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Background In 2002, Bison embarked on plan to capture significant market share from their competitors in the curved stair-lift market. SA had been a long-standing consultant to Bison on many projects prior to this and therefore we were involved right from the start in formulating exactly how radical new thinking could be used to deliver a huge list of market-leading, customer-oriented features.

With a projected development budget of over £1million and a timescale of two years, the plan was to offer world-leading levels of performance and features. Bison intended to punch “way above their weight”.

Challenge The full project brief was much too complex to summarise here, but two of the market-leading features required high-level technical innovation. Firstly, they needed a rail that could fit any shaped staircase using a set of modular rail sections. This was absolutely fundamental to enable Bison to substantially beat the very long delivery times offered by competitors.

Secondly, the lift needed to be extremely slim when parked. This new lift was to park in half the space of the major competitors. This was a huge challenge on a curved lift, affecting every design decision and pushing the technology to the limit.

Solution Working closely with an excellent firm of electronics engineering consultants, SA created and validated the core mechanical concepts for every major part of this extremely complex and safety critical machine. This left Bison’s in-house team free to complete the introduction of a new Straight Lift that had started 18 months earlier.

As each work package reached the “feasible” stage, we worked closely with the Bison team to ease their transition onto this new project as the workload on the Straight Lift ramped down.

Deliverables The process of conceptualising and refining involved 25 separate sub-systems and took over 12 months of intensive work. Every safety critical structure was validated by SA using advanced simulation tools before production tooling was made. Very few parts needed tool mods during the final validation testing.

The Bison 80 Stair-lift represents a major step forward in comfort and reliability. It is a truly class-leading product offering a wide range of options and accessories. Bison’s key objective of consistently offering the shortest delivery lead time has been met thanks mainly to the modular rail concept that took so much effort to make work.

Results The Bison 80 truly surprised the industry when it was launched and has sold well from the start. It continues to do excellent business for Bison and is loved by the dealers who install and service it and the end users who ride on it.