Editing Northern Counties Committee (section)

===NCC===
MR (NCC) locomotive policy continued BNCR practice and remained largely independent of [[Derby Works|Derby]] until [[Bowman Malcolm]] retired at the end of 1922. Von Borries compounds were still being built during this period. The last were two narrow gauge Class S 2-4-2 tank engines outshopped in 1919 and 1920. In 1920, the NCC's broad gauge stock included twenty five 2-4-0 tender locomotives as compared with twenty two 4-4-0s. The remaining broad gauge locomotives were sixteen 0-6-0s, four 2-4-0 saddle tanks and two 0-4-0 dock tanks.

Midland Railway and LMS influence became increasingly apparent during the building and renewal programmes undertaken by Malcolm's successors [[William Kelly Wallace|William Wallace]] and, later, H.P. Stewart. The modernisation and standardisation of NCC locomotives began in 1923 with the delivery of three standard G7 boilers from Derby. Two of these were to be used in rebuilding "Light Compounds" Nos.59 and 62 to [[NCC Class U1|Class U1]] 4-4-0 locomotives. From this time on, with few exceptions, all boilers would be LMS standard ones (G6, G7, G8). Derby works could more economically deal with these boilers than York Road and so they would be sent to Derby for overhaul. The boilers would return some four or five months later with a new firebox fitted, ready for installing in the next suitable engine coming into the works.

==== NCC locomotive classes ====
The BNCR introduced class letters for its locomotive stock in 1897. The MR (NCC) and later the LMS (NCC) continued to use the system adding new classes as required.

The following tables list details (where available) of NCC locomotive classes that were extant at the time of the amalgamation of the BNCR with the Midland Railway in 1903 and those classes which entered NCC stock subsequently.

=====Broad gauge steam locomotives=====
{|class="wikitable"
|-
!Class
!Wheel <br />
arrangement
!Driving <br />
wheel diam
!Cylinders <br />
bore x stroke <br />
(in)
!Boiler <br />
pressure <br />
(psi)
!Tractive <br />
effort <br />
(lbs)
!Locomotive <br />
weight
!Remarks
|-							
|| [[BNCR Class A|A]] || 4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 18 & 26 x 24 || align=right|175 || align=right|16 065 || 45t 1cwt || Compound
|-
|| [[NCC Class A1|A1]] ||4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 18 x 24 || align=right|200 || align=right|18 360 || 46t 7cwt ||	
|-
|| [[BNCR Class B|B]] || 4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 16 & 23{{frac|1|4}} x 24 || align=right|160 || align=right|11 560 || 39t 17cwt || Compound
|-
|| B1 || 4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 16 & 23{{frac|1|4}} x 24 || align=right|160 || align=right|11 560 || 43t 9cwt || Compound
|-
|| B2 || 4-4-0 || 6&nbsp;ft 0 in||  ||  ||  || ||
|-
|| [[NCC Class B3|B3]] || 4-4-0 || 6&nbsp;ft 0 in|| 18 x 24 || align=right|200 || align=right|18 360 || 45t 2cwt ||	
|-
|| C || 2-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 16 & 23{{frac|1|4}} x 24 || align=right|160 || align=right|11 560 || 37t 6cwt || Compound
|-
|| C1 || 2-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 16 & 23{{frac|1|4}} x 24 ||  ||  || 43t 8cwt || Compound
|-
|| [[BNCR Class D|D]] || 4-4-0 || {{convert|7|ft|0|in|m|abbr=on}} || 18 & 25 x 24 || align=right|160 || align=right|13 685 || 46t 9cwt || Compound
|-
|| [[NCC Class D1|D1]] || 4-4-0 || {{convert|7|ft|0|in|m|abbr=on}} || 19 x 24 || align=right|170 || align=right|14 904 || 46t 12cwt ||	
|-
|| E || 0-6-0 || 5&nbsp;ft 2{{frac|1|2}}in || 18 & 26 x 24 ||  ||  ||  || Compound
|-
|| E1|| 0-6-0 || 5&nbsp;ft 2{{frac|1|2}}in || 18 & 26 x 24 || align=right|175 || align=right|18 593 || 43t 11cwt || Compound
|-
|| F || 2-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 17 x 24 ||  ||  || 37t 10cwt ||	
|-
|| F1 || 2-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 17 x 24 ||  ||  || 38t 1cwt ||	
|-
|| G ||	2-4-0 || {{convert|5|ft|6|in|m|abbr=on}} || 16 x 22 ||  ||  || 34t 0cwt ||  	
|-
|| G1|| 2-4-0 || {{convert|5|ft|6|in|m|abbr=on}} || 16 x 22 ||  ||  || 38t 1cwt ||	
|-
|| H ||	2-4-0 || {{convert|5|ft|6|in|m|abbr=on}} || 15 x 22 ||  ||  || 33t 5cwt ||	
|-
|| I ||	2-4-0 || {{convert|5|ft|6|in|m|abbr=on}} || 15 x 20 ||  ||  || 29t 4cwt ||	
|-
|| J ||	2-4-0ST|| 5&nbsp;ft 2{{frac|3|8}}in || 15 x 20 || align=right|140 || align=right|8 925 || 37t 8cwt ||	
|-
|| [[NCC Class K|K]] ||	0-6-0 || 5&nbsp;ft 2{{frac|1|2}}in || 17 x 24 || align=right|170 || align=right|16 184 || 38t 9cwt ||	
|-
|| [[NCC Class K1|K1]] || 0-6-0 || 5&nbsp;ft 2{{frac|1|2}}in || 17 x 24 || align=right|170 || align=right|16 184 || 39t 8cwt ||	
|-
|| L ||	0-6-0 || {{convert|4|ft|6|in|m|abbr=on}} || 17 x 24 ||  ||  || 38t 16cwt || 	
|-
|| L1 || 0-6-0 || {{convert|4|ft|6|in|m|abbr=on}} || 17 x 24 ||  ||  || 38t 15cwt ||	
|-
|| M ||	0-4-2 ||  || 17 x 24 ||	 ||  || 39t 8cwt || ex-[[Londonderry & Coleraine Railway|L&C Rly]]	
|-
|| [[BNCR Class N|N]] || 0-4-0ST || 4&nbsp;ft 0{{frac|1|8}}in || 16 x 22 || align=right|130 || align=right|12 707 || 30t 0cwt || Dock engines
|-
|| T* || 0-2-2T ||  ||  ||  ||  || 25t 10cwt || Railmotor units
|-
|| U ||	4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 19 x 24 ||  ||  || 47t 12cwt|| 	
|-
|| [[NCC Class U1|U1]] || 4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 18 x 24 || align=right|170 || align=right|15 696 || 50t 14cwt ||	
|-
|| [[NCC Class U2|U2]] || 4-4-0 || {{convert|6|ft|0|in|m|abbr=on}} || 19 x 24 || align=right|170 || align=right|17 388 || 51t 10cwt ||	
|-
|| [[NCC Class V|V]] || 0-6-0 || 5&nbsp;ft 2{{frac|1|2}}in  || 19 x 24 || align=right|170 || align=right|20 031 || 28t 17cwt ||	
|-
|| [[NCC Class W|W]] || 2-6-0 || {{convert|6|ft|0|in|m|abbr=on}} || 19 x 26 || align=right|200 || align=right|22 160 || 62t 10cwt ||	
|-
|| [[NCC Class WT|WT]] || 2-6-4T || {{convert|6|ft|0|in|m|abbr=on}} || 19 x 26 || align=right|200 || align=right|22 160 || 87t 0cwt || 	
|-
|| [[NCC Y Class|Y]] || 0-6-0T || {{convert|4|ft|7|in|m|abbr=on}} || 18 x 26 || align=right|160 || align=right|20 830 || 49t 10cwt || ex-[[LMS Fowler Class 3F|LMS Class 3F]]
|-
|| 91<sup>†</sup> || 0-4-0T ||  ||  ||  ||  ||  || [[Sentinel Waggon Works|Sentinel]] shunter
|}

<small>* Class T became extinct in 1913; the designation was reassigned to the ex-Ballycastle Railway 4-4-2T narrow gauge locomotives when they were acquired in 1924.<br /><sup>†</sup> No class letter was assigned to No.91.</small>

=====Narrow gauge steam locomotives=====
{|class="wikitable"
|-
!Class
!Wheel<br />
arrangement
!Driving<br />
wheel diam
!Cylinders<br />
bore x stroke<br />
(in)
!Boiler<br />
pressure<br />
(psi)
!Tractive<br />
effort<br />
(lbs)
!Locomotive<br />
weight
!Remarks
|-
|| [[BC&RBR Nos.1, 2 & 3|O]] || 0-4-2ST || {{convert|3|ft|1|in|m|abbr=on}} || 12 x 19 || align=right|140 || align=right|8 800 || 22t 10cwt || ex-[[Ballymena, Cushendall and Red Bay Railway|Cushendall Rly]]
|-
|| [[B&LR Nos.1 & 4|P]] || 2-4-0T || {{convert|3|ft|9|in|m|abbr=on}} || 11 x 18 || align=right|120 || align=right|4 937 || 17t 12cwt || ex-[[Ballymena and Larne Railway|B&L Rly]]
|-
|| [[B&LR Nos.2, 3 & 6|Q]] || 0-6-0T || {{convert|3|ft|3|in|m|abbr=on}} || 13{{frac|1|2}} x18 || align=right|140 || align=right|10 010 || 21t 2cwt || ex-[[Ballymena and Larne Railway|B&L Rly]]
|-
|| [[B&LR No.5|R]] || 2-6-0ST || {{convert|3|ft|3|in|m|abbr=on}} || 14 x 18 || align=right|140  || align=right|10 765 || 25t 13cwt || ex-[[Ballymena and Larne Railway|B&L Rly]]
|-
|| [[BNCR Class S|S]] || 2-4-2T || {{convert|3|ft|9|in|m|abbr=on}} || 14{{frac|3|4}} & 21 x 20 || align=right|160 || align=right|13 150 || 31t 17cwt || Compound
|-
|| [[NCC Class S1|S1]] || 2-4-2T || {{convert|3|ft|9|in|m|abbr=on}} || 14{{frac|3|4}} & 21 x 20 || align=right|160 || align=right|13 150 || 33t 0cwt ||  Compound
|-
|| [[NCC Class S2|S2]] || 2-4-4T || {{convert|3|ft|9|in|m|abbr=on}} || 14{{frac|3|4}} & 21 x 20 || align=right|200 || align=right|16 438 || 42t 1cwt || Compound
|-
|| [[Ballycastle Railway Nos.3 & 4|T]] || 4-4-2T || {{convert|3|ft|7|in|m|abbr=on}} || 14{{frac|1|2}} x 21 || align=right|160 || align=right|13 964 || 39t 11cwt || ex-[[Ballycastle Railway|Ballycastle Rly]]
|}

=====Diesel locomotives=====
{|class="wikitable"
|-
!Class
!Wheel<br />
arrangement
!Driving<br />
wheel diam
!Engine<br />
horsepower<br />
(bhp)
!Tractive<br />
effort<br />
(lbs)
!Locomotive<br />
weight
!Remarks
|-
|| [[NCC Class X|X]] || 0-6-0 || 4&nbsp;ft 1{{frac|1|8}}in || align=right|330 || align=right|24 000 || 49t 0cwt || No.17, [[diesel-hydraulic]]
|-
|| 20* || 0-6-0 || {{convert|3|ft|7|in|m|abbr=on}} || align=right|225 || align=right|15 000 || 28t 6cwt || No.20, [[diesel-mechanical]]
|-
|| [[LMS diesel shunters#7407 / 7057|22]]* || 0-6-0  || {{convert|3|ft|2|in|m|abbr=on}} || align=right|225 || align=right|15 000 || 27t 3cwt || No.22, ex-LMS, [[diesel-hydraulic]]
 |-
|| [[BCDR No.28|28]]* || 1A-A1 || {{convert|3|ft|7|in|m|abbr=on}} || align=right|500 ||  || 48t 0cwt || No.28, ex-[[Belfast & County Down Railway|BCDR]], [[Diesel-electric locomotive|diesel-electric]]
|}
<small>* No class letters were assigned to Nos.20, 22 and 28.</small>

:The tabulated data in this section are mainly derived from a review of NCC locomotive diagrams.