Peter:
Well, I don't know about "Big Bertha"(although she did consider Skoda to be an arch rival - -
http://www.quel.nl/Toeleveranciers/skoda-steel/19041 ) but I do know that circa 1847 Krupp sent a 6.5 cm cannon to the Spandau Arsenal to be tested and they let it sit out in the weather for almost 2 years. When Krupp pressed the Spandau officials about the testing, they replied that on brass versions were to be accepted. A historical note that circa 1882 the railroad connected Suhl, probably with Krupp steel, and it is then that one can see the market to explode. Also, Emil Skoda,
http://en.wikipedia.org/wiki/Emil_%C5%A0koda , was in charge at Skoda:
http://www.pilsensteel.cz/en/historie/ .
Kind Regards,
Raimey
rse