The interior equipment of passenger coaches typically accounts for 10 to 20% of total coach weight.

Due to the fact that interior parts (seats, interior panels etc.) are usually non-structural components, there is big lightweight potential.

Interior fittings

In a modern saloon-type coach (German "Großraumwagen") of 25 m length, interior fittings (sides without windows and roof) have a surface of roughly 150 m². Typical conventional components have a surface weight of 6,5 kg/m², yielding a total weight of roughly 1 ton per coach.

New construction variants may substantially reduce this figure. Especially the sandwich option using prepregs with a foam or honeycomb core may reduce the mass of interior fittigs by some 35%.

Seats

Lighter seats are another effective means of weight reduction in coach interior equipment. The use lighter passenger seats formed part of the refit programme realized on several coaches at SBB.