Six Great Western Railway outside-framed 0-6-0 locomotives, originally built by Beyer, Peacock & Co. as 322 class tender engines, were subsequently rebuilt in 1878-85 as saddle tank locomotives by George Armstrong at Wolverhampton Works. They were numbered in sequence as 322-327, No. 323 having exchanged numbers with No. 359, No. 325 with No.337, and No. 327 with No. 366. From 1918 all apart from No. 324 became pannier tanks, when they were reboilered with Belpaire fireboxes. No. 322 was the only one ever to have a fully enclosed cab. They were principally stationed in the Birmingham/Wolverhampton area, and at Stourbidge, and including their previous existence as tender engines all ran over a million miles up to their withdrawal between 1921 and 1932.