My father was a line Chief in 69-70 and always referred to it as the Belslow. Perhaps a name change at some point?
Lineys are always good at making up names. The Chiefs sat in the office all night pushing paper, so what would they know?
I think the slug epithet used in the LSS crew-room came from them slithering slowly but surely around the world, leaving behind a trail of knackered engine fitters and slimy patches on the pans. Unlike the beautiful and graceful Shiny Tens that we also looked after.