With thanks to Versalift09 for the info, the
Chinese are making SOX lamps with a new design of arc tube.They also show them with GES caps.
At first thought those arc tubes would be a right pig to make without breakages, however CFL lamps are made in a similar shape so perhaps they have perfected it. With more arc tube per inch than for a conventional lamp there are more lumens. The efficiency of a low pressure lamp is driven predominately by heat loss, so more arc tube in the same envelope size raises efficiency.
They must have got good getters and glass seals to get lifetimes like that as well. Apparently China and Brazil are growing users of SOX lamps, given the size of China and that most areas outside cities will have no road lighting, you want the most efficient lighting otherwise the power required soon gets enormous. The growth in cities and rural electrification is growing far faster than power stations can be built, hence the requirement for efficiency.
I guess GES as they don’t have a history of B22d caps...
And just be sheer coincidence, last night thorncollector posted images of some
55W Chinese SOX lamps and also some 36W ones. Shame they aren't the curly type!