London and North Eastern Railway

The total route mileage was 6,700 miles (10,800 km). The North Eastern Railway had the largest route mileage of 1,757 miles (2,828 km), whilst the Hull and Barnsley Railway was 106.5 miles (171.4 km). The company retained a decentralised management, with headquarters functions divided between York, Edinburgh and London. The office of the Chief General Manager was at King's Cross station and the Chairman's office was at Marylebone station.

It covered the area north and east of London. It included the East Coast Main Line from London to Edinburgh via York and Newcastle upon Tyne and the routes from Edinburgh to Aberdeen and Inverness. It also included the Great Central Main Line, from London Marylebone to Sheffield. Most of the country east of the Pennines was within its purview, including East Anglia. The main workshops were in Doncaster, with others at Darlington, Inverurie and Stratford, London.

The company also owned the most westerly track and stations in Great Britain, in the form of the West Highland Railway to Arisaig and Mallaig, previously owned by the North British Railway.

The LNER inherited four of London's termini: Fenchurch Street (ex-London and Blackwall Railway); King's Cross (ex-Great Northern Railway); Liverpool Street (ex-Great Eastern Railway); and Marylebone (ex-Great Central Railway). In addition, it ran suburban services to Broad Street (London, Midland and Scottish Railway) and Moorgate (Metropolitan Railway, later London Transport).

The LNER owned:

7,700 locomotives, 20,000 coaching vehicles, 29,700 freight vehicles, 140 items of electric rolling stock, 6 electric locomotives and 10 rail motor cars

6 turbine and 36 other steamers, and river boats and lake steamers, etc.

In partnership with the London, Midland and Scottish Railway (LMS), the LNER was co-owner of the Midland and Great Northern Joint Railway, the UK's biggest joint railway, much of which competed with the LNER's own lines. The M&GNJR was incorporated into the LNER in 1936. In 1933, on the formation of the London Passenger Transport Board, the LNER acquired the remaining operations of the Metropolitan Railway Company.

The LNER was the majority partner in the Cheshire Lines Committee and the Forth Bridge Railway Company.

It depended on freight from heavy industry in Yorkshire, the north east of England and Scotland, and its revenue was reduced by the economic depression for much of the early part of its existence. In a bid to improve financial efficiency, staffing levels reduced from 207,500 in 1924 to 175,800 in 1937. For investment to retain freight traffic, new marshalling yards were built in Whitemoor in Cambridgeshire, and Hull in Yorkshire to attempt to retain freight traffic.

Sir Ralph Wedgwood introduced a Traffic Apprenticeship Scheme to attract graduates, train young managers and provide supervision by assistant general manager Robert Bell for career planning. The company adopted a regional managerial system, with general managers based in London, York and Edinburgh, and for a short time, Aberdeen.

For passenger services, Sir Nigel Gresley, the Chief Mechanical Engineer built new locomotives and new coaches. Later developments such as the streamlined Silver Jubilee train of 1935 were exploited by the LNER publicity department, and embedded the non-stop London to Edinburgh services such as the Flying Scotsman in the public imagination. The world record speed of 126 miles per hour (203 km/h) was achieved on a test run by LNER Class A4 4468 Mallard.

In 1929, the LNER chose the typeface Gill Sans as the standard typeface for the company. Soon it appeared on every facet of the company's identity, from metal locomotive nameplates and hand-painted station signage to printed restaurant car menus, timetables and advertising posters. The LNER promoted their rebranding by offering Eric Gill a footplate ride on the Flying Scotsman express service; he also painted for it a signboard in the style of Gill Sans, which survives in the collection of the St Bride Library. Gill Sans was retained by the Railway Executive in 1948, although modified for signage, and Gill Sans was the official typeface until British Rail replaced it in the mid 1960s with Rail Alphabet for signs and Helvetica or Univers for printed matter.

Continental shipping services were provided from Harwich Parkeston Quay.

The company took up the offer in 1933 of government loans at low interest rates and electrified the lines from Manchester to Sheffield and Wath yard, and also commuter lines in the London suburban area.

On 14 February 1927, two passenger trains collided head-on at Hull Paragon station, Yorkshire due to a signalman's error. Twelve people were killed and 24 were injured.

On 27 February 1927, an express passenger train collided with a light engine at Penistone, Yorkshire due to a signalman's error.

On 17 August 1928, a passenger train struck a lorry on a level crossing at Shepreth, Cambridgeshire and derailed. The fireman, and the lorry driver, were killed.

On 27 June 1928, an excursion train collided with a parcels train that was being shunted at Darlington, County Durham. Twenty-five people were killed and 45 were injured.

On 9 June 1929, a steam railcar overran signals and collided with an excursion train at Marshgate Junction, Doncaster, Yorkshire.

On 4 October 1929, a freight train departed against a danger signal at Tottenham, London, and then stopped foul of a junction where the crew abandoned the locomotive. An express passenger train collided with it and derailed.

On 17 January 1931, a newspaper train departed from Thorpe-le-Soken station, Essex against signals and collided head-on with a light engine at Great Holland. Two people were killed and two were seriously injured.

On 27 May 1931, a passenger train overran signals and collided head-on with another at Fakenham East station, Norfolk. One person was killed and fifteen were injured.

On 8 September 1933, a passenger train ran into wagons at Bowling, West Dunbartonshire due to a signalman's error. Five people were injured.

In November 1934, a Class D16/2 locomotive derailed at Wormley, Hertfordshire when it collided with a lorry on a level crossing. Both engine crew were killed.

On 15 June 1935, an express passenger train ran into the rear of another at Welwyn Garden City, Hertfordshire due to a signalman's error. Fourteen people were killed and 29 were injured.

On 15 February 1937, a passenger train entered a curve at excessive speed and derailed at Sleaford North Junction, Lincolnshire. Four people were killed and sixteen were injured, one seriously.

On 15 February 1937, a freight train derailed at Upton, Sleaford due to excessive speed on a curve. The train had been diverted due to the earlier derailment.

On 6 March 1937, a passenger train derailed at Langrick, Lincolnshire due to the poor condition of the track.

On 13 June 1937, an excursion train overran signals and was derailed by trap points south of Durham. Nine people were injured.

On 26 January 1939, an empty fish train (the official enquiry shows it was a passenger train) ran into the rear of a passenger train at Hatfield, Hertfordshire.

On 1 June 1939, a passenger train collided with a lorry on an occupation crossing at Hilgay, Norfolk and was derailed.

On 8 June 1939, a passenger train departed against a danger signal from Manchester Central station, Lancashire and collided with another passenger train. Several people were injured.

On 10 February 1941, an express passenger train overran signals and ran into the rear of a passenger train at Harold Wood, Essex. Seven people were killed and seventeen were seriously injured.

On 28 April 1941, a fire broke out on an express passenger train which was brought to a stand at Westborough, Lincolnshire. The rear three carriages were burnt out. Six people were killed and seven were injured. Among those killed were the two eldest children of Hubert Pierlot, the Prime Minister of the Belgian government in exile.

On 2 June 1944, WD Austerity 2-8-0 locomotive No. 7337 was hauling a freight train which caught fire as it approached Soham, Cambridgeshire. The train comprised wagons carrying bombs. The train was divided behind the burning wagon, with the front portion being taken forward with the intention of isolating the wagon in open countryside. Its cargo detonated at Soham station, killing the fireman and the Soham signalman and injuring the trains' driver and guard. Soham station was severely damaged, but the line was re-opened within eighteen hours. For their actions, Benjamin Gimbert and James Nightall were awarded George Crosses.

In July 1944, a passenger train was derailed at Pannal Junction by points that were half-open.

On 5 January 1946, a freight train became divided on the East Coast Main Line in County Durham. The front section was brought to a stand but the rear section crashed into it. The wreckage fouled signal cables, giving a false clear signal to a passenger train on the opposite line which then crashed into the wreckage. Ten people were killed.

On 10 February 1946, a passenger train crashed at Potters Bar, Hertfordshire due to a signalman's error. The wreckage fouled signal cables, giving a false clear to an express passenger train which then ran into the wreckage. A third passenger train then collided with the wreckage. Two people were killed.

On 2 January 1947, a passenger train overran signals and ran into the rear of another at Gidea Park, Essex. Seven people were killed, 45 were hospitalised.

On 9 August 1947, a passenger train ran into the rear of another at Darlington, County Durham due to a signalman's error. Twenty-one people were killed and 188 were injured.

On 26 October 1947, an express passenger train entered a crossover at excessive speed and derailed at Goswick, Northumberland. Twenty-eight people were killed and 65 were injured.