Broad Beans - 3 rows?

Last year I sowed 4 rows of broad beans (to overwinter) - 2 rows at 9" apart with a gap of 24" between the double rows - as my book says!

This year, because of space, I was only going to grow 2 rows at 9" apart but, my question is, what would be the problems with planting 3 rows, each row 9" apart (18" overall)? I can imagine all sorts of possible problems such as the roiw in the middle wouldn't do as well, but does anyone know, for certain, or has anyone actually grown 3 rows of beans?

There's a chap on my allotment, who, I think, grew about five rows in a long block last year, but I haven't seen him for some time so am unable to ask him the question.

I'd be grateful for your opinions.

 

I used the five row block too and never had problems,in fact they seemed much more robust and cropped very well. Exibition Longpod was my choice.

 

Thanks for your reply, Paladin. Can you tell me what spacing you used, please? I was thinking of 9" between plants and 9" between rows.

 

I went for a Span or 6" between the seeds and my dibber:D,10" between the blocks.
Each row was staggered from the next...Imagine the pattern a Five looks on a Dice repeated down the line.....Get what I mean?

 

Paladin
I like the concept - very high density. Do you have particularly fertile soil or particularly favourable conditions or do you think that your system would work for "average conditions" (whatever those might be!)?

 

Thanks, Paladin, that's what I wanted to know!