Very early stuff this time. I've got an idea for a new publication, but the concept means I will have to have much better coverage of the early locomotives than I did in "Introduction to". So I think I'm going to have to do a lot of drawing, and this one is starting very near the beginning! Its tempting to simply reuse the E.L. Ahrons drawings in RCTS, which are out of copyright, but I don't feel comfortable doing it.
As far as I can see no-one really talks about classes this early, but this is one of five long boiler goods engines which were probably built in 1849 by R.B. Longridge & Co. for the Shrewsbury & Birmingham Railway. Longridge seem to have been associated with Stephensons to some extent, and were based in Bedlington, Northumberland. They featured the gothic style firebox. One was sold to the Shrewsbury and Chester, but all five came to the GWR in 1854. In 1868 one was rebuilt into a saddle tank with a new boiler and cylinders and altered wheelbase. According to RCTS a similar conversion was considered for the others, but in the end they were withdrawn between 1868 and 1877. They don't seen to have been reconstructed as much as many other early locomotives. The saddle tank, with a further reconstruction in 1875, worked on until 1889.