Forums Posts

by adam.wilson@chcc.nsw.gov.au Joined 19-01-2023 02:36 PM Posts 1

Hi Colleagues, We are currently updating our standard drawings. There has been some animated discussion on the inclusion of step irons in sewer manholes and other pits. One school of thought is step irons are vital for access and egress, and must be included in all accessible pits and manholes. The other school of thought is step irons corrode and deteriorate with age, cannot be trusted, and only serve to clutter the confined space and restrict access for a temporary ladder, harness, tripod, etc. How have other utilities approached this issue? Thanks, Adam Wilson Group Leader Water & Waste Services City of Coffs Harbour

by carlos.sousa@ontoit.com Joined 25-10-2022 12:19 PM Posts 2

Hi Adam, I worked at the Water Corporation in WA some years ago, and during this time, there were similar discussions around the use of step irons in sewer manholes and other pits. The general approach taken by the Water Corporation was to avoid using fixed ladders and step irons in new access chambers, wet wells, etc. However, there could be exceptions based on a risk assessment. The reasoning behind this approach was that the deterioration of steps and the concrete anchoring them is a risk not easily mitigated, and relying on them for support, even when using safety harnesses, can still lead to injuries. In addition, there is no good way to inspect the integrity of the steps and confirm they are safe to use. Using certified anchor points for davit arms, for example, is a safer alternative.Furthermore, protruding steps in a confined space can cause problems if someone needs to be lifted out due to unconsciousness or severe injury. The Water Corporation's design documents and drawings are freely available for download and I recommend checking out S151 and DS 51. On this topic, S151 - Prevention of Falls Design, section 3.4 states that "fixed ladders shall not be provided for access into wet-wells, valve pits, access chambers, and other below-ground structures. The provision of a fixed ladder shall be based on a risk assessment." but also states "wastewater pump stations without a non-fail isolation valve or penstock shall have an access ladder installed". DS 51 - The Design and Construction of Wastewater Pumping Stations and Pressure Mains, section 4.4.4 also states that "fixed ladders and step irons shall not be installed in new sewerage access chambers, wet wells, or other similar assets such as scour pits, valve pits, air valve pits, and the like." As a final not - and apologies if I sound preachy - I would like to emphasize that good change management, including thorough consultation with key stakeholders such as O&M personnel and contractors, is essential in making these decisions. In addition, implementing training programs to ensure that newly adopted practices are clearly understood can also be crucial for achieving good outcomes. I hope this helps with your discussions. Best Regards, Carlos Sousa Senior Associate Ontoit (ontoit.com)