Hi Ray If you are referring to services such as drainage then the use of drag boxes could be an option but I am fairly sure the use of drag boxes are undesirable for reasons I am not exactly sure why ? another option would be benching the sides as the dig progresses , depending on ground conditions @ 1.5 m then 1 bench would suffice . but as you could imagine a dig over 2.5 and more would require a fair amount of benching thus could end up with a 6 or 7 meter top distance which would need a lot more resources for soil extraction. and a place to find and put temporarily , drag boxes for this reason are very good . but remember good practice with drag boxes also need a step generally waist height from the top of the support box . with this would come all associated regs such as confined spaces which I would associate with CS hope this gives some help j

Damn, lost my response when I used the spell checker! Here we go again, I left the details deliberately a bit sketchy because I was interested in the initial responses ie what questions would be asked. Now the games up I will add that the work is utility based installations of flow meters and associated equipment. I am aware of the different methods for supporting excavations and indeed the operatives have temporary works designs they should be using ie shuttering. However, they seem reluctant to use shuttering and I suspect because of the time and aggravation it takes to install. As a rule the work areas are quite restricted and therefore stepping back may not always be an option. My concern is that people are entering the excavations without proper support. Just looking for a solution to a niggling problem - keep the ideas coming. Cheers.

Ray, In my "Gas" days we used "hit & miss" shoring to prevent sides collapsing, but only where operatives were not entering. Where they had to make connections, etc., then a bell-hole was created with total shuttering. In addition, we tried to make any connections above ground & then drop them into the cutting. Whilst I was there, an employee from another utility was killed in a <1.5m deep trench when he bent down to carry out some work & a large piece of clay broke off, trapping him against his chest; & whilst depth is an important factor, it must not be the only one. Zyggy

Brings back the age old problem we have of £ versus time again doesn't it ? I am not saying right or wrong here because if every trench cut in the country was bound by rigorous shoring techniques then a lot of clients or the paymasters would have second thoughts wouldn't they ? As zyggy points out about the clay falling scenario this could have been to all intense purpose at the last 10 meters of a 300 meter run.thus making a slight mockery of the quantum of risk test I imagine . If it is possible then it surely needs guarding against ? Until of course some clever chaps devise systems where guys don't need to enter trenches at all to bed gravel or blind with sand ect .then possibly reducing the shoring to a minimum . j

Remember Cotswold Geotech - the very first Corp Manslaughter prosecution. Depth there was greater than 1.5 ms but wasn't the argument that is was short duration work only... I'd say "popping in" to make a quick connection isn't a very safe approach. Stuff happens - just when you least expect it - as previous poster has confirmed. So shoring it is, trench boxes or some other suitable menas of protection. Phil

Hi Ray, Regardless of the fact that the excavation is 'in progress' you're still putting guys in the hole do hand dig at various stages, so, it still needs to be supported whilst this is going on. I did some work with one of the big utilities companies last year and they were using 'Verti-shores', to get the guys in the hole to do the spadework. I was quite impressed at how quickly they were put in place/ or removed - two or three minutes tops -and they can be operated by one man. Ideal for working in areas with not a lot of space around the excavation and where you need to get workers in and out quickly. William

Ray, Think I see what you mean... Have found source of downloadble pdf of HSG185 but guess I had better not reveal my sources "on screen". Send me a pers mail. Phil