- Concrete sleeper
-
A concrete sleeper is a railroad tie made out of steel reinforced concrete.
History
Concrete sleepers were first made in Germany in 1906 for use between Nuremberg and Bamberg.[1]
Types
Concrete sleepers can be of one piece of uniform dimensions, or of variable dimensions. Concrete sleepers can also consist of two separate blocks connected by a steel tie rod. Exceptionally, the concrete can be poured as two separate longitudinal slabs as has been used in Namibia.
Slab track consists of a continuous concrete roadbed without division into separate sleepers, and these are most often used in tunnels.
Austrak has developed a concrete Timber Replacement Sleeper that can be inter-dispersed with timber sleepers. These sleepers have a similar profile to the timber but have the benefits of concrete - especially when it comes to holding gauge.
Advantages
- Do not rot like timber sleepers.
- Extra weight makes track more stable, particularly with changes in temperature.
- Unlike wooden sleepers, concrete sleepers don't expand under hot conditions causing tracks to buckle.
- Withstand fire hazards better than wooden sleepers.
- Longer life than wooden sleepers
- Less maintenance means lower ongoing costs and less track closures
Pads
Concrete sleepers usually have rubber pads of about 10mm thickness between the rail and the baseplate to absorb somne of the shock of the passing train.
Disadvantages
- When trains derail and the wheels hit the sleepers, timber sleepers tend to absorb the blow and remain intact, while concrete sleepers tend to shatter and have to be replaced.
- Concrete sleepers are heavier and need stronger people and even special tools to carry them.
- Gives more retentivity to the track.
- Cost more, especially initial cost.
Alternatives
Sleepers made of recycled plastics, which are less brittle than concrete, are under development.[2]
Characteristics
Gauge and weight
- 1,676 mm (5 ft 6 in) - 300 kg
Axleload
Manufacture
Concrete sleepers are made upside down in moulds, several sleepers long. Pandrol clip bases or other fittings are inserted into the moulds. Pretensiled steel wire are installed in these moulds, and then the concrete is poured. It takes several days for the concrete to cure, after which the sleepers are removed from the moulds and cut into individual sleepers. The bottom of the mould is marked with the logo of the manufacturer and a datestamp.
Occasionally sleepers are made with conduits for track circuit wiring, or extra fixtures for guard rails.
Sleepers can be made using a Long Line method or a Short Line method; each method has its advantages and disadvantages.
Ingredients and components
- Portland cement made into suitable concrete.
- Steel wire usually galvanised, and pre-tensioned.
- Railclips such as Pandrol.
Transport
When transported in small piles, pieces of timber are interposed between the layers of concrete sleepers.
Installation
Oldest
The 597 mm (1 ft 11 1⁄2 in) gauge Lynton and Barnstaple Railway (1898 to 1935) in North Devon, experimented with concrete sleepers at a number of locations along the line. Currently unknown why experiment was not continued.
Some concrete sleepers can now be seen on display at Woody Bay Station www.lynton-rail.co.uk
Chaired bullhead concrete sleepers have been around since at least the 1950s.[4]
Turnouts
Concrete sleepers for turnouts are much longer than normal sleepers, have gaps for switch motors, have sleepers indivually designed, and are generally made by a small number of specialist manufactures. If a turnout is needed in a hurry, it may be made with timber sleepers which can simply be drilled to suit.
Problems
German rails have experienced cracking of their sleepers on high speed lines.[5]
Examples
Ghana
Concrete sleeper plant at Huni Valley, Ghana:
- Number: 2 m
- Cost: Euro 85m
- Cost each: Euro 42.5 per sleeper.
- Cost of plant: Euro 7
- Jobs: 130
- Output: 400,000 per annum
- Output: 1096 per day (about 0.5 km of track).
- Makers: Kampac and Rail.One
- Gauge: possibly dual gauge 1435 mm/1067 mm
Pakistan
- Line: Karachi - Lahore main line.
- Gauge: 1676 mm gauge.
- Cost per km: Rs33·85m
- Rail: UIC-54 rails
- Number per km: 1,640
- Fastenings: Vossloh
List of plants
Angola
(Three plants needed)
- North - Bengo Province
- Centre - Liangongo - Benguela
- South - Caraculo [6]
Australia
(clockwise)
Townsville Austrak - 1067 mm - defunct [7]
Mackay Austrak - 1067 mm - defunct [7]
Rockhampton Austrak - 1067 mm [7]
610 mm are also made for cane tramways.
Mittagong - 1435 mm
Taree - 1435 mm
Denman - 1435 mm
Mittagong [8]
Grafton [8]
Wagga Wagga (Bomen) Austrak - 1435 mm
Geelong (Avalon ] Austrak - 1435 mm & 1600 mm
Port Hedland Austrak - 1435 mm
Wedgefield Austrak - 610 mm, 1067 mm, 1435 mm [9]
Wickham - 1435 mm
Katherine Austrak - 1435 mm - defunct [7]
Tennant Creek Austrak - 1435 mm - defunct [7]
- Austrak - Australia's largest manufacturer of concrete railway sleepers [10]
Bangladesh
Botswana
China
China United Railway Logistics [13]
Ethiopia
Germany
- 1435 mm [16]
Ghana
Huni Valley - 1435 mm/1067 mm dual gauge (?) [17]
India
[18] First use in 1977 [19]
Patil Group - 8 plants - first in 1971 [20]
Nandgaon, Maharashtra
Madhepura [21]
Kathua [22]
Vishal Nirmiti [23]
Iraq
Kenya
Korea, North
Rahung [26]
Korea, South
Pusan [27]
Libya
- Khoms [28] by Walterbau ,[29] Germany.
- Ra's Lanuf - for Russian contract
Malaysia
Mozambique
Namibia
Romania
Russia
Viazma [33]
Saudi Arabia
- Ha'il - Transport in Saudi Arabia 32.5T axleload - 1435 mm [34]
- Rail.one [35]
- PCM Strescon Overseas Ventures Ltd;www.pcmstrescon.com;manufactures Heavy Haul 32.5T Axle Load Standard Gauge Sleepers at their Long Line Factories at Al Jouf and Hatifa,Kingdom Of Saudi Arabia by Wegh Group ,[36] Italy.
Sierra Leone
Racegroup [37]
South Africa
Switzerland
Tribeton [40]
Thailand
- Wihan Daeng in Saraburi Province [41]
See also
- Sleeper
- Ladder track - longitudinal sleepers
- Tubular Modular Track
- Bi Block sleepers [42]
- Cement in Africa
References
- ^ http://www.dsiminingproducts.com/au/references/details/article/prestressed-concrete-sleepers-germany.html
- ^ http://www.azom.com/news.asp?newsID=8437
- ^ http://www.fmgl.com.au/irm/ShowStaticCategory.aspx?CategoryID=213&HideTopLine=True
- ^ ndrailusers » Mag09
- ^ :: View topic - German track in big trouble
- ^ Railways Africa - NAMIBE RAILWAY INSPECTED
- ^ a b c d e f Austrak: Factories - Overview
- ^ a b Rocla
- ^ Laing O'Rourke - Intelligent Thinking Intelligent Construction
- ^ Austrak: In Profile
- ^ [1]
- ^ RailwaysAfrica
- ^ Concrete Sleeper - Trains and Railroads Product - from China Railway United Logistics Co., Ltd. | asiaproduct.net
- ^ EthioBlog - Archives for: January 2008, 22
- ^ Consta
- ^ Walter Beton Concrete Sleepers Germany
- ^ http://www.railone.com/en/top-navigation/news/press/news-single-view/browse/3/article/railone-beteiligt-sich-an-der-erneuerung-der-western-and-central-line-in-der-republik-ghana/90.html
- ^ a b Manufacturer of Prestressed Concrete Railway Sleepers from India, Prestressed Concrete Monoblock Railways Sleeper
- ^ IRFCA
- ^ Patil Group Of Industries
- ^ http://www.ircon.org/railways.asp
- ^ http://www.highbeam.com/doc/1P3-1000014461.html
- ^ http://wikimapia.org/10924305/Vishal-Nirmiti-Pvt-Ltd-Concrete-sleeper-Plant
- ^ Sudan Tribune
- ^ September 2004 Panapress 24 June 2004
- ^ Past news
- ^ Pusan Industrial Co
- ^ Walter-Beton
- ^ http://www.railway-technology.com/contractors/rail/gallery.html
- ^ allAfrica.com: Mozambique: Reconstruction of Sena Line Behind Schedule (Page 1 of 1)
- ^ Railway to new opportunity
- ^ http://www.railwaysafrica.com/blog/category/africa-update/sadc/namibia-sadc/
- ^ Viazma Concrete Sleeper Plant
- ^ RailwaysAfrica 2007/6 p36
- ^ http://www.railway-technology.com/contractors/engineering/pfleiderer2/Press27.html?WT.mc_id=DN_PR&mxmroi=15093578/2651435/false
- ^ http://www.gwegh.it
- ^ http://www.racecgroup.com/our-services/rail-construction/
- ^ INFRASET
- ^ http://www.railwaysafrica.com/2009/11/infraset-sleepers-for-ore-line/
- ^ http://www.tribeton.ch/uploads/media/We_re_right_on_track.pdf
- ^ ITALIAN-THAI Development Public Company Limited
- ^ Wallonia
Concrete sleeper research URL http://ro.uow.edu.au/
External links
Media related to Concrete sleeper at Wikimedia Commons
Categories:- Rail infrastructure
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