National Railway Museum rail railway saddle tank Tank engine train transport york architectural architecture Asia building classical-design collections Colonial color colored colors colour coloured colours columns decorations decorative heritage high historic historic-building historical history inside interior museum national-museum ornamental ornamentations rotunda significant Singapore substantial Victorian arched arches banners exterior external Flags landmark Masonic-influence shade shadows sunlight sunshine windows authority construction dome domed height stained-glass tiled tiles zinc-fish-scaled-tiles