Failure Analaysis

   Fracture Mechanics

   Failure as a Design      Criterion

 Structural Failures
 ::  Unforeseen Loads & Consequences
 Human System Interaction  Failures
 ::  Flawed Decision Making
 :: Flawed Safety culture
 Failure of Design Management
 ::  Visionary Management Style
- De Lorean Motor Company
 ::  Inaccurate Assessment of Market Needs
- (Poor Concept Realisation) Sinclair C5 Electric Vehicle
- (The Right Product at the Wrong Time) Hughes Aircraft Company 'Spruce Goose'


Clive Sinclair is a British inventor whose interests range over amplifiers, radios, calculators, pocket TV’s and electric vehicles. His first electric vehicle was the Sinclair C5, and is the product for which he is, somewhat unjustly, most famous. At the time, this vehicle was claimed to be ‘a revolution in personal transport’.

On January 10 1985, the Sinclair C5 made its debut in the London traffic under the critical eye of a cynical press. It took advantage of a 1983 change to the law (designed to help disabled drivers and milk float manufacturers) and was carefully designed so that anyone over the age of 14 could drive it, without insurance, driving licence, road tax or crash helmet, and even if they had been disqualified from driving a car by the courts. It was meant to be a ubiquitous, utilitarian environmentally friendly town vehicle – this ideal is a good one and has been emulated by other manufacturers in the intervening years, even if the engine is not always electric, e.g. the SMART car [5].

It was essentially, a 99 lbf battery operated, single seat tricycle with a 250 W motor, a white plastic body (designed by Lotus), a 1 ft3 boot, and front and rear lights. It retailed for £399 by mail order. Its dimensions were width and height 2’ 6", and length 6’ 9". Steering was via handlebars between the thighs of the driver, and the brakes were similar to bicycle brakes. An additional £143 bought extra items (rear view mirrors etc) deemed ‘essential’ by most safety commentators.

Sinclair had obtained an ex-De Lorean henchman to run Sinclair Vehicles and persuaded the Welsh Development Agency and Hoover to invest in producing the vehicles at a plant in Wales (based on projections of sales of 200 000 to 300 000 vehicles per annum). His past reputation as a successful entrepreneur carried all resistance before him. He spent some £3 million on a 3-month ‘primary contact’ advertising at launch of the vehicle (some of the claims in this campaign later backfired when the Advertising Standards Authority stated that it would look into complaints regarding safety assertions).

The original concept called for radical new battery technology, which was not possible at the time. Thus the concept, as realised, was changed to provide a small lightweight vehicle operating on existing lead-acid battery technology. The battery contributed 1/3 of the total weight. The maximum speed was 15 mph and it required pedal assist up steep hills and in order to get moving. Range was about 20 miles using a ‘drive and coast’ technique, and the battery required an 8 hour charge time.

Other drawbacks of the vehicle included the low position of the drivers body (at bumper height in the event of a collision with another vehicle), poor visibility in traffic, an ineffective horn, poor lights, dazzle from vehicle headlights, a large turning circle, and problems with the gearbox moulding. An additional hazard arose from incessant breathing of exhaust fumes, which were just about at face level!

Sales of the vehicle were very slow, and many countries would not licence the vehicle for use on their roads without modifications to improve safety. By about August some stores were discounting the price to £140. On 12 October 1985, Sinclair Vehicles was placed in the hands of the receiver, and entered voluntary liquidation in November. The loss to Sinclair was about £8.6 million and Hoover and the Welsh Development Agency also lost money.

Causes:
  1. Incomplete development of a useful and saleable package prior to market entry. The vehicle was poorly executed, unreliable and unsafe. Many of these problems arose from weight/power restrictions imposed by insurmountable problems with battery technology.
  2. Development was probably rushed to exploit the temporary loophole in the law regarding electric vehicles, and did not consider the consequences of future safety legislation.
Design Failure:

The basic failure here was incorrect assessment of the market for the type of vehicle, which did not lend itself to innovative realisation, at least when based on existing battery technology.

It is worth noting that Sinclair C5 tricycles currently sell for around £900 in the UK!

References:
  1. http://www.ellis-online.co.uk/sinclair/c5review.html
  2. http://lurch.ucd.ie/~sinclair/Planet_Sinclair/sst_c5.htm
  3. http://lurch.ucd.ie/~sinclair/Planet_Sinclair/in021196.htm
  4. http://www.nvg.org/sinclair/planet/c5which.htm
  5. http://www.smartcarmanchester.co.uk/factsheet.html

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Structural Failures | Human System Interaction Failures | Failure of Design Management

Failure Analysis  -  Fracture Mechanics  -  Failure As A Design Criterion