Editing LMS Coronation Class (section)

== Construction history ==

=== Locomotives ===
The first five locomotives, Nos. 6220–6224, were built in 1937 at the LMS [[Crewe works|Crewe Works]] at an average cost of £11,641 each.<ref name="Baker">{{cite book |last=Baker |first=Allan C. |title=The Book of the Coronation Pacifics Mk2 |year=2010 |orig-year=1998 |publisher=Irwell Press |location=Clophill |isbn=978-1-906919-17-7 }}</ref>{{rp|76, 80, 82, 86, 88}} They were all intended to haul the ''Coronation Scot'', so the locomotives and the special trainsets bore a common livery. The locomotives were streamlined and painted [[Caledonian Railway]] blue with silver horizontal lines along each side of the locomotive. The special trainsets that they hauled were painted the same shade of blue and the silver lining was repeated along each side of the coaches.{{r|Haresnape|p=123}}

In 1938 the second five locomotives of the class, Nos. 6225–6229 (named after Duchesses) were also built in streamlined form at an average cost of £11,323 each.{{r|Baker|pp=92, 94, 98, 100, 102}} They were painted in the same shade of crimson lake which had already been applied to the Princess Royal class; the same style of horizontal lining that had been a feature of the first five locomotives was continued, but in gilt. Although the crimson lake matched the standard LMS rolling stock, there was no attempt to apply the gilt lining along the sides of these coaches. A prototype trainset was built with such lining for exhibition in America, but it was never put into service due to the outbreak of the [[Second World War]].{{r|Roden|p=49}}

Stanier, the designer of the locomotives, felt that the added weight and difficulty in maintenance due to the streamlining was too high a price to pay for the actual benefits gained at high speed.<ref>{{cite magazine |last=Marsh |first=Phil |title=Stanier did not like streamlined locos! |magazine=[[The Railway Magazine]] |date=February 2006 |volume= 152|issue=1258 |editor-last=Pigott |editor-first=Nick |editor-link=Nick Pigott |location=London |publisher=IPC Media |issn=0033-8923 |pages=27–29}}</ref> Therefore, in 1938 a third batch of five locomotives (again named after Duchesses) was built, Nos. 6230–6234, without streamlining at an average cost of £10,659 each.{{r|Baker|pp=106, 110, 112, 116, 118}}

During 1939 and 1940, a fourth batch of ten locomotives (Nos. 6235–6244) was built in streamlined form commencing with No. 6235 ''City of Birmingham''. The names of cities for the locomotives would seem to have been adopted because the LMS was fast running out of names of Duchesses. These locomotives cost an average of £10,659 for the first five and £10,838 each for the second five.{{r|Baker|pp=120, 124, 130, 134, 136, 138, 142, 144, 148, 150}} The names of the cities in this batch were in strict alphabetical order. This came to an end when No. 6244 ''City of Leeds'' was patriotically renamed ''King George VI'' in 1941.{{r|Baker|p=150}}

The fifth batch, again named after cities, comprised four locomotives, Nos. 6245–6248. These engines were built during 1943 and the average cost was held to £10,908 due to the incorporation of recycled boilers.{{r|Baker|pp=156, 162, 166, 168}} During the Second World War, the Materials Committee of the government tried to balance the needs for steel between civilian departments and the War Department when allocating those resources.<ref>{{cite journal |last1=Howlett |first1=Peter |title=Resource allocation in wartime Britain: The case of steel, 1939–45 |journal=Journal of Contemporary History|date=July 1994 |volume=29 |issue=3 |pages=523–544 |doi=10.1177/002200949402900308 |s2cid=153341906}}</ref> Despite these constraints, the entire batch was still outshopped in streamlined form.<ref name="Jenkinson">{{cite book |last=Jenkinson |first=David |title=Profile of the Duchesses |year=1982 |publisher=Oxford Publishing Company |location=Oxford |isbn=0-86093-176-5}}</ref>{{rp|loc=Plates 135, 144 and 148}}

The theme of cities continued into 1944 when another batch of four, Nos. 6249–6252, was built without streamlining. The cost of these locomotives averaged £11,664 each.{{r|Baker|pp=172, 174, 178, 182}} A follow-up batch of three locomotives (Nos. 6253–6255) was built in 1946 and this batch attracted an inflationary average cost of £15,460 each.{{r|Baker|pp=186, 190}} The problem of hanging smoke was addressed and smoke deflectors were now incorporated into the design.

The final two locomotives were constructed to the modified design of [[George Ivatt]] who succeeded both Stanier, following his retirement, and Stanier's immediate successor [[Charles Fairburn]], who unexpectedly died in office.{{r|Roden|p=59}} The first, No. 6256 built in 1947, was the last of the class to be built before nationalisation and it was therefore named in honour of its original designer ''Sir William A. Stanier, F.R.S.''. The unveiling of the nameplate was performed by Stanier himself.{{r|Roden|p=64}} In 1948, the privately owned railways were nationalised and incorporated into [[British Rail]]ways.<ref name="Banks">{{cite book |last=Banks |first=Chris |title=British Railways Locomotives 1948 |date=1990 |publisher=Oxford Publishing Co. |location=Yeovil |isbn= 0-86093-466-7}}</ref>{{rp|7}} It was within this new regime that No. 46257 was completed – in common with other LMS locomotives, 40000 had been added to the original numbers.{{r|Banks|pp=8, 189}} The spiralling costs after the Second World War, combined with the design changes, resulted in the individual cost of these locomotives escalating to £21,411.{{r|Baker|pp=196, 200}}

=== Tenders ===

==== Overview ====
[[File:Crewe railway station geograph-2413395-by-Ben-Brooksbank.jpg|thumb|The lack of a handrail on the tender shows that this is an ex-streamlined Type A. The locomotive is No. 46225 ''Duchess of Gloucester'' photographed in 1961, so the table below shows that the tender is No. 9799.]]

The original design of tender, which came to be known as Type 'A' was designed for the first ten streamlined locomotives. These were of welded tank construction and included side sheets extending from the rear of the tender, which had the effect of reducing drag from eddies between the tender and the leading coach. 28 of these were constructed to be coupled with all the 24 streamliners (Nos. 6220–6229 and Nos. 6235–6248) as well as four of the unstreamlined locomotives (Nos. 6249–6252).{{r|Jenkinson|loc=Tender Designs and Changes}} In practice, it would seem that the side sheets made it more difficult to access the water filler as well as the couplings.

A second, more traditional design followed for the initial batch of five unstreamlined locomotives (Nos. 6230–6234). Again they were of welded tank construction, but lacked any of the streamlining add-ons. Even without the streamlining Type 'B' tenders were distinguishable from Type 'A' by having a slightly different profile at the front and steps and handrails at the rear.{{r|Jenkinson|loc=Tender Designs and Changes}}

The third design, by George Ivatt, initially was Type 'C1' and it was paired with the three locomotives Nos. 6253–6255. It was partially riveted and resembled a Type 'A' at its front end and a Type 'B' at the rear. The design was quickly followed by Type 'C2', which differed from the 'C1' in that it had a lower front edge and was fitted with Timken roller bearings. Only two 'C2's were built and they were coupled to the last two of the class, Nos. 6256 and 46257.{{r|Jenkinson|loc=Tender Designs and Changes}}

Whilst nearly fifteen of the tenders remained wedded to their original locomotives, others received new partners – the very first tender to be manufactured swapped partners seven times. After the Second World War, when the streamlined tenders were de-streamlined, it was difficult to spot any mismatches. The most readily visible mismatches were those of locomotives Nos. 6249–6252 where pre-produced Type 'A' streamlined tenders were married to unstreamlined locomotives.{{r|Jenkinson|loc=Plate 168}}

An unusual feature of all Coronation Class tenders was that they were fitted with a steam-operated coal pusher to bring the coal down to the firing plate. When this was in operation a plume of steam could be seen rising from the rear face of the coal bunker backwall.{{r|Jenkinson|loc=Plates 122 and 197}} This equipment greatly helped the locomotive's fireman to meet the high demands for power during the non-stop run of {{convert|399|mi|km}} between [[London Euston railway station|London Euston]] and [[Glasgow Central railway station|Glasgow Central]], when operating the ''Coronation Scot'' train.<ref>{{cite journal |title=Tender of L.M.S. "Coronation" class locomotive |journal=The Engineer |date=1939 |volume=168 |page=466}}</ref>

==== Table of tender and locomotive pairings ====
All LMS tenders were given their own unique identity numbers and they tended to be constructed in advance of the locomotives they would be paired with. Hence, they were made in four batches, Nos. 9703–9709, 9743–9752, 9798–9817 and 10622-10624.{{r|Jenkinson|loc=Tender Designs and Changes}}

The following table lists the locomotives to which they were attached.{{r|Jenkinson|loc=Notes to Nos. 6220-46257}} Of note is the fact that locomotive No. 46221 had its tender (No.9816) withdrawn ahead of time in 1962; the locomotive was then paired to the Princess Royal tender No. 9359 until its withdrawal in May 1963.{{r|Jenkinson|loc=Notes to No. 6221}}
{| class="wikitable collapsible collapsed"
! Tender no.
! Type
! Original loco. <br/> & style
! 2nd loco.
! 3rd loco.
! 4th loco.
! 5th loco.
! 6th loco.
! 7th loco.
! 8th loco.
! Withdrawn
|-
| 9703
| A
| 6220 (Jun 1937) <br/> Str.
| 6240 (1944) <br/> Str.
| 6220 (1944) <br/> Str.
| 6242 (1946) <br/> Str.
| 46253 (1951) <br/> Conv.
| 46242 (1951) <br/> Semi
| 46241 (1956) <br/> Semi
| 46242 (1956) <br/> Conv.
| Oct 1963
|-
| 9704
| A
| 6221 (Jun 1937) <br/> Str.
| 46253 (1961) <br/> Conv.
|
|
|
|
|
|
| Jan 1963
|-
| 9705
| A
| 6222 (Jun 1937) <br/> Str.
| 46220 (1949) <br/> Semi.
|
|
|
|
|
|
| Apr 1963
|-
| 9706
| A
| 6223 (Jul 1937) <br/> Str.
| 6224 (1946) <br/> Str.
|
|
|
|
|
|
| Oct 1963
|-
| 9707
| A
| 6224 (Jul 1937) <br/> Str.
| 6230 (1945) <br/> Conv.
|
|
|
|
|
|
| Nov 1963
|-
| 9743
| A
| 6225 (May 1938) <br/> Str.
| 6249 (1945) <br/> Conv.
|
|
|
|
|
|
| Nov 1963
|-
| 9744
| A
| 6226 (May 1938) <br/> Str.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9745
| A
| 6227 (Jun 1938) <br/> Str.
|
|
|
|
|
|
|
| Dec 1962
|-
| 9746
| A
| 6228 (Jun 1938) <br/> Str.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9747
| A
| 6229 (Sep 1938) <br/> Str.
| 6239 (1945) <br/> Str.
|
|
|
|
|
|
| Oct 1964
|-
| 9748
| B
| 6230 (Jul 1938) <br/> Conv.
| 6224 (1945) <br/> Str.
| 6223 (1946) <br/> Semi
|
|
|
|
|
| Oct 1963
|-
| 9749
| B
| 6231 (Jul 1938) <br/> Conv.
| 6249 (1945) <br/> Conv.
| 6225 (1945) <br/> Str.
| 46236 (1949) <br/> Semi
| 46247 (1952) <br/> Semi
| 46246 (1961) <br/> Conv.
|
|
| Jan 1963
|-
| 9750
| B
| 6232 (Jul 1938) <br/> Conv.
|
|
|
|
|
|
|
| Dec 1962
|-
| 9751
| B
| 6233 (Jul 1938) <br/> Conv.
|
|
|
|
|
|
|
| Feb 1964
|-
| 9752
| B
| 6234 (Aug 1938) <br/> Conv.
|
|
|
|
|
|
|
| Jan 1963
|-
| 9798
| A
| 6235 (Jul 1939) <br/> Str.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9799
| A
| 6236 (Jul 1939) <br/> Str.
| 46225 (1949) <br/> Semi
|
|
|
|
|
|
| Oct 1964
|-
| 9800
| A
| 6237 (Aug 1939) <br/> Str.
| 6242 (1944) <br/> Str.
| 6237 (1944) <br/> Str.
|
|
|
|
|
| Oct 1964
|-
| 9801
| A
| 6238 (Sep 1939) <br/> Str.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9802
| A
| 6239 (Sep 1939) <br/> Str.
| 6229 (1945) <br/> Str.
|
|
|
|
|
|
| Feb 1964
|-
| 9803
| A
| 6240 (Mar 1940) <br/> Str.
| 6220 (1944) <br/> Str.
| 6240 (1944) <br/> Str.
|
|
|
|
|
| Oct 1964
|-
| 9804
| A
| 6241 (Apr 1940) <br/> Str.
| 6242 (1944) <br/> Str.
| 6241 (1944) <br/> Str.
| 6220 (1946) <br/> Str.
| 46222 (1949) <br/> Semi.
|
|
|
| Oct 1963
|-
| 9805
| A
| 6242 (May 1940) <br/> Str.
| 6241 (1944) <br/> Str.
| 46245 (1953) <br/> Semi
|
|
|
|
|
| Oct 1964
|-
| 9806
| A
| 6243 (Jun 1940) <br/> Str.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9807
| A
| 6244 (Jul 1940) <br/> Str.
| 6245 (1945) <br/> Str.
| 46247 (1952) <br/> Semi
| 46236 (1952) <br/> Semi
|
|
|
|
| Mar 1964
|-
| 9808
| A
| 6245 (Jul 1943) <br/> Str.
| 6244 (1945) <br/> Str.
|
|
|
|
|
|
| Oct 1964
|-
| 9809
| A
| 6246 (Aug 1943) <br/> Str.
| 46247 (1961) <br/> Conv.
|
|
|
|
|
|
| Jun 1963
|-
| 9810
| A
| 6247 (Sep 1943) <br/> Str.
| 6248 (1944) <br/> Str.
|
|
|
|
|
|
| Sep 1964
|-
| 9811
| A
| 6248 (Oct 1943) <br/> Str.
| 6247 (1944) <br/> Str.
| 46245 (1952) <br/> Semi
| 46241 (1953) <br/> Semi
| 46242 (1956) <br/> Conv.
| 46241 (1956) <br/> Semi
|
|
| Sep 1964
|-
|  9812
| A
| 6249 (Apr 1944) <br/> Conv.
| 6231 (1945) <br/> Conv.
|
|
|
|
|
|
| Dec 1962
|-
| 9813
| A
| 6250 (May 1944) <br/> Conv.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9814
| A
| 6251 (Jun 1944) <br/> Conv.
|
|
|
|
|
|
|
| Oct 1964
|-
| 9815
| A
| 6252 (Jul 1944) <br/> Conv.
|
|
|
|
|
|
|
| Jun 1963
|-
| 9816
| C1
| 6253 (Sep 1946) <br/> Conv.
| 46253 (1951) <br/> Conv.
| 46242 (1951) <br/> Semi
| 46253 (1955) <br/> Conv.
| 46221 (1961) <br/> Conv.
|
|
|
| 1962
|-
| 9817
| C1
| 6254 (Sep 1946) <br/> Conv.
|
|
|
|
|
|
|
| Oct 1964
|-
| 10622
| C1
| 6255 (Oct 1946) <br/> Conv.
|
|
|
|
|
|
|
| Oct 1964
|-
| 10623
| C2
| 6256 (Dec 1947) <br/> Ivatt
|
|
|
|
|
|
|
| Oct 1964
|-
| 10624
| C2
| 46257 (May 1948) <br/> Ivatt
|
|
|
|
|
|
|
| Oct 1964
|}

=== Modifications ===

==== Double chimneys ====
Single chimneys were fitted to Nos. 6220–6234 when built.{{r|Baker|p=59}} Following a successful trial using No. 6234 ''Duchess of Abercorn'' on 26 February 1939,{{r|Roden|pp=38–42}} these were replaced with [[double chimney|double blastpipes and chimney]]s between 1939 and 1944, the last being No. 6220 ''Coronation''. From No. 6235 onwards, all the locomotives were built with double blastpipes and chimneys.{{r|Baker|pp=59, 66}} {{r|Jenkinson|loc=Plate 77}}

==== Smoke deflectors ====
Following a report by George Ivatt in 1945, smoke deflectors were introduced due to drifting smoke obscuring the crew's forward vision.<ref name="Peacock"/>{{r|Roden|p=64}} The first locomotive to be fitted with smoke deflectors from the outset was No. 6253 ''City of St. Albans'' in September 1946. All the following four locomotives included this feature. The first unstreamlined locomotive to be retrofitted was No. 6232 ''Duchess of Montrose'' in February 1945.{{r|Baker|p=59}}

==== Removal of streamlining ====
George Ivatt's 1945 report also recommended the removal of all streamlining casings and they were removed from the fitted locomotives from 1946 onwards.{{r|Roden|p=64}} It had been found to be of little value at speeds below {{convert|90|mi/h|km/h|abbr=on}}, and was unpopular with running shed employees as it caused difficulty of access for maintenance. The first step towards de-streamlining was carried out during the Second World War when many of the streamlined tenders had their side sheets cut away at the rear of the tender. Many photographs exist showing this measure.{{r|Jenkinson|loc=Plates 34,96,114,125 and 144}}<ref name="Talbot11">{{cite book |last=Talbot |first=Edward |year=2011 |title=LMS POWER, The 'Coronation' Class |location=Stafford |publisher=Edward Talbot |isbn=978-0-9542787-5-5}}</ref>{{rp|pp=100–104 and 106 |at=Plates 147–150, 154–157 and 159}} The removal of the streamlining proper commenced in April 1946 with No. 6235 ''City of Birmingham''. All de-streamlining coincided with the fitting of smoke deflectors. No. 6243 ''City of Lancaster'' was renumbered as 46243 in April 1948{{r|Banks|p=148}} and, as it was not de-streamlined until May 1949, it became the only locomotive to carry its British Railways number while streamlined.

Initially, locomotives that had previously been streamlined could be readily recognised by the sloping top to the front of their smokeboxes, as well as slightly smaller front-facing cab windows.{{r|Baker|pp=56, 62}} {{r|Jenkinson|loc=Plate 86}} In due course all were re-equipped with cylindrical smokeboxes and larger cab windows, often, but not necessarily, at the same time.{{r|Jenkinson|loc=Plates 17, 41 and 127}}The first locomotive to receive a cylindrical smokebox was No. 6226 ''Duchess of Norfolk'' in October 1952. The last one to retain the sloping top was 46246 ''City of Manchester'' which appeared with its new smokebox in May 1960.{{r|Baker|p=59}}

Even following the conversion to cylindrical smokeboxes, it was still possible to distinguish some non-streamliners from ex-streamliners. On the former (Nos. 46230-46234 and 46249-46252, but not 46253-46257) the running plates veered downwards at right angles to connect with the buffer beam in the style of the Princess Royal Class.{{r|Jenkinson|loc=Plate 56}} The ex-streamliners did not have any such connection,{{r|Jenkinson|loc=Plate 3}} except No.46242 ''City of Glasgow'' which was rebuilt in 1952 following a serious collision.{{r|Jenkinson|loc=Plates 120 and 123}}

==== The final locomotives ====
The final two locomotives Nos. 6256 and 46257 ''Sir William A. Stanier, F.R.S'' and ''City of Salford'' were given many new features. In order to raise the mileage between general overhauls from 70,000 to 100,000, measures were taken to decrease wear to the axle bearings and [[hornguide]]s through the use of roller bearings and manganese steel linings. Other modifications included further superheating area, a redesigned rear frame and cast steel trailing truck, rocking grate, hopper ashpan and redesigned cab-sides.{{r|Roden|p=64}}{{r|Nock84|p=146}}

==== Automatic warning system ====
During the twentieth century, [[Signal passed at danger|signals passed at danger]] (SPADs) were increasingly perceived as a significant danger to the public. Only the [[Great Western Railway]] truly accepted the challenge posed. Prior even to 1910, it commenced installing [[Automatic Train Control]] (ATC), a system where each distant signal was accompanied by a ramp between the tracks with which a shoe on the locomotive would make contact as it passed over it. When the signal denoted "clear", an electric current would pass through the ramp which was detected by the shoe, thereby sounding a bell in the cab. With the signal at danger, the electric current would be cut off and when the shoe detected this it would activate a warning horn. In later forms, the brakes would be applied should the driver fail to acknowledge the warning.<ref>{{cite book |last=Rolt |first=L.T.C |author-link=L.T.C. Rolt |title=Red for Danger |edition=1st |year=1955 |publisher=The Bodley Head |location=London |pages=202–203}}</ref>

In 1952, the UK's most disastrous SPAD ever occurred at [[Harrow and Wealdstone rail crash|Harrow and Wealdstone]], in which No. 46242 ''City of Glasgow'' was severely damaged. The lack of an ATC system on most of Britain's railways was at last seen as an urgent issue. From 1956 the BR-designed [[Automatic Warning System]] (AWS) was installed. It was similar to ATC but relied on an induced magnetic field rather than an electric current and featured a visual indicator in the cab. The receiving system was installed on the Coronation class locomotives from 1959 onwards. The outward evidence of on-board AWS comprised a protective shield behind the front screw coupling, a box to house the necessary batteries immediately in front of the cab on the right-hand side and a cylindrical vacuum reservoir above the right-hand running plate.{{r|Baker|p=69}}