Where possible from a Health & Safety perspective, we will seek to avoid man entry surveys in confined spaces. Sometimes though no safe alternative exists. A safe and efficient process for managing man entry surveys is then needed. The objectives and outputs are similar to CCTV surveys, however we find that the human eye is better able to identify defects than cameras are. Flow monitoring, weather monitoring and gas detection systems are set up before and during the schedule of work. A safe system of work is set out to enable the survey to be completed and to allow the surveyors to perform their work including creating a quick and safe evacuation procedure; this is supported by PPE including breathing apparatus where necessary. After this the man entry survey is relatively straightforward.
What it involves?
Flow monitoring, weather monitoring and gas detection systems are established before and throughout the schedule of works. A safe system of work is set out to enable the survey to be completed and to allow the surveyors to perform their work including creating a quick and safe evacuation procedure; this is supported by PPE including breathing apparatus where necessary. The survey is itself thereafter is relatively straightforward.
- Strict compliance to national, customer and site-specific protocols is critical for all man entry surveys.
- All relevant parties must be informed of the team’s arrival and agreed timetable for work.
- Emergency service communication lines must be confirmed.
- The access and egress areas must be appropriately secured and guarded.
- Pre-entry checks should be made, including checking functionality and certification of rescue equipment.
- Entry checks should be made, including gas and air tests, effluent depths, flow rates and communication channel effectiveness.
- Survey and exit.
- Minimum 1200mm diameter pipe.
- Safe chamber access/entry and exit in relation to size of pipe, chamber and equipment being used.
- Known flow rates and depths in different weather conditions.
- Over-pumping / tankering for high flows.
What You Gain from a Man Entry Survey
is rare for very large sewers and tunnels to be effectively surveyed by CCTV, so it is necessary to a team of specialists to complete the survey supported by a team that will manage their safety during the operation. The key to a successful pipe problem investigation and resolution is the initial investigation works which necessitates a detailed and quality inspection is vital. In contrast the subsequent report, plans, photos and video files are relatively straightforward to produce. The outputs are very similar to CCTV surveys; however, they are strengthened with a better perspective from the human eye.
On larger pipes diameter variations are more common and the nature of debris and deposits needs to be understood to facilitate their removal. Brick built pipes are commonly used and brick related defects like drop outs and mortar degradation require particular attention. Care has to be taken to identify defects in the bottom of the pipe which can be obscured by effluent / water and can include significant voids.
How we can help
Safety is paramount. We don’t take risks when working on man entry surveys. We adhere to the industry standards but know that all clients have different needs from a survey. We will find out what the client wants/expects before presenting it in the format that best suit that purpose. Our site teams are highly experienced and qualified to Industry standards relating to working on man entry surveys. They know the best ways of using different entry types and have also received training and certification in the use of Breathing Apparatus (B.A.). During man entry surveys we work with our mining and tunneling partners where appropriate to provide additional equipment and skilled personnel when needed.