this plant is a large (15 feet high) rambler, as you've said, and ramblers should be pruned in September. They only flower once a year, in one big flush - this rose is a particularly vigorous one, with arching growth, and is suitable for rampaging through a tree. It's not particularly suitable for growing up a pillar or over a trellis because it puts on a lot of growth. If its growing somewhere you have to keep it much smaller than it wants to be, I'd suggest you try moving it to give it more space. There are pruning guides on line for ramblers - the RHS and the BBC both have instructions online - just google 'Seagull rambler rose pruning guide'.

thanks bamboo, its been in 18 years, and is over my garage and my neighbours garage, we just hack it but would like to make it flower nicely I will post a picture.