The people that make HES
HES takes care of having the right people in the right place. We believe each and every team member has to perfectly fit in the team and in their role. They are the organization and bring the right mindset to the table.
"First the who and then the what."
Management Team

Ivan van Winsen
Managing Director
Ivan has nearly 10 years of experience in the offshore sector. Graduated from Delft University of Technology with a master's degree in ship hydrodynamics he started his career with Heerema Marine Contractors as marine engineer. He has worked on several commercial and innovation projects worldwide, as well as leading the Heerema Simulation Center.
He loves technical challenges and working with a group of enthusiastic people that all bring their individual expertise to the table, resulting in the best possible solutions! Over the last years he led the internal development of the Motion Compensated Gripper Frame and led the development team within HES. As per August 1st he has been appointed as Managing Director.
In his free time he loves sailing with his wife and two sons, reading and cooking.

Henk Smienk
Engineering Manager
Outside the office he spends his time with his girlfriend, three boys and one little girl, likes to be outdoors, skiing and running long distances is relaxing to him.

Silvan Slijpen
Commercial Manager
Management Update
"The core focus will be to maintain the company culture of a young and energetic scale-up, building on our company brand and use 60 years of Heerema experience to become the engineering consultancy firm for offshore renewable projects. "


Alessio Pistidda
Sr. Specialist Marine Engineer

Andres Yepez Calderon
Structural Engineer

Arjen Franken
Specialist Structural Engineer

Arthaud Adriaenssens
FEM Engineer

Casper van Lynden
Marine Engineer

Christof Westland
Specialist Engineer

Daan Koetzier
Graduate student
Outside of work, Daan can often be found surfing the waves of Scheveningen, making music, climbing and playing padel or tennis.

Dimitrios Tsiropoulos
Specialist Engineer

Dennis Dane
Software Engineer
In his spare time he likes to develop his website, 3d-printing, Arduino projects, skiing and water sports.

Eelco van Vliet
Specialist Engineer

Elisa Romero Pascual
Product Lead Floating Wind
After finishing her Civil Engineering MSc, Elisa joined HMC as a Marine Engineer, where she worked for several Installation and Decommissioning projects for 5 years. During her last year at HMC she worked at the Simulation Centre, where she could be part of innovative and out of the box offshore projects. After that she joined a maritime simulation software company where she lead the product team.
At HES, Elisa is working on floating wind, leading the technical developments and looking for commercial opportunities.
In her free time, she likes to cycle, practice yoga, read and spend time with family and friends.

Ellemijn Rog
Sr. Installation Engineer
Ellemijn started at HES with 5 years of experience in the offshore renewable industry. With a master’s degree in marine engineering, she has developed a wide perspective on the offshore wind market in the last years. She has experience as an installation and cost engineer, an integral role in multidisciplinary and international teams. She enjoys to participate in the newest developments of the offshore wind market. Within HES, Ellemijn uses her experience to strengthen the fixed and floating wind developments. In her spare time Ellemijn enjoys to play field hockey, running, cycling and hiking.

Farkas Beothy
Marine Engineer
Farkas did his BSc in Mechanical Engineering in Hungary, then came to the Netherlands for his Masters. After graduating cum laude from his MSc Marine Technology in Delft, Farkas started Heerema Engineering Solutions. In his work, he tackles problems in both abstract and practical ways to gain in-depth insight into the subject and find feasible solutions to the problem. His main focus at HES is doing marine engineering tasks within the floating wind development team. In addition, he also participates in projects that involve CFD, motion analysis, and internal development works.
In his free time Farkas plays Ultimate Frisbee at a high level. He likes cooking, go on bike rides, and recently picked up Kitesurfing.

Gino Parisella
Sr. Marine Engineer

Ian Mullens
Engineer

Jelle ter Braak
Specialist Engineer
Jelle’s journey in the offshore industry started by finishing his MSc Offshore Engineering at the TU Delft. After working in the structural department at HMC where he co-developed a purpose built Finite Element Package he moved to HES. For three years Jelle has worked with several clients and has been involved in multiple interesting innovation projects related to the XL monopile installation market. The projects include but are not limited to subsea monopile templates and motion compensated gripper frames where he is working on hydrodynamic, control and simulation topics.
In his free time Jelle enjoys food, reading, making music and photography.

Jim Zwartveld
Specialist Engineer
-1-1.jpg?width=720&name=Joep%20(2)-1-1.jpg)
Joep van der Spek
Marine Engineer
Joep joined HES as a working student in 2019 and stayed for almost 2 years while pursuing his MSc degree in Marine Technology, specializing in Ship & Offshore Structures. He worked on smart solutions for wind installation and automation of hydrodynamic analysis.
He graduated on the initial load assessment of semi-submersible floating offshore wind turbines under wind/wave misalignment with a major turbine supplier. After his graduation, he returned to HES to strengthen the floating wind development team. Among other topics, he focusses on floating wind developments for internal and external projects.
In his free time, he enjoys backpacking and can be found around Delft road cycling or playing basketball.

Joris Meursing
Work student

Karin Leijs
Offshore Engineer
-1-1.jpg?width=720&name=Kathryn%20(2)-1-1.jpg)
Kathryn McPherson
Software Engineer
With 12 years of engineering experience in the oil and gas industry, Kathryn has experience in every phase of a project, from concept studies to design, interface engineering, integration testing, offshore installation analysis, pre-commissioning, and decommissioning. Her main area of expertise is the design and installation of subsea pipelines. She also has a background in mathematics and a master's degree in space science. In 2023, Kathryn joined HES and has been working on the Metis logistics tool. She approaches challenges systematically, ensuring technical accuracy, and enjoys working in a team. In her spare time, she likes to spend time with her family, go running and cycling, and occasionally take part in triathlons.

Katrien de Jong
Work student
Next year, Katrien will be pursuing a master's degree in Offshore Engineering as part of the European Wind Energy Program. By being a work student at HES, she is able to gain valuable insights into what working in the industry might be like after completing her master's degree.
When she's not studying or working, Katrien enjoys running, cooking, drawing, and spending time with her friends. Katrien is always up for a challenge and loves learning new skills.

Lizette Dittmar - van Halewijn
Sr. Administrator

Machteld Rouwe
Graduate student

Mark Hoorn
Structural Engineer
In addition to his work, Mark enjoys cooking, baking, and hiking in his free time. Cooking allows him to unwind and express his creativity in the kitchen, while baking allows him to experiment with new techniques and flavors.

Patrick Symes
Installation Engineer

Reinier van Rossum
Technical Authority Wind Installation

Robert Weegenaar
Sr. Installation Engineer

Sam de Bode
Installation Engineer

Thiemen van Groeningen
Work student
When this opportunity was given by HES, he took it with both hands and started as a working student in February 2023. As he has really enjoyed it since, he hopes to stay part of and contribute to the HES team. In his free time, he plays in a football team, loves sailing and when there is a proper breeze he is probably out at sea kitesurfing.
-1-1.jpg?width=720&name=Thijs1%20(2)-1-1.jpg)
Thijs van Essen
Marine Engineer

Thom Haafkes
Marine Engineer

Thomas Balder
Development Lead

Toon van der Linden
Geotechnical Engineer

Quint van Suijlen
Graduate student
Riding his motorcycle, sailing, football, DIY and spending time with his friends and family keep him busy during non-business hours.

Heerema Marine Contractors is certified Climate Neutral
Implementing zero-emission technologies on board our vessels is a continuous and challenging journey. Therefore, in 2020, we started investing in carbon offsetting projects that align with our mission to create sustainable value(s). By doing so, we already have a neutral footprint today while working on the future.