Hartwich Tiemeyer

Hartwich Tiemeyer

Valmet Automotive is convinced that the variation of roof systems will grow, with new kinds of convertibles in car segments where we have seldom seen open tops before, like SUVs, crossovers, and the small vehicle segment. Continuing just-auto's series of interviews with leading roof manufacturers, Matthew Beecham talked with Hartwich Tiemeyer, Head of Design Engineering for Roof System, Valmet Automotive about convertible roof developments.

Could you tell us more about your soft-top sound insulation roof system? How did you achieve that innovation and how does the noise compare to a hard top? 

Innovative engineering is a conscious target at Valmet Automotive. We want to improve on current solutions, but also to find ideas and solutions that the industry has not seen before.

The new soft-top sound insulation system is therefore a result that combines 10 percent novel thinking and 90 percent hard work. We have a systematic approach to making improvements and have developed and manufactured roofs that are in many ways bench-marking solutions. So taking the best solutions we have, scrutinising them and throwing in new ideas, we now have a roof with an optimised combination of weight and mass and the equivalent interior sound insulation of a similar sedan.

In developing roofs for electric cars, what are the special considerations?

For the most part there are no special EV considerations. The same requirements apply both to electric and conventional cars with regard to appearance, reliability, convenience, interior and luggage space. However, the general trend towards lighter roof systems is very important for EVs, as these vehicles tend to exploit weight saving solutions in all structures.

In addition to sound insulation and roof system weight, we understand that Valmet Automotive is also developing solutions to provide more space to the driver, passengers and luggage and reducing the overall vehicle weight.  Could you give us some examples of how you are doing that?

These are focus areas in our roof systems development. We supply lightweight roofs by measuring every part and component in the roof, using innovations and state-of-the-art light weight materials, such as magnesium and aluminum. However, the roof is not an "add-on" but an integral part of the car and a convertible is a platform derivate that requires special attention from early on. Therefore, achieving these targets usually require profound cooperation with the customer brands.

Solar technology in cars seems to be another way beside weight reduction to promote the image of ecological awareness and could be a trend for future sunroof development. What's your view?

Today, solar roof solutions are still mostly just that - image promotion. However, this is a technology that makes sense and offers exciting possibilities. Heating up or cooling down the car interior with solar energy is a sustainable and logical approach. Much will depend on the technological development - solar roof efficiency and pricing. This may well turn into a trend but we will have to wait.

Over the past few years, we've seen the emergence of two-, three- and four-part retractable hardtops. Could this trend render the coupé obsolete?

It's hard to see that happening. Rather, we see that the roof systems will allow the customers a much wider range of choice that before. Coupés, various forms of RHTs, and of cause, Soft Tops complement each other in the manufacturers' offering. Yet we are thrilled to see the diversification in roof systems and want to pioneer new, advanced solutions.

Could you give us some idea of the pace of growth of the retractable hardtop market in Europe?  What is the size of it today?  How big could it become in a few years?  

The remainder of this interview is available on just-auto's QUBE research service