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Baulk road is the name given to a type of
railway track A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, ...
or 'rail road' that is formed using rails carried on continuous
timber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...
bearings, as opposed to the more familiar 'cross-sleeper' track that uses closely spaced sleepers or ties to give intermittent support to stronger rails. Baulk road was popularised by
Isambard Kingdom Brunel Isambard Kingdom Brunel (; 9 April 1806 – 15 September 1859) was a British civil engineer who is considered "one of the most ingenious and prolific figures in engineering history," "one of the 19th-century engineering giants," and "one ...
for his
broad gauge A broad-gauge railway is a railway with a track gauge (the distance between the rails) broader than the used by standard-gauge railways. Broad gauge of , commonly known as Russian gauge, is the dominant track gauge in former Soviet Union (CIS ...
railways in the UK, but has also been used for other railways and can still be found in modified form in special locations on present day railways.


Development

Brunel sought an improved design for the railway track needed for the
Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...
(GWR), authorised by
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 1835 to link London and
Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
. He refused to accept received wisdom without challenge. The gauge that had been adopted by most railways at that time had been fine for small mineral trucks on a horse-drawn tramway, but he wanted something more stable for his high-speed railway. The large diameter wheels used in stage coaches gave better ride quality over rough ground, and Brunel originally intended to have his carriages carried in the same way – on large diameter wheels placed outside their bodies. To achieve this he needed a wider track gauge and he settled on a broad gauge but it was soon eased slightly to . When the time came to build the passenger carriages they were designed conventionally with smaller wheels under the bodies, but with the broad track gauge the bodies could be much wider than on the standard gauge. His original intention to have the wheels outside the width of the bodies was abandoned. Early locomotive-powered railways had used short
cast iron Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...
rails carried on stone blocks. A few were trying timber sleepers to support the rails and to maintain the gauge between them. These rails were brittle and broke easily, and they gave a rough ride due to the difficulty of maintaining a smooth line between the blocks or sleepers.
Wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a ...
rails were being manufactured but they were of poor quality due to the difficulty of cooling them evenly during manufacture. Brunel decided to use a continuously supported wrought iron rail, a bridge rail with a smaller rail section that cooled more evenly. This was an inverted-U section with wide flanges that could be bolted to the timber bearer, which was known as a 'longitudinal' baulk. The rail was usually kept off this by small wooden packing pieces that could be replaced when they were worn out by the passage of the trains, and therefore avoid the expense of replacing the heavier longitudinals. The rails were bolted to the longitudinals by long fang bolts or coach screws, and the rail joints were later supported by a base plate formed with a plug in the void of the inverted U shape rails so as to keep the rails in line with each other. The longitudinal baulks, and therefore the rails, were kept to gauge by 'transoms' – transverse timber spacers – and iron tie-bars. The transom kept the longitudinals from getting too close together; the tie rods stopped them spreading too far apart. In later years the tie rods were replaced by strap bolts. These were bolted to the transoms and passed through a hole drilled through the longitudinal to a nut on the outside. On the first section of the GWR, from
London Paddington station Paddington, also known as London Paddington, is a Central London railway terminus and London Underground station complex, located on Praed Street in the Paddington area. The site has been the London terminus of services provided by the Great We ...
to a temporary station at known as 'Maidenhead Bridge', Brunel had the track tied down to timber piles so that the gravel ballast (which was necessary on all railways for drainage) could be packed very firmly. It was packed so firmly, in fact, that the track was forced upwards between the piles and thus gave an undulating ride, just the thing that Brunel had tried to address by using continuous bearings and firm packing; cutting the piles away from the transoms solved the problem. The bridge rail for this line weighed but this was soon increased, generally to . The longitudinal baulks were around . wide and . deep or , but the sizes varied depending on the timber available and the weight of traffic to be carried. Transoms were around and initially spaced at intervals but this was reduced over time to around . The GWR also used conventional cross-sleepered track, especially on lines. Although its last broad gauge track was replaced by standard gauge in 1892, baulk road continued in service for some time afterwards.
Converting Converting companies are companies that specialize in modifying or combining raw materials such as polyesters, adhesives, silicone, adhesive tapes, foams, plastics, felts, rubbers, liners and metals, as well as other materials, to create new produ ...
broad gauge baulk road to standard was done by cutting the transoms and slewing the longitudinal and its rail to its new position. Between 1852 and 1892 an ever-increasing length of the Great Western Railway had been laid as
mixed gauge In railway engineering, "gauge" is the transverse distance between the inner surfaces of the heads of two rails, which for the vast majority of railway lines is the number of rails in place. However, it is sometimes necessary for track to c ...
that could be used by trains of either gauge. For baulk road this meant laying an additional longitudinal between the existing two (one rail was common to both gauges), but this significantly increased the cost and complexity of the track compared to cross-sleepers.


Alternative systems

Vignoles rail was a light section that today would be classed as flat-bottomed rail. In its original form it was only about deep and was used on baulk road interchangeably with bridge rail.
William Henry Barlow William Henry Barlow FRS FRSE FICE MIMechE (10 May 1812 – 12 November 1902) was an English civil engineer of the 19th century, particularly associated with railway engineering projects. Barlow was involved in many engineering ent ...
’s
Barlow rail Barlow rail was a rolled rail section used on early railways. It has wide flaring feet and was designed to be laid direct on the ballast, without requiring sleepers. It was widely adopted on lightly trafficked railways, but was ultimately unsuccess ...
was patented in 1849 as a purely metal road. Deep rails with an inverted, curved V section were designed to be laid directly into the ballast; gauge was maintained by iron tie bars between the rails. The rails weighed but this was later increased to . They were used on lines such as the
West Cornwall Railway The West Cornwall Railway was a railway company in Cornwall, Great Britain, formed in 1846 to construct a railway between Penzance and Truro. It purchased the existing Hayle Railway, and improved its main line, and built new sections between Pen ...
,
Wycombe Railway The Wycombe Railway was a British railway between and that connected with the Great Western Railway at both ends; there was one branch, to . History The Wycombe Railway Company was incorporated by an act of Parliament passed in 1846. The act ...
,
South Wales Railway The South Wales Railway ( cy, Rheilffordd De Cymru) was a main line railway which opened in stages from 1850, connecting the Great Western Railway from Gloucester to South Wales. It was constructed on the broad gauge. An original aspiration was to ...
and New South Wales Railways. They soon fell out of favour as it proved difficult to pack the ballast properly. A large number were sold to the engineers building
Clevedon Pier Clevedon Pier is a seaside pier in the town of Clevedon, Somerset, England on the east shore of the Severn Estuary. It was described by Sir John Betjeman, as "the most beautiful pier in England" and was designated a Grade I listed building in 2 ...
who bolted them together to use as girders. Other pieces of Barlow rail can occasionally be found in fencing near ex-GWR lines. Discarded samples found buried in ballast being recovered from the Didcot Newbury and Southampton Railway can be seen at Didcot Railway Centre. The
Bristol and Exeter Railway The Bristol & Exeter Railway (B&ER) was an English railway company formed to connect Bristol and Exeter. It was built on the broad gauge and its engineer was Isambard Kingdom Brunel. It opened in stages between 1841 and 1844. It was allied with ...
and the
Bridport Railway The Bridport Railway was a railway branch line that operated in the county of Dorset in England. It connected Bridport with the main line network at Maiden Newton, and opened on 12 November 1857. It was extended to West Bay in 1884, but the ex ...
used Brunel's bridge rail section but laid it on iron MacDonnell plates. These had three ridges to keep the rail in line and were laid directly into the ballast without any timber supports. It proved difficult to keep in alignment. Seaton rail was similar to Vignoles rail but with the flanged foot angled down to give an inverted V section that was then used on triangular longitudinal.


Other applications

Baulk road was used by John Coode for a number of railways that he built as part of large construction schemes for harbour
breakwater Breakwater may refer to: * Breakwater (structure), a structure for protecting a beach or harbour Places * Breakwater, Victoria, a suburb of Geelong, Victoria, Australia * Breakwater Island Breakwater Island () is a small island in the Palme ...
s at places such as
Portland Portland most commonly refers to: * Portland, Oregon, the largest city in the state of Oregon, in the Pacific Northwest region of the United States * Portland, Maine, the largest city in the state of Maine, in the New England region of the northeas ...
and
Table Bay Table Bay (Afrikaans: ''Tafelbaai'') is a natural bay on the Atlantic Ocean overlooked by Cape Town (founded 1652 by Van Riebeeck) and is at the northern end of the Cape Peninsula, which stretches south to the Cape of Good Hope. It was named ...
. The great widths between the rails and between the transoms allowed him to support the tracks on piles and discharge rocks from wagons directly between the rails to form the foundations of the breakwaters. A variant of baulk road can still be seen today on some older under-line bridges where no ballast is provided. The design varies considerably, but in many cases longitudinal timbers are supported directly on the cross-girders, with transoms and tiebars to retain the gauge, and modern rails and base-plates or
chairs A chair is a type of seat, typically designed for one person and consisting of one or more legs, a flat or slightly angled seat and a back-rest. They may be made of wood, metal, or synthetic materials, and may be padded or upholstered in vario ...
laid on top. It can also be found in places where easy drainage is required or where access is required under rail vehicles for maintenance.


See also

*
Permanent way (history) The railway track or permanent way is the elements of railway lines: generally the pairs of rails typically laid on the sleepers or ties embedded in ballast, intended to carry the ordinary trains of a railway. It is described as permanent way b ...
*
Rail tracks A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, ...
*
Ladder track Ladder track is a type of railway track in which the track is laid on longitudinal supports with transverse connectors holding the two rails at the correct gauge distance. Modern ladder track can be considered a development of baulk road, which ...
– generic term for longitudinally supported rails with gauge constraining transverse ties *
Slab track A ballastless track or slab track is a type of railway track infrastructure in which the traditional elastic combination of ties/sleepers and ballast is replaced by a rigid construction of concrete or asphalt. Characteristics In ballastless t ...


References

{{Brunel Permanent way Great Western Railway Works of Isambard Kingdom Brunel