SCs inability with tomatoes

They are self-pollinating in that the flowers don't need another plant for pollination, but the pollen still needs to drop from the stamen to the stigma. Usually that's helped by the wind or bees. In a greenhouse/polytunnel you don't normally have enough air movement for proper pollination. Commercial growers release bumblebees in to their giant greenhouses for this reason, I often see them in our greenhouse too.

Tomatoes have an optimum range of temperature (15-30°C) and relative humidity (60-85%) for proper pollination. Above 32°C the pollen becomes sticky and doesn't move properly. I have a temperature and humidity sensor in the greenhouse and I can see on one hot day in August the temperature got to 32°C and the humidity was 45%. Dumping water on the paving slabs barely made a difference, so I'm looking to stop the greenhouse getting too hot with shade netting. Gardeners in places like Texas don't bother growing tomatoes during the summer months, it's just too hot. 

I have one variety which hasn't produced any ripe fruit yet, it's Honey Drop from the seed swap, they're just sitting there on massive trusses barely doing anything!