In the early days no provision was made for boiler expansion within the frames.  Boilers were not over-lengthy and the effects of expansion were ignored.  The boiler was thus securely attached at both back and front.  At the back there were angle irons bolted to the firebox and inner frames.  Later, expansion brackets were provided, and their positioning can best be explained by reference to certain drawings in STIRLNG SINGLES.  The brackets were bolted to the sides of the firebox, leaving the bottom of the bracket free to slide over the tops of the inner frames.  See illustration on page 30 which shows an end-on view of the bracket secured by means of the stay bolt.  This is an simple solution and avoids making additional holes in the firebox casing.  It also means that its height can be changed, or the size of the bracket changed.  This needs to be done when the firebox is empty and cold.  One man climbs into the firebox with a spanner and removes the securing nut. The fitter outside withdraws the bolt, positions the bracket, inserts the bolt and the nut is replaced on the inside.  The depth of frame has to match the position of the expansion bracket, and thus the boiler. 

The expansion bracket had to be placed horizontal, so it needed a horizontal row of stay bolts, but fireboxes tended to having sloping grates.  See figure on page 79 of STIRLING SINGLES.  The rows of stay bolts are set at an angle, the angle increasing which each lower level of stay bolts.  So the choice of a row of horizontal stay bolts was limited to the upper rows on the casing.  This figure purports to represent No. 776, but drawings are never fully accurate.

The illustration of the 2-2-2 on page 90 is of Nos. 238/232, but the dimensions written on it refer to No. 234.  So Doncaster were good at just altering figures but not the drawing itself.  On the actual drawing they would have put two short lines under the figure to denote "not to scale".

Stirling Singles Boiler drawings

There is great difficulty tracking down boiler alterations because of the practice in the Drawing Office at that time.  Minor dimensional changes were written on the drawing (with two short lines below) and eventually the drawing could be redrawn incorporating all the changes.  Earlier copies of the drawing would be scrapped when no longer needed after all earlier boilers had been brought into line.  This is best illustrated by listing all boiler drawings for Stirling single-wheelers recorded in the boiler drawings register, and recording the dimensions entered on the existing drawings at around 1955 when a senior draughtsman (Roy Burton) analysed all the surviving early boiler drawings. M denotes boiler drawing was missing by the 1950s.  There are limited details for drawings prior to N31 (October 1869).









h s
(sq ft.)

h s
(sq ft)

(sq ft)


N27 1868 10'-2"



4' 0½"

192 19/16"       (a)
?   10'-6" M



4' 0½"

          92 (b)






[3' 11½"]






No.1 (c)






[3' 11½"]






8, 33 (d)



11' 5"

4' 2"

6' 2"

3' 11½"












[3' 11½"]









10' 6"

4' 2"

5' 10"

4' 0½"






232 & 238



11' 5"

4' 2"

6' 2"

4' 0½"






1002 & 1003



11' 1"

4' 2"

6' 10"

3' 11½"






1003 & 1004



11' 3"

4' 2"

6' 8"

3' 11½"









11' 5"

4' 2"

6' 2"

4' 0½"







[a] Boiler for No. 6 Class 2-2-2. There were two N27 boiler drawings, the other had a 10ft-0in barrel for 0-6-0s and 0-4-2s
[b] Boiler for 2-2-2 No. 92
[c] Boiler for first 4-2-2, No.1, with small firebox
[d] Boiler for 2nd, 3rd 4-2-2s, Nos. 8, 33, with large firebox and midfeather. Later 4-2-2s had same size firebox, without midfeathers
[e] First 4ft-2in diameter boilers, applicable to 4-2-2 Nos. 661-68
[f] Boilers for 8ft singles “with Strengthened Frames”
[g] The drawing office used N51 for two different boiler designs
[h] 1002 & 1003 entered traffic as 234, 229
[i] Domed boilers for 8ft singles Nos. 22, 34, 93, 95, 221, 544, 776
[j] Domed boilers for 7ft-6in singles Nos. 235, 236, 872 (fitted at King’s Cross), 877, 880.  Drawing also shows following dimensions,
     which confirm it has a deep firebox.   All these 2-2-2s always had high frames
     Expansion bracket 2ft-8¾in below boiler centre line
     Bottom of firebox casing at the rear 5ft-0in below boiler centre line
     Bottom of firebox casing at the front 5ft-6in below boiler centre line

Low frame 4-2-2s could have deep fireboxes and either high or low frames. It is believed all the 2-2- 2s (which all certainly had high frames) only ever had deep fireboxes.

Dwg. N88 was superseded under Ivatt by dwg N119.

Stirling Singles General Plan drawings

At one time a complete set of General Plan drawings was kept at Doncaster.  The LDO mainly held post-1866 drawings, which were registered in the P (goods) and Q (passenger) ranges. The Works Manager appears to have also held a good collection dating from the Sturrock era.  These drawings enabled Geo. Fredk. Bird to write an excellent account of GNR engines around 1900. There was no consistency where dimensions were taken, as the drawings were from several sources, by different draughtsmen over a long period of time.  So for example the diameter of the barrel was sometimes measured internally and at others external.  It is thought the drawings Bird saw were kept in the Works Manager's Office, rather than the Locomotive Engineer's Drawing Office (LDO), because there was at least one omission in his book suggesting one particular drawing was absent, but the LDO held the necessary copy. He makes no mention of the Ivatt engine classes which were probably of little use to the Works Manager, but instead quoted the Works Lists which were use in the Erecting Shop.

The following General Plan drawings relating to Stirling's single-wheelers were entered in the Q drawing register as follows, with the exact wording quoted.

Q19 (1/1868) 7ft. express passr eng. 4. 6. 14. 21. 41. 49 &c
Q23 (3/1870) 7. 6 express pass engine No. 92
Q24 (3/1870) 8. 0 Express pass engs Nos. 1. 8. 33. 2. 3
Q37         8. 0 Passr Engines 1. 2. 3. 5
Q38         8. 0 Passr Engine 1. 2. Cross Sections
Q5 (8/7/1880)  Outside Elevation 8ft. Express Engs.
Q6 (31/7/1880)  Express Passr. Engs 8ft Passenger Nos. 662-71
Q43 (31/10//1884)  7' 6" Passr Engs Nos. 1000 & 1001 232 & 238 18½" X 26"
Q44 (1/7/1885) 7' 6" Wheel Express Passr Engines Cyls. 18½" X 26" Nos. 232, 238 (Outside Elev)
Q45 (1/1886)  7' 6" Wheel Express Passr Engines Cyls. 18½" X 26"  [Nos. 229-31/33-37/39/40]
Q47 (1/1888)  Express Passr Engs 8'-0" Cyls. 18" X 28" Section  [771-7/7/8, 1001/2]
Q48 (2/1888)  Express Passr Engs 8'-0" Cyls. 18" X 28" Outside Elevation    [771-5/7/8, 1001/2] [also 2, 3, 7, 22, 33/34, 53, 93/95, 221, 544, 776, with high frames]
Q51 (12/1894) Express Passr Eng 8'-0" wheels 19½" X 28" cyls Nos. 1003.1004.1005.1006 [also 1007/08]
Q59 (1/1899)  Arrangement Rebuild 8'-0" passenger  [22, 34, 93/95, 544, 776, with domed boilers]
Q60 (10/1897) 7'-0" wheel express passenger engine [21, 41, 61, 55, rebuilt with new boilers; engine numbers shown on dwg.]

Stirling Singles Cylinder drawings

There were three cylinder drawings during the Stirling period, suggesting a high degree of standardisation:

M33 (12/1869) 18in x 28in for No.1
M47 (4/9/1884) 18½in x 26in for 7ft-6in singles
M59 (2/1894) 19½in x 28in cylinders for 1003 & 1004 [and also Nos. 1005-08]

Stirling Singles Frame drawings

During the same period, the following frame drawings were made, with the exact wording in the drawing register quoted:

O7 (7/1867) for 7' single passr 4. 6. 14. 21. 41. 55. 61. 222
O12 (1/1870) for No. 1
O14 (1/1870) for 7. 6 Pass Eng No. 92
O32 (31/10/1884) for Nos. 1000, 1001 232, 238
O33 (1/1/1886) for Nos.
1002, 1003 234, 2   [2 should have been written as 229]
O37 (6/1886) for 8ft. singles [Nos. 776 onwards with helical bearing springs for driving wheels]
O43 (4/4/1894) for Nos. 1003 & 1004 [and also Nos. 1005-08]


In 1885 Stirling introduced steel plate in place of "Best Yorkshire Iron" or similar varieties of wrought iron.  Boilers built from 1886 onwards would almost certainly have been made from steel, though there could still be a number of wrought-iron boilers left in reserve and pressed into service as a last resort.  Steel probably lengthened the life expectancy of the boiler, though still subject to other issues such as pitting in hard water areas.  It appears that Doncaster perhaps based their future requirements on an expectancy of say 30 years.  Analysing fitment dates of new replacement boilers between 1890 and 1893 (i.e. ignoring boilers for new engines) produces annual figures of 30, 32, 30, 32, which when divided into the approximate total of engines in stock of around 900, suggest an expected boiler life of 30 years.  The numbers of spare boilers fitted in 1894-95 were 39 and 44, suggesting initial optimism had been replaced by realism and the boiler construction formula had been adjusted.  Another problem was that under Stirling boilers were not transferred from one engine to another but instead stayed with their original owners throughout their lives.  This meant that visits to Works for repairs could be a lengthy business, often for several months, which was an expensive way to run a business.  Also, the engines in which these replacement steel boilers had been fitted would have had wrought-iron frames, and so it could be expected that in most cases these steel boilers would outlive their engines.

The philosophy changed in 1896 after Ivatt arrived (plus a new Chief Asst. Locomotive Engineer, D. Earle Marsh) but it needed a build-up of spare boilers for the new system to function properly.  The intention now was to refurbish boilers taken out of frames at general repairs or scrapping.  This applied to boilers regardless of whether made of iron or steel).

As far as the single-wheelers were concerned, in September 1896 2-2-2 No. 874 received a new boiler and its discarded boiler(new 5/1892) was after repairs fitted to No. 239 (12/1896), which thus became the first engine to receive a second-hand boiler, which incidentally was afterwards numbered 1712 in the duplicate list.  But No. 239's discarded boiler (new in 11/1887) was scrapped so this did not start a chain reaction.  In December 1897 two more engines acquired second-hand boilers, 0-6-0 No. 723 and 2-4-0 No. 864.  In 1898 there were eleven examples, which included three 4-2-2s. These were No. 3 (8/1898) which received the boiler off No. 771 (new 11/1884); No. 778 (11/1898) which received the boiler off No. 3 (new 6/1884); No. 545 (12/1898) which received the boiler off No. 778  (new 11/1887); No. 545's boiler (new 6/1887) was not heard of afterwards.  Thereafter the use of second-hand boilers became more frequent.  Approximately half of the Singles boilers in service at the beginning of 1896 were subsequently re-used.  The record was held by the new boiler fitted to No. 670 (3/1892), subsequently fitted to Nos. 549 (11/1899), 548 (3/1903), 666 (12/1904) and scrapped (10/1906).  This gives a total working life of just over 24 years, which was also a record if you exclude the special case of No. 1's present boiler.  The shortest working life was the domed boiler carried by No. 872 (5/1910-12/1913), whilst the shortest for a straightback boiler was the one carried by No. 94 (5/1898-8/1903).

The re-use of boilers was not restricted to single-wheelers and these examples have been quoted only because they were the first engines involved in the new system.  At the time of the changeover there were Stirling boilers still awaiting allocation and they were not all used immediately.  Two late examples were "new" boilers fitted in 1899 to 0-4-2 Nos. 76 (6/1899) and 19 (11/1899).  Straightback boilers continued to be ordered by Ivatt for saddle tank engines.  This was planned to avoid problems with the dome getting in the way.  The last batch of these boilers was Boiler Order (BO) 604 issued (3/8/1911) shortly before Ivatt's retirement.  In general these saddle tank engines thereafter acquired 4ft-5in diameter domed boilers from August 1912 (No. 802), a practice anyway inaugurated by Ivatt in March 1906 (No. 913). 

But the oddest example concerned the 4ft-5in diameter straightback boilers fitted from 1886 onwards to the No. 120 Class (Ivatt G2) 0-4-2WTs.  Between December 1895 and February 1896, a further six new boilers were fitted to Nos. 159, 245/48, 531, 628/57, which was the fulfillment of a Stirling order.  This was followed by an odd one fitted in September 1897 to No. 246.  Between February 1899 and March 1901 a further five new boilers were fitted to Nos. 247, 504/05, 622/25.  As Stirling boilers were usually built in batches of six, it is likely the 1897 boiler was the first of a batch of six (possibly ordered in 1895), whose fitting had been suspended temporarily after the first one had been fitted.   This could have been done so as to give preference to Boiler Order 512 (20/3/1898) for (reasonably) similar boilers but with domes.  If so, this proved to be a mistake.  The boilers were not exactly one-for-one; the barrel was longer, firebox casing shorter, pitched higher, weight in working order almost 5 tons greater.  After a short delay the first four of these domed boilers were fitted instead to 0-4-2WTs (a closer match) Nos. 116/18/22/32 (between October 1899 and December 1904), whilst the straightback boilers were fitted (as stated above) during February 1899 and March 1901.

As examples of how long steel boilers could last, the first batch of Ivatt boilers intended for general replacement were domeless "standard" boilers, date of ordering unknown, fitted to ten 0-6-0s in 1897-99.  One lasted 6 years, whilst two survived at Grouping (perhaps because they were latterly fitted to 0-6-0STs and had a quiet life). They lasted until 1926 and 1929.  Apart from the absence of a dome, this boiler type existed in the Gresley J50 class until 1965.


Initially, the Locomotive Drawing Office (LDO) made no use of any engine classification, and terms such as front-coupled saddle-tank seem to have sufficed.  The Works had what has become to be referred to as a Works List, thought to be an easy reference for storing and retrieving drawings.  However it only covered engines built in Doncaster Works as presumably contractor's drawings were kept separately.  The only source of this List is in Bird's book and presumably he didn't enquire about contractor's drawings.  Without Bird's discovery it would have been impossible to segregate many of the detail differences within the various main classes. To simplify matters Ivatt introduced an Engine Classification in mid-1900, using a letter to represent the wheel arrangement followed by a number to segregate the different types.   At this date there were ten different wheel arrangements.  The arrangements were ordered in descending order of driving wheel diameter of the main class in this sub-division.  The main classes were therefore A1, B1, C1, D1 etc to K1 (but no I1).  Then within each letter there were sub-divisions to cover variations, for example A1, A2, A3, A4, A5 etc.  The key classes of each wheel-arrangement are set out below.  In the case of Stirling classes, the first appearance of an example with an Ivatt domed boiler is used instead.


A1 4-2-2 8'-2" 776 7/1896
B1 2-2-2 7'-8" 876 4/1898
C1 4-4-2 6'-8" 990 5/1898
D1 4-4-0 6'-8" 400 12/1896
E1 2-4-0 6'-8" 1061 2/1897
F1 0-4-2T 5'-8" 118 10/1899
G1 0-4-4T 5'-8" 763 7/1898
H1 2-6-0 5'-2" 1181 10/1899
J1 0-6-0 5'-2" 1091 12/1897
K1 0-8-0 4'-8" 401 (a) 2/1901

(a) Engine Order for No. 401 was issued 6/4/1900, hence it appeared in the scheme

Ivatt later added :

L1   0-8-2T No. 116 (8/1903)
MC 0-4-0T Motor Coach No. 2 (10/1905)
N1   0-6-2T No. 190 (4/1907)

Gresley added :

O1   2-8-0 No. 456 (12/1913)

This system was then in general use in the LDO, whilst the Works continued to rely on their List of Drawings system.


In addition to Engine Diagrams, the LDO issued Boiler Diagrams which could provide fuller information, especially when one engine diagram had to make do for more than one boiler variation.  These were not coded to differentiate them, until Gresley produced a Boiler Diagram List.  Its date of introduction is open to speculation.  I don't recall seeing any Boiler Diagram with a date. I have found a note (which I made about 1962) of finding Boiler Diagram 4 with no date on it.  The List includes Class H4 (LNER K3) which therefore dates the List as (presumably) post-March 1920.  The presence of Class O1 at the end of the List is puzzling.  It could mean the list was compiled at say January 1921, with O1 then at the top of the list, but afterwards displaced by the Pacific boiler.  The GNR Boiler Diagram List continued in use until about 1928 when a comprehensive one was prepared for all Sections of the LNER.







1 6'-5" 19'-0" 9'-5½" A1 4-6-2 1470 4/1922 94
2 4'-8" 14'-85/8" 8'-0" C1 4-4-2 990 5/1898 4
3 5'-6" 15'-63/8" 6'-6" C1 " 251 12/1902 1
4 4'-5" 10'-1" 5'-6" D2 4-4-0 400 12/1896 11
5 4'-8" 10'-1" 5'-6" D3 " 1359 11/1912 8
6 4'-8" 10'-1" 6'-4" D1 " 1321 6/1898 7
7 4'-8" 11'-8" 8'-0" H2 2-6-0 1630 8/1912 6
8 5'-6" 11'-111/8" 8'-6" H3 " 1640 4/1914 3
9 6'-0" 12'-15/8" 9'-6" H4 " 1000 3/1920 96
10 4'-5" 10'-6" 5'-6" J13 0-6-0ST 1201 8/1897 9
11 4'-2" 10'-6" 6'-2" J23 0-6-0T 157 12/1913 12
12 4'-2" 11'-5" 6'-2" L1 0-8-2T 116 8/1903 -
13 5'-6" 16'-13/8" 9'-6" O1 2-8-0 456 12/1913 2

There were some sub-divisions, e.g. 4A and 10A, to cover non-standard Stirling boilers and 1A was introduced in 1927 for LNER Class A3.


In the following chapters, some information has been taken from GREAT NORTHERN LOCOMOTIVE HISTORY (RCTS, for Norman Groves) which in turn extracted information from LOCOMOTIVES OF THE LNER (RCTS).  References throughout these chapters to Groves, refers the reader to his monumental effort covering all the engines of the GNR throughout its history.

It is fortunate that George Frederick Bird had access to the majority of the surviving General Plan drawings still in existence at the time of his research (though he did miss a couple which the Locomotive Drawing Office still held at that time).  For individual engine history of GNR engines surviving at 1900, there are the Repairs to Engines volumes, which the present author rescued about 1965 as the Drawing Office was being run down.  The volumes were deposited at the NRM around 1975.

Plant Works A 4-2-2 A 4-6-2,  B 2-2-2 C 4-4-2 C 4-4-2T D 4-4-0,  E 2-4-0 F 0-4-2 F 0-4-2T
G 0-4-4T H 2-6-0, J 0-6-0 J 0-6-0ST,  J 0-6-0T K 0-8-0,  L 0-8-2T MC Motor coach,  N 0-6-2T,  O 2-8-0