A baulk road* is the name given to a type of railway track that is formed using rails placed on continuous wooden beams, as opposed to the more usual track, which uses ties arranged transversely with a certain spacing.
This type of track was popularized by engineer Isambard Kingdom Brunel on his wide gauge (2,140 mm (7'0.30")) railways in the United Kingdom, but has also been used on other railways and can still be found in modified form on special locations on current railways.
Development
Brunel sought an improved design for the railway track needed on the Great Western Railway (GWR) (authorized by an Act of Parliament in 1835), which would connect London and Bristol.[1].
He refused to accept previous experiences without first reconsidering them. The 1,435 mm (4' 8") gauge, which had been adopted by most railways at the time, was fine for the small ore-laden cars of a horse-drawn tram, but he wanted something more stable for his high-speed railway. Carriages with large diameter wheels were known to provide better ride quality over rough terrain, and Brunel originally intended to haul his trains in the same way: on large diameter wheels set on the outside of the boxes. of the vehicles. To achieve this, he needed a wider track width and decided on 7 feet (2134 mm), but this was soon widened slightly to 2140 mm (7'0.30"). When it came time to build passenger cars, they were conventionally designed with smaller wheels under the frames, but with the large gauge adopted the carriages could be much wider than with the standard gauge. Thus, his original idea of placing the wheels outside the width of the car bodies was abandoned.[2].
Early locomotive-driven railways had used short rails made of cast iron, supported by stone blocks. Tests had been carried out with wooden sleepers to support the rails and maintain the track width between them, but given their fragility, the rails broke easily, causing irregular movement of the vehicles due to the difficulty of maintaining a smooth profile between the blocks or sleepers. Wrought iron rails were already being produced, but were still of low quality due to the difficulty of cooling them evenly during manufacturing. Brunel decided to use a continuously supported wrought iron rail, a rail with a smaller inverted "U" section, which cooled more uniformly. He completed the rail design with two outer wings, which could be fastened with nails to the longitudinally arranged wooden beams. The rails were kept at the correct distance from each other by small wooden braces, which could be replaced when they deteriorated from passing trains and therefore avoided the expense of replacing the heavier longitudinal beams. The rails were fastened with long nails or screws, and the joints between rails were fixed with plates arranged in the interior hollow of the inverted U-shaped section.[2].
Plate track
Introduction
A baulk road* is the name given to a type of railway track that is formed using rails placed on continuous wooden beams, as opposed to the more usual track, which uses ties arranged transversely with a certain spacing.
This type of track was popularized by engineer Isambard Kingdom Brunel on his wide gauge (2,140 mm (7'0.30")) railways in the United Kingdom, but has also been used on other railways and can still be found in modified form on special locations on current railways.
Development
Brunel sought an improved design for the railway track needed on the Great Western Railway (GWR) (authorized by an Act of Parliament in 1835), which would connect London and Bristol.[1].
He refused to accept previous experiences without first reconsidering them. The 1,435 mm (4' 8") gauge, which had been adopted by most railways at the time, was fine for the small ore-laden cars of a horse-drawn tram, but he wanted something more stable for his high-speed railway. Carriages with large diameter wheels were known to provide better ride quality over rough terrain, and Brunel originally intended to haul his trains in the same way: on large diameter wheels set on the outside of the boxes. of the vehicles. To achieve this, he needed a wider track width and decided on 7 feet (2134 mm), but this was soon widened slightly to 2140 mm (7'0.30"). When it came time to build passenger cars, they were conventionally designed with smaller wheels under the frames, but with the large gauge adopted the carriages could be much wider than with the standard gauge. Thus, his original idea of placing the wheels outside the width of the car bodies was abandoned.[2].
Early locomotive-driven railways had used short rails made of cast iron, supported by stone blocks. Tests had been carried out with wooden sleepers to support the rails and maintain the track width between them, but given their fragility, the rails broke easily, causing irregular movement of the vehicles due to the difficulty of maintaining a smooth profile between the blocks or sleepers. Wrought iron rails were already being produced, but were still of low quality due to the difficulty of cooling them evenly during manufacturing. Brunel decided to use a continuously supported wrought iron rail, a rail with a smaller inverted "U" section, which cooled more uniformly. He completed the rail design with two outer wings, which could be fastened with nails to the longitudinally arranged wooden beams. The rails were kept at the correct distance from each other by small wooden braces, which could be replaced when they deteriorated from passing trains and therefore avoided the expense of replacing the heavier longitudinal beams. The rails were fastened with long nails or screws, and the joints between rails were fixed with plates arranged in the interior hollow of the inverted U-shaped section.[2].
The longitudinal beams, and therefore the rails, were kept at the nominal width using 'crossbars' - transverse wooden spacers - and iron tie bars. The crossbars kept the beams from coming too close together, and the braces kept them from spreading too far apart. In later years, the braces were replaced with bolts screwed to the crossbars. These threaded bolts passed through the longitudinal beams through a hole, being held in place by a nut placed on the outside.[2].
On the first section of the GWR, from Paddington Station to a temporary station at Taplow (known as 'Maidenhead Bridge'), Brunel reinforced the fastening of the longitudinal girders by adding wooden piles, so that the ballast could be compacted very firmly between the two tracks. In fact, it became so compacted that the track was displaced upwards between successive piles, causing the wavy profile of the track that Brunel had tried to avoid. Cutting the piles, making them independent of the crossbars, solved the problem.[3] The rail used weighed 21.3 kg/m, but this was soon increased to 30.8 kg/m.[2] The longitudinal beams had a section (width by thickness) of around 305x127 mm or 254x178 mm, but the sizes varied depending on the wood available and the weight of the traffic to be transported. The cross members were around 152x229 mm and initially spaced at 15 ft (4.57 m) intervals, but this was reduced over time to around 11 ft (3.35 m).[2].
The GWR also used conventional track with cross sleepers, especially on the standard gauge (1,435 mm (4' 8") lines). Although its last wide gauge track was converted to standard gauge in 1892, the longitudinally supported track continued in service for some time afterwards. Conversion from gauge to standard gauge was accomplished by cutting the cross members and moving one of the girders and its rail to its new position. Between 1852 and 1892, an increasing length of the Great Western Railway was adapted as mixed gauge track, which could be used by trains of different gauges. For longitudinal support tracks, this meant placing an additional beam between the two existing ones (one rail was common for both widths), but this significantly increased the cost and complexity of the track compared to the conventional solution with sleepers.[4].
Alternative systems
The Vignoles rail was a light section that today would be classified as a flat bottom rail. In its original form, it was only about 4 inches (102 mm) deep and was used on longitudinally supported track interchangeably with inverted "U" section rail.[4].
The Barlow rail, patented in 1849 by William Henry Barlow, is a type of track with a purely metal support. The rails, with a deep inverted curved V section, were designed to sit directly on the ballast. The width was ensured by iron connecting bars between the rails, which weighed 46.1 kg/m (later increased to 49.1 kg/m). They were used on some lines: West Cornwall Railway, Wycombe Railway, South Wales Railway and New South Wales Railways. They soon fell into disuse, as they made it difficult to compact the ballast properly. A large number of these rails were sold to the engineers building Clevedon Dock"), who screwed them together for use as girders. Other pieces of Barlow rail can occasionally be found on fences near the former GWR lines. Abandoned specimens recovered buried in the ballast of the Didcot Newbury and Southampton Railway can be seen at the Didcot Railway Centre.
The Bristol and Exeter Railway and the Bridport Railway used Brunel's inverted "U" section of rail, but laid it on MacDonnell iron plates. These had three ridges to keep the rail in line and were laid directly on the ballast without any wooden supports, but the system made it very difficult to keep the track aligned.[2]
Seaton's rail was similar to that of Vignoles, but with the foot wings arranged at a downward angle to form an inverted V section, which was then mounted on longitudinal wooden beams of triangular section.[2].
Other applications
Longitudinally supported track was used by John Coode&action=edit&redlink=1 "John Coode (engineer) (not yet drafted)") for a series of 7-foot (2,134 mm) gauge railways which he built as part of large port breakwater construction works in places such as Portland and Table Bay. The wide distances between the crossbars and between the two rails, mounted on beams elevated on piles, allowed the breakwater to be unloaded directly from the wagons between the rails to form the foundations of the breakwaters.[5][6].
A variant of this route can still be seen today in some old underground bridges, where ballast was not used. The design varies considerably, but in many cases the longitudinal beams rest directly on transverse beams, with cross members and tie bars to maintain track clearance, and modern rails and bedplates or supports placed on top. It can also be found in places where easy drainage is required or where access under rail vehicles is needed for maintenance.
References
[1] ↑ MacDermot, E T (1927). History of the Great Western Railway. 1 (1833–1863) (1 edición). London: Great Western Railway.
[2] ↑ a b c d e f g h Mann, JW (1993). «Great Western Permanent Way». Broadsheet (Broad Gauge Society) (29): 10-16.
[3] ↑ Slinn, JN (1978). Great Western Way. Woking: Historical Model Railway Society.
[4] ↑ a b MacDermot, E T (1931). History of the Great Western Railway. 2 (1863–1921) (1 edición). London: Great Western Railway.
The longitudinal beams, and therefore the rails, were kept at the nominal width using 'crossbars' - transverse wooden spacers - and iron tie bars. The crossbars kept the beams from coming too close together, and the braces kept them from spreading too far apart. In later years, the braces were replaced with bolts screwed to the crossbars. These threaded bolts passed through the longitudinal beams through a hole, being held in place by a nut placed on the outside.[2].
On the first section of the GWR, from Paddington Station to a temporary station at Taplow (known as 'Maidenhead Bridge'), Brunel reinforced the fastening of the longitudinal girders by adding wooden piles, so that the ballast could be compacted very firmly between the two tracks. In fact, it became so compacted that the track was displaced upwards between successive piles, causing the wavy profile of the track that Brunel had tried to avoid. Cutting the piles, making them independent of the crossbars, solved the problem.[3] The rail used weighed 21.3 kg/m, but this was soon increased to 30.8 kg/m.[2] The longitudinal beams had a section (width by thickness) of around 305x127 mm or 254x178 mm, but the sizes varied depending on the wood available and the weight of the traffic to be transported. The cross members were around 152x229 mm and initially spaced at 15 ft (4.57 m) intervals, but this was reduced over time to around 11 ft (3.35 m).[2].
The GWR also used conventional track with cross sleepers, especially on the standard gauge (1,435 mm (4' 8") lines). Although its last wide gauge track was converted to standard gauge in 1892, the longitudinally supported track continued in service for some time afterwards. Conversion from gauge to standard gauge was accomplished by cutting the cross members and moving one of the girders and its rail to its new position. Between 1852 and 1892, an increasing length of the Great Western Railway was adapted as mixed gauge track, which could be used by trains of different gauges. For longitudinal support tracks, this meant placing an additional beam between the two existing ones (one rail was common for both widths), but this significantly increased the cost and complexity of the track compared to the conventional solution with sleepers.[4].
Alternative systems
The Vignoles rail was a light section that today would be classified as a flat bottom rail. In its original form, it was only about 4 inches (102 mm) deep and was used on longitudinally supported track interchangeably with inverted "U" section rail.[4].
The Barlow rail, patented in 1849 by William Henry Barlow, is a type of track with a purely metal support. The rails, with a deep inverted curved V section, were designed to sit directly on the ballast. The width was ensured by iron connecting bars between the rails, which weighed 46.1 kg/m (later increased to 49.1 kg/m). They were used on some lines: West Cornwall Railway, Wycombe Railway, South Wales Railway and New South Wales Railways. They soon fell into disuse, as they made it difficult to compact the ballast properly. A large number of these rails were sold to the engineers building Clevedon Dock"), who screwed them together for use as girders. Other pieces of Barlow rail can occasionally be found on fences near the former GWR lines. Abandoned specimens recovered buried in the ballast of the Didcot Newbury and Southampton Railway can be seen at the Didcot Railway Centre.
The Bristol and Exeter Railway and the Bridport Railway used Brunel's inverted "U" section of rail, but laid it on MacDonnell iron plates. These had three ridges to keep the rail in line and were laid directly on the ballast without any wooden supports, but the system made it very difficult to keep the track aligned.[2]
Seaton's rail was similar to that of Vignoles, but with the foot wings arranged at a downward angle to form an inverted V section, which was then mounted on longitudinal wooden beams of triangular section.[2].
Other applications
Longitudinally supported track was used by John Coode&action=edit&redlink=1 "John Coode (engineer) (not yet drafted)") for a series of 7-foot (2,134 mm) gauge railways which he built as part of large port breakwater construction works in places such as Portland and Table Bay. The wide distances between the crossbars and between the two rails, mounted on beams elevated on piles, allowed the breakwater to be unloaded directly from the wagons between the rails to form the foundations of the breakwaters.[5][6].
A variant of this route can still be seen today in some old underground bridges, where ballast was not used. The design varies considerably, but in many cases the longitudinal beams rest directly on transverse beams, with cross members and tie bars to maintain track clearance, and modern rails and bedplates or supports placed on top. It can also be found in places where easy drainage is required or where access under rail vehicles is needed for maintenance.
References
[1] ↑ MacDermot, E T (1927). History of the Great Western Railway. 1 (1833–1863) (1 edición). London: Great Western Railway.
[2] ↑ a b c d e f g h Mann, JW (1993). «Great Western Permanent Way». Broadsheet (Broad Gauge Society) (29): 10-16.
[3] ↑ Slinn, JN (1978). Great Western Way. Woking: Historical Model Railway Society.
[4] ↑ a b MacDermot, E T (1931). History of the Great Western Railway. 2 (1863–1921) (1 edición). London: Great Western Railway.