When Patrick Stirling died on 11 November 1895 he left the GNR locomotive stock in sound condition. He had spent some thirty years gradually replacing the stock he had inherited, usually on a one-to-one basis resulting in the haphazard numbering of the fleet. At last 1894 and 1895 were the first years in which he had not needed to make such replacements. He was also in the process of making the 4ft.-5in. diameter boiler a standard feature in his future 0-6-0 goods engines, which diameter he had previously used in 1871 for his 174 Class mineral engines. It appears likely that in January 1895 he ordered 10 new 0-6-0s with 4ft.-8in. diameter coupled wheels and 4ft.-5in. diameter boilers. The relevant drawings for these and other proposed goods engines were as follows:
| Wheels | Boiler | Boiler dwg. | General Plan dwg. | Engines |
|---|---|---|---|---|
| 4ft.-8in. | 4ft.-5in. | N65 (15/1/1895) | P36 (15/1/1895) | 1021-30 |
| 5ft.-2in. | 4ft.-2½in. | N66 (11/1895) | P37 (11/1895) | 1031-45 (from Dubs) |
| 5ft.-2in. | 4ft.-5in. | N71 (18/2/1896) | — | 1081-90 |
All these boilers were straightback (domeless) in Stirling tradition. In addition, batches of 0-6-0ST engines with straightback boilers were built as follows:
4ft.-0½in. diam. boilers: Nos. 1046-60, 1211-15 (Neilson), 111, 155 (Doncaster)
Thereafter all boilers for new construction had domes.
At the time of Stirling’s death (11 November 1895) there were 74 straightback boilers under construction (or on order) for renewal purposes. These covered 12 boiler types for 23 different engine classes. They were fitted to existing engines and not surprisingly it was March 1901 before the last one was fitted. These post-1895 Stirling boilers are listed in PART 1.
Ivatt continued to order 4ft.-0½in. diam. straightback boilers for renewal purposes only, mainly for saddle tank engines to avoid the cost of having to replace the saddle tank with a new one having provision for a taller dome. The last batch was ordered on 3/8/1911, shortly before Gresley took over. Though this foretold the demise of the straightback boiler in traffic, the actual end came in October 1933 with the withdrawal of Class J57 No. 3144A.
Early on, Ivatt also ordered 10 4ft.-5in. diam. straightback boilers for existing 0-6-0s (Classes J5, J8 and J9), but several of these later found their way to 0-4-2s (Class F3) and 0-6-0STs (Class J16).
Three domeless boilers for 8ft. 4-2-2s were ordered in 1897 suggesting sufficient material had been found to justify their construction. They had traditional Ivatt washout plugs, They were fitted to Nos. 94, 69 and 771 in 1898.
Finally, six more straightback 8ft. boilers with Ivatt washout plugs were ordered (12/7/1898), again suggesting further material had come to light. These were fitted to Nos. 548, 7, 670, 778, 664 (at Ardsley shed) and No. 2.
The boiler fitted to No. 778 (August 1900 to June 1904), was later fitted to No. 668 (July 1910 to June 1912), then acted as a stationary boiler (SB268) at Doncaster Carr engine shed (September 1912 to May 1925) and has finally served in the preserved GNR No. 1 since May 1925.