DEE-Ltd 'Hailed' For Taxi Turning Circle Solution

DEE-Ltd 'Hailed' For Taxi Turning Circle Solution

22nd July, 2013

Warwickshire-based automotive design specialist, DEE-Ltd, has successfully reduced the turning circle of a new generation front-wheel-drive taxi to within the strict limits required to comply with Transport for London’s Condition of Fitness (CoF) for licensed taxis. DEE-Ltd’s innovative solution will now be carried forward as a converter modification when Nissan’s NV200 London taxi variant goes on sale later this year.

DEE-Ltd Managing Director, Neil McAdam says, “The constraints on manoeuvrability and turning angles with front-wheel-drive vehicles are well known – and meeting the very strict requirements for operating in London demanded a radical approach. We have worked very closely with our colleagues at Nissan to produce a viable production-ready package which fulfils all the operating criteria – and does so cost-effectively”.

The turning circle requirement was established in 1906 to ensure that all London cabs could negotiate the famous Savoy Hotel’s roundabout in a single manoeuvre. The long established Black Cab achieves the strict turning circle criteria by employing high angle front wheel steering combined with rear wheel drive. Recent additions to the marketplace have incorporated electronically controlled rear wheel steer with varying degrees of success.

Nissan’s revolutionary new product will be the first vehicle to achieve the 7.62 metre (25 ft) turning circle requirement with a front wheel drive vehicle and front wheel steering alone.

To achieve this performance and reduce the base vehicles original turing circle of 10.6m, DEE-Ltd has incorporated a number of innovative modifications to the base platform installed as part of the conversion process. To enable the front wheels to achieve the high steering angles and provide clearance to the body structure the front track has been increased by 150mm.

The innovative new suspension system replaces the existing McPherson strut configuration with a new high angle double knuckle design as a direct bolt on upgrade. Drive to the front wheels is achieved via a new ‘double cardan’ joint developed to deliver maximum torque at the extreme angles of articulation. Importantly, DEE has been able to retain all the base vehicle’s ride and handling characteristics and all major components including disc callipers, wheel and tyres have been carried over.

The Nissan Taxi project with Vectayn is the latest major collaborative engineering programme for DEE-Ltd, since it moved to its new technical centre south of Coventry late last year. It already has a strategic alliance with Enhanced Protection Systems, to develop light wheeled platforms for defence applications. DEE-Ltd’s prototype, powertrain and motorsport business has also grown, with the company recently recruiting design engineers to work on both domestic and export market programmes.