The Namibian Department of Transport and Consulting Engineers,Kleber & A s s o c i at e s , h ave displayed their faith in the Tubular Tr a c kTe c h n o l o gy by specifying it for the first 25 km of the railway linereconstruction between Aus and Luderitz in southern Namibia.

This section comprises steep gradients and sharp curv at u r e , w h i l eextreme temperature variations are also experienced in this portion ofthe Namib desert. The main contract was awarded to a fully-fledgedNamibian Company, The Roads Contractor Company Limited, o fW i n d h o e k , N a m i b i a .

The system comprises twin reinforced concrete beams, linked withsteel gauge bars on which rails are continuously supported. As aballastless system, it is then laid directly on a specially designedf o r m ation with a 50 to 80 mm grout layer under the beams to fine-tunevertical alignment. Pre-cast modular sections will be manufactured atAus and the laying of the modules will be done by the technologyp atent holder, Tubular Track (Pty) Ltd, a South African company.

Resilience in the system is achieved by the use of rubber-bonded corkpads developed by British manufacturer Tiflex and placed continuouslybetween the rails and beams. An interesting aspect of this rail link isthe extensive sand dunes encountered as the line approaches the portof Luderitz. The ballastless nature of the Tubular Track system allow sit to solve many of the normal problems associated with laying trackon sand, as the fouling of ballast is no longer an issue.

The Tubular Track beam-track railway system, researched anddeveloped in South A f r i c a , has been viewed with scepticism by manyc o n s e rv at i v e s . H ow e v e r, recent tests and results carried out by majorrail authority, S p o o r n e t , the national rail body in South A f r i c a , should domuch to allay these uncertainties.

L a b o r at o ry testing and approval of the system was done at theSpoornet Track Testing Centre in South A f r i c a , while further in-trackmain line testing is currently being done between Rustenburg andThabazimbi in north-west South Africa on a line carrying heavy iron oreand coal traffic. The system has also been in use for some years incoal-loading and other sidings, as well as at Metrorail passengerp l atforms with constant rail-to-platform heights.

<#> R A I LWAYS AFRICA

Quote from Spoornet Report BBB5815 dated June 2004:"The Tubular Track(r) modules were designed and tested in the laboratory for 22

ton/axle loading and 5 MGT's per year for a design period of 20 years. Theresults of the laboratory tests and numerical analyses presented in this report, aswell as two other reports that will be referenced herein, indicate that the Tu b u l a rTrack(r) system, as tested, is a well-engineered alternative to conventional ballasttrack in terms of its technical perf o rm a n c e . "

Spoornet is respected world-wide for its narrow gauge (1065mm)r a i lway expertise and for the research and development carried out atits Track Testing Centre.

The benefits of Tubular Track include the follow i n g :

■ L ower maintenance costs.■ Reduced rail stresses allow lighter rails to be used.■ Vertical and horizontal track geometry remains virtually constant.■ Ballast and tamping costs are eliminat e d .■ No ballast fouling in sandy or bulk-loading environments.■ No loss of track resilience due to ballast degradat i o n .■ D r a i n age problems can be easily identified and dealt with.■ A narrower formation width is required, g e n e r ating considerable

s avings on earthworks. e

NEW RAILWAY TECHNOLOGYIN THE NAMIB DESERT

VIEW FROM AUS: COMPLETED FORMATION ( Nominal 3 m width )SHOWING 1:40 GRADES and 200 m RADIUS

TUBULAR MODULAR TRACK INSTA L L ATION ON NORTHWEST ORE LINE

TUBULAR TRACK