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Case Study

IMT-Isca Platform Supply Vessel (PSV) Series: G-Flex

Project title: IMT-Isca Platform Supply Vessel (PSV) Series: G-Flex
Start Date: 08/07/2025
Project Summary:

Project summary: Engineering consultancy and ship designer Longitude Engineering have recently completed a project to provide alternative fuel systems engineering for a groundbreaking new vessel design by Dykstra Naval Architects, for Greenpeace International.

About IMT-Isca Series and the G-Flex PSV

 

 

The IMT-Isca design series represents the next generation of platform supply vessels (PSVs), evolved from the successful IMT-984 or G-Class series, with a focus on efficiency and low-fuel consumption, whilst meeting contemporary regulations.

Its name is inspired by the Celtic word for flowing water and the River Exe – a nod to both the fortitude and flexibility of the design series, and to Longitude’s cultural heartland of Exeter.

The G-FLEX is the first PSV in the series.

 

Key Characteristics

The IMT-Isca G-FLEX is designed with efficiency and flexibility at its core, to ensure your project success amid a versatile offshore energy market:

  • Flexible design: multi-thruster and different engine options, multiple accommodation arrangements including for up to 12 passengers.
  • Optimised for low-energy consumption: designed for IMO Tier III NOx compliance, optional battery installation and possible usage of HVO or alternative fuel.
  • Efficiency at its core: the flexibility in design and low-fuel consumption combine to drive lower-cost operations
  • Expertise you can trust: Brought to you by vessel design house Longitude Engineering, fused with the PSV experience of acquired OSD-IMT, and the marine operational experience of our sister company, ABL – the energy and marine consultants.

 

Principal Characteristic

  • L.O.A.: 83.95 m
  • L.P.B: 77.64 m
  • Beam: 18.00 m
  • Depth: 7.80 m

 

Other Information

  • Draft design: 6.50 m
  • Total deck area: 810 m2
  • Gross tonnage: <3500 tonnes
  • Accommodation: multi-option accommodation arrangements – 24 crew + 12 passengers in a mix of single and dual berth cabins

 

 

The value we delivered

Built on proven PSV pedigree with evolution from the successful IMT 984 G-Class.

Fused design, operational, and risk expertise from Longitude and ABL.

Unmatched design flexibility in propulsion, fuel options, and accommodation layouts.

Optimised for future sustainability, including battery and alternative fuel readiness.

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