LNER Peppercorn Class A2 explained

Powertype:Steam
LNER Peppercorn Class A2
Designer:Arthur Peppercorn
Builder:Doncaster Works
Builddate:1947–1948
Totalproduction:15
Whytetype:4-6-2
Uicclass:2′C1′ h3
Leadingdiameter:3feet
Driverdiameter:6feet
Trailingdiameter:3feet
Wheelbase:60feet
Engine Total:34feet
Coupled:13feet
Length:71feet
Locoweight:101LT
Locotenderweight:160.5LT
Axleload:22LT
Fuelcap:9LT
Watercap:5000impgal
Cylindercount:Three
Cylindersize:19x
Valvetype:Piston valves
Totalsurface:2461square feet
Tubearea:1212square feet
Fluearea:1005square feet
Superheaterarea:680square feet
Fireboxarea:245square feet
Firearea:50square feet
Boilerpressure:250psi
Tractiveeffort:404302NaN2
Operator:London and North Eastern Railway » British Railways
Operatorclass:LNER: A2
Powerclass:BR: 8P7F
Axleloadclass:Route Availability 9
Withdrawndate:November 1962 - June 1963, April 1965 - December 1966
Disposition:One preserved; remainder scrapped

The London and North Eastern Railway (LNER) Peppercorn Class A2 is a class of steam locomotive designed for express passenger work by Arthur Peppercorn, the chief designer of the LNER after Edward Thompson. All save the first of the 15 built were constructed under British Railways after nationalisation in 1948. Only one example is preserved.

Design

The A2s were a development on the 6 ft 2 in driving wheel locomotives of Peppercorn's predecessor, Edward Thompson. Thompson's designs were rebuilds of preexisting Gresley designs, in addition to being constrained by wartime pressures. With a dilapidated locomotive and rolling stock fleet, Peppercorn designed his A2s to augment Thompson's designs and replace the aging Gresley locomotives.

Peppercorn's design was influenced greatly by Thompson's A2/3 design, although his design differed most obviously with the less stretched look. This was achieved by moving the outside cylinders forward over the leading truck and amending the steam ducts, shortening the smokebox and wheelbase while retaining the same cylinder and valve gear arrangement. However, this came at the cost of either discarding the Kylchap exhaust or the self-cleaning device in the smokebox, of which the former was omitted by the design team. A new smoke deflector design was fitted, although the omission of the Kylchap exhaust led to visibility issues during service. Some Gresley styled features returned in the form of the V-shaped cab and the 'Banjo Dome' steam collector. Much of the rest of the locomotive remained the same as the Thompson A2/3, utilising the same 250psi boiler with a total heating surface of 3141.04 sq-ft, heated by a 50 sq-ft grate, powering a 19in by 26in cylinder, controlled from an electrically lit cab. This gave a tractive effort of 40,430 lb all whilst staying in a maximum axle load of 22 tonnes. The boiler utilised a small percentage of nickel plate for the barrel, saving 7cwt without compromising integrity.

Construction

The first of the Peppercorn A2s, No. 525 A.H.Peppercorn, was outshopped from Doncaster in December 1947 on the eve of nationalisation, and named after the designer of the class, Arthur Peppercorn. The first two of the class were turned out in LNER apple green livery, and this colour was also applied to the next 13 engines delivered between January and August 1948. Repainting in British Railways Brunswick green began the following year. Another 20 members of the class were also planned, but were put on hold and ultimately cancelled on 4 May 1948 after the 1948 Locomotive Exchanges. No. 60539 Bronzino emerged in August 1948 with Kylchap double blastpipe and chimney in place of the self-cleaning apparatus as an experiment, with Nos. 60526, 60529, 60532, 60533 and 60538 similarly modified in 1949.

LNER 1946 Nos BR Nos Year
525 60525 1947
526–531 60526–31 1948
60532–39 1948

Performance

The class's 50 sq ft grate, a remnant of the P2 lineage (from both Thompson and Peppercorn) boilers, meant the A2's were capable of high power and endurance; however, with the exception of the Aberdeen road, there was little need for this large grate firebox in the postwar era, and as a result, on comparable duties the A2's were heavier on fuel than the Gresley machines which pre-dated them, but for outright power and haulage capability, they were the logical successor to the P2 class, and finally provided the answer the Edinburgh-Aberdeen route required. As a result, they were amongst the last multi-cylindered express steam locomotive classes to remain in service in the UK.

Stock list

Only No. 525 was built during LNER ownership, but 526-31 received LNER 1946 numbers. From 60532 onwards, the A2s received BR numbers from new, BR numbers being the LNER 1946 numbers with the addition of 60000. With the exception of No. 525, named after the last Chief Mechanical Engineer of the LNER, they were named after racehorses.

LNER No.BR No.NameEntered ServiceWithdrawn
525 60525align=left A.H. Peppercorn
52660526 align=left Sugar Palm
52760527align=left Sun Chariot
52860528align=left Tudor Minstrel
52960529align=left Pearl Diver
53060530 align=left Sayajirao
53160531 align=left Bahram
-align=left Blue Peter
-60533 align=left Happy Knight
-60534align=left Irish Elegance
-60535align=left Hornets Beauty
-60536align=left Trimbush
-60537 align=left Bachelors Button
-60538align=left Velocity
-60539align=left Bronzino

Service

Initially, the A2s were based at depots the length of the East Coast Main Line, ranging from New England (Peterborough) in the south to Edinburgh's Haymarket. It is said that Edinburgh Haymarket and Aberdeen Ferryhill shed welcomed the engines in stark comparison to the Thompson A2/2 and A1/1. In 1949, five were put to work on the Edinburgh-Dundee-Aberdeen route and proved the ideal engines for its stiff gradients and sharp curvature. The A2s also worked to Perth, Glasgow, Carlisle, Newcastle upon Tyne and occasionally more southerly outposts. In 1963, Nos. 60525, 60530, and 60535 crossed the LNER-LMS divide and were allocated to a Glasgow depot, Polmadie. They replaced ex-LMS Coronation Class over the ex-Caledonian Railway route to Carlisle.

The final years of the A2s came in eastern Scotland with many notable performances over the Aberdeen road during the early 1960s. No. 60527 Sun Chariot started from Aberdeen with a 400-ton train and reached Montrose, Arbroath and Dundee ahead of schedule. In 1961 on Stoke bank in Lincolnshire, the location of Mallard's 1938 world speed record, No. 60526 Sugar Palm achieved 101mi/h with the up “West Riding” express. Withdrawals began in the following year. Neither 60526 Sugar Palm or No. 60525 A. H. Peppercorn were saved for preservation.

Withdrawal

Withdrawal in England occurred during 1962 and 1963. Withdrawal in Scotland was completed in 1966.[1] The last three engines - 60528 Tudor Minstrel, 60530 Sayajirao and 60532 Blue Peter - were retired in June 1966.

Year Quantity in
service at
start of year
Quantity
withdrawn
Locomotive numbers Notes
1962 15 8 align=left 60526/29/31/34/36–39 align=left
1963 7 2 align=left 60525/33 align=left
1964 5 0 align=left align=left
1965 5 2 align=left 60527/35 align=left
1966 3 3 align=left 60528/30/32 align=left No. 60532 preserved.

Preservation

See main article: LNER Peppercorn Class A2 60532 Blue Peter. One Peppercorn A2, 60532 Blue Peter, has survived.

Sources

External links

Notes and References

  1. Peppercorn 'A2s'. Evan. Green-Hughes. Hornby Magazine. 64–67. 42. December 2010. Hersham. Ian Allan Publishing. 1753-2469. 226087101.