The

NER NER may refer to: * New European Recordings, a record label * ISO 3166-1 three letter code for Niger * Named entity recognition, a text processing task that identifies certain words as belonging to one class or another * Northeast Regional, an Amt ...

class Z (LNER Class C7) was an

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

class of locomotives designed by

Vincent Raven Sir Vincent Litchfield Raven, KBE (3 December 1859 – 14 February 1934) was an English railway engineer, and was chief mechanical engineer of the North Eastern Railway from 1910 to 1922. Biography Vincent Raven was born the son of a clergy ...

. It was introduced in 1911.

Construction

Originally classified NER Class V2, the first 20 were built in 1911. Ten were saturated and the others were superheated. The saturated locos were superheated between 1914 and 1915, while all subsequent locomotives were superheated. 50 class Zs were built between 1911 and 1918, in 5 batches. Originally the locomotives were built with

Schmidt Schmidt may refer to: * Schmidt (surname), including list of people with the surname * Schmidt (singer) (born 1990), German pop and jazz singer * Schmidt (lunar crater), a small lunar impact crater * Schmidt (Martian crater), a List of craters on ...

superheater A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There ar ...

s, however from 1931 onwards 27 C7s were fitted with

Robinson Robinson may refer to: People and names * Robinson (name) Fictional characters * Robinson Crusoe, the main character, and title of a novel by Daniel Defoe, published in 1719 Geography * Robinson projection, a map projection used since the 1960 ...

superheaters.

Variations

No.2212

The last of the 50 locos, No.2212 was built with Stumpf Uniflow cylinders. This arrangement had been used on LNER Class B15 No.825 with an untidy result, however the arrangement had been tidied up for No.2212. Double-length cylinders were required, thus a longer front bogie and smaller wheels were fitted. This arrangement, although requiring special attention (as with No.825) was used until 1934, when No.2212 was fitted with standard cylinders.

C9

In early 1931, Gresly rebuilt No.727 and 2171 (who were entering Darlington for repairs) with an articulated

booster Booster may refer to: Amusement rides * Booster (Fabbri ride), a pendulum ride * Booster (HUSS ride), an evolution of the Breakdance ride * Booster (KMG ride), a pendulum ride Arts, entertainment, and media Fictional characters * Booster, a cha ...

bogie, thus making them technically 4-4-4-4s. However the articulated bogie was considered split between the loco and tender in order to simplify classification. Originally the booster gearing was 1.5:1, however the trials of C1 No.4419 (also having boosters) showed that the booster help was practically nonexistent above , meaning that the locomotives’ boosters were practically useless with the express, which would have to run with a speed of at least . Hence,

Darlington Darlington is a market town in the Borough of Darlington, County Durham, England. The River Skerne flows through the town; it is a tributary of the River Tees. The Tees itself flows south of the town. In the 19th century, Darlington underwen ...

recommended that the booster gearing was to be changed to 1:1. This required larger cylinders to supply the same tractive effort, which required the boiler to operate at 200psi (25 psi higher than the C7s, which are 175psi) . Some have concerned about engaging the booster at higher speeds, however the unitary 1:1 gearing was considered to make this easier. The boilers were “Diagram 100” boilers (the ones used on the B17s), and followed

Doncaster Doncaster (, ) is a city in South Yorkshire, England. Named after the River Don, it is the administrative centre of the larger City of Doncaster. It is the second largest settlement in South Yorkshire after Sheffield. Doncaster is situated in ...

practises, rather than

practises (which was used on the standard C7s). They also have

s, rather than

ones. The growing amount of Gresley A1s, A3s and A4s marked the experiment redundant (seeing the A4s were scheduled to climb

Cockburnspath Cockburnspath ( ; sco, Co’path) is a village in the Scottish Borders area of Scotland. It lies near the North Sea coast between Berwick-upon-Tweed and Edinburgh. It is at the eastern extremity of the Southern Upland Way a long-distance footpa ...

hauling a 312 tons load at an average speed of ).

Withdrawal

Withdrawal of the C7

Had

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not intervened, withdrawal would have started before 1940. However withdrawal was pushed back to August 1943. Withdrawal was quick, however, with only 14 surviving to nationalization. Within a year,

British Rail British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...

ways withdrew the remaining C7s, with none surviving into preservation.

Withdrawal of the C9

Their boilers were considered non-standard (compared to the C7s), thus they were withdrawn in April 1942(2171) and January 1943(727), before the first standard C7 was withdrawn. Neither of the two survived into preservation.

Loco details

Numbers in parentheses were allocated but not applied.

References

External links

LNER Class C7/NER Class ZLNER Class C9
{{LNER Locomotives Z class 4-4-2 locomotives Scrapped locomotives Standard gauge steam locomotives of Great Britain Passenger locomotives Railway locomotives introduced in 1911