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The design development of the Opel Signum

19 August 2003 | by Sam Livingstone

The Opel Signum production car debuted in its final production form at this year's Geneva Motor Show, alongside the GTC Genève concept car which previewed the design direction of Opel's forthcoming new-generation Astra, due later in the year. The irony is that the Signum owes its genesis partly to the current generation Astra, because the original 1997 Signum concept car was created largely as a ‘teaser’ and testbed for the new form language of the current generation Astra, in addition to it's role as an architectural study for a new type of flagship model for Opel.

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Signum 97 design team Frank Leopold, Niels Loeb, Uwe Muller

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Alternative theme scale model

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Digital rendering, 1996

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Model review of original Signum concept at Bertone studios

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The Signum concept car was created at the Opel satellite studio at Stile Bertone near Turin, Italy. The positive response that the Signum received at the 1997 Geneva Motor Show led Opel to turn that car into a runner and consider its potential for production intent.

By the end of 1997 it was decided that the Signum would become a production car and it was brought into the new Vectra ‘palette’ (to use Opel’s in-house terminology for the wide range of vehicles based on this platform).

With the phasing out of the Omega sedan and wagon, Opel had embarked on a strategy to create a wider range of vehicle types from the Vectra platform (which is also shared with other GM models as part of the worldwide Epsilon platform).

The new Vectra wagon was to become a practical high-capacity vehicle (achieving similar space to the Omega wagon), while the Signum would be a new hybrid architecture, targetting the business, luxury and sports-oriented customer.

The long wheelbase and short rear overhang may have originated from the exterior theme of Signum the concept car, but the implicitly lengthy rear cabin area this created meant that the priority of the production car’s design was its interior design concept.

With the Zafira and its ‘Flex 7’ seating freshly on the market, Opel saw the opportunity for creating a new and more versatile interior for the production Signum than was in the original concept car or any production car in the European D-sector.

Michael Pickstone, chief designer for the Vectra pallete, oversaw the development of the interior design concept that started from the modern luxury interior of the Signum concept car, embraced the Vectra front architecture and introduced a rear seat area versatility not seen before in this vehicle size. By the end of 1998 Karim Giordimaina, the Signum’s interior assistant chief designer, and the rest of the design team has produced a full size interior model.

At the same time six, 1:3 scale clay models of the exterior were being developed. Because much of the design theme was evolved from the 1997 Signum concept and the front end architecture inherited from the Vectra, the development was quick, and by the end of 1998 there was a complete exterior clay model from Kurt Beyer, the Signum exterior assistant chief designer, overseen again by Michael Pickstone.

Refinement of the interior and exterior full size clays continued in parallel with digital design development using Alias Autostudio, Unigraphics and the in-house virtual reality facilities, and by mid 1999 there was a complete fibreglass interior/exterior model. This was then signed-off by management for production with only interior design details still being resolved in late 1999 and early 2000.

Meanwhile, development of the Signum2 concept car had been progressing in parallel. It was revealed to the press in late 2000, and made its public debut much later at the 2001 Frankfurt Motor Show. This car was based very closely on the design being developed for production and helped prepare the market for the production version in a similar way that the Mercedes Benz Vision A did for the A-class. It also introduced a more definitive version of the Opel corporate face, with a stronger trapezoidal grille theme, and an interior that reflected themes from the production Signum.

The Signum, now being launched across Europe under the Opel and Vauxhall brands, is a variant of the Vectra range (or ‘palette’) already comprising sedan, hatch and the newly announced estate. The wheelbase is 130mm longer than the hatchback and sedan, but its rear overhang is 90mm less and thus its total length is only marginally greater, and it is 180mm shorter than the voluminous estate with which it shares the same wheelbase.

The Signum’s rear cabin area is defined by two ‘business class’ rear seats, with a smaller occasional center rear seat giving ‘4+1’ seating. The two main rear seats can recline to a 30 degree angle (from horizontal) and slide fore and aft 130mm to provide a variable trade-off between luggage and rear leg room. 

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Signum 2 concept sketches

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Signum 2 concept interior

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Signum chief designer Michael Pickstone, Color+Trim design manager William Franke

All rear seats can be folded flat to create one large load bay. The ‘+1’ central rear seat can be flipped down and inverted to provide armrests with cup holders, or can be replaced with the optional ‘Travel Assistant’ which has two folding tables, a cooler, a bin, cup-holders, a 12-volt power outlet, a holder for a DVD player, as well as an optional module for separate audio programs in the front and rear.

The emphasis on the rear cabin space, versatility and habitability is the focus of the Signum interior. And it is the linchpin to its exterior profile, which is clearly not that of the fastback style D-sector hatchback, or that of the D-sector estate car with lengthy rear overhang.

In many respects it is more akin to a stretched C-class hatchback, and it is this unique proportion that creates the Signum's particular appeal and defines its conceptual design. In product research clinics this was borne out when existing D-sector car customers could not ascribe the Signum to a particular vehicle type such as estate or hatchback, but were attracted to its uniqueness and had a perception of it being more of a premium product relative to existing variants.

Although the car’s proportions are clearly part of a different proposition to the customer, Michael Pickstone points out that they are not different enough to be uncomfortable or odd. This was important as the vehicle was designed to appeal to a broad variety of users who want some of the space and versatility benefits of an MPV, but don’t want the height or extrovert family image.

Michael Pickstone also emphasized that whilst it is being marketed to the business user, the Signum has many clear benefits for the family user, which he has first hand experience of with his daughter sitting, headphones on, drink and games to hand, feet happily swinging out of reach of her father’s seat back!

The Signum may be a high risk concept because it breaks new ground, targets part of the declining D-sector market and because Opel doesn’t have the level of brand equity that brings implicit customer trust in its new vehicle concepts in the way that brands such as BMW can be confident of for their forthcoming X3. But arguably the higher risk strategy for any company is to stagnate and not to innovate, and Opel have already reaped dividends from their innovative Zafira and look likely to succeed with their clever new Meriva as well.

Alone the Signum stands as a significant contribution to the conceptual design development of mainstream cars. As part of the Opel range it further signposts the brand’s commitment to innovative interiors and thus to a more customer-focused brand that is trying harder than the competition. Exactly what Opel needs.

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Sketches for the 1997 Signum concept

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Full size plaster model, 1996

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Signum concept, 1997

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Signum concept interior

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Exterior assistant chief designer Kurt Beyer working on Signum sketch development at the GM Europe Design Center, Germany

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Initial two proposals for Signum on Epsilon platform, Spring 1998

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Alternative theme scale model development, Late1998

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Alternative theme scale model development, Late1998

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1:3 scale models with original Signum concept car

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First 'see through' Fiberglass model in spring 1999

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Fiberglass model. Hatch design with glass graphic extending to bumper. Note 'Vectrum' codename.

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Full scale clay model with Dinoc film applied, late 1999. Note round wheelarch, body color upper hatch, and more massive bumper

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Concept development for the Signum 2

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Signum 2 concept sketches

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Signum2 concept rear seating system

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Signum 2 concept, 2001

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Production Opel Signum, 2003

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