The inside core structure and the outside mold had to withstand the pressure of about 30 tons of molten copper, and the casting had to be done in one continuous operation to prevent cracks or flaws.
Valandi alumise külje toestus ja valuvormi välimine külg pidid taluma umbes 30 tonni sulavase survet, kusjuures sulametalli tuli kallata vormi ühtlaselt, et valandis ei tekiks pragusid või mõrasid.