Turnout technology company VAE SA is supplying the turnouts and part of the switching systems for the Gautrain rapid- rail link. The first 24 turnouts for the maintenance and storage depots have already been delivered and VAE SA engineering manager Mark Smith says that the installations within the depot are well under way.

Smith says that VAE SA will be supplying a total of 86 60E2 turnout sets, expansion joints and insulated rail joints for the whole project, with a few possible additional sets to be supplied later. These include twenty-four 1:9 sets with a 190-m radius, which have already been supplied, forty-eight 1:12 ballast track turnouts, with a 500-m radius, ten 1:12 low- vibration track (LVT) slab turnouts, also with a 500-m radius and two 1:18,5 slab track turnouts, with a 1 200-m radius that will all be manufactured by 2010, when the last four sets will be delivered.

“The turnouts are where the tracks split at different angles, 1:9, 1:12 and 1:18,5. The bigger the angle, the more gradual the split is. Therefore, the train can travel at a higher speed. The sharper the curvature and angle within the set, the slower the train may pass through it,” explains Smith.

VAE SA will reach the next milestone on the project in mid-July, when the first inspections take place. These inspections will be of the 1:12 sets, which are longer turnouts at a different angle to the smaller 1:9 sets. These sets are for the main line where the Gautrain will be travelling at higher speeds. Gauteng province and Bombela will inspect the laid-out 1:12 sets at the Isando plant.

Once the sets have been approved, VAE SA will continue manufacturing the rest of the turnouts until the completion of the project in 2010. Forty-eight 1:12 sets will be manufactured for the ballast track, which is a track that rests on compacted ballast stones that lie on a formation of compact earth and is mainly used for open lines, above ground.

VAE SA will start manufacturing the LVT sets in February 2009, which, despite also being 1:12, are slab track turnout sets that will run inside the tunnels. The biggest turnout sets that VAE SA will be manufacturing for the Gautrain project are the 1:18,5 sets, which the company will also begin manufacturing in February 2009. These sets will be going into the main line of the Gautrain.

While all the sets for the Gautrain are being manufactured locally at the VAE Isando manufacturing plant, the rail is being imported, as the system requires specialised rail with a 60E2 profile. This is the first time this type of profile is being used in South Africa. The rail is imported and then manufactured into sets at Isando where all the machining and fitting, together with other processes, are carried out.

The LVT turnouts use a booted-block system, which consists of a concrete block with cast-in rail fasteners that rest on a high-density polyethylene pad. The concrete LVT block, except for the top section, is encased in a rubber boot to avoid any vibrations from the train cascading down into the concrete slab inside the tunnels and on the viaducts.

This technology is new to South Africa and requires minimum maintenance, but offers high reliability, as this prevents vibrations from the train transferring into concrete floors, which could cause cracks or breakouts.
Smith says that a completely new design is being used for the Gautrain turnouts. South Africa usually uses narrow gauge between the rails, referred to as standard gauge or Cape gauge locally. The South African standard gauge, or distance between two rails, is 1 067 mm, but the Gautrain will run on European standard gauge, which is 1 435 mm. This was a key consideration in VAE SA’s design of the turnouts.

“Due to the change in gauge, all the turnout sets for the project required a totally new design. We could not use anything that already exists in South Africa,” says Smith.

The depot 1:9 sets also differ from the other sets in that they are set on a horizontal plane, which means that both the rails rest flat on the sleepers. The 1:12 and 1:18,5 sets will be attached to the sleepers at a 1:20 inclined angle. This will keep the train stable at high speeds.

Other new design aspects of the Gautrain turnouts include the new Piroll roller system, which will assist switchblade movement. Further developments are the use of a new rail fastening system within turnout sets. All existing railway lines throughout South Africa use Pandrol E-Clip fastenings within turnout sets, but the Gautrain will use the Pandrol Fastclip system, which holds the rail to the concrete.

Asymmetrical swing-nose crossings will be used on the 1:12 and 1:18,5 sets, but not on the 1:9 sets, as the train will not run through the depot at high speeds. These swing-nose crossings, which are mechanised crossings that move from one side to the other, provide continuous support for the train wheels while changing the direction of the train. The asymmetrical swing-nose crossings are also a first for South Africa.

Smith explains that, in order to get the first turnout sets delivered in time, VAE SA had to fly parts in from all over the world. He says that, although a number of companies are now set up to manufacture locally, these local companies did not have enough time initially to get tooling, jigs and manufacturing methods ready. Austria, Germany, the UK, Korea and Spain have supplied VAE SA with a few of the initial fittings in order to complete the first few 1:9 depot turnout sets.

The company’s Austrian division, Voestalpine Austria, manufactured the first asymmetrical switchblade blanks, with the VAE Bloemfontein manufacturing plant undertaking the machining of such switchblades to suit the 1:9 turnout sets. The VAE Isando manufacturing plant has now installed and started running a brand-new CNC long-bed milling machine, which will manu- facture the 1:12 switchblades and crossings. All the turnout sets are transported to the sites by truck.

VAE SA is a supplier and manufacturer of permanent-way products, such as rail turnouts, points and crossings, as well as steel components for railway tracks, across the African continent. The company has manufacturing facilities in Kimberley, Isando and Bloemfontein.


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