Had a think about Wayne's pics. I've never cast metal apart from lead in my life but I'm intending giving it a go so I've gathered and read a fair bit about it. I mentioned the horn core prints earlier and I've circled in yellow all the visible core prints in this pic. Core prints are corresponding depressions in the sand in which a baked sand core is placed. The core is longer than the void it needs to bridge or fit so that it gets held in place by its extremities. All the horizontal bits of steel rod in this case will be replaced with sand cores the same length and diameter after the pattern is removed and before the drag and cope are fitted back together. Thus sand against sand becomes the mold, but any cavity receives metal from the pour.
The pink oval is the area of the feed runners (the horizontal bars). The vertical rounded top parts may be risers or feeders - I'm not sure which - perhaps they're both. Comparison of these pattern vs Ron's actual track link pics shows where the runners were cut off the track during finishing.
But the interesting part is the two vertical pins. This track link shape is known as an odd side pattern. The pattern is one piece so I'm thinking it must have been placed pins downward into a complimentary shape (can't think of the name) that defined the parting surface. The top half was rammed up in a flask and screed off and then the whole carefully turned over on the moulding board and this other mystery shape removed and parting powder sprinkled over the parting surface and then the other half of the flask fitted onto the first and then this second side of the pattern was rammed up.
Regards
Alex
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