Mammoth culverts set new record

When the City of Tshwane required 3 m x 3 m custom-made jacking box culverts for a service delivery project at Iscor Heights, Pretoria West, Rocla found an out-of-the-box solution. The culverts were manufactured with an in-the-wall joint that can be sealed with a rubber ring if required.

The project required 90 large-sized culverts to create two 50 m long underroad tunnels, 6 m below the road surface, in order to provide new water services to the area.

“We have worked with Rocla on various projects over the years, so we knew that these large jacking culverts would have to be specifically designed and manufactured, and that Rocla was the only company that had that kind of creative capability,”

Rocla’s 3 m x 3 m custom-made jacking box culverts are the largest of their kind to be manufactured by the company

comments Len Nel, contracts director, Esor Construction.

The largest jacking pipe Rocla had manufactured in the past measured 3 000 mm x 2 500 mm, which was too small for the project.

“After many meetings to discuss the design and verify the technical requirements of the jacking culverts to ensure that the final product would meet the loading requirements, the final culvert weighed in at an excess of 10 t per product – a major design and manufacturing coup for Rocla,” Nel adds.

The timeframe from approved product specification and design to mould completion was only 16 weeks for the 90 culverts. Due to the enormous size of the culverts, the delivery to site required an abnormal load permit and they were offloaded into the pit at site with a side boom crane.

“Rocla is extremely proud to have been involved with this unique project. It tested our design team’s expertise and our manufacturing processes to the limit, but showed that no project is too big for Rocla to collaborate on. It will certainly become one of Rocla’s historical milestones,” says Brendan van Vuuren, sales representative, Rocla. Rocla forms part of the Infrastructure Specialist Group, which also includes Technicrete.

Rocla manufactures various culvert designs and culvert base slabs, along with stormwater pipes and other infrastructure products such as HDPE and pressure lined sewage pipes, concrete poles, manholes, bus shelters, sanitation units, and concrete cabins.

The project required 90 large-sized culverts to create two 50 m long under-road tunnels, 6 m below the road surface, in order to provide new water services to the area