GER Class L77

Infobox Locomotive
powertype=Steam
name = GER Class L77
LNER Class N7


caption =
designer = A. J. Hill
builder =
builddate =
totalproduction =
whytetype = 0-6-2T
gauge = standard gauge
leadingsize =
driversize = 4' 10"
length =
weight = 61 tons 16 cwt to
64 tons 17cwt
fueltype = coal
fuelc

waterc

cylindercount = two inside
cylindersize = 18" x 24"
firearea =
boilerpressure = 180 psi
tractiveeffort = 20,515 lbf
railroadclass= 3MT|

The Great Eastern Railway (GER) Class L77, LNER Class N7, is a class of 0-6-2T steam locomotives. They were designed by Alfred John Hill of the GER and introduced in 1914. The design was perpetuated by Nigel Gresley of the LNER after the 1923 grouping.

Overview

The N7s had superheaters and piston valves. They were unusual (for inside-cylinder locomotives) in having Walschaerts valve gear.

Some were fitted with condensing apparatus for working on the Metropolitan Line and the East London Line but the condensing apparatus was removed between 1935 and 1938.

British Railways numbers were 69600-69733.

ub-classes

* N7 Introduced 1914, GER Class L77 with Belpaire firebox
* N7/1 Introduced 1925, LNER development of GER design with Belpaire firebox
* N7/2 Introduced 1926, LNER locos with Belpaire firebox and long-travel valves
* N7/3(1)Introduced 1927, LNER locos with round-top firebox
* N7/3(2)Introduced 1943, rebuild of N7/1 with round-top firebox
* N7/3(3)Introduced 1943, rebuild of N7/2 with round-top firebox
* N7/4 Introduced 1940, GER locos rebuilt with round-top firebox

Preservation

One, No. 7999 (BR No. 69621) has been preserved on the North Norfolk Railway and is currently operational (Having had work done on the front end). However, it is owned by the East Anglian Railway Museum. It was the last engine built by the Great Eastern Railway's Stratford Works in 1924 and was preserved in 1962. It was also named in honour of its designer A J Hill in 1989.

ources

* Ian Allan ABC of British Railways Locomotives, 1948 edition, part 4, pp 54-55

External links

* [http://www.lner.info/locos/N/n7.shtml LNER encyclopedia]
* [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7 Railuk database for N7] , [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7/1 N7/1] [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7/2 N7/2] [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7/3 N7/3] [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7/4 N7/4] and [http://www.railuk.co.uk/steam/getsteamclass.php?item=N7/5 N7/5]
* [http://ukhrail.uel.ac.uk/cgi-bin/rlylocos?NO=69621&NA=&CL=&CO=ANY&BL=&WN=&LO= Preserved locomotive datbase entry for 69621]