Shaun

See link below for a quick heads up.

http://www.hse.gov.uk/pubns/cis64.pdf

Shaun, PH2,

I'm not sure hsg185 is available/appropriate now (precedes current WAH regs)

Anyway, you need to ensure you can avoid pipes and cables, so refer to the safe digging practices guidance:

http://www.hse.gov.uk/pubns/books/hsg47.htm

you might need a Cat + Genny (and training!)

JohnW

Shaun

There is no minimum depth now (though some books still state 1.20m). Trench support is determined by the type of material you will be excavating e.g. generally you will need little support if excavating through rock but will need a lot of support if excavating through a loose material such as sand. A classic example is that may people think that clay is a stable material unfortunately it isn't as its stability is determined by many factors.

It all comes down to competency which, though a book is useful, would leave me concerned if someone came on site to carry out, or supervise, an excavation if they had only learnt about it in a book.

There is a publication called, I believe, Trenching Practice, that is a good source of information. If you google it you should be able to find it