Foreword
At the begining of the twenties, the Barcelona tramways company was suffering of lack of tramcars to cope with an increasing patronage. But in 1921 the City Council  forced it to increase the fleet and this is at the origin of the 500-class cars.

The project
The first drawings, in 1924, referred to this car as the extended green as the last 800-class cars came from the builder with this livery rather different of the standard mustard yellow. The project was inspired in the design of the  836-857 batch known as 'big platforms', where two windows more were added. The car was fitted with two 'maximum traction' bogies.

The big end platforms still in a second drawing. Longer platforms lead the car to a lenght of 10,77 m, and all the windows were from the same lenght. The bogies was converted to Brill 77E type with 2 motors of 28HP each and the car fitted with two trolley poles. The new car was christened as big platforms lenghtened car. Several authors attibute the car to an american  Stone & Webster design but if general features are according to this type is also certain that the origin is in an improved existing city tramcar design as the project name suggests very clear.
 
 

The first design. 1924	Car 508 in front of Borrell  depot. 1926

Building the cars
An agreement was made between the tramway company and the 'Girona' local builder. The builder supplied the bodies and some equipment early in 1926 and Tranvías de Barcelona assembled the cars. Cars 501-505 were ready in 6th may of that year. Their name still as extended green and entered into service in 10.6.1926.

The new tramcars (company XIII type) distinguished by their power and capacity as well as their typical and hard noise but were the best ones in the fleet during the International Exhibition that was held in the city in 1929. Despite their name, the livery was the standard one and most still but some were converted to a more brightly orange with a white band  livery during liveries trials in early thirties.
 
 

Car 509 in Bonanova sq. c.1930	Car 525 in the  Rambla. 1936

Changes
The 500-class was also suffering from bombs, fires and attempts in the years before the Spanish Civil War. Some were easy repared but other needed a hard overhaul and reconstruction and some minor changes were provided as the roof  end design and platform front changes. In the forties, the whole 500-class suffered also standard platforms changes from 1942 onwards. Livery changed to red and cream.
 
 

Car 532, after a fire reconstruction in Lesseps depot. 1937	A 500-class in  Drassanes.  Fifties
A 500-class in green livery in   Universitat sq.  c.1957	Car 516 in route 66. 1967

From 1946 onwards, the class was converted to single-ended ones and fitted with pneumatic doors in the front end  and others  in the rear end also. Some returned  to four doors again in 1951-2 due to the need to permit passengers access from the left side from central promenades as Rambla to avoid accidents when passengers crossed the streets to board the tramway.

Projects and  prototypes
The success of the class lead to Tranvías de Barcelona to project as late as 1948 a new batch of 50 similar cars to work in a projected standard gauge new line to Sant Adrià de Besòs and Badalona. Route and cars never came to an end.

One of the main problems of the class was the noise and in the midd fifties some cars were fitted with sandwich wheels and new helicoidal gears. When new Mayor J.M. de Porcioles came to the Council and with a new  special Transport Act for the city, the whole class was to be modified. Car 546 was selected to get a new body and equipments but never were implemented and the car was finally withdrawn in 1960.
 

The 546 prototype. 1959	The 513 prototype in route 62. 1964

Some time later, the car 550 received a minor roof overhaul and was fitted with a new route indicator but no one other car followed. The last changes were for the car 513 that received a new body (in the style of a Pegaso-Seida 1000-class bus) and also new electrical equipment as well as ex PCC seats and entered in service in 1964 and was withdrawn some time later.

The end
The class but 546 still in service until 1966 when 502 was withdrawn after an accident. After the withdrawal of all the truck cars came the end for the 900-class and 500-class. The 47 remaining '500' cars were witdrawn in 18.7.1968 -after 42 years in service- when routes 39, 51, 53, 55 and 66 were converted to buses. All cars were sold for scrap except 525 (left for unknown reason in a depot) and  547 preserved for museum purposes and run as an heritage car in the withdrawal of the remaining tram routes from 1969.
 

Car 525 in Diputació depot. 1976	Car 547 in its last trip, in 18.3.1971, the last tramways day.

Car 547 was intended for restoration  in midd eighties and bogies, controllers and seats were recovered. But all the steelframe was in a very poor state and car was put aside until 1999 when was finally scrapped.

Car 525 is the sole survivor after been purchased by a food company and preserved in poor state in a store near Barcelona, but no plans for restoration or sale are known by now.