Apprenticeship

Since the 1950s, the UK high technology industry (Aerospace, Nuclear, Oil & Gas, Automotive, Telecommunications, Power Generation and Distribution etc.) trained its higher technicians and professional engineers via the traditional indentured apprenticeship system of learning – usually a 4–6 year process from age 16–21. There were 4 types of traditional apprenticeship: craft, technician, higher technician, and graduate.  Craft, technician and higher technician apprenticeships usually took 4 to 5 years while a graduate apprenticeship was a short 2-year experience usually while at university or post graduate experience.  Non-graduate technician apprenticeships were often referred to as "technical apprenticeships". The traditional apprenticeship framework in the 1950s, 1960s and 1970s was designed to allow young people (from 16 years old) an alternative path to A Levels to achieve both an academic qualification (equivalent to today's level 4 or 5 NVQs) and competency-based skills for knowledge work. Often referred to as the "Golden Age" of work and employment for bright young people, the traditional technical apprenticeship framework was open to young people who had a minimum of 4 O Levels to enroll in an Ordinary National Certificate or Diploma (ONC, OND) or a City & Guilds engineering technician course. Apprentices could progress to the Higher National Certificate, Higher National Diploma (HNC, HND) or advanced City and Guilds course such as Full Technological Certification. Apprenticeship positions at elite companies often had hundreds of applications for a placement. Academic learning during an apprenticeship was achieved either via block release or day release at a local technical institute. An OND or HND was usually obtained via the block release approach whereby an apprentice would be released for periods of up to 3 months to study academic courses full-time and then return to the employer for applied work experience. For entrance into the higher technical engineering apprenticeships, O Levels had to include Mathematics, Physics, and English language. The academic level of subjects such as mathematics, physics, chemistry on ONC/OND, and some City & Guilds advanced technician courses, was equivalent to A level mathematics, physics and chemistry. The academic science subjects were based on applied science in subjects such as thermodynamics, fluid mechanics, mechanics of machines, dynamics and statics, electrical science and electronics.  These are often referred to as the engineering sciences. HNC and HND were broadly equivalent to subjects in the first year of a bachelor's degree in engineering but not studied to the same intensity or mathematical depth. HNC was accepted as entrance into the first year of an engineering degree and high performance on an HND course could allow a student direct entry into the second year of a degree.  Few apprentices followed this path since it would have meant 10–12 years in further and higher education. For the few that did follow this path they accomplished a solid foundation of competency-based work training via apprenticeship and attained a higher academic qualification at a university or Polytechnic combining both forms of education; vocational plus academic. During the 1970s, City and Guilds assumed responsibility for the administration of HNC and HND courses.

Question: How long is a general apprenticeship in terms of years?