Simplify the following text for a Grade 4 native English-speaking person.
Original: In 1923 a new design of enclosed double deck tram was introduced by P.J Baker , General Manager of the tramways , with a rounded top that would fit through the arch .
Simplified: In 1923 a new design of enclosed double deck tram was built by P.J Baker , General Manager of the tramways . It had a rounded top that would fit through the arch .