Sue - thank you so much for your research and the correct explanation. The growth on this years ( primocanes) is very vigouous very tall canes and as the article says I should top head now.
I must say that of all the raspberries I have bought or inherited on allotements these ones are exceptionally vigourous and the autumn fruit yield very good. I bought them as plants rather than canes and although they seemed expensive at 6 Euros each they paid for themselves with their first Autumn crop. I have a full bed of new growth already.
Again it was very kind of you to do the research for me and I will crack on and remove any poor floricanes and head the tall primocanes.
Thanks Martin