Alister van Tonder, ZS1OK reports:
The 2018 Sanlam Peace Trail run took place on Saturday 22nd of September in support of the trail running taking place on the slopes of Lions Head and Signal Hill. This event forms part of the larger Cape Town Marathon, which took place on the following day, Sunday 23rd.
The Hamnet operators consisted of ZS1JMT Michael and Virginia holding the fort at The Glen in the vicinity of the Round House Restaurant in Camps Bay, and the team at Signal Hill consisting of John ZS1JNT and Ian ZS1OSK, and with Alister ZS1OK at the base. Matt ZS1MTF assisted by setting up a VHF/UHF cross-band repeater in a vehicle parked on the slopes of Table Mountain which provided a relay between The Glen and to the base located, located at the new Green Point Athletics Track, as well as to the Signal Hill team. While there was no directly line of sight between the cross-band repeater to the base – it was well within the lee of Signal Hill, the cross-band repeater worked very well. Matt set the VHF transmitter power to 20 watts which ensured that with the extra power a good signal was provided whereas the line of sight UHF link to The Glen was using 5 watts.
The base was operational by 05h30 with the comms being verified between the different locations by 06h00. The start of the race was delayed by more than 30 minutes due to race safety issues, but once it started the well planned operating procedures by the race organisers ensured things went smoothly.
There were a handful of minor runner injuries, but overall no major incidents. As with most competitive sports it was vital to verify runners were not taking short cuts or taking advantage, and matters of this nature took up some bandwidth.
The team of Michael ZS1MJT and Virginia were the first to stand down after the race sweep had progressed well beyond their location. The team Signal Hill is very busy as both the long and the short course runners pass through their check point. By the time the sweep passed the Noon Gun, they also stood down, since any injured runners would thereafter had to continue down the slopes rather than being taken back up to Signal Hill. Support was concluded when the based stood down at 13h30.
This was the second year we have used cellular APRS for the race sweeps. Last year we had some teething problems with the cellular APRS, but this year it worked really well and we had regular fixed interval position updates via aprs.fi for both race sweeps. There were only small areas that did not have cellular coverage.
Yes, radio based APRS has its place – the race sweeps find the mangoes APRS radios bulky and heavy – but having cellular based APRS provided good operational feedback. To provide effective VHF digipeater coverage for this event would be quite a daunting task, requiring many suitably located digipeaters.