The line followed the valley of the River Calder for much of the way, making for easier gradients but by-passing many important manufacturing towns.

[2][3] In 1835, the company was reconstituted with capital fixed at £800,000; Stephenson was again appointed chief engineer, and plans were deposited for the following parliamentary session.

The eastward diversion was to form easier gradients than previously proposed, but nearer Manchester there were three inclines, each about 4 miles (6 km) long at 1 in 165 and 1 in 130.

It was nearly finished in December 1839 when a portion of the invert[note 1] failed, allowing the side walls to move by 3⁄4 inch (19 mm), requiring them to be rebuilt.

Stephenson explained the failure by saying The blue shale through which the excavation passed at that point, was considered so hard and firm, as to render it unnecessary to build the invert very strong there.

In this case, falling away like quicklime, it had left the lip of the invert alone to support the pressure of the arch above, and hence its springing inwards and upwards.

[9][8] On Wednesday 3 July 1839, the line was formally opened from Manchester to Littleborough and two trains conveying the directors and invited guests ran as far as Summit Tunnel.

As the eastern end of the M&LR was isolated by the uncompleted Summit Tunnel, the NMR provided locomotives for this section until the line was completed.

Passengers could now book from Manchester to Leeds, the journey from Littleborough to Hebden Bridge was made in road coaches provided by the company.

When Summit Tunnel was completed, the line was inspected by Sir Frederick Smith who sanctioned its opening to the public on behalf of the Board of Trade in February 1841.

[12] In July 1844, the M&LR seized all the Midland Railway[note 4] goods wagons on its system in order to run a cheap excursion from Dewsbury to Liverpool—at the time a commonplace form of accommodation.

[12] On 16 September 1847, a train headed by a 2-2-2 engine was derailed by a broken rail at Sowerby Bridge, killing two passengers and injuring one.

Over a distance of 410 yards (370 m) the chairs had worked loose in the stone blocks, the gauge varied by up to 1 inch (2.5 cm) each way and the rails were badly worn.

[15] The companies agreed to make a connecting line from the M&LR at Miles Platting to a new station at Hunt's Bank and on to the terminus of the Manchester and Bolton Railway (close to the present-day Salford Central station) and over an S-shaped link to join the L&MR to the west of its terminus in July 1838.

The Hunt's Bank site was purchased privately by Samuel Brooks, vice-chairman of the M&LR, and presented to the company in August 1838.

The Manchester and Leeds Railway stayed at Hunslet Lane after 1846, but diverted most of its trains via the LNWR route through Batley in 1848.

This crossed over the Midland Railway's Leeds–Bradford line at Holbeck and terminated at a temporary station, about 1⁄4 mile (0.4 km) from Wellington, near the site of Leeds Central where the permanent structure was opened about 1851.

A 1+3⁄4-mile (2.8 km) single line branch to Heywood was made, opening on 15 April 1841 without getting parliamentary authorisation, until obtained retrospectively on 10 May 1844 in the Manchester and Leeds Railway Act 1844 (7 & 8 Vict.

It left the main line at Castleton, but at the time the locality was known only as Blue Pitts, 2 miles (3.2 km) south-west of Rochdale.

[21] When the Hunt's Bank extension was authorised, an Oldham branch was included in the Manchester and Leeds Railway Act 1839 (2 & 3 Vict.

The method of working was devised by Captain Laws, the company General Manager;[22] it used a balancing load of mineral wagons on a reserved track, with a cable passing round a large drum at the head of the incline.

It was authorised on 31 July 1845 to make a 28-mile (45 km) line from a junction at Sandhills, near Liverpool Exchange station, to Bury.

[31] The West Riding Union Railways Company was formed in 1846 from the wreckage of George Hudson's duplicity; he had promised to promote a southward line from Bradford to Halifax and elsewhere.

This was done on 17 November 1846; the actual construction of the line was carried out by the M&LR, which changed its title the following year to the Lancashire and Yorkshire Railway.

The bill was successful and the branch was authorised by the Ashton, Stalybridge and Liverpool Junction Railway Act 1844 (7 & 8 Vict.

c. cix), on 21 July 1845, authorised the branch from Miles Platting to connect with the Manchester and Birmingham Railway at Ardwick.

[38] Seeing potential in expanding eastwards, especially in connecting directly to an east coast port,[note 9] the M&LR sponsored the promotion of a line from its Wakefield station.

The line was opened on 1 April 1848 by which time the company had amalgamated with the M&LR and others to form the Lancashire and Yorkshire Railway on 9 July 1847.

c. clxxxv) also of 16 July 1846 authorised branches from Pontefract to Methley, opened on 12 September 1849, and from Knottingley to Askern, joining the Great Northern Railway.

[40] The Lancashire and Yorkshire Railway Act 1847 also authorised a south connection at Castleton from the M&LR main line onto the Heywood branch, allowing direct running from Manchester to Bury.