When the Festen were built they were very modern. They were even equipped with electric lighting and ventilation. The current was provided by petrol engines (Diesel engines were considered not safe enough for the forts). Here you can see three of the four engines type MKD 142. They had a capacity of 24 litres and make 240 rpm. They gave 25 hp for a consumption of 5,5 l. per hour. The engines have a large balance wheel which is needed because they have just one cylinder. For more information www.mutzig.net.