National Transport Minister Barbara Creecy has again outlined the need to revitalise rail, revealing government’s target to move 250 million tonnes of freight on the Transnet network by 2030 - a substantial increase from 150 million tonnes in 2023/24.
Poised to provide rail clients with their 6 decades-plus wealth of experience is Colossal Concrete, Southern Africa’s largest manufacturer of precast concrete railway products. The company also has a robust portfolio of other infrastructure products.
Colossal transition
Technical and strategic consultant to Colossal, Kobus Burger - who received the Concrete Achiever of the Year award in 2009 from The Concrete Society of South Africa for his work on the pivotal Gautrain project, and what is now known as the universal sleeper - says Colossal has worked closely with Transnet and other clients to develop various products.
This began with replacing costly, scarce and (at times) poor quality wooden sleepers with modern concrete alternatives.
The first success was replacing wooden sleepers on turnout switches with the universal sleeper. This, together with the Infrabolt, was first installed successfully in 2005. Since then, Colossal has replaced approximately 480 378 meters of timber sleepers - which equates to an estimated 3 431 turnout switches.
Burger explains: “Traditionally, turnout switches were laid out dimensionally correctly on timber sleepers and then drilled and fastened onto the timber with coach screws. Each coach screw would be in a specific and unique position. With the more modern turnout switches, concrete sleepers are used with the fastenings in exact positions - millimetre-correct - so assembly can be done much like a Meccano set.”
Burger describes the Universal sleeper as a pre-stressed concrete plank: “We pull out the timber, insert a pre-stressed concrete sleeper and then drill through the concrete (without drilling through the pre-stress wire) and attach the sleeper to the steel work using the Infrabolt. We were awarded the prestigious Fulton Award in 2007 for creating the Universal sleeper and the Infrabolt.”
The next product developed to replace timber sleepers was the low profile sleeper after a need to find a sleeper that could replace timber sleepers at platforms - as well as in tunnels - was identified. “It is interesting to note that most tunnels in South Africa were designed to accommodate steam locomotives. In addition to their limited vertical height, the later electrification of railway lines created an additional height challenge. Normal concrete sleepers are thicker than timber and, to accommodate this, we created the world’s first low profile concrete sleeper,” Burger explains.
Another technical challenge identified by Colossal was the transition between the resilient track on the ballast beneath the conventional track, and the solid track on the concrete inside tunnels: “We developed a transition beam that is pre-stressed and post-tensioned to ensure that the transition from the resilient to the solid track is a gradual one. This was a major achievement, as some of the tunnel portals were on a curve and we had to measure the radius and produce the transition beam accordingly. Transition beams have been successfully installed at tunnel portals on the ore and coal lines.”
Other noteworthy products developed by Colossal Concrete include:
- Transition sleepers used in the interface of the 1 in 20 inclination of the open line sleepers and flat turnout sleepers. Various transitions from flat to 1 in 40, 1 in 60 and 1 in 80 are available
- Signal sleepers with conduits to protect cables during tamping
- The check rail sleeper for small radius curves
- Derailment containment sleepers for bridges and viaducts
- OHTE masts with augured foundations, which were used during the electrification of the Kimberley to De Aar line
Innovation further down the track
Colossal can also add the Gautrain commuter rail project to its list of noteworthy successes. At 1435 mm, this was the first standard gauge track in South Africa. When it came to supplying sleepers, Colossal competed with European competitors.
“We supplied the LVT (low-vibration track) for the Gautrain’s tunnels. This is the same system used in the longest rail tunnel in the world - which is the Gotthard Base tunnel in Switzerland - with a route length of 57km and a track length of 114km. In addition to this, we developed three types of sleepers and six types of turnout sleeper sets. All these product track solutions for the Gautrain have performed exceptionally well over the past 15 years.”
Innovation station
Colossal’s innovation mind-set has extended further into rail sector-related products such as rail electrification poles, masts, level-crossing systems, cattle grids, railway culverts, heavy-duty retaining wall beams and drain channels.
Durasafe protective shelters - a lockable concrete enclosure to protect rail signalling boxes - prevent trains from being illegally forced to a standstill and then looted. Burger says this opens up opportunities for further products that will protect other infrastructure installations from vandalism in the future.
As the producer of South Africa’s largest diameter concrete pipes - Colossal also provides product for much-needed storm water and sewage reticulation projects. Additionally, its large-diameter concrete pipes (2250mm-plus) are used at new power stations for the disposal of waste – and Colossal’s concrete poles have been used extensively for the roll-out of fibre optic cables.
“Different sectors use different rail and infrastructure products, according to different requirements. We are proud to provide each client with the specific products and solutions which are best for them.
Finally, we are also considering extending our product portfolio to new market segments,” Burger concludes.
