MMG Ocean
MMG Ocean, specialises in engineering and manufacturing services to the marine, aquaculture, fishing and renewables sectors. They are experts in coded welding and marine fabrication with a dedicated focus on quality and innovation.
MMG Ocean delivers premium design, prototyping, and fabrication engineering solutions. With an emphasis on quality and innovation, providing comprehensive services from concept to completion.
Problem to Be Solved:
Re-design of Pig Insertion Trolley for Offshore Pipeline Operations
Pipeline Inspection Gauges (“PIGs”) are used in offshore oil & gas pipelines for cleaning and inspection. These are heavy cylindrical units (typically 300–750kg, up to 2000kg) that must be safely aligned and inserted into pressurised pipeline systems using specialised trolleys.
Due to the explosive operating environment, powered systems are not permitted, meaning that solutions must rely on manual mechanical systems for safe operation.
The Challenge:
MMG Ocean and their partners, Ocean Kinetics (Shetland), identified a critical usability issue:
- Existing pig trolley required excessive manual force to operate
- Inefficient push mechanism and poor mechanical advantage
- Design limitations including:
- Underperforming gearbox and worm wheel
- Short handle limiting applied torque
- Misaligned components affecting efficiency
Target requirement:
- Enable safe, ergonomic manual insertion of loads up to 1500kg
- Maintain compliance with hazardous area constraints
- Improve reliability and usability for offshore operators
PEM Approach
PEM delivered a full engineering redesign process, combining applied research and industry-focused engineering:
Engineering Assessment & Problem Definition
- Inspection of existing system and identification of inefficiencies
- Functional breakdown of force transmission and mechanical losses
- Benchmarking of gearbox and drive configurations
Design & Analysis
- Mechanical calculations to define required torque, gear ratios, and force inputs
- Development of a parametric Excel tool to test multiple configurations
- Selection and optimisation of drivetrain architecture
Digital Engineering
- 3D CAD modelling (SolidWorks) of new concept design
- Component-level redesign (gearbox position, shafts, sprockets, handle)
- Design for integration with existing trolley structure
Simulation & Validation
- Structural simulations of key components (shaft, gearbox mount, handle, sprockets)
- Verification of stress, torque capacity, and safety margins
- Ensured robustness under high-load conditions

Martin McGuinness, Managing Director
“ PEM's expertise and support were instrumental in helping us optimise this design. Their practical engineering approach, combined with advanced analysis and modelling capabilities, provided valuable insight throughout the development process. We greatly appreciated the collaborative nature of the project and look forward to future opportunities to work together. " Martin McGuinness- MD MMG Ocean.