This picture shows two machined aluminium starter blocks ( or dummies) in place ready for the start of a DC cast. The dummy is entered into the picture frame mould by about 3/4-1" at the start of the cast and provides the initial chill for the solidification of the molten metal feed from the launder. After about 30 seconds of mould filling the starter block descends supported on a hydraulic ram at a speed of 2-4" per minute depending upon the alloy being cast. The picture frame mould is about 5" deep so after 2-3 minutes the cast aluminium slab emerges into the secondary water sprays and steam & hissing are heard. Casting a full length slab of 150-160" would take about fifty minutes.