified Compliance: Certified to NZ DOL Grade system based on calculated loads from globally recognised safety standards. Witness of physical testing when requested:
ROPS (ISO 3471 & ISO 8082)
FOPS (ISO 8083)
OPS (ISO 8084)
Work Examples
Bullet proof & chain shot protective cabins
Cabin Operator Protective Structures (COPS)
Falling Object Protection (FOPS)
OPS certification
Operator Protective Structures (OPS)
Physical testing
Roll Over Protective Structures (ROPS)
Log frontal impact screens
NZ Police Occupant Protective Structure (OPS)
Lifting & Crane Equipment
Structural Design: Customized engineering drawings for heavy lifting systems and crane frameworks.
Load Analysis: Precise weight distribution and capacity calculations for structural safety.
Compliance Assessments: Rigorous evaluations to ensure full alignment with regulatory lifting standards.
Certification Support: Specialised engineering sign-off for lifting systems, custom attachments, and cranes. Statutory Design Verification by third parties is available.
Work Examples
Cradles, Cranes, Cranstan lifts
Davits
Gantry cranes, Goliath cranes
Jib cranes, Jib extensions
Lifting beams, Lifting jigs, Load cells, Lifting lugs
Monorails, Mobile & vehicle cranes, Maritime cranes
Ship cranes, Salvage operations, Strain gauges, Spreader beams
Expert Witness, Failure and Simulation Services
Expert witness
Expert Witness Testimony — Delivering clear, independent, and legally robust evidence for courts, arbitrations, and dispute resolution panels.
Forensic Failure Analysis — Investigating structural and mechanical failures to uncover the root cause and prevent future liabilities.
Silo & Bulk Storage Engineering — Diagnosing structural distress, asymmetrical flow issues, and wall buckling in heavy-duty storage silos.
Pressure Vessel Compliance — Expert forensic assessment and design validation of high-pressure vessels under ASME and international codes.
Independent Peer Reviews — Providing critical third-party verification of engineering designs to de-risk high-value projects.
Insurance Technical Support — Assisting loss adjusters and insurers with rigorous, objective technical investigations for complex claims.
Work Examples
Failure investigation & cause analysis
Forensic engineering
Insurance claim assistance
Litigation
Microscopy, metallography, Electron Discharge Spectography (EDS)
Probable cause
Failure Investigation & Cause Analysis
Forensic Investigation: In-depth engineering analysis of structural, mechanical, and component failures.
Root Cause Identification: Advanced diagnostics to pinpoint exactly why a system failed.
Risk Assessments: Quantitative evaluations to prevent similar hazards across your operations.
Corrective Solutions: Practical, actionable engineering fixes to permanently resolve mechanical vulnerabilities.
Work Examples
Auger mount
Bolt failures, Broken axle, Broken chassis, Broken stub axle
Centrifuge impact damage, Cold store, Coolstores, Cracked oil sight glass,
Crash investigation
Debarker drum failure, Diesel spill, Digger boom cracking
Excavator drownings
Fatality reports, Flammable gas explosion, Forklift bearing failure, Forklift collision
Frozen heat exchangers, Fruit store fire
Gas cylinder material failure, Gearbox failure
Hub puller fatality
Kenworth crankshaft fracture
Lawyer report
Mussel buoy moulding machine
NZ Police report
Ombudsmen report
Peer review, Port crane gearbox shaft fracture
ROPS damage
Silo collapse, Smart meter fire, Straddle carrier collision
Train wreck derailment
Welded connection fatigue failure, Wood chipper failure
Simulation & Engineering Analysis
We utilise cutting-edge digital modeling tools to validate machinery and reduce risk before deployment:
FEA Modeling: High-resolution Finite Element Analysis to predict physical material stress.
Fatigue Assessment: Structural life-cycle analysis to forecast component wear and tear.
Stability Verification: Computer-simulated strength and balance testing under peak operational loads.
Thermal Analysis: Advanced simulation of intense pressure and heat differentials on materials is available if needed.
Work Examples
Trash rack vibration
Plastic analysis
Rubber & steel interaction analysis
Plastic molding valves thermal analysis
Fluid flow analysis
Jet blending analysis
Mechanical Engineering Services
Engineering Services
Promech provides a comprehensive suite of engineering services backed by extensive sector experience. Using advanced digital tools and rigorous analysis, our team delivers high-value, compliant designs tailored to the specific needs of commercial, municipal, and heavy industrial clients. Most professional work is completed in-house with third party specialists sub-contracted in to supplement complex activities when necessary.
Comprehensive Engineering Solutions
We operate across the entire project lifecycle, offering specialized expertise in the following areas:
Design & Modelling: Computer-Aided Design (CAD), engineering design, and Building Services (HVAC).
Advanced Analysis: Finite Element Analysis (FEA), acoustic design, noise control, and energy management audits.
Compliance & Testing: NZTA certification, expert witness evidence, failure investigations, and Roll-Over Protective Structures (ROPS) frames.
Project Lifecycle: Pre-feasibility and feasibility studies, contract documentation, bid evaluation, quality control, commissioning, and project management.
Specialised Sectors: Industrial, commercial, transport, municipal services, and process evaluation/control.
Pressure Equipment
Design Verification: Certified engineering oversight for complex pressure vessel drawings.
Stress Analysis: Advanced pressure and thermal load calculations for containment systems.
Tank Wagons: Compliance design and structural validation for dangerous goods transport tanks.
Certification Support: Regulatory pressure equipment sign-offs.
Work Examples
Stockholm melting pots
Air receivers
Dangerous goods tanks
Gas cylinders
Vacuum tanks
Mercaptan decanting vessels
Plant & Machinery Design
Mechanical Systems: Advanced engineering design for specialised industrial production systems.
Heavy Machinery Design: Structural planning built specifically for extreme industrial durability.
Efficiency Optimization: Streamlined mechanical layouts engineered to boost manufacturing throughput.
Work Examples
Accumulators, Aluminium cabinet design, Actuator design
Bearing supports
Clutches, Couplings
Hydraulic cylinder design
Mechanical trips
Servo design
Steel cabinet design
Power packs
Petrochem
API 650
AS 1692
Work Examples
Bunds
Chemical scrubbers, Concrete foundation plinths, Confined spaces
Diesel tanks
Fire fighting plant & equipment, Fuel tanks
Jet blends
Kerosene tanks
Marine tank, Methanol tanks
Oil tanks
Petrol tanks, Pipe bridges, Pressure Equipment, Pressure piping
Seismic certification of plant & equipment, Storage tanks
Toluene tanks
Underground tanks
Working at heights
Building Services
Work Examples
Air conditioning
Car park ventilation, Commissioning
Computerised Maintenance Management Systems (CMMS)
Design Briefs, District Health Boards
Fire protection, Farm store ventilation
Heat pumps, Heating, Ventilation, Air Conditioning (HVAC)
High Efficiency Particulate Air Filters (HEPA filtration)
Medical centers, Medical gases, Mobile dental trailers
Peer review, Project Execution Plans (PEP)
Materials Handling
Innovative Flow Generation Concepts — Sizing and engineering optimal hydraulic systems, pumping networks, and fluid dynamics for efficient fluid transport.
Detailed Process Drawings — Delivering precise P&IDs, 3D CAD modeling, and layout blueprints that streamline project installation and compliance.
Screw Conveyor Design & Fatigue Stress Analysis — Custom solids-handling engineering backed by advanced stress analysis to eliminate fatigue and ensure long-term mechanical reliability.
Work Examples
Bulk grabs
Coal conveyors, cement plant, chip roller
Fertiliser conveyors, spreaders & spinners
Honey processing plant
Lumpbreakers & delivery chutes
Palm kernel pushers
Pollen extraction, Pet food plant
Sugar lifting equipment, Salt conveyors & chutes, Screw conveyors, Storage tanks & bunkers, Silos
Weigh equipment, Wood chippers & processing plant, Wash bays
Site Operations, Temporary Works & Rigging
Specialised Lifting Equipment, Rotor Lifting Jigs & Cranes — Bespoke engineering of high-capacity lifting beams, generator rotor lifting jigs, and powerhouse crane certifications.
Temporary Works Engineering — Safe, code-compliant design of falsework, formwork, retaining structures, and temporary water diversions during construction.
Mobile Painting Platforms — Custom-designed access platforms and blast/paint rigging tailored for safe asset maintenance inside deep shafts or along penstocks.
Road Plates — Heavy-duty, high-load structural steel road plates engineered for heavy site vehicle transport over excavations.
Work Examples
Boat loaders, Bollards
Certified bench workstations, Chassis chocks, Cover rollers
Frames, Forklift mast repairs
Lifting frames, Lifting devices, Load out platforms & ramps
Sugar bag lifting frames, Shaft design
Pine lifting frames
Vehicle ramp
Wheel chocks
Trench Shield Design, CAD Drafting, & Certification
We provide accurate, workshop-ready production drawings and oversee essential commissioning quality control checks, witness of physical testing and design certification.
Work Examples
Aluminum trench shoring equipment
Drag shields
Trench boxes
Slide rail systems
Steel shoring equipment
Soldiers, Struts (fixed & adjustable)
Certified repairs
Get in Touch
For all enquiries please give us a call during office hours or complete the form below and someone will get back to you as soon as possible.