Taking the B-TrainBy: Sloanebuilt Trailers Taking the B-Train. Sloanebuilt Trailers of Smeaton Grange, in Sydney's west, recently delivered a matching pair of B-Train trailers to Southern Highlands operator Gunlake Quarries. These immaculate aluminium tri-axled trailer sets were required for a specific regular daily transfer of hard rock aggregate and concrete products from the company's quarry near Marulan, NSW, to its concrete plants at Silverwater, Glendenning, near Smeaton Grange, and Narellan.