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Meet our Trustees

Trustees are responsible for the strategic direction, governance, financial and educational performance of the trust, and directing how it is managed and run. They determine the mission, vision and trust improvement strategy. 

Trustees ensure that the trust complies with all legal and statutory requirements, and hold the executive team to account. 

Tom Ashford - Chair

Tom has over 20 years' experience working in the Financial Services sector, occupying both technical and leadership positions within IT departments. Tom holds numerous professional IT qualifications and certifications, and is a graduate in Computer Science from the University of Sheffield. 

Tom lives locally and has two children who attend schools in the area. He has held various voluntary and governance roles for a number of years, working to improve outcomes for young people across Sheffield.

Chasca Twyman - Co-Vice Chair

Chasca joined the Trust Board in 2023. She works as a consultant for the National Governance Association and was a National Leader of Governance (2021-23) under the reformed programme. She is also Chair of Governors at a large rural secondary school in the Peak District.

As a former University academic, Chasca's professional experience in higher education means she has excellent strategic and analytical skills that transfer well into Trust and school governance. Her work as a Trustee in the charity sector further broadens and deepens her relevant governance expertise. 

Chasca holds a PhD in the Social Sciences.

David Beaumont - Co-Vice Chair & Chair of Learner Experience (Inclusion) Committee

David works as a Senior Educational Psychologist in Derbyshire. Previously he has worked in teaching in special and mainstream schools. He is on the National Committee of the Educational Psychologists Body. He is also an experienced governor.



Sarah Draper - Chair of Remuneration Committee

Sarah joined the trust Board in 2019, and was previously Local Governing Board Chair at Chaucer School. She has been involved in school governance for the last 10 years.

Born and brought up in Birmingham, Sarah entered teaching in 1978, progressing to Headship in 1997. After 10 years as Headteacher in a North East Sheffield school, Sarah spent 6 years working in the Local Authority's Children and Young People's Service, ultimately as Assistant Director for Inclusion and Special Educational Needs. 

Now 'retired' Sarah spends her time looking after grandchildren, horse riding, gardening at home and on an allotment. Ensuring all children and young people experience the best possible education has been her passion during her working life and continues to be so as a trustee of TSAT.

Duncan Marrison - Chair of Finance and Resource

Duncan has over 15 years of experience as a finance professional across a range of sectors but with particular focus on those driven by technology, data, analytics and direct to consumer business models. He has experience of refinancing large PLCs, restructuring businesses and working closely with regulators to achieve improved outcomes for consumers, both as a CFO and as a consultant. He currently works as a Finance Director for a Telecommunications business. 

He is married with two young boys and outside of work is passionate about music and sport.

Derren Sanders - Chair of Risk & Governance

Derren is an experienced executive across a number of business areas. Since qualifying as a Chartered Accountant with PricewaterhouseCoopers, he has advised, led and helped reshape businesses to achieve their potential. 

Latterly, he moved to Abu Dhabi to lead HSBCs business in the Emirate, before subsequently moving to a local UAE bank. He undertook the role of Chief Operating Officer in their wholesale banking division, helping redefine the business strategy and operations, leading its digital and operational improvement and customer service programmes, as well as leading the banks simultaneous merger with two other local banks.

Derren recently relocated back to Sheffield with his wife and two children and is currently the Operations and Finance Director of an African bank, working from London and home. 

Derren has worked with charities, youth development and educational institutions variously throughout his career, and the trustee role at TSAT continues this. He is a keen sportsman, with cycling, cricket and golf being his current passions alongside continuing his decade long support for junior rugby through coaching and refereeing.

Jane Acklam OBE - Chair of Learner Experience (Quality of Education) Committee

Jane is the former CEO of South Penine Academies. She has considerable experience as a highly successful Headteacher and Principal. Jane has led a range of sponsored academies to improve and opened two free schools. She has been a National Leader of Education since 2009, and effectively supported and built capacity in a wide range of schools, locally and regionally.

Jane is a qualified Executive Coach, having a strong commitment to individual coaching, supporting others to determine and identify goals, ensuring they have achievable actions and the tactics to ensure they can sustain success. Values are at the heart of Jane's coaching style. 

Jane has been awarded a Teaching Award, as Headteacher of the Year, in the national annual awards. She has a wealth of experience working for the Department for Education, on the Headteacher Board for West Yorkshire and Lancashire and as a Teaching and Leadership Adviser for the then National College for Teaching and Leadership. 

Jane was awarded an OBE for services to education in the 2017 New Year's Honours List.   

John Cullen

John is an experienced Chartered Surveyor who has worked across both the public and private sector delivering large scale development projects. He was formerly the Senior Director and Head of Projects UK on the Operations Board for a national property developer with responsibility for delivering a pipeline of developments across the country. 

John is married with two grown up children, each of whom went through local primary and secondary education before going onto university. He lives locally and enjoys off road cycling and walking.


Liz Winders

Liz joined the Trust Board in 2021. She worked in universities in London, Oxford and Sheffield, managing and leading professional services, before retiring as Secretary and Registrar at Sheffield Hallam University. She then worked as a freelance consultant in higher education, specialising in governance and regulation, working with national funding and regulatory bodies and individual institutions. 

Liz has experience of non-executive roles on trust boards and governance bodies for a university, local public services and policing. 

Liz has always been passionate about realising potential, challenging disadvantage and expanding opportunities through education.

Liz is married with one grown up child. She enjoys walking, yoga, singing and gardening.