The reader will be familiar with Norman Groves' epic "GREAT NORTHERN LOCOMOTIVE HISTORY" (RCTS, 1986).  In Volume 1 (1847-66), Groves describes in detail the ramifications of the early GNR engines, with rebuildings from tender to tank and tank to tender.  Unfortunately the story is not complete, due to limitations in the surviving records for the period. In particular Groves drew attention to the Stock totals at 30th June 1866, which gave 436 engines and 355 tenders (see p. 14 of this volume).


The number of engines in stock at 30th June 1866 was 437, viz Nos. 1-473, less numbers 264-99 not yet allocated.  The discrepancy in total, i.e. 436 or 437, cannot be explained.  If there was one tender engine omitted (for some obscure reason), then there was presumably one tender similarly omitted, and that total should have read 356. Either way, the inference is that there should have been 81 tank engines. Groves only gives 71 tank engines in stock at 30th June 1866, made up of:

31 Sharps (numbered between 1 and 50), 2 Hawthorn rebuilds (111/17), 6 Bury rebuilds (121-26), 6 Fairbairn (127-32, based on research by Geo. Fredk. Bird), 3 more Hawthorn rebuilds (134/39/40), 3 Wilson rebuilds (144/49, plus presumably 153, rebuilt 1866, though not stated in which half of year), 3 ex-NGR (218-20), 10 new ex-Avonside (241-50), 3 ex-LBHJR (395-97), 2 ex-WYR (470/71) and 2 new from Avonside (472/73).

This leaves a discrepancy of 10 (81 minus 71) tenders missing, which Groves suggested was due to a tender shortage.


A closer look at the figures may offer a different explanation.  There is the possibility that a further 10 tender engines were converted to tank engines prior to June 1866, which have not shown up in the surviving records, as even Groves had to acknowledge Bird in the case of Nos. 127-32.


Now consider the engine numbering system, which was 1-100 and 200-299 for passenger engines; 101-199 and 300-499 for goods engines.  All four series had a mixture of tender and tank engines. Stirling gradually replaced the older engines, on an engine by engine basis, and the replacement was reasonably equivalent to the engine it replaced.  As far as the passenger engines were concerned (whether tender or tank), the replacements were all tender engines (except for tank engines Nos. 241-50, replaced in 1877-80).  Thus, intriguingly, the numbers 218-20 (replacing passenger tank engines) were taken by mixed-traffic 0-4-2s surrounded by passenger 2-2-2s, 2-4-0s and one 4-2-2.


But with the goods engines the replacement (tender versus tank) closely matched the engine being replaced (tender versus tank), with no known exception. Therefore this is a good indication of precisely which were the goods tender engines and which were the goods tank engines at the close of 1867 when Stirling started replacing the older engines. (This logic does not work for the passenger engines, but it is unlikely there were any rebuilds to passenger tank engines other than those noted by Groves.)


Based on this assumption, at the close of 1867 there were 88 tank engines:

Passenger: 31 Sharp's rebuilds (see Groves' list for numbers), 218-20, 241-50, total 44.

Goods: Nos. 111/16-34/36-40/44/49/53/55/59/61/62/66/67, 392/95-99, 470-73, total 44.


Deleting from this list of 88 engines the 71 engines set out above (that Groves records as having been rebuilt as tank engines prior to June 1866) leaves the following 17 engines, of which the 10 (i.e. 81 minus 71) underlined (below) should additionally have been rebuilt prior to June 1866:

Nos. 116/18-20 (rebuilt 1864-66, presumably as tank engines), 133 (repaired 1866, presumably rebuilt then as a tank engine), 136/37 (rebuilt 1862-66, presumably as tank engines), 138 (condensing gear fitted 1/1865, and presumably rebuilt then as a tank engine), 155 (rebuilt 8/1866 as a saddle tank), 159 (rebuilt 1867, but not shown if as a tank engine or not), 161 (rebuilt 1866, presumably as a tank engine), 162 (rebuilt 1867, but not shown if as tank engine or not), 166 (shopped 1860, and presumably rebuilt then as a tank engine), 167 (repaired 1867, when most likely rebuilt), 392 (repaired 1867, when most likely rebuilt; though this engine was replaced within a year); 398/99 (both rebuilt as 0-6-0ST 12/1866).

Thus seven engines (i.e. 17 minus 10) were rebuilt as tank engines after June 1866.



Engines built/rebuilt as tank engines by June 1866, according to Groves


Engines underlined above, additionally rebuilt as tank engines by June 1866


Total tank engines in stock at June 1866 


  + 355 tender engines
 = 436 total stock

Engines rebuilt as tank engines after June 1866


Total number of tank engines at end of 1867