Believe they are called cat ladders?

There are numerous hazards associated with entering sewers, from confined spaces (toxic, flammable and explosive gases) to health hazards. Suggest you do a search of the HSE website. A starter for ten below. http://www.hse.gov.uk/pubns/indg198.pdf

It's a fairly standard part of any confined spaces entry course (at least, it has been in every course I've done). You DON'T need a fall arrest harness, you need a rescue harness any time you're going in through a manhole, you need a tripod and arrest winch, and the first man in tests each rung / step in turn as he descends, and the man on the winch keeps the cable tight at all times, so if a rung gives way you don't fall anywhere (more than an inch or two, anyway). But as noted, anyone that has done a general confined space entry course should know this. Make sure that your winch accommodates the height of descent you need. I've done entries in manholes that had shafts deeper than the standard winch cable length. My other advice for doing sewer entry is not to eat much immediately beforehand.

Dear all Thank you for your responses however, I used to work for the very water company mentioned and still have all of the documents recommended in this post. What I am really interested in is the use of the CAT ladders. I am aware that without testing the ladders there is no guarantee of stability/integrity. We have CAT ladders on our contract being used for loft access, hence the interest particular interest in the ladder.

To be honest it is unwise to rely greatly on the cat irons at least until the first person has descended!! Even then they are unreliable and it is always best done with the harness on and attached to the winch for absolute security. At 135ft I never knew anyone use them!! Any use above ground should mean that there is a reliable programme of test and maintenance. Bob

Jarsmith You may find that water companies have standard drawings for access into chambers/pits/wells etc but local arrangements with their operatives dictate what the contractor is asked to supply.

Hi All, I used to work for Thames Water, and Veolia Water, and was also a member of Water UK (industry body)you could try contacting them, they may have guidance on this issue, as I remember this has been a long running area of concern. Guidance on confined space entry and working at height is definately available, and their safety comittee have members that review relevant British Standards prior to publishing, might be worth giving them a try. Simon