This engine was built by the North British Locomotive Company, a Scottish manufacturer, in 1908. The proportions were perfect, with a classical British aesthetic, as if it were a smartly dressed English gentleman. The leading and driving wheels in particular were masterfully proportioned, and the mechanical structure was solid and durable. Locomotives of this class served the TRA for as long as half a century.
謝嘉亨轉動放置在轉盤上、他最鍾愛的 BT40 型火車頭，1908 年由英國 N.B.L 製造的車款，整體比例完美，具英式古典工藝美學特色，宛如衣著整齊的英國紳士，尤其前導輪與後動輪的比例配置精湛，機械結構堅固耐用，在台鐵服役時間長達半世紀。