The Gala is shuddering. The new bus seat from the Spanish company FAINSA is shaken so violently that only 24 hours in a test machine are equivalent to one year of daily use. FAINSA guarantees the seat for five years, but tests are run much longer than that. Juan Canals, technical executive at the company, now knows that the first seat for which FAINSA has used high strength steels is at least as good as its predecessor, even though its weight has been cut by more than 30 percent.

FAINSA came into contact with high strength steels back in the 1990s. The possibilities offered by the material aroused thoughts, but neither passenger carrying capacity nor safety requirements were then the subject of particularly lively discussion.

Today it is different. The safety of bus traffic has been subjected to detailed scrutiny in the EU. Several countries, including the important markets in Great Britain and Italy, decided to specify three-point seatbelts for long-distance buses. The same rules will eventually apply in all EU countries.

Safety increases weight

It was obvious that the new safety rules would make the seats heavier. The backrest needs sturdy reinforcements to withstand the stresses imposed if seatbelts are fitted. Ultra-high strength steel solved the problem and gave a two-fold gain to FAINSA:

“We secured the best possible material for our best products,” declares Juan Canals.

When work began, the company thus had limited experience of the properties of high strength steels, but the necessary knowledge was available close at hand.

“We began by getting in touch with SSAB Swedish Steel in Spain, since we had already discussed high strength steels with them previously,” says Juan Canals.

The calculations were very promising and showed that great weight savings could be achieved. Even at that stage, FAINSA had already excluded other materials.

Teamwork in development

The intensive period that followed involved a new type of teamwork for FAINSA.

The company developed close cooperation with several suppliers.

The Gala has hit the weight target due to a clever combination of tubes and pressed parts made of ultrahigh strength steel.

“Many of the parts must be able to withstand very high forces,” explains Juan Canals. “This applies, for instance to the brackets to which the backrest is secured. For these, we have also specified thicker hotrolled, ultra-high strength steel.”

Development of tubes made of advanced high strength steels has begun only in recent years, and limited knowledge is therefore available of how such tubes should best be bent. The FAINSA design expands the field of application of this type of material, and the main tube in the backrest is of advanced design that also provides anti-whiplash protection.

“Designing a backrest is a complicated matter,” declares Juan Canals. “Above all, it must be comfortable for passengers of all sizes, but it must also be safe both for the seat occupant and for the passenger in the seat behind.”

So the seat must not be too rigid, since it could otherwise cause injuries to the passenger in the seat behind, if he has forgotten to fasten his seatbelt.

FAINSA has a routine for seats for a wide variety of applications. The company was founded in 1935, and the present President and owner, Juan Singla, joined the company in 1945. FAINSA is a family company, and the fourth generation of Singlas has now begun working on seats.

From bike to aircraft seats

“But our operations did not begin with bus seats,” explains Juan Singla. “Our first products were bike and motorcycle seats. We are now working on passenger seats for buses and trains, but we are also considering the possibility of developing aircraft seats.”

Bildtext:Juan Canal is technical executive at Spanish FAINSA.

Text: Håkan Johansson News Magazine No 1, 2005