The Dollis Brook Viaduct, also known as the Dollis Road Viaduct, Dollis Viaduct or Mill Hill Viaduct, is a

railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

viaduct A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide v ...

to the west of

Finchley Finchley () is a large district of north London, England, in the London Borough of Barnet. Finchley is on high ground, north of Charing Cross. Nearby districts include: Golders Green, Muswell Hill, Friern Barnet, Whetstone, Mill Hill and H ...

North London North London is the northern part of London, England, north of the River Thames. It extends from Clerkenwell and Finsbury, on the edge of the City of London financial district, to Greater London's boundary with Hertfordshire. The term ''nort ...

, United Kingdom. It carries the

London Underground The London Underground (also known simply as the Underground or by its nickname the Tube) is a rapid transit system serving Greater London and some parts of the adjacent ceremonial counties of England, counties of Buckinghamshire, Essex and He ...

Northern line The Northern line is a London Underground line that runs from North London to South London. It is printed in black on the Tube map. The Northern line is unique on the Underground network in having two different routes through central London, two ...

from Mill Hill East station to

Finchley Central station Finchley Central is a London Underground station in the Church End, Finchley, Church End area of Finchley, north London. The station is located on the High Barnet tube station, High Barnet branch of the Northern line, between West Finchley tube ...

. It is the highest point on the London Underground above ground level, reaching nearly . It is located on a branch that was formerly part of the

Edgware, Highgate and London Railway The Edgware, Highgate and London Railway was a railway in North London. The railway was a precursor of parts of London Underground's Northern line and was, in the 1930s the core of an ambitious expansion plan for that line which was thwarted by ...

Etymology

The official name of the viaduct is taken from

Dollis Brook Dollis Brook runs through the London Borough of Barnet in north London. It is a tributary of the River Brent, which is itself a tributary of the River Thames. The Dollis Valley Greenwalk follows almost all of Dollis Brook, apart from a short sec ...

which it crosses. The brook was marked on an 1877

Ordnance Survey , nativename_a = , nativename_r = , logo = Ordnance Survey 2015 Logo.svg , logo_width = 240px , logo_caption = , seal = , seal_width = , seal_caption = , picture = , picture_width = , picture_caption = , formed = , preceding1 = , di ...

map and the name may have originated from a farm called Dollis, previously in

Hendon Hendon is an urban area in the Borough of Barnet, North-West London northwest of Charing Cross. Hendon was an ancient manor and parish in the county of Middlesex and a former borough, the Municipal Borough of Hendon; it has been part of Great ...

. This was earlier named Dalys in 1563, (the) Doles 1574, Dallys 1584 and in its current form of Dollis in 1822. This probably meant "the portions or shares of land (in the common field)", from the

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English p ...

word dole. The name is not thought to be connected with the area of

Dollis Hill Dollis Hill is an area in northwest London, which consists of the streets surrounding the 35 hectares (86 acres) Gladstone Park. It is served by a London Underground station, Dollis Hill, on the Jubilee line, providing good links to central Lon ...

, further south. Dollis Hill is thought to mean a "hill associated with a family called Dalley".

History

The viaduct was designed by John Fowler and Walter Brydone, chief engineer for the Great Northern Railway (GNR) from 1855 to 1861. The contractor that built the bridge was Smith, Knight & Co. The viaduct came into use on 22 August 1867 with the opening of the GNR's single-track

line from

Finsbury Park Finsbury Park is a public park in the London neighbourhood of Harringay. It is in the area formerly covered by the historic parish of Hornsey, succeeded by the Municipal Borough of Hornsey. It was one of the first of the great London parks ...

Edgware Edgware () is a suburban town in northern Greater London, mostly in the London Borough of Barnet but with small parts falling in the London Borough of Harrow and in the London Borough of Brent. Edgware is centred north-northwest of Charing Cros ...

, via

and

Mill Hill Mill Hill is a suburb in the London Borough of Barnet, England. It is situated around northwest of Charing Cross. Mill Hill was in the historic county of Middlesex until 1965, when it became part of Greater London. Its population counted 18, ...

, which was authorised by an

Act of Parliament Acts of Parliament, sometimes referred to as primary legislation, are texts of law passed by the Legislature, legislative body of a jurisdiction (often a parliament or council). In most countries with a parliamentary system of government, acts of ...

in 1862.

Although built to carry two tracks, the viaduct initially carried only one. Following the construction of a branch northwards from Finchley to Barnet in 1872, the original Edgware route effectively became a branch of the newer line. In the 1920s, the

London and North Eastern Railway The London and North Eastern Railway (LNER) was the second largest (after LMS) of the " Big Four" railway companies created by the Railways Act 1921 in Britain. It operated from 1 January 1923 until nationalisation on 1 January 1948. At th ...

(LNER, successor to the GNR) planned to electrify the line but work was not carried out until the 1930s when the

Northern Heights plan The Northern line is a London Underground line that runs from North London to South London. It is printed in black on the Tube map. The Northern line is unique on the Underground network in having two different routes through central London, two ...

led to the doubling and electrification of the lines. This was in preparation for a transfer of the lines to the London Underground for it to form part of the system's

. The start of the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

prevented the plans being completed and only the section of the line to Mill Hill East was electrified and reopened in 1941, whilst the High Barnet branch was electrified in 1940. From this point on London Transport trains used only one of the tracks on the Mill Hill branch and the other track was soon lifted. Freight on the line lasted until 1964 when the line west of Mill Hill East was abandoned, leaving the present arrangement.

Length, span and architecture

The viaduct's 13 segmental

arch An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it. Arches may be synonymous with vaul ...

es carry it across the valley of the

, and over Dollis Road. Each arch spans at the springer level, and is based on tapered

piers Piers may refer to: * Pier, a raised structure over a body of water * Pier (architecture), an architectural support * Piers (name), a given name and surname (including lists of people with the name) * Piers baronets, two titles, in the baronetages ...

. In each pier there is an opening with an arched

soffit A soffit is an exterior or interior architectural feature, generally the horizontal, aloft underside of any construction element. Its archetypal form, sometimes incorporating or implying the projection of beams, is the underside of eaves (to ...

and a dished invert. The viaduct is made from brick. It is the highest point on both the Northern line and the highest point on the London Underground above ground level, reaching nearly . It is not, however, the highest

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

on the Underground system, which is near

Amersham Amersham ( ) is a market town and civil parish within the unitary authority of Buckinghamshire, England, in the Chiltern Hills, northwest of central London, from Aylesbury and from High Wycombe. Amersham is part of the London commuter belt. ...

(

Metropolitan line The Metropolitan line, colloquially known as the Met, is a London Underground line between in the City of London and and in Buckinghamshire, with branches to in Hertfordshire and in Hillingdon. Printed in magenta on the tube map, the line i ...

) in the

Chiltern Hills The Chiltern Hills is a chalk escarpment in England. The area, northwest of London, covers stretching from Goring-on-Thames in the southwest to Hitchin in the northeast - across Oxfordshire, Buckinghamshire, Hertfordshire, and Bedfordshire. ...

, at above sea level.

Around the viaduct

Below the viaduct can be found the

Dollis Valley Greenwalk The Dollis Valley Greenwalk (or Green Walk) is a footpath route in the London Borough of Barnet in London, England, between Moat Mount Nature Reserve in Mill Hill and Hampstead Heath. The route is designed to act as a link between the Capital ...

, a

long-distance footpath A long-distance trail (or long-distance footpath, track, way, greenway) is a longer recreational trail mainly through rural areas used for hiking, backpacking, cycling, horse riding or cross-country skiing. They exist on all continents exce ...

between

Moat Mount Open Space Moat Mount Open Space is a 110-hectare park and nature reserve in Mill Hill in the London Borough of Barnet. It is part of Moat Mount Open Space and Mote End Farm Site of Borough Importance for Nature Conservation, Grade II, which includes Barne ...

and

Hampstead Heath Hampstead Heath (locally known simply as the Heath) is an ancient heath in London, spanning . This grassy public space sits astride a sandy ridge, one of the highest points in London, running from Hampstead to Highgate, which rests on a band o ...

. This is designed to link many green spaces and wildlife corridors along the way and is approximately long. The geology nearby is of

London Clay The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from t ...

with small amounts of other rock types. An examination in the late 19th century of the railway cutting between Finchley and Hendon station found a large extent of glacial beds and

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s, and these were thought to extend as far northwest as the viaduct.

References

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External links