Civil Engineering March 2022 | Vol 30 No 2

36 March 2022 Civil Engineering T he Occupational Health and Safety Act requires that all structures that are to be climbed by personnel be signed off as “safe to climb”. Eskom’s tel- ecommunications department has a large number of telecommunication towers which have exceeded their design life and therefore require maintenance and/or replacement. This article outlines a pro- ject performed by Trans-Africa Projects (TAP) to evaluate existing telecommuni- cations towers to determine whether the structures are still fit for purpose and safe to climb or need to be decommissioned and replaced. BACKGROUND Many of Eskom’s telecommunication towers are lattice steel structures made of either tubular steel poles or steel angle sections. The towers support antennae at various levels above the ground for communication purposes, as shown in Figure 1. Five towers in the KwaZulu-Natal region that had been identified as a safety concern were analysed. These towers did not have structural drawings and part of the project scope was to scan the towers and develop structural drawings for analysis and maintenance purposes. Table 1 shows the location of the towers under investigation. The design standard used for the analysis of these telecommunication Structural evaluation of existing telecommunication towers Rishen Moodley Pr Eng Chief Structural Engineer Trans-Africa Projects rishen@taprojects.co.za Siyabonga Dubazana Pr Eng Chief Civil Engineer Trans-Africa Projects siyabongad@taprojects.co.za Table 1 Site locality Tower no. Site name Co-ordinates Tower height Tower type 1 Matchana RS 28º45’02”S 31º50’28”E 40 m Four leg, angled painted lattice 2 Manguzi RS 27º01’22”S 32º40’58”E 45 m Three leg, tubular galvanised lattice 3 Hlutankungu RS 30º17’36”S 30º18’48”E 36 m Three leg, tubular galvanised lattice 4 Umgeni RS 29º48’51”S 30º53’10”E 40 m Four leg, angled painted lattice 5 Dundee RS 28º07’7.4”S 30º13’5.5”E 15 m Four leg, angled painted lattice Figure 1 Telecommunication towers under investigation Tower 1 Tower 2 Tower 3 Tower 4 Tower 5