The original service was operated by trains composed of an engine and three carriages. Thirty-two passengers could be accommodated in each carriage, which had longitudinal bench seating and sliding doors at the ends, leading onto a platform for boarding and alighting. It was reasoned that there was nothing to look at in the tunnels, so the only windows were in a narrow band high up in the carriage sides. Gate-men rode on the carriage platforms to operate the lattice gates and announce the station names to the passengers. Because of their claustrophobic interiors, the carriages soon became known as "padded cells". These trains were however, preserved in London Transport Museum as the first static exhibit to the metro train.