The Metropolitan Railway (also known as the Met) was a passenger and goods railway that served London from 1863 to 1933, its main line heading north-west from the capital’s financial heart in the City to what were to become the Middlesex suburbs. Its first line connected the main-line railway termini at Paddington, Euston, and King’s Cross to the City. It opened to the public on January 10, 1863 with gas-lit wooden carriages hauled by steam locomotives, the world’s first passenger-carrying designated underground railway.
Despite concerns about undermining and vibrations causing subsidence of nearby buildings and compensating the thousands of people whose homes were destroyed during the digging of the tunnel construction began in March 1860. The line was mostly built using the “cut-and-cover” method from Paddington to King’s Cross; east of there it continued in a 728 yards (666 m) tunnel under Mount Pleasant, Clerkenwell then followed the culverted River Fleet beside Farringdon Road in an open cutting to near the new meat market at Smithfield.
The trench was 33 feet 6 inches (10.2 m) wide, with brick retaining walls supporting an elliptical brick arch or iron girders spanning 28 feet 6 inches (8.7 m). The tunnels were wider at stations to accommodate the platforms. Most of the excavation work was carried out manually by navvies; a primitive earth-moving conveyor was used to remove excavated spoil from the trench.
Within the tunnel, two lines were laid with a 6-foot (1.8 m) gap between. To accommodate both the standard gauge trains of the GNR and the broad gauge trains of the GWR, the track was three-rail mixed gauge, the rail nearest the platforms being shared by both gauges. Signalling was on the absolute block method, using electric Spagnoletti block instruments and fixed signals.
Construction was not without incident. In May 1860, a GNR train overshot the platform at King’s Cross and fell into the workings. Later in 1860, a boiler explosion on an engine pulling contractor’s wagons killed the driver and his assistant. In May 1861, the excavation collapsed at Euston causing considerable damage to the neighboring buildings. The final accident occurred in June 1862 when the Fleet sewer burst following a heavy rainstorm and flooded the excavations. The Met and the Metropolitan Board of Works managed to stem and divert the water and the construction was delayed by only a few months.
Trial runs were carried out from November 1861 while construction was still under way. The first trip over the whole line was in May 1862 with William Gladstone among the guests. By the end of 1862 work was complete at a cost of £1.3 million.