2 December 2014The Passenger Rail Agency of South Africa (Prasa) has unveiled the high-powered Afro 4000-series diesel locomotive, which it says will improve the efficiency of passenger rail services in South Africa.Mosenngwa Mofi, the chief executive of Prasa Rail, said at the launch at Cape Town station on Monday that the introduction of the new locomotive was “a realisation of a dream – a dream that will change the travelling experience of all South Africans”.The new high-powered locomotive marked a turning point in the State-owned entity’s ambitious plans to modernise and rehabilitate South Africa’s railway network, which has suffered from ageing infrastructure and rolling stock and delays.According to a report in Business Day, the new locomotives were designed in Spain by rail industry manufacturer Vossloh according to Prasa specifications to suit local conditions and come fitted with the latest technology.UpgradeThe upgrade project was outsourced by Prasa to Swifambo Rail Leasing, a local company who, in turn, awarded the contract to Vossloh to supply 70 new high-tech locomotives at a cost of R3.5-billion. Fifty of these will be Euro Dual electro-diesel and 20 are Euro 4000 diesel locomotives.“The critical factor is to improve the journey experience and encourage more long- distance travel,” Mofi said. “This can only be achieved by providing reliable, efficient locomotives to haul these trains, thus minimising en-route delays.”Mofi said Prasa would also acquire other new, modern trains over the next 10 years as part of a R51-billion contract with the Gibela Rail Consortium.The Spanish locomotives will be tested for three months, and would start operating officially in March 2015.Long distanceThe new locomotives will be used primarily to serve the long-distance market, with 10 of the 70 locomotives allocated to the Eastern Cape region.The trains will run along six long-distance corridors, including the Johannesburg to Cape Town route. This will be increased to 10 corridors as soon as Prasa received the new stock during the first half of 2015.The locomotives have a display unit with various management systems that will allow the driver to detect and reset any faults. They are the first in the country to have two driving cabs – allowing the train to travel in both directions without turning.The trains have automatic doors and open gangways that would allow for visibility throughout the train.SAinfo reporter and SAnews.gov
An intercomparison of zenith-sky UV-visible spectrometers was held at Camborne, UK, for 2 weeks in September 1994. Eleven instruments participated, from nine different European institutes which were involved with the Second European Stratospheric Arctic and Mid-latitude Experiment (SESAME) campaign. Four instruments were of the Systeme d’Analyse d’Observations Zénithales (SAOZ) type, while the rest were particular to the institutes involved. The results showed that the SAOZ instruments were consistent to within 3% (10 DU) for ozone and 5% for NO2. For ozone the results from these instruments agreed well with total ozone measurements by Dobson and Brewer spectrophotometers and integrated ozonesondes when the air mass factors for the SAOZ were calculated using the ozonesonde profiles. Differences of up to 10% in ozone and 30% in NO2 were found between different instruments. In some cases these differences are attributable to the different absorption cross sections used in the analysis of the spectra, but other discrepancies remain to be investigated. A prominent source of error identified in the campaign was uncertainty in the derivation of the amount of absorber in the reference spectrum, which can contribute an error of up to 3% (10 DU) in ozone and 1.5×1014 molecules cm−2 in NO2.