Casting method and casting apparatus for dc casting

A method for casting longitudinal cast products (90) comprising: casting longitudinal cast products (90) in a semi-continuous manner using a DC casting apparatus (10) having a mold (30), wherein the mold (30) has top (31) and bottom (32) openings and is configured to at least partially solidify molten metal that is entered into the mold (30) via the top opening (31) and to output the cast product (90) via the bottom opening (32), recording a thermal image of the cast product (90) that is output via the bottom opening (32), determining at least three non-overlapping temperature ranges comprising a first temperature range, a second temperature range and a third temperature range, wherein the third temperature range comprises temperatures higher than and not including 90°C, determining a peak temperature in the thermal image; comparing the peak temperature with the at least three temperature ranges; and a.) when the peak temperature is comprised in the first temperature range, casting the cast product (90), b.) when the peak temperature is comprised in the second temperature range, displaying an information indicative of a maintenance requirement of the casting apparatus (10) and carrying out maintenance of the casting apparatus (10) after the cast product (90) is cast and before a subsequent casting operation is carried out, c.) when the peak temperature is comprised in the third temperature range, aborting the casting of the currently cast cast product (90) and displaying an information indicative of an emergency shutdown.