The dock and the associated machinery had a book value of 440,000 marks .
Due to low usage , dock had brought just 6,200 marks ' average annual gross income during 1870 -- 1879 , which was not enough to cover even the costs .
The dock and the associated machinery had a book value of 440,000 marks , but due to low usage , it had brought just 6,200 marks ' average annual gross income during 1870 -- 1879 , which was not enough to cover even the costs .